Accumulator:In automated packaging operations, a device, a table, or a type of conveyor designed to permit gathering of packages or objects. Accumulators isolate one operational unit from another, allowing each to be run independently of the other for short periods of time. Accumulators are used to provide a temporary storage area after an operation that can’t be stopped (such as a baking oven). Accumulators can increase the output of a production line by allowing individual stations to be slowed temporarily to clear a problem without having to stop the entire production line.ACL: See applied ceramic lettering.Actuator: (a) On aerosols, the ringer button that, when depressed, opens the aerosol valve mechanism and allows for dispensing of the product, (b) A motor or transducer that converts electrical, hydraulic, or pneumatic energy to effect motion.Additive synthesis (color): The combining or adding together of different light wavelengths to produce another color. Additive synthesis usually refers to the combining of red, green, and blue wavelengths since these are the only ones detected by the human eye. Red light plus blue light is seen as magenta, red light plus green light is seen as yellow, and blue light plus green light is seen as cyan. When all three wavelengths are mixed in roughly equal proportions, the human eye sees white.Adhesion: The attachment of one material to another, primarily by molecular attraction.Adhesive: A substance that can be used to join two surfaces. A typical adhesive is a liquid capable of forming molecular attractions to (wetting) the substrates and then solidifying by evaporation of volatiles, cooling, or chemical reaction.Aerobic: A general term describing those microorganisms that propagate only in the presence of oxygen.Aerosol: In packaging, a gas-tight, pressure-resistant container, a valve, a product, and a propellant that forces the product from the container when the valve is opened.Aerosol container: A container equipped with a dispensing valve, the construction and design of both of which are strong enough to retain the compressed or liquefied gas that acts as the propelling agent for the discharge of the contents through the valve. Aerosol containers must meet Department of Transportation (U.S.A.) or Transport Canada regulations with respect to construction and ability to withstand pressures.A-flute: See flute.Airplane tuck: A folding carton design, where the two tuck flaps are both placed on one panel.
Aluminum foil:A rolled section of aluminum less than 152 micrometers (0.006 inch) thick.
Ambient:Describes common or prevailing uncontrolled atmospheric conditions. Ambient temperature, for example, would refer to a temperature in the typical room comfort range. A specimen tested at ambient conditions would have been tested at whatever the room conditions were that day. American Society for Testing and Materials (ASTM): A consensus organization for developing standards and test methods. The majority of testing procedures used in the packaging industry have been developed by ASTM committees.
Amorphous polymers:Plastics that have an essentially random arrangement of the polymer chains. At melt conditions, all thermoplastic polymers are amorphous. See also crystalline polymers.
Ampoule:A relatively small container made from glass or plastic tube, the end of which is drawn into a stem and closed by fusion after filling. The bottom may be flat, convex, or drawn out.An ampoule is opened by, breaking the stem.
Anaerobic:A general term describing those microorganisms that will propagate only in the absence of oxygen. Certain types of packaging, notably canned products, create oxygen less conditions in which these organisms can propagate. One of the more common of these, Clostridium botulinum, produces deadly toxins.
Anilox roll:A metal roller, engraved with a fine cell pattern, used with a rubber roller to meter the ink to the plates in a flexographic printing press.
Animal glue:A protein-based adhesive derived from animal skins, bones, and hooves. It is not commonly used in modem packaging.
Anneal:Broadly, to expose a material to a controlled heating and cooling cycle in which internal molecular structures have time to move and assume new positions. Metals that have been hardened by rapid cooling or by work stresses are annealed to soften them and make them more malleable. Completed glass containers are annealed by being cooled slowly, to minimize internal stress from uneven cooling. Plastics are also annealed to remove internal stresses.
Anti-Skid:A method of preventing slippage.The anti-skid properties of a corrugated container reflect the ability of stacked boxes to resist slipping or skidding over one another when the load is abruptly shifted or tilted during the distribution cycle.
Anti-Stat:Repels static electricity away from itself and the product it surrounds. Like poly bags, antistatic foam is always pink in color.
Aseptic packaging:A package and product system in which the product and package are individually rendered aseptic (sterile) and then combined and sealed under aseptic conditions. In contrast, in a typical canning operation neither can nor food is sterile when they are brought together and sealed. Sterility is achieved by heat-treating the sealed can.
ASTM:See American Society for Testing and Materials.
Automatic bottom:A carton construction having a pre-glued, folding bottom with multiple folded flaps that automatically position themselves to form a composite bottom closure when the carton is erected. Typically used for manual erections.
Back-off:The loss of torque in a closure following application. See also torque loss.
Bag:A preformed, flexible container, generally enclosed on all but one side, which forms an opening that may or may not be sealed after filling. May be made of any single flexible material, of multiple independent layers of flexible materials, or of laminated materials.The term “sack,” although often used as a synonym for “bag,” generally refers to heavier duty or shipping bags.
Bag-in-box (BIB):A packaging system in which a flexible bag or pouch is enclosed in an outer box made of a rigid material such as paperboard or corrugated board. Some retail products are sold this way, but BIB packages are most often found in industrial and hospital- restaurant-institutional product delivery systems.
Bar code:A machine-readable symbol. The symbol value is encoded in a sequence of high-contrast rectangular bars and spaces. The ratio of the widths of bars to spaces contains the information. A number of different bar code systems are available, depending on the application. The most common code for retailing is the Universal Product Code (UPC).
Barrier:The ability to stop or retard the movement of one substance through another. In packaging, the term is most commonly used to describe the ability of a material to stop or retard the passage of atmospheric gases, water vapor, and volatile flavor and aroma ingredients.
Base box:A measure used in the sheet metal industry, being the weight in pounds of 112 sheets measuring 14 inches by 20 inches. The amount of applied tinplating is also often reported in base box units. In metric, the preferred unit of measure is kilograms per 100 square meters.
Basis weight:Generally, the weight of a given area of a material. In metric, this is reported as the grammage: the grams per square meter of a given material. Older measuring systems have various traditional units depending on the material. In paper, the basis weight is the weight in pounds of a ream of paper cut to its basic size. The basis weight for most packaging papers is calculated on the area of 500 sheets of 24 by 36 inches, or in pounds per 3,000 square feet of paper. Some white papers are Calculated on a ream of size 25 by 38 inches. For paperboard, basis weight is expressed in pounds per 1,000 square feet.
Beers tray:A tray-style paperboard folding carton having glued comers. The tray is folded flat during manufacturing for economy of shipping and storage space. Each comer has a diagonal score on the sidewall that allows the sides of the tray to fold inward into a collapsed position.
Biaxial orientation:See orientation.
Billow forming:A thermoforming process where the hot, softened plastic sheet is first inflated to increase its area (the billow) and then pulled or pushed to the finished shape, using molds, plugs, pressure, or vacuum. Forming a billow as a first step results in a more even distribution of material in the finished part.
Blank:(noun) A piece of material from which a container or a part will be made by further operation.For example, in metal can manufacture, a blank is the plain, flat metal plate, cut to size but not formed to shape, and in box making it is any die-cut, scored, or otherwise partially prepared section of paper stock, in the flat, to be formed into a paper box.
Blanket roll:A resilient rubber roll that receives the wet ink image from the printing plate and then transfers it to the substrate to be printed. Printing processes using blanket rolls are often referred to as being offset. Lithography is always offset (uses a blanket roll). Packaging flexography is rarely offset except when used to print round containers.
Blister packaging:A type of packaging in which the item is secured between a preformed (usually transparent plastic) dome or “bubble” and a paperboard surface or “carrier.” Attachment may be by stapling, heat-sealing, gluing, or other means.
Block copolymer:A copolymer in which the two participating monomers join in alternating blocks or units.
Blocking:An undesired adhesion between touching layers of a material, as might occur under moderate pressure and/or temperature during storage or use. A common problem with plastic roll stock, stacked plastic sheets, and tapes.
Blown-film extrusion:The manufacture of thin plastic films by extruding a bubble of plastic and then inflating the bubble. In film manufacturing the extrusion and inflation are a continuous process.
Board (paper):A thick sheet of paper or other fiber substance. Variations are cardboard (nonspecific term), chipboard, fiberboard, paperboard, containerboard, boxboard, carton board, linerboard, and so on.See also paper and paperboard.
Boxboard:A general term designating the type of paperboard used for making folding cartons and setup paper boxes.
Box Marker’s Certificate:A statement printed on a corrugated fiberboard box or asolid fiberboard box testifying that all applicable construction requirements of the carriers have been observed and identifying and locating the box-maker.
Bottle:A container having a round neck of relatively smaller diameter than the body and an opening capable of holding a closure for retention of the contents. Specifically, a narrow-necked container as compared with a jar, or wide-mouthed container. The cross section of the bottle may be round, oval, square, oblong, or a combination of these. Bottles are generally made of glass or plastics but can also be earthenware or metal.
Bottom fill:Filling machines that employ this method have valves or stems that reach to the bottom of the container being filled. Such devices permit the filler to work while submerged, preventing turbulence, air incorporation, and foaming while the container is being filled with product.
Branching:Describes a polymer chain that has additional side chains branching away from the main or linear chain.
Brightness:A measure of the reflectance of light. Two objects may both be described as being red; however, the one that reflects the greatest amount of received wavelength will appear to be brighter. Brightness, when used to describe the reflectance of all wavelengths (white light), is used to specify papers. Brightness is expressed on a scale of 0 to 100.
Brightwood tray:A paperboard tray consisting of a bottom, four sidewalls, and four glue flaps that hinge off two of the sidewalls. The tray (blank) is shipped flat, then erected and glued at the packaging area.
Burst strength:A measure of the ability of a sheet to resist rupture when pressure is applied to one of its sides by a specified instrument under specified conditions. It is largely determined by the tensile strength and extensibility of the paper or paperboard. The Cady tester and the Mullen tester are the most common burst testing devices. Testing for bursting strength is common to determine grades of corrugated and solid fiberboard.
Calibration:The reconciliation of a measuring device to a known or absolute value. In its strictest sense, calibration of a measuring instrument implies trace ability to a national standard.
Caliper:(a) The thickness of a material such as paper, film, or foil, measured under specified conditions, (b) The precision instrument used to measure thickness.
Can:(a) (noun) A container, usually metal, generally having a capacity of less than 40 litres (10 gallons.) The word “can” is usually applied to consumer sizes and institutional sizes, (b) (verb) To pack a product in a can or (in the case of foods) a wide-mouthed glass container for processing, shipment, or storage.
Can end:The factory-applied end is referred to as the bottom end or maker’s end. The end delivered open to the filler is called the top end or the customer’s end.
CAP:See controlled atmosphere packaging.
Cardboard:A term erroneously used as a synonym for paperboard. It is not a recognized term in the paper industry, but it continues to be used to denote a stiff, moderately thick paperboard and as a general term for folding cartonboard, chipboard, corrugated board, and fiberboard.
Carrier web:A sheet of material whose purpose is to support or carry another material. For example, a polyester film may be metallized and the metallized surface further treated so that a hot iron will transfer a pattern of metallizing to another substrate. The polyester web serves to carry and support the metallizing until it can be transferred. The carrier web is then discarded or recycled. See also release paper.
Carton:A folding box generally made from paperboard. In domestic commerce, the term “carton” is generally recognized as the acceptable designation for folding paperboard boxes but never for a shipping container. In maritime and export usage, the term “carton” refers to a corrugated or solid-fiber shipping container.
Cartonboard:A paperboard used for folding cartons and made from furnish designed to produce a stock that is bendable enough to be folded without cracking along score lines.
Cascading (wax):A wax treatment system in which completed corrugated boxes are passed through a series of flowing curtains of molten wax. The wax coats both of the outer surfaces and also runs down into the medium and around the flutes, saturating the fibers with wax. A cascaded box can be made to be essentially waterproof.
Case:A nonspecific term for a shipping container. In domestic commerce, the term “case” usually refers to a box made from corrugated or solid fiberboard, wood, or metal. In maritime or export usage, “case” refers to a wooden or metal box. It may also refer to a fixed quantity of unit packages as commonly accepted for specific products. The use of “case” should be avoided in packaging because of a possible confusion with the use of “case” to indicate “in this instance.” For example, the sentence “Damage was found in three cases” can mean either that damage was found in three physical containers or that damage was found in three instances or situations.
Casein adhesive:An adhesive made from acidified milk curd. Casein adhesives have good cold-water resistance but can be readily dispersed in hot water. This property makes them ideal for labeling refillable beverage bottles, where the label must resist cold-water immersion but must be readily removed at the refill point.
Cast film:A film that is extruded in a thin curtain from a slotted die and then cooled and solidified by being passed over a chilled roll.
Cavity mold:A mold for shaping metal or plastics having a cavity form. A female mold.See also plug mold.
Cellular plastic:A plastic that has been expanded with a gas, resulting in a product having increased volume and decreased density.
Centipoise:One hundredth of a poise. A measure of viscosity, approximately defined as the viscosity of water at room temperature (20.2C).
CD:See cross direction.
Changeover:The resetting or reconfiguring of a machine or production line to run a different product or package.
Chemical pulp:A papermaking pulp produced by treating wood fibers with chemicals, usually based on acid or alkaline sulfur compounds. The chemicals dissolve the lignin compounds that bind cellulose fibers together, freeing the fibers from the wood structure with a minimum of damage to the fiber, thus producing a superior papermaking pulp. See also kraft process and ground wood pulp.
Child-resistant closure:A closure designed so that young children have difficulty opening the container. Child-resistant closures are designed to take advantage of a child’s limited ability to combine motions. In most countries the requirements of a child-resistant closure are defined by law.
Chill roll:A roll used to chill or remove heat from a substrate.
Chipboard:A low-quality paperboard made of recycled paper for use where specified strength or printing quality is not necessary. It may be a bending or nonbending grade. Chipboard is used for pads, dividers, backing sheets, and filler pieces.
CFCs:See chlorinated fluorocarbons.
Chlorinated fluorocarbons (CFCs):A group of propellants used in aerosols and as a blowing agent for some plastics until the late 1980s. Concern over depletion of the ozone layer has virtually eliminated CFCs from packaging applications.
Chlorotrifluoroethylene (CTFE):A plastic material characterized by good moisture- and oxygen-barrier properties as well as good clarity and easy thermoformability. Its cost restricts it mostly to the pharmaceutical industry. Aclar is an Allied Signal product based on CTFE.
Choked neck:A narrowed or constricted opening in a glass container.
Chromalin:A preprint proofing method using photographic reproductions. Chromalins are composed of four layers of plastic that simulate the four process colors, bound together into a single page. Chromalins are used to check the positioning of the graphic elements and the approximate colors. True color can be verified only on the press, using the intended substrate.
Clarity:Freedom from turbidity or haze. In flexible packaging materials, clarity testing equipment consists of a light source that, projects a light beam through the film. Clarity is expressed as a function of the transmitted light. (Reference method: ASTM D 2457.)
Clay-coated board:A fully bleached sheet, which is coated with clay to impart a permanence of color and brightness, as well as an excellent printing surface.Although it is primarily used in folding cartons for products such as cigarettes, cosmetics and liquor, it is also used as an outer liner for corrugated applications requiring sophisticated multicolor graphics.
Closure:Any device used to close a bottle, jar, can, or similar container to retain the contents. Most closures are held in place by a screw thread. However, closures may also snap over the finish, plug in to it, or fasten in another way. A closure may be required to effect a hermetic seal to preserve the contents.
Closure liner:A layer of material placed inside a closure to provide a cushion to which the container finish is held by compression, thus forming a seal that prevents leakage, evaporation, or the entrance of air into the package. Traditional liners are formed from a soft, resilient backing piece (for example, a pulpboard or cellular plastic) and a facing material selected for chemical compatibility and barrier characteristics appropriate to the product. Flowed-in liners are plastic compounds (usually vinyls) that combine the functions of the backing and facing materials and are applied in liquid form and then cured. Venting liners, designed to vent gases generated by the product, have facings provided with small vent holes or areas that are capable of physically moving when exposed to pressure.
CMQ plate:Can-making-quality steel. A black plate substantially free of objectionable oxide or scale and lightly oiled to help reduce rusting.
Coefficient of friction (CoF):The ratio of the force required to move one surface over another to the total force pressing the two surfaces together. Dynamic CoF is the force required to continue the movement of one surface over another, as opposed to static CoF, which measures the force required to initiate motion. Static CoF is always greater than dynamic CoF.
Co-extrusion:The extrusion of two materials simultaneously from a single die in such a way that the two separate materials fuse together to form a single structure. The two materials still retain their individual properties except for the immediate contact area.
CoF:See coefficient of friction.
Cohesion:The tendency of a mass to hold together. The internal bond strength due to the mutual attraction of molecules for one another within a material.
Cohesive seal:A seal produced by an adhesive that adheres only to itself and requires only contact pressure to bond. Also known as cold seal.
Cold flow:The flow of a viscoelastic material over time when subjected to a load. Usually used in reference to plastics. Also known as creep.
Cold-seal adhesive:An adhesive typically based on natural rubber and having the characteristic of great adhesive attraction for itself but little attraction for other materials. Used on plastic films where normal heat sealing can’t be used. The surfaces to which a cold-seal adhesive has been pre-applied are simply brought into contact with one another.
Collapsible tube:A cylindrical tube shape that is squeezed or flattened to eject the contents. Originally, collapsible tubes were made of tin, lead, or aluminum. Modem collapsible tubes are also made from plastics and from laminated materials.
Color key:A proof used to show how the color image will be assembled. Produced in layers that match the process or line colors, color keys are tacked onto a mounting paper along one edge. This allows individual layers to be lifted for Inspection. A color key is not as accurate in reproducing colors as a chromalin.
Color separation:Separation of color artwork into its primary color components through the use of filters (photographic separation) or by electronic scanning. Images are normally separated into the respective process-printing ink colors yellow, magenta, cyan, and the key color, usually black).
Column stack:A layout of shipping containers in a palletized load wherein all containers are aligned vertically in columns without interlock.
Combined Board:The term used to indicate a completely fabricated sheet assembled from several components, such as “corrugated” fiberboard or “solid” fiberboard.
Combined weight of facings:A value used in carrier regulations to specify the amount of paper in a corrugated construction. The weight of the two facings is added together. The weight of the medium is disregarded.
Compatibility:The ability of a container or material to resist chemical degradation or physical change caused by the product, or to chemically change or physically degrade the product contained.
Composite can:A rigid container with a body made of paper plies and ends made of metal, plastic, or another material. The body is usually wound from paper alone or paper and plastic laminates in either a spiral pattern or a convolute pattern. Spiral winding can produce only round cans, while convolute windings are able to produce cans in other shapes, as well as round. Round cans are easier to seal hermetically.
Compression:Compression performance is defined as the ability of a container to resist external compressive loads applied to its faces.Adequate compression, or stacking strength, is necessary for a corrugated container to perform its intended function.
Compression set:The extent to which a cushioning material fails to recover its original form when a load has been removed from it after being imposed for a given period.
Compression strength:The maximum load that can be applied to a container under specified conditions. Static compression strength usually refers to a container’s ability to withstand a stationary load for a period of time. Dynamic compression strength is the load at failure when an increasing load is rapidly applied. Viscoelastic materials such as corrugated board or plastics will have different compression strength test values, depending on how fast the load is applied. See also dynamic compression and static compression.
Conditioning:Holding paper or other packaging material under controlled conditions so that it attains a specified moisture content and temperature. Preparing packages for test by regulating the moisture content and temperature of the packaging material.
Conductive:Accepts static electricity but dissipates the charge throughout the foam thus reducing it to a harmless level.
Cone-top can:A can with a lop having the general shape of a conical section. The top usually has a screw closure.
Constant-level filling:A filling system in which the containers are filled to an exact level regardless of variations in the container’s actual volume. This gives a visual appearance more acceptable to the consumer.
Constant-volume filling:A filling system in which a precisely measured volume of product is placed into a container. Constant-volume filling is used where dosage is critical or where product cost is high. Small variations in actual container volume will result in visually different fill levels that might be interpreted as irregular fill volumes. The container can be designed so that the actual fill level cannot be seen.
Consumer package:The package that ultimately reaches the consumer. The unit of retail sale.
Container:(a) In general, any receptacle or enclosure for holding a product used in packaging and shipping. (b) A large, reusable enclosure to be filled with smaller packages and discrete objects (as in containerization), to consolidate shipments and allow transport on railway flatcars, flatbed trailers, or aircraft; in ships’ holds; or as deckloads.
Containerboard:The paperboard components (liner-board and corrugating medium) from which corrugated board is manufactured.
Continuous-motion machine:A machine configuration in which an action is performed on a product or package without stopping the movement of the product or package. Most continuous-motion machines have a rotating carousel into which the package is inserted. The operation (for example, filling, capping, or labeling) is completed while the package is rotated around the carousel and then ejected onto a moving conveyor at the end of the operation. See also intermittent-motion machine.
Continuous thread (CT):The helical threaded neck finish of containers or the closures designed for application to these finishes. CT denotes continuity of thread in order to differentiate it from lug or other interrupted thread forms. CT finishes have GPI finish designations in the 400 series.
Continuous-tone image:An image in which the gradation from black to white is continuous. Black-and-white photography is a continuous-tone image.
Contrast:Describes the difference between the lightest and darkest portion of an image.
Controlled Atmosphere Packaging (CAP):CAP describes a storage or warehousing technique rather than a specific package construction or method. Similar to modified atmosphere packaging (MAP), CAP extends product shelf life by changing the composition of the surrounding atmosphere from the normal to some other proportion of oxygen, nitrogen, and carbon dioxide. Unlike MAP, CAP involves monitoring the proportion of gases and adjusting them as necessary. For example, the storage of produce at low oxygen concentrations would slowly deplete the oxygen and increase the carbon dioxide component and the relative humidity. In CAP these would periodically be adjusted to maintain a steady-state atmosphere.
Converter:A manufacturer that takes raw materials and converts them into a usable package or package component. Most commonly used in reference to manufacturers of flexible packaging materials. For example, a converter may print a polypropylene film; combine it with paper, foil, and polyethylene; and slit it to the widths required by a user.
Convolute winding:A method of winding a composite can body in which the paper or winding material advances to the mandrel in a direction perpendicular to its axis. A tube is formed by having each ply wrapped around itself and placed directly over the preceding ply. The length of the tube is the same as the width of the paper from which it is wound. Also see spiral winding.
Convoluted:A process in which flexible foam passes through a machine which distorts and cuts it in a way that leaves interlocking high and low points. This is commonly used for items such as circuit boards, which can have an uneven surface and need something that can conform to it.
Copolymer:Any polymer that has been produced from two monomers. More generally, the term is used to describe any polymer that has been produced from more than one monomer.
Cork:The light, tough bark of the cork oak tree. A closure made of cork or, by extension, any plug-type bottle closure.
Corner Cut Tray- CC Tray:Similar to the design style tray except the corner formed by scoring and slotting are cut off in the manufacturing process. This then forms a simple tray, which cannot be set up by joining at the corners. This tray is often used as interior packing in a shipping container and usually covers the top or bottom of the object in the box.
Corona treatment:A treatment to alter the surface of plastic and other materials to make them more receptive to adhesives or printing inks. An electrical discharge creates ozone, which in turn oxidizes the substrate surface and creates polar sites that contribute to strong bond formation.
Corrugated board:A packaging material consisting of a central member (medium) that has been fluted on a corrugator and to which one or two flat sheets of linerboard have been glued to form single-faced corrugated board or single wall corrugated board. Double wall is the combination of two mediums and three facings, and triple-wall is the combination of three mediums and four facings. Corrugated board is generally made in one of four flute sizes, designated A, B, C, and E. See also flute.
Cover For HSC:(A.)Full telescoping bottom and cover.Both top and bottom are HSC’s but the dimensions of the outer HSC cover are adjusted to fit over the bottom HSC to the full depth of the bottom HSC. ( B ) Telescoping bottom and partial telescoping cover, HSC style.Same as (A) above, except the HSC cover only extends part way down the depth of the HSC bottom.
Crease:(a) (noun) A line or mark made by folding any pliable material, or a similar mark, however produced.(b) (verb) To form a crease in a sheet of any material, usually for the purpose of providing a bending line.
Creasing rule:An oval-edged steel strip used to form a crease or bending line in paperboard or boxboard stock.See also cut-scoring rule.
CR closure:See child-resistant closure.
Creep:See cold flow.
Critical G:The acceleration level, expressed in G, beyond which damage is likely to occur.
Cross direction (CD):The direction at right angles to a material’s flow through a machine. Flow direction through a machine may impart directional properties to a material. For example, paper acquires a directionality during manufacture known as cross direction (perpendicular to the paper flow through the machine) and machine direction (parallel to the paper flow).
Crosslinked:A polymer in which individual molecular chains are linked by side branches to adjacent chains.Crosslinking may be present to varying degrees. A heavily crosslinked polymer is classed as a thermoset plastic.
Crown closure:A metal closure that crimps over a bead on a bottle finish. The major application has been for carbonated beverages.
Crystalline polymers:Plastics with high molecular regularity in their molecular formation are considered to be crystalline in nature. These typically more dense polymers include polyamides, polyesters, and polyethylene. Many properties of a polymer are related to the degree of crystallinity. See also amorphous polymers.
Crystallization:The formation of regular molecular patterns within a mass of material, resulting in physical changes in the properties of the material, particularly the way it refracts light.
CT closure:See continuous thread.
Cullet:Glass recovered from production rejects or from consumer recycling programs, crushed, and added to the normal glass furnace charge. In addition to reducing waste going to landfill, cullet also reduces the energy required to fuse new raw materials into glass.
Curtain coating:A wax treatment for corrugated boxes in which the box blank is passed under a curtain of molten wax. The wax coats the box, providing for a surface that will shed water. A box can be coated on one or both sides. The box will still absorb atmospheric moisture, since the majority of fibers (in the interior of the flutes) are still exposed to air.
Cushioning:The protection from physical damage afforded to an item by placing about its outer surfaces materials that have been designed to absorb the shock or reactions caused by external forces. Resilient materials are used for cushioning.
Cut-scoring rule:A steel strip, one edge of which is ground to the center or a side face. Used for partially cutting through boxboard stock, for example, making a partial cut for the purpose of forming a fold line. See also creasing rule.
Cylinder board:A grade of paperboard made on a cylinder-type papermaking machine. Cylinder boards have several layers of pulp pressed together to form a single sheet with calipers of 380 micrometers (0.016 inch) and up. The fibers tend to orient themselves into the direction in which they pass through the cylinder machine, causing the board to have considerable differences in stiffness and tear strength in one direction as compared with the other. Cylinder boards generally use recycled fibers for the center plies and a clay-coated white liner to produce a good printing surface.
Cylinder machine:A papermaking machine in which a rotating screen cylinder is used to remove fiber from the finish. A number of cylinders, usually six to eight, in sequence are used to build up a multilayer paperboard. Sometimes referred to as a vat machine.
Dead fold:The ability of a material to remain in place when folded or creased. Aluminum and paper are described as having good dead-fold properties, while most plastics have poor dead-fold properties.
Deflection:A term used in compression testing to indicate the deformation or reduction in dimensions made in the testing direction between established preload and ultimate failure load.
Deformation:Any distortion of the form or outline of an article.
Demographics: A statistical description of specifically measurable aspects of the population. For example, age, gender, income level, educational level, home ownership, and so on.
Density:The weight of a given volume of a material. In English units this is usually expressed in pounds per cubic foot. In metric units density is given in kilograms per cubic meter, although in packaging, grams per cubic centimeter is more common. Relative density is the ratio of the density of the observed object to that of water. (Density of water is 1 gram per cubic centimeter.) Relative density, being a ratio, is unit less.
Design brief:The central planning document in a package development project. A package design brief is a comprehensive document detailing what the package is supposed to achieve, in what marketplace, with what customers, by what means, and in conjunction with what other activities. The design brief has a full, detailed description of the objectives developed for the project.
Design speed:The theoretical capacity of a machine or line under perfect running conditions. The speed of the machine as designed, running empty, is the design cycle rate.
Die:(a) Any metal device that is used to cut or impart a shape to another material. For example, a steel-rule cutting die is used to cut paper or paperboard shapes from a press sheet, (b) A device used to shape metal in drawn can or draw-and-iron can manufacture, (c) A device to give form to an extruded plastic material.
Die-cut:Any operation in which a form that incorporates sharp cutting edges is pressed into a substrate to cut out a designed shape. For example, cutting dies are used to cut paperboard shapes that will subsequently be folded into cartons.
Differential tinplate:Electrolytic tinplate having different weights of tin coatings on opposite sides of the sheet.
Dimensional stability:The ability of a material to retain its dimensional shape under given processing or use conditions.
Distribution package:A package whose primary purpose is to facilitate efficient distribution and to protect and contain the product during distribution.
Double Wall Board:A corrugated board construction composed of three linerboards and two fluted mediums. The board is stiffer and stronger than single wall and is used for containing heavier products such as major appliances.
Double-reduced steel:Steel that is rolled to a thickness somewhat greater than desired, annealed to remove work-hardening, and then rerolled to the required thickness. The effect of work-hardening after the second rolling produces a stiffer, higher-temper steel.
Double seam:The seam at which the can ends are attached to the can body. The joint is formed by curling the top or bottom cover flange over and around the body flange of a can, resulting in a chime section of five thick nesses of metal and forming an extra-strong, leak proof joint.
Draft:The degree of taper of a sidewall or the angle of clearance designed to facilitate removal of articles from a mold.
Draw-and-iron can:A two-piece can that is produced by pushing a drawn initial shape through a series of ironing rings, each with a diameter slightly less than the previous one. This has the effect of ironing out and thinning the metal in the can walls, producing a can with greater metal area than the starting blank. Since the can walls are very thin, the can is used only in those applications in which an internal pressure is able to support the can walls. Examples are carbonated beverages and some juices that use nitrogen to produce internal pressure.
Draw-and-redraw can:A two-piece can that has a body formed to shape by pushing (drawing) a flat can blank through a circular die ring and then, in a second operation, re-forming the can through a second draw operation. Draw and redraw cans are able to have depths greater than the can diameter. Unlike draw-and-iron cans, wall thickness is the same as in the starting blank. Drawn can a two-piece can that has a body that is formed to shape by pushing (drawing) a flat can blank through a circular die ring. Typically, the depth of a drawn can is no greater than the diameter.
Drop Test:The method of determining if a packaging design adequately protects the contents. It is not necessary to test all designs. This should be utilized only if a customer requires it.
Dry-bond laminating:A laminating method where two substrates that are not readily permeable to adhesive solvent vapors are joined. An adhesive is applied to one substrate, and then the coated surface is dried of all volatiles. Depending on the adhesive formulation, the remaining adhesive solids will be tacky or can be made so by nipping the substrates against a heated combining roll.
Dry-end treatment:In papermaking, any treatment, such as clay coating, that is applied after the paper is formed and partly or completely dried. Dynamic coefficient of friction See coefficient of friction.
DS Lid:Is the same as DST, but designed to fit over the design style tray partially or fully on the depth dimension.
DST – Design Style Tray:This container, when assembled by the user, looks something like an HSC but is not joined by the manufacturer, using adhesives, etc. as the RSC or HSC. The tabs formed by scoring and slotting at each of the four corners are folded in, joined, and set up by the user who joins them with adhesive or occasionally staples. This box is often seen in use as a 4-6 pack beer container with open top.
Dynamic compression:Describes the rapid application of a compressive load, for example, by a clamp truck handling corrugated boxes, or the laboratory determination of box compressive strength using a stress/strain machine. See also compression strength and static compression.
Dyne level:A measure of surface energy. The dyne level will indicate whether a material’s surface will be receptive to forming a chemical bond with an adhesive, coating, or ink. Generally, in packaging, the dyne level of a surface needs to be 37 dynes or higher, depending on the nature of the adhesive substance. (Reference method: ASTM D 2578.)
Economic order quantity (EOQ):Beyond the actual cost of manufacture, product cost is affected by the cost of setting up the production line and the cost of storing inventory beyond what can be immediately used. The longer the production run, the lower the setup cost per part. However, inventory costs increase as more product needs to be stored beyond immediate needs. EOQ describes the point at which the two costs added together are at a minimum.
ECT:See edge crush test.
Edge crush test (ECT):A test used to determine the stiffness of a corrugated board. Briefly, a small section of board standing on edge is compressed to failure. The load at failure can be related to the probable compression strength of a shipping container made from that board.ECT values are one of the optional corrugated board specifying values required by carrier rules.The other option is the Mullen burst test. (Reference method: TAPPIT811.)
Efficiency:See output efficiency.
Elastomer:A material that has high elongation properties. Most packaging elastomers are synthetic polymers, except for natural rubber. Elongation the difference in length, expressed as a percentage of the original length, when a plastic specimen is subjected to a tensile load. Elongation at yield is the elongation at the point at which the specimen will not return to its original dimensions. Elongation at break, or ultimate elongation, is the elongation at fracture.
E.L.E Ester-Like Ether:Polyurethane foam which has a look and feel of polyester.
Environmental chamber:A chamber or enclosure used to create specific environmental conditions, most typically ranges of temperature and humidity. Environmental chambers are used to simulate use conditions, usually for the purpose of accelerated testing of packages and products.
Environmental stress cracking:The fracture of a plastic part due to movement of molecules trying to relieve internal stresses. Stress cracking is a physical phenomenon and is not related to chemical compatibility. However, certain agents are known to accelerate or contribute to stress cracking, even though they themselves do not chemically react with the plastic. Environmental stress-crack resistance is abbreviated ESCR. (Reference method: ASTM D 2561.)
Equilibrium moisture content:The moisture content of a substance at which it will neither gain nor lose moisture in an atmosphere having a given relative humidity.
Equilibrium relative humidity:The humidity at which the moisture content of a material and the surrounding relative humidity are in equilibrium. The material will neither absorb moisture nor lose moisture to the air.
Equity:The value, trust, or recognition given to a product or company based on a long-standing satisfaction with the product or company.
ERH:See equilibrium relative humidity.
ESCR:See environmental stress cracking.
Essential oil:A volatile substance that can be detected by the sense of smell, and an important component in the perception of flavor or aroma. Also referred to as a sensory active agent (SAC).
Ethalam:Polyethylene roll stock, which is laminated in layers to achieve a desired thickness.
Ethylene-ethyl acrylic acid (EEA):A polar polymer that is used in various adhesive preparations to improve heat sealabilty in difficult substrates. EEA develops good bonds with aluminum foils. Used in blends with other resins to improve heat seal and other properties.
Ethylene-vinyl acetate (EVA):A polar polymer used as the base or backbone polymer for most packaging hot melt adhesives.
Ethylene-vinyl alcohol (EVAL):Can be regarded as a copolymer of polyethylene in which varying amounts of the -OH functional group have been incorporated. EVAL is one of the best oxygen barriers available to packagers. However, its susceptibility to water requires that for most applications it be laminated into a protective sand which with materials that will keep the EVAL layer away from water. The abbreviation EVOH is sometimes used instead of EVAL.
Expanded Polyester:(AKA: Ester) Government spec, flexible foam, which is highly durable, flame-retardant, and resistant to discoloration.
Expanded Polyethylene:(AKA: Ethafoam) Semi rigid, closed dell foam, which is extruded into planks of various thicknesses.This is usually used for heavier items.
Expanded Polystyrene:(AKA: E.P.S) Rigid foam, which is fabricated and cut using wire, heated with electricity. It is also available in antistatic form.
Expanded Polyurethane:(AKA: Ether, Flexible) Flexible open cell foam of various densities, poured to form large “buns” which can be sliced to any thickness.
Extensible:A material that is capable of being stretched under normal processing conditions.
Extrusion:The process of forming a thermoplastic by forcing the polymer melt through a shaped orifice. The extruded plastic is immediately chilled, and the resulting shape would be in the profile of the extrusion die.
Extrusion bonding:A process wherein a film of molten polymeric material is extruded and immediately pressed between two substrate materials while still hot. The cooled polymer will bond the two materials together.
Extrusion Coating:A process wherein a film of molten polymeric material is extruded onto the surface of a substrate material and cooled to form a continuous coating.
Eye-mark:A machine-recognizable mark, printed on web-fed packaging materials. The eye-mark is the reference point from which the machine will register other operations such as further decoration, heat sealing, or package cutoff.
Face liner:That linerboard of a corrugated construction that will eventually be printed and used as the exterior face of a corrugated box. In the manufacture of corrugated board, the face liner is the second one applied to the fluted medium. The linerboard against which the corrugated flutes are first pressed will typically have a series of faint embossed lines resulting from the heat and pressure of the corrugating rolls.
Ferrule seal:A metal seal that is clamped around the finish of a glass bottle. Ferrule seals are used to join the aerosol actuator fitment to a glass bottle, and to hold the rubber septum in place over a glass vial.
FFS machine:See form-fill-seal machine.
Fibreboard:The general term applied to fabricated paperboard used in container manufacture. May be of either corrugated or solid construction.
Film (plastic):Generally used to describe a thin plastic material usually not more than 76 micrometers (0.003 inch) thick. Above this, thin materials are usually referred to as a sheet.
Finish:That part of a glass or plastic container that will receive the closure device.
Fin seal:A type of seal resulting from sealing together the contiguous edge areas of two sheets, usually by heat, resulting in a finlike protuberance.
Flame treatment:A treatment that involves exposing a material (such as a plastic bottle) to a gas flame to increase the polarity of the surface. The amount of flame treatment depends on the condition and position of the flame and the time of exposure. See also corona treatment.
Flaps:The closing members of a fiberboard box.
Flash:Excess plastic material that is squeezed out between the mold parts during molding.
Flask filling:See volumetric filling.
Flex cracking:Cracking or fracture of a substrate as a result of repeated flexing, as might be experienced during manufacture or shipping.
Flexible packaging:A package or container made of flexible or easily yielding materials that, when filled and closed, can be readily changed in shape. Normally applies to bags, envelopes, pouches, or wraps made of materials ranging in thickness from 13 to 76 micrometers (0.0005 to 0.003 inch), such as paper, plastic films, foils, or combinations of these.
Flexography:A method of printing using flexible rubber or photopolymer printing plates in which the image to be printed stands out in relief. Fluid ink metered by an engraved roll is applied to the raised portions of the printing plate and then transferred to the substrate.Flexographic printing is used to print sheets of preformed corrugated board and for printing roll-fed plastics and papers.
Flexural modulus:The ratio, within the elastic limit, of the applied stress on a test specimen in flexure to the corresponding strain in the outermost fibers of the specimen, measured in pounds per square inch or kilograms per square centimeter. (Reference method: ASTM D 790.)
Flexural strength at yield:The measure of resistance of the material to fracture during bending. Measured in either pounds per square inch or kilograms per square centimeter. (Reference method: ASTM D 790.)
Flute:The undulation or corrugationpressed into medium paper as used in the construction of corrugated fiberboard. Flute sizes have been standardized by carrier regulations and are designated by size (from largest to smallest) as A-flute, C-flute, B-flute, and E-flute. There is a size specification for D-flute, but no commercially significant quantities are made.
Foam-in-place:A chemical process, usually based on urethane chemistry, that produces foamed cushioning conforming to the item.
Foil:An unsupported thin metal membrane less than 152 micrometers (0.006 inch) thick. Above 152 micrometers thickness, the metal is called sheet. In many European countries the French word feuille (also pronounced “foil”) is used to describe any thin material (for example, plastic films) as well as thin metals.
Folders:Each of these are self-locking, which permits the customer to set them up without the use of adhesives or tape, the box is made with a number of slots, locking tabs and slits.In the manufacturing process, special dies are used to “punch” these out on our equipment. These dies are made using an imported birch plywood on which steel strips (rule) are mounted that do the cutting, creasing, and slitting at relatively high speed on our due cutters.
Folding carton:A plain or printed container made of bending grades of paperboard, in a variety of sizes and shapes. Delivered either flat or folded, glued, and collapsed, to be set up, filled, and closed by the user. This is a general class of paperboard container distinct from setup boxes and corrugated and solid fiber boxes.
Font:The complete set of letters, numbers, and punctuation marks of a particular design and size.
Formation:The evenness with which cellulose fibers are distributed in a finished paper. Short cellulose fibers flow out fairly evenly and produce a paper with good formation. Long fibers tend to tangle and flow out in clumps during papermaking. This results in an uneven distribution of fiber in the paper. The different fiber densities will affect local paper properties such as density, tear strength, and ink absorption, to name a few.
Form-fill-seal machine:A filling machine that is fed with a flexible packaging stock from a roll. The stock is folded to the desired package shape and stabilized by heat sealing. The product is placed into the formed package, and the remaining Opening is sealed. Machines can be configured so that the stock travels horizontally through the machine (horizontal form-fill-seal) or vertically through the machine (vertical form-fill-seal).
Fourdrinier machine:A papermaking machine in which the mixture of cellulose fiber and water is poured out onto a moving screen in the first step of forming the paper sheet.
FPF- Five Piece Folded:This box is shipped flat, ahs five panels or sides. The fifth panel forms a tuck-in pieces when set up by the customer. It is often used to ship such articles as umbrellas, light fixtures, and window shades. When the box is opened by the customer, it is through the small inner and outer flaps at each end.The long objects such as fluorescent light tubes, are drawn out through the end. This box is not joined in any way by the manufacturer, but is assembled and closed by the user. Through die-cutting this box can be made self-locking so that the box locks together without the us of a closure material like tape on the ends.
Fragility (of a product):A quantified value of some input, such as vibration, compression, or shock, at which loss of value or damage will occur.
Fragility factor:Most commonly, fragility factor is used to describe the shock level, expressed in G, at which some part of the product will be damaged.
Fragility factors:Are used to calculate the area and thickness of shock-absorbing materials when designing protective packaging.
Free-flowing powder:A powder that will flow freely and form an even cone with a low angle of repose when poured out onto a level surface. Such powders will have an even density throughout and can be metered by dispensing a set volume. See also non-free-flowing powder.
Friction-fit pry-off closure:A closure that depends on a friction fit (interference fit) for the seal. Paint can covers and cocoa tin lids are examples.
Furnish:The mixture of cellulose fibers and other additives that will be fed into a papermaking machine to form the paper.
Gain:In printing, the increase in dot size inherent in the transfer of ink to a substrate. Flexography in particular has significant gain from the designed dot size. Gain can cause process colors to be inconsistent and can fill in universal product codes and make them unreliable.
Gang die:A cutting die, most typically as used for folding carton manufacture, that will cut a number of cartons from the press sheet with each pressing, as opposed to a one-up die that cuts a single carton.
Gas permeability:The ability of a gas or other volatile substance to penetrate and pass through a material. Materials that will allow significant passage of gases are said to be permeable, while materials that resist or stop the passage of gases are said to offer gas barrier properties.
Gas transmission:The movement of gas through packaging materials. The gas transmission (permeability) through a film is measured in terms of the volume of gas (at standard temperatures and pressure) that will pass through a given area of film of a given thickness over a given time and at a specified temperature and humidity.
Gauge (also gage):(a) (noun) An instrument for exact measuring, (b) (verb) To measure exactly.
Gauge (film):A unit of measure, usually of thickness, expressed by a number that has a dimensional equivalent that varies for different materials and for different standards. When measuring the thickness of a film, 100 gauge = 0.001 inch. Thus, a 75-gauge film would be 0.00075 inch thick.
Gauge (metal plate):A unit of measure describing the thickness of steel from which containers are made. For sheet steel, the gauge system used in the United States is the U.S. Manufacturer’s Standard.
G level:A measure of acceleration expressed as the ratio of observed acceleration to that of gravity (g).
Gloss:The amount of surface sheen or reflectance of a substrate.
Glue:Although the term is frequently used to describe any sticky substance that can be used to join two surfaces, it most correctly refers to a protein-based substance derived from animal cartilage, bones, and skins. True animal glues are rarely used in packaging. The preferred term for synthetics is adhesive.
Gob:The measured amount of molten glass sufficient to make one container, as it is delivered to the blank mold of an individual station machine.
Grain:The arrangement or direction of fibers in a fibrous material such as paper or wood, or the direction or molecular orientation in a nonfibrous material.
Grammage:The weight in grams of 1 square meter of material. Grammage can be used to describe either a film or sheet material or the rate of application of a liquid adhesive or coating.
Gravure printing:A method of printing that uses cells etched or engraved into the surface of a metal cylinder to meter and correctly pattern the ink. Gravure printing presses used in packaging are predominantly roll fed.
Green strength:The strength of an adhesive bond prior to thorough curing or drying. Usually used in connection with emulsion-type adhesives, where the early breaking of the emulsion results in rapid development of a strong bond, which improves further at a much slower rate as the water evaporates.
Groundwood pulp:A papermaking pulp that is produced by physically grinding the cellulose fiber out of the parent wood mass. Ground wood processes are inexpensive and fast. However, they damage fiber, reducing the papermakingquality of the pulp produced. Ground wood pulps also retain significant non fibrous components such as lignins, which further reduce paper quality. Ground wood pulps are used to produce low-quality papers such as newsprint. See also chemical pulp and pulp.
Halftone art:A halftone image is composed of a large number of dots of ink of varying sizes. Areas where the dots are larger will appear to be more strongly colored, while areas with smaller dots (highlights) will be less strongly colored. If the ink being used is black, a range of gray values going from black to white can be created.
Handleware:Glass or plastic bottles having attached handles formed as part of the molding process.
Hand sample:In the manufacture of paperboard cartons, a sample design produced by the carton designer to illustrate a proposed design for a customer.
Haze:A value related to the light transmittance of a material such as plastic film.
Heat resistance:Conventionally taken to be the maximum temperature that a material will withstand and still retain at least 50% of its physical properties when subjected to this temperature for a specified time.
Heat seal:A method of joining two surfaces by heat fusing them or their coatings together. The quality of the seal is determined by, the seal substances, time, temperature, and pressure.
Heat-seal strength:The strength of a bond formed by heat sealing. It can be measured in tensile or peel modes.
Heat-shrink property:The property that allows a plastic material to shrink when heated to approximately glass transition temperature.
Heat-transfer printing:A decorating method that uses heat to melt and transfer a preprinted thermoplastic ink pattern from a carrier film onto the object to be printed. A heated die is pressed against the carrier film to effect a transfer of the decoration. A major application is to transfer preprinted decorations onto plastic bottles. Trade-named methods are Therimage, Di-Na-Cal, Electrocal, and Letraset.
Hertz(Hz):A measurement of frequency in which one hertz equals one cycle per second.
HFFS:See horizontal form-fill-seal.
High-density polyethylene (HDPE):A hydrocarbon polymer that has linear chains allowing for dense packing. HDPE is economical, can be processed easily by most methods, has good moisture barrier properties, and has good chemical resistance. It has a comparatively low melting point, is soft, has high elongation, and has poor gas barrier properties. It is used for most household product bottles, many plastic bags, and injection-molded dairy crates and beverage carriers, among other applications.
Homopolymer:A polymer that is produced by the polymerization of a single monomer species.
Hoop strength:A circular container’s resistance to crushing forces. Usually used in reference to a metal can’s ability to withstand external pressures during heat processing.
Horizontal form-fill-seal (HFFS):A form-fill-seal machine in which the roll-fed flexible packaging material isunwound and shapedwhile traveling horizontally through the machine’s operating stations. An HFFS machine occupies greater floor space than a vertical form-fill-seal machine, but it has the advantage of having the possibility of installing more operating stations (for example, multiple filling stations) along the travel path.
Hot-melt adhesive:An adhesive, solid at room temperature, that is liquefied by heat, applied molten, and forms a bond by cooling and solidifying. Based on thermoplastic polymers generally modified with resins and/or waxes. Usually used in range of 120 to 205C (250 to 400F).
Hot-stamp printing:A decorating method that uses heat to melt and transfer a thermoplastic ink or substance from a carrier film onto the object to be printed. A heated die with the desired pattern engraved into it is pressed against the carrier film to effect a transfer of a decorative pattern. A major application is to transfer aluminum metallizing. The resulting pattern will have a high metallic luster.
Hot tack:The stickiness of a heat-activated adhesive at melt temperatures.
HRI:Hospital-restaurant-institutional. A segment of the packaging market requiring packages containing larger quantities and possibly special features as compared to the same product offered in retail establishments
HSC- Half Slotted Flaps:This is the same in appearance as an RSC, except there are no top flaps. When no separate cover is used, this box is often used as a book box, banana shipper, and so on.
Hue:That characteristic that places a color in its correct position in the spectrum and allows us to differentiate between colors such as red, green, blue, and so on.
Humidity:Water vapor in air. Absolute humidity is the actual weight of water vapor contained in a unit weight of air. Relative humidity is the ratio of actual humidity to the maximum humidity that air can retain without precipitation at a given temperature and pressure. Relative humidity is expressed as a percentage of saturation.
Hygroscopic material:A material that will absorb moisture from the air. A hygroscopic material will reach an equilibrium point for a specific relative humidity, at which point moisture will be neither gained nor lost.
Hysteresis:The equilibrium moisture content of paper will vary slightly depending on whether the equilibrium point is reached from a humidity that is lower than or higher than the current humidity. Thus, two equilibrium moisture content curves can be drawn for paper, one for moisture contents determined by increasing the humidity around a dry paper sample and another by drying a moisture-saturated paper sample. This effect is known as hysteresis.
Icon:In graphic arts, a recognizable symbol, image, or wordmark.
I.L.M Indent Load Deflection:This numerical rating determines the firmness of the foam. 30 – 50psi > soft 50 – 70psi > medium. 75 – up > hard.
IML:See in-mold labeling.
Impact strength:The ability to withstand impact forces without damage.
Impulse sealing:A heat-sealing technique in which a surge of intense heat is momentarily applied to the area to be sealed, followed immediately by cooling.
Incline impact test:A test intended to determine the ability of a shipping container to withstand impact stresses and to determine the degree of protection afforded to the product by the outer container and/or its interior packing. Such tests simulate the types of shock pulses experienced by lading in railcar switching. Also referred to as a Conbur test. (Reference method: ASTM D 880.)
Induction innerseal:A seal made by exposing an aluminum foil coated with a thermoplastic adhesive substance to an electrical field. The field induces eddy currents, which heat the aluminum foil, melting the adhesive material. This in turn adheres the aluminum foil to a bottle’s opening circumference. Induction seals provide tamper evidence and a hermetic seal when used as an inner seal beneath a normal threaded closure.
Injection blow molding:A method of manufacturing plastic bottles and jars in which a preform or parison is injection-molded rather than blow-molded. The preform is transferred to a second mold, where compressed air is used to expand it to the full container shape.
Injection molding:A method of molding plastic materials in which the polymer melt is injected into a closed mold, the cavity shape of which is identical to the desired part shape and which encloses the part on all surfaces.
Injection stretch blow molding:Injection blow molding in which the perform, is mechanically stretched during the blowing cycle. The mechanical stretching imparts orientation and thus improves the material’s strength properties.
In-line:A machine, for example, a printing press, where the operating stations are placed in a horizontal line. See also straight-line configuration.
In-mold labeling (IML):A process in which precut labels coated with a heat-sealable adhesive are placed into the mold cavity before the plastic is introduced. During the molding process, the adhesive is activated by the heat of the plastic melt, causing the label to adhere to the plastic container as it is being formed.
Interior Packaging (Inner Packing):Each of the following styles are used mainly inside a shipping container to prevent damage to the product being shipped.
Intermittent-motion machine:A machine configuration in which an action is performed on a product or package while the product or package is stationary. When a series of operations are performed (for example, filling, capping, or labeling), the package will be stopped for each action. Because of the start-and-stop nature of intermittent-motion machines, they are not capable of the high speeds associated with continuous-motion machines. However, they are simpler and less expensive. See also continuous-motion machine.
Internal overhang:The overhang of the edge of a boxor container over one of the internal deckboards of a pallet. Excessive internal overhang at the load-bearing walls of a box or container can significantly reduce the available stacking strength of a unitizcd pallet load. See also overhang.
Jar:A rigid container with a wide mouth.
JIT:See just-in-time manufacturing.
Joint:The joint is that part of the box where the end of the scored and slotted blank are joined together by taping, stitching, or gluing. When accomplished in the box manufacturer’s plant, it is as a manufacturer’s joint; when effected at the time that the box flaps are sealed in a box user’s plant (usually on automatic equipment), it is called a user’s joint.
Just-in-time manufacturing (JIT):A manufacturing philosophy in which the storage of work in progress is eliminated or reduced to an insignificant minimum. JIT eliminates the need for warehousing and further reduces cost by eliminating inventory costs.
KDF:See knocked down flat.
Keyline:A keyline provides graphic arts departments with the main structure (container edges, scores, and so on) and the sizing and placement of graphic elements for a package composition.
Knocked down flat (KDF):Refers to boxes, cartons, and other containers that are stored and shipped in the flat and subsequently erected or set up for loading.
Kraft process:The extraction of cellulose fiber from the parent wood mass by dissolving the binding lignins with alkaline sulfate chemicals. The kraft process, when used with long-fiber softwoods, yields the strongest of the wood-based papers.
Lamaterial:A material composed of multiple layers of different materials, joined together to make a single sheet. The component layers may be applied coatings or other sheet materials bonded to the base material with adhesive substances. The objective is to combine materials having specific desired properties to create a new material with a combination of properties not available from any single material.
Land:The sealing surface of a glass or plastic bottle.
Lehr:An oven used to anneal glass in order to reduce internal stress that would result from too-rapid cooling. L
etterpress:A printing process using relief plates similar to flexography. Letterpress inks, however, are viscous pastes metered by roller trains.
Lightning closure:An old closure method for (usually) glass bottles that consists of a ceramic plug that is held down tightly with an attached heavy wire bail that cams the plug up and down. The hermetic seal is effected by a rubber grommet around the plug. Lightning closures have been superseded by more economical and effective modem closure systems. However, they are still used to develop an old-fashioned persona.
Linear low-densitypolyethylene:See low-density polyethylene.
Line art:An illustration composed of solid blocks of color with no variation in tone or saturation. The colors in the illustration are exactly those of the applied inks.
Liner:A creased fiberboard sheet inserted in a container and covering all sidewalls.
Liner (closure):See closure liner.
Linerboard:A paperboard, frequently called liner, used on either one or two sides of fluted medium paper to manufacture corrugated board. Linerboards are usually made from kraft pulps on fourdrinier machines.
Lithography:A printing method that is based on the mutual repellency of oil and water. A lithographic printing plate is chemically altered to produce oil-attracting and water-attracting areas. When an oil-based ink is applied, it will adhere only to the oil-receptive area. Lithographic printing plates would wear quickly if applied directly to paper substrates, so the image is transferred or offset onto a rubber blanket cylinder and then to the substrate, hence the term offset lithography. Offset lithography (also known as offset or litho) is mostly used to print paper and paperboard stocks for labels and cartons. Most packaging lithographic presses are sheet fed, although there are some roll-fed presses. Oil-based inks do not adhere as well to plastic surfaces, so the process has limited application in this area.
Low-density polyethylene (LDPE):LDPE, linear low-density polyethylene (LLDPE), and blends or copolymers with other modifiers are usually regarded as one family with similar applications. LDPE and LLDPE are both branched hydrocarbon polymers differing from high-density polyethylene (HDPE) in that they have significant side branching that prevents dense packing of the molecules. LDPE side branches are relatively long, while LLDPE (a polyethylene copolymer with octenc or hexene) has many, but very short, side branches. LDPE and LLDPE are characterized by good clarity, high elongation, and the lowest melting point of packaging polymers. Major applications are for heat-sealable coatings and films, stretch- and shrink-wraps, and retail and industrial bags.
M Mailer lock:A type of locking feature used on folding cartons to effect a more durable seal. Appears as an added tab that tucks into a slot on what would be a conventional tuck-end carton.
Make-ready:The setting up of a machine to perform an operation. For example, the make-ready of a printing press would include mounting printing plates, charging ink fountains, threading the material to be printed, trial passes to register printing stations, and other activities required to prepare the press before a full production run can be made.
Manufacturer’s joint:In corrugated containers, the joint made by the box maker in the manufacture of a corrugated container.
MAP:See modified atmosphere packaging.Matched die mold A metal mold composed of two matching halves used to thermoform a heated plastic sheet to a desired pattern.
MD:See machine direction.
Mechanical adhesion:A theory of adhesion that proposes that bonds are formed when liquid adhesive flows into irregularities and cavities in the material surface. When the adhesive solidifies, it becomes trapped and can no longer be removed.
Meahanical pulp:See groundwood pulp.
Medium:A paper stock designed to be formed into the fluted geometry used for the manufacture of corrugated fiberboard. Modem medium stock is mostly made from semi chemical pulp and recycled fiber. Medium has to be receptive to starch adhesives, be thermoformable, and be stiff. Medium is generally composed of short fibers and has poor folding and tear properties.
Mesophyllic:Describes a microorganism that prefers ambient conditions for propagation.
Metallizing:The deposition, in a vacuum chamber, of vaporized aluminum molecules over the surface of a plastic film or paper substrate, thus providing a lustrous metallic appearance. Metallizing plastic films also improves the films’ various barrier properties. In some instances the aluminum layer is used to dissipate static electrical charges.
Micron:A depreciated, although still used, term for micrometer. One millimeter = 1,000 micrometers. (25.4 micrometers = 0.001 inch.)
Migration:The transfer of a component of a material to a contacting material. In packaging this is often the undesired movement of a component of the packaging material into the product contained, or the loss of a desirable component into the packaging material itself. The latter is also referred to as “scalping.”
Mil:A unit of measure. One mil = 0.001 inch.
Modified atmosphere packaging (MAP):A packaging method in which the atmosphere contained within a package has been changed to contain carbon dioxide, oxygen, and nitrogen in proportions different than those of normal air, in order to increase shelf life.
Modulus of elasticity:The ratio, within the elastic limit of the material, of stress to the corresponding strain. (The ratio of the change of a dimension to the force producing the change within the elastic limit of the material.) Expressed as pounds per square inch or kilograms per square centimetre. (Reference method: ASTM D 638.)
Mold shrinkage:The decrease, or allowance for decrease, in the dimensions of a molded part caused by the cooling and conversion of polymer melt from a plastic state to a solid state.
Monoaxial orientation:See orientation.
Monomer:The single reactive unit that is polymerized into a polymer molecule.
MSW:Municipal solid waste.
Mullen burst test:A test of a material’s resistance to bursting. The test is performed by gradually increasing the pressure on a rubber diaphragm pressing against the test surface until it bursts the test material. The pressure at which this happens is recorded as the burst strength. The Mullen burst lest is one of the test options required by carrier rules for specifying corrugated board. (The other option is the edge crush test.) (Reference method: TAPPIT810.)
Net weight filling:A filling method where the appropriate amount of product is weighed and then deposited into the container.
Nip:(a) (noun) The point at which two adjacent rotating rolls meet or touch, (b) (verb) To bring two surfaces together, usually between two rotating rolls.
Nominal:(Nom) When polyethylene is poured into planks, it expands slightly, as it cools. 2?, 3?, & 4? thick planks usually end up 2.25?, 3.75?, & 4.5?. Unless specified as net thickness, we will ship as nominal.
Non-free-flowing powder:A powder that will not pour evenly and that forms an uneven cone with a variable angle of repose when poured out onto a level surface. Such powders will have uneven density throughout and must be weighed during fillingoperations. See also freeflowing powder.
Nonpolar molecule:A molecule in which the sharing of electrons between the participating atoms is equal, with the result that the molecule has no significant polarity, or attraction for other molecules.
Nylon (PA):A polymer made by the reaction of a dibasic acid and an amine. There are many dibasic acids and many amines, giving the possibility of many polyamides, only one of which is used in packaging. Nylon is used almost entirely as a film or sheet material in packaging applications. The film is clear, is a good oxygen barrier, is particularly tough and abrasion resistant, and can be drawn easily into thermoformed trays. It is, however, a poor moisture barrier, does not heat-seal, and has a cost disadvantage. Its primary usage is for the thermoformed half of luncheon meat and cheese vacuum packs, and in applications that require particular abrasion resistance (for example, coffee vacuum packs) or toughness. </a
OCC:Old corrugated containers. A term used in classifying paper for recycling.
OPF-One Piece Folder:This container is shipped flat to the customer. He places his object to be shipped, in the center of the container. He folds over the two inner flaps, then fold over the two outer flaps from the opposite direction and seals the container with tape.This box is often used to ship books, binders, and other like items.
Off-line:An activity that is performed outside of the main production line and that does not stop a production line. For example, parts and fixtures for a subsequent run might be prepared while the machine is running on the current product. Such off-line preparations reduce the time that a production line is not running.
Offset printing:An indirect printing process in which the inked image created by the image-producing plate (lithographic, gravure, or flexographic) is transferred to an intermediate roll (the blanket roll) and subsequently applied to the substrate. See also blanket roll.
One-up die:In carton manufacture, a die constructed to cut a single carton. One-up dies are usually constructed to verify dimensions and register. Gang or production dies will normally cut multiple cartons with each impression. In rare instances, a carton may be so large that the production die itself is a one-up die. opacity The ability of a material to stop the transmittance of light.
Opening force:The physical force (in grams) to bring a folding carton from its knocked-down-flat position to an open or erected position. open timeThe amount of time between when an adhesive is applied and when the substrates to be bonded are brought together.
Orientation:The process of mechanically stretching plastic film or parts in order to produce an alignment of molecules. If done in one direction, the film is said to be monoaxially oriented. If done in two directions, the film is biaxially oriented. Orientation markedly improves many physical properties.
Output:A packaging line’s output (designated Y) is the exact quantity of quality product passing a point just before warehousing or shipping in a given time. A machine’s or station’s output (designated y;) is the exact quantity of quality product leaving that machine in a given time.
Output efficiency:Efficiency is a ratio of output over input, but in packaging production, this definition has many subtle variations. Efficiency is best used to describe a station’s or packaging line’s actual operating time over the available time. (Other authorities call this “capability.”)
Ovenable board:A paperboard that can be placed in a convection or microwave oven with food. The base board is usually a solid bleached sulfate. A heat-tolerant polymer such as poly (ethylene terephthalate) is applied to the surface to provide liquid hold-out.
Overhang:A condition in which the edges of packages or products go beyond the perimeter of a pallet, losing support for the package or product and making them more vulnerable to abrasion and damage. Pallet overhang is responsible for considerable damage during shipping and handling and should be avoided. See also internal overhang.
Package:A form that is intended to contain, protect/preserve, aid in safe and efficient transport and distribution, and finally act to inform and motivate a purchase decision on the part of a consumer.
Package design brief:See design brief.
Packaging line:A group of integrated special-purpose machines that combine product and package inputs and produce a new product. The individual machines, each performing a different function, are referred to as stations.
Pad:A corrugated of solid fibreboad sheet or other authorized material used for extra protection or for separating tiers of layers of articles when packed for shipment.
Pallet:A portable platform on which groups of packages are unitized into a single load to facilitate efficient distribution. Pallets may be made of plastic, metal, fiberboard, or other materials. However, the most common material is still wood. The most common pallet size is 1,000 millimetres by 1,200 millimetres (40 inches by 48 inches).
Pallet area utilization:The percentage of the total available pallet area that is actually occupied by product. Since warehouse costs are usually calculated by area, a high pallet area utilization is the most economical.
Pallet overhang:See overhang.
Paneling:A condition occurring when the body of a filled and closed can has been partially flattened or pulled inward due to a handling or processing condition.
Pantone Matching System (PMS):A commercial color specifying system commonly used in graphic arts. Pantone Inc. produces books containing color swatches printed on selected substrates. Each color is identified by a number code. Designers can reference the numbers when calling up different ink colors during discussions with customers, printers, and ink producers.
Paper and Paperboard:Sheet material produced by the matting of fibers (usually cellulose). “Paper” and “paperboard” are nonspecific terms that can be related to either material caliper(thickness) or grammage (weight). The International Standards Organization (ISO) states that material weighing more than 250 grams per square metre (51 pounds per 1,000 square feet) shall be known as paperboard. In U.S. practice, material over 300 micrometres (0.012 inch) thick is paperboard. The paper industry has few definitive terms. For example, boxboard, cardboard, and cartonboard arc all terms used to describe heavier paper stock.
Parison:(a) A partially formed glass shape that will be blown into a glass container, (b) The extruded hot plastic tube that will be placed in a mold to be inflated into a bottle or other hollow form.
Partitions:A set of corrugated or solid fibreboard pieces slotted so they interlock when assembled for corrugated and solid fibreboard boxes.
Pathogen:A microorganism capable of causing sickness or death.
PCR:Post-Consumer Recycle.Recyclable material, whose origin is in consumer waste as opposed to in-plant reprocessing, industrial waste, or commercial waste.
Performance specification:A specification that describes the desired measurable performance characteristics of the completed container system or subsystem rather than specifying, in detail, the materials of construction.
Performance testing:Most commonly used to describe the evaluation of a shipping container or system. The test protocols are designed to determine whether the container or system will carry and protect the product without damage by simulating conditions of the transport and storage environments.
Permeability:The property of a film or package that permits the diffusion of gases and liquids through an essentially continuous film or container.
Persona:In package design, a package is often described as if it were a person. The persona of a package should be similar to that of the targeted customer.
Phenolic:A thermoset plastic made by the reaction of phenol and formaldehyde. Phenol formaldehyde or phenolic plastics are also known by the trade name Bakelite.
Physical distribution environment:Those events that take place between the end of the manufacturing process and the delivery of a product to the final consumer.
Pin Adhesion:Integrity of bond between liner and medium. This test measures the force necessary to separate the liners from the medium of corrugated board.This force is expressed in pounds per unit area usually five (5) square inches of corrugated board.
Pin Holing:Minute holes in thin-gauge aluminum foils caused by the inclusion of gases and other impurities. Pin holing seriously reduces a foil’s barrier properties.
Piston filler:A filling machine in which the product is metered by drawing it into a cylinder of a set volume and then ejecting a measured amount into the container.
Plastic:Any material capable of being formed or shaped. In modem usage plastic describes a large number ofhigh-molecular-weight synthetic polymers that can be molded into useful shapes. The terms “plastic” and “polymer” are interchangeable in most discussions.
Plasticating extruder:A machine having a screw device rotating inside a strong steel barrel. Polymer pellets are fed into a hopper in one end, and the action of the screw, supplemented by heating elements, melts and fluidizes the polymer feedstock. The melt, at a consistent temperature, is then ready to be ejected into whatever die, mold, or other forming device will be used to shape the plastic.
Plasticizer:A material that, when added to other polymeric materials, imparts a softness or flexibility by acting as an internal lubricant.
Pluck:(AKA: Stripping) The process of removing any die cut sections from a piece of foam. Sometimes it is desired by the end user to keep the pieces in place.
Plug-assist vacuum forming:A thermoforming method that uses a plug to give a preliminary shape to a plastic sheet. The partly formed shape is pulled to its final shape by a vacuum.
Plug mold:That part of a mold that has the protruding profile and that, in most instances, would fit into a mating cavity. Sometimes referred to as the male mold.
Ply:A single layer, as would be found, for example, in a multilayer laminate.
PMS:See Pantone Matching System.
Point of difference:In a package presentation, those elements that establish the differences or advantages of one product compared to its competitors.
Polar molecule:A molecule in which the sharing of electrons between the participating atoms is unequal, resulting in a molecule having a significant polarity, or attraction for other molecules. This type of molecule can be thought of as having the properties of a small magnet.
Polycarbonate (PC):A polymer with exceptional impact properties, used for large drinking-water bottles, returnable milk bottles, and any application where outstanding impact performance is required. Its current cost limits expansion into most packaging applications.
Polymer:A large molecule composed of repeating units. In some contexts polymer is synonymous with plastic.
Polymer terminology, abbreviations, and spelling:Proper chemical names of many polymers are long, awkward to pronounce, and sometimes difficult to spell. In the workplace, this problem is circumvented by, using trade names or abbreviations. However, this has introduced a different problem: a host of different abbreviations have been adopted without any specific standard as to how an abbreviation should be made, resulting in a number of different abbreviations for the same material. This text follows the recommendations of the American Society for Testing and Materials, Standard Terminology for Abbreviations Relating to Plastics, Designation: D 1600, except as noted. An abbreviated list of themost common plasticsshowing preferred spellings and abbreviations is given below. The trade name is shown for those polymers known primarily by a trade name Acrylonitrile-butadiene-styrene ABS Acylonitrile- butadience-system CAB Cellulose acetate-butyrate CS Casein CTF E Chlorotrifluoroethylene EEA Ethylene-ethyl acrylic acid EMA Ethylene-methacrylic acid EPD Ethylene-propylene polymer EVA Ethylene-vinyl acetate EVAL Elhylene-vinyl alcohol (frequently Abbreviated EVOH) HDPE High-density polyethylene LDPE Low-density polyethylene LLDPE Linear low-density polyethylene MDPE Medium-density polyethylene mPE Polyethylene manufactured using metallocene catalysts (not yet in ASTM listing) PA Polyamide (nylon) PAN Polyacrylonitrile PC Polycarbonate PCTFE Polychlorotrifluoroethylene PET Poly (ethylene terephthalate) (frequently abbreviated PETE) PETG Poly (ethylene terephthalate) glycolcopolymer PP Polypropylene PS Polystyrene PTFE Polytetrafluoroethylene PUR Polyurethane PVAC Poly (vinyl acetate) (frequently abbreviated PVA) PVAL Poly (vinyl alcohol) (frequently abbreviated PVOH) PVC Poly (vinyl chloride) PVDC Poly (vinylidene chloride) (saran) SAN Styrene-acrylonitrile
Polymerization:The chemical reaction during which monomer units join together to form higher-molecular-weight polymer chains.
Polypropylene (PP):A hydrocarbon polymer polymerized from propylene gas. PP films are mostly oriented (OPP or BOPP); in this form they are used for high-clarity wrapping stock and, when printed, they are the predominant film for snack food packaging. OPP has excellent clarity, low elongation, and good moisture-barrier properties. Gas barrier and heat sealability, are provided by other added material layers.PP has a higher softening point than PE and is used to make bottles where elevated temperature will be a factor, as in hot filling. Extrusion blow-molded and injection-molded PP does not have good low-temperature performance.
Polystyrene (PS):Polystyrene is a hard, brittle (unless modified), and exceptionally clear polymer. It forms a good base sheet for thermoforming into portion cups, point-of-purchase displays, merchandising units, internal product supports, and display packages. It is injection-molded into a variety of boxes and shape used for cosmetics, jewelry, compact discs, hardware, and other items. PS can be readily expanded with blowing agents to make cellular plastics of varying densities. These can be formed into containers or used as shapes for protective and shock-absorbing applications.
Poly (vinyl acetate) (PVAC):Poly (vinyl acetate) is primarily used for the manufacture of water-based white emulsion adhesives. The abbreviation PVA is frequently used instead of PVAC.
Poly (vinyl chloride) (PVC):Poly (vinyl chloride) in sheet form is the main material used for thermoformed display package blisters. It is also thermoformed into portion packaging and point-of-purchase displays. PVC films have good clarity and can be made into cling-type-films. Some plastic bottles requiring good clarity or resistance to hydrocarbon solvents are made of PVC.
Poly (vinylidene chloride) (PVDC):Poly (vinylidene chloride) has excellent overall barrier properties and is used primarily as a coating to improve the barrier qualities of PET, OPP, PA, and other films.
Porosity:A characteristic of a material that allows free passage of air or liquid.
Pot life:Some adhesives or coatings may be composed of two reactive components that are blended immediately before use. The chemical reaction, usually polymerization, will eventually convert the mixture into a set solid. Pot life refers to the length of time during which the material can still be worked and applied to the substrate.
Prebreak:To pre-fold paperboard along a score and return it to a flat at the carton manufacturer’s folding and gluing machine. Pre-breaking allows for easier carton erection at the point of filling.
Perform:The injection-molded preliminary shape that will subsequently be transferred to a blow mold for inflation to a finished part.
Preprint:A corrugated board in which one liner has been printed before assembly into a finished board. The printed liner is usually a high-quality bleached stock, and since it is printed before assembly into a corrugated sheet, the printing is of a superior quality.
Press-on/twist-off:A metal closure device with a plastic liner, but initially having no screw threads. The closure is dropped over a glass bottle having screw threads on the finish. Applied heat expands the plastic liner material to conform and set into the shape of the bottle threads. The closure is removed by a normal twisting action.
Press sheet:A single sheet of paper or paperboard of the size that will fit a specific sheet-fed printing press.
Pressure fill:A filling method in which the fluid product is pumped into the container.
Pressure-sensitive adhesive:A fully dried but permanently tacky adhesive that will adhere to a substrate on contact. Adhesive tapes and pressure-sensitive labels are based on pressure-sensitive adhesives. Most pressure sensitive adhesives are based on synthetic elastomers or natural rubber.
Primary package:The first wrap or containment of a product.
Principal display panel (PDP):The panel that will be used to carry the primary information concerning the product. The principal display panel and the information that is required to appear on this panel are legally defined by national packaging codes.
Process colors:Cyan, magenta, yellow, and key color (CMYK), used in package printing to produce photographic images. The key color is normally black.
Process printing:A printing method that will reproduce full-color images.
Profile extrusion:Extrusion of plastic to produce a profile of constant cross section and infinite length. Plastic tubes, soda straws, and a plastic material resembling corrugated board are examples of extruded pans.
Propellant:An easily liquefied gas that will boil away inside an aerosol container to provide a constant driving pressure as the contents are depleted. Most modem propellants are based on blends of various hydrocarbons.
Psychographics:A study of motivations, perceptions, and attitudes.
Psychrophilic:Describes a microorganism that will tolerate and propagate at reduced temperatures.
Pulp:The extracted mass of fiber, water, and other constituents to which a wood source is reduced by mechanical or chemical means in the process of papermaking. Pulping is the activity of producing a pulp. An extracted pulp will be cleaned and further refined before being blended into the furnish that will feed a papermaking machine. See also chemical pulp and groundwood pulp.
Random copolymer:A copolymer in which the participating monomer units appear in a random order in the molecular chain.
Recycling:Most packaging foam is recyclable.Polyurethane is ground up, rebounded, and is used for carpet pads. Polyethylene is ground, returned to pellet form, and reused in polyethylene products.Polystyrene is also ground and reused in manufacturing polystyrene products.
RE, RE/RS, & RS Tray:Roll end, end/side, or side tray.These trays are not die cut.The sides or ends “roll” by means of extra scores (creases) in the manufacturing process. This allows sides or ends to fold up and to be joined by the customer to form a relatively inexpensive tray (compared to die cut).
Register:Exact alignment of one part or operation with another part or operation. Most often applied to printing to describe whether applied colors are in their exact correct position relative to one another.
Registration lug:A small protrusion or depressed cavity, usually on the base of a bottle or jar, used to facilitate proper positioning of the container in automatic decorating processes such as labeling or direct printing.
Regular Slotted Container (RSC):A corrugated box cut from a square or rectangular blank and having all cuts, scores, or creases in either machine or cross direction. It is the most economical container to make and requires no extra tooling to produce. The (Regular Slotted Container) is a standard box the general public thinks of where the top and bottom outer flaps meet and the top and bottom inner flaps have a space between them when folded. This container is joined in the manufacturing process by adhesive (glued) tape, or wire staples (stitched).
Variations of RSC:
Relative humidity:See humidity.
Release paper:A paper that has been coated with a release agent (an anti-adhesive most commonly silicone based) to prevent the formation of a permanent adhesive bond. Release papers are used to hold pressure-sensitive labels and to back certain adhesive tapes.
Relief printing:A printing method that uses a plate on which the image is formed by those portions of the plate that are raised above (stand out in relief to) the main plate surface. Flexography, letterpress, and letterset are relief printing processes.
Removal torque:The rotational force required to remove a screw-threaded closure.
Repetitive shock:A constant low-frequency input of relatively high amplitude such as might be experienced by a single unrestrained container riding in the back of a truck.
Reroll Stock:Aluminum billets intended to be, rolled into foil.
Resonance:A spring-mass relationship in which the output is greater than the input. All masses have a specific frequency or frequencies at which resonance will occur. Resonance can be induced by transport vibrations and is a common cause of damage. See also stack resonance.
Retort:A large pressure-cooking chamber used for thermal processing of packaged food products.
Retortable pouch:A flexible package able to withstand the rigorous temperature and pressure conditions of a commercialretort. Retortable pouches, or retort pouches, are constructed of a laminate composed of polyester, foil, and a polyolefin heat-seal medium. The military is the main consumer of retorted foods.
Reverse printing:Printing on the reverse side of transparent film so that the printing will be on the inside of the package and will be observed through the film. Reverse-printed films are usually laminated so that the printing is locked between two plies. Reverse printing takes advantage of the glossy exterior surface of the printed film.
Reverse reading:Describes an image that is the mirror or reverse image of the desired text or illustration. A direct-print printing plate will be reverse reading so that when the image is transferred to the substrate, an image that reads correctly will be formed. Where a blanket roll will be used (as in lithography), the image will be correct reading on the printing plate, reverse reading when transferred to the blanket roll, and correct reading when transferred to the substrate.
Reverse-tuck carton:A tuck-end carton where the two tuck flaps come from two different panels. In the setup carton, they come from reverse sides. Reverse type or lettering that is formed by coloring the area around the letter and allowing the substrate color to show through rather than printing the letter shape itself. Fine reverse type should be avoided, since printing processes have varying degrees of gain, which will lend to fill in the reverse-type letter.
Rheology:The study of fluid flow (viscosity) characteristics.
Rockwell hardness:A measure of the hardness of steel. The Rockwell hardness gauge impresses a steel ball into the surface of the metal to be tested, and the indentation depth is recorded. Metal hardness is related to temper and stiffness.
Roll-on metal closure:A closure that starts as an aluminum shell having no threads. The shell is dropped over the bottle finish, and embossing rolls force the aluminum to conform to the threads in the bottle finish. The term “roll-on-pilfer-proof” (ROPP), often used to describe this closure, should be avoided, since few closures could thwart a determined tamperer.
Rotational molding:A method of shaping large, seam less plastic containers in which a charge of plastic is placed into a metal mold, which is then sealed. The mold is rotated on several axes while external heat is used to melt the contained plastic, which then flows to evenly coat the entire inside of the mold. The mold is cooled while still rotating and then opened to release the part.Large industrial bins and drums are, made by rotational molding.
Rule 41:A rule in the Uniform Freight Classification of the rail carriers containing requirements for corrugated and solid fiberboard boxes.
Rule 222:A rule in the National Motor Fright Classification of the motor common carries containing requirements for corrugated and solid fiberboard boxes.
Runner:In injection molding, one of the passages that take plastic melt from the injection point (sprue) and distribute it to the various cavities in a multicavity mold.
Run speed:The instantaneous operating rate of a machine at a point in time.
Saturation:The strength of a color. SBS board a solid bleached sulfate material with a clear white appearance throughout. Used extensively in the food, cosmetic, and pharmaceutical industries.
Scalping:The extraction of an essential oil or flavoring ingredient out of the product by the packaging material.
Score:(a) (verb) To make an impression or a material cut in a flat material such as paperboard to facilitate bending, creasing, folding, or tearing, (b) (noun) The crease or cut made on a paperboard to facilitate bending, creasing, folding, or tearing.
Score allowance:In corrugated container production, the amount of material added at each score to allow for folding of the corrugated board. Score allowance will vary from supplier to supplier and depends partly on the geometry of the scoring wheels. As a general rule, the score allowance is about one half of the board thickness.
Screen:The dot pattern imposed onto an original photograph in preparation for printing. The screen is identified by, the number of dots per linear inch (DPI). Screens used in package printing most often range between 65 and 150 DPI.
Screen Printing:A decorating method that uses a metal or plastic mesh screen that has been masked or blocked off in the nonprinting areas. Ink wiped across the screen will pass only through the remaining porous areas to create an image.
Seam:The impression of crease in corrugated or solid fibreboard to locate and facilitate folding.
Secondary package:A package or containment of a primary package.
Serif:A font style with decorative extensions at the terminal points of the characters.
Setup box:A stiff, three-dimensional paperboard box that is set up and ready to fill, as distinguished from a folding carton that needs to be erected before filling.
Sheet:(a) Plastic or other material that is in the form of flat sheets as opposed to being wound into a roll. (b) A flat plastic material that is of heavier caliper than film, generally taken to be more than 75 micrometres (0.003 inch) thick.
Sheet extrusion:The manufacture of plastic sheet by extruding a curtain of the plastic melt onto chill rolls. Sheet fedA printing press or other material processing operation that is fed with flat sheets of the substrate material rather than from a roll.
Shelf life:The expected time within which the quality of a product is acceptable.
Shelf stable:A food product that has an extended shelf life with no need for refrigeration or other special storage conditions.
Shipper:A shipping container.
Shrink-wrap:A plastic film, usually polyethylene, polypropylene, or poly(vinyl chloride), that is wrapped loosely about another container or product and then made to shrink and conform tightly about the container or product by the brief application of heat.
Shock:A sudden and rapid change in velocity. In packaging, shock is frequently expressed as the G level.
Shunting:Rolling one railroad car into another at speeds high enough to activate the coupling mechanism that will join the two cars together.
Single Face:One layer of paper (outside liner) laminated to one layer of fluted paper (medium). This material is often seen in use as light bulk wrappers.
Single Wall:Outside liner laminated to medium, which is laminated to another sheet (inside liner). This construction is the prevalent corrugated construction.When looked at the edge of the sheet of corrugated, only one layer of fluted material (medium) can be seen.
Skive:Process of shaving polyethylene planks to produce a net thickness.
Slip Cover:A friction-tit cover (usually metal) that slides over a matching metal can base.
Slip Sheet:A tough fiber, plastic, or composite sheet on which a load can be assembled and unitized.
Slit lock:The small slits on either side of a folding carton’s tuck flap that will engage the shoulders of a dust flap and create a more secure tuck closure.
Slot:A cut made in fiberboard sheet, having any length and a normal width of one-fourth inch.
Soda-lime glass:See glass.
Solid Fibreboard:A solid board made by laminating two or more plies of containerboard.
Solids content:The amount of nonvolatile component remaining in an adhesive, ink, or other coating material after all volatiles are removed, expressed as a percentage of the original mixture.
Specific adhesion:A theory of adhesion that proposes that adhesive bonds are formed when polar molecules of the adhesive and substrate are brought into close enough proximity that they form a bond by mutual attraction of opposite polarities.
Specification:A document or set of documents detailing the exact dimensional, aesthetic, and functional requirements of each component in a packaging system and the assembled system. Specifications will also detail how the individual characteristics will be measured and list causes for rejection.
Spiral winding:A method of continuous winding in which the paper advances at an angle to the axis of a rotating mandrel. Round paperboard tubes are made by, overlapping several plies of paper and bonding them together with an adhesive. The process produces a continuous round tube that slides off the mandrel as the winding progresses. The tube is cut to length to form bodies for fiber cans, mailing tubes, and other packages. Spiral winding can only produce round forms. See also convolute winding.
Spot color:A specified color (for example, one chosen from a PMS color book) used instead of combining the four process colors.
Spot labeling:A label that is applied to a small area of the container.
Sprue:In injection molding, the passage that brings molten plastic from the end of the extruder to the passage or passages that will distribute the plastic to the mold cavities. In a single-cavity mold, the sprue would lead directly to the gate. In a multicavity mold, the sprue would join the runner system.
Stacking strength:The ability of a container to hold a static load, as would be found in a warehouse situation, for an extended period.
Stack resonance:A condition in which a each package in a series of stacked packages goes into resonance with the package below it. Under such conditions, each package will amplify the input of the package immediately below it, causing increased movement (and potential for damage) as one goes up the stack.
Staged weighing:A method of weighing product for filling in which the product is portioned, weighed, and stored in a series of separate chambers. In a typical staged weighing system, portions consisting of approximately one quarter of the desired fill weight of the product are placed in holding chambers. The contents of these holding chambers are emptied into a chamber equipped with weight sensors, and the weight of the con tents is entered into the machine’s memory. The weighed amount is transferred into a final holding chamber and is held there until the machine’s control system calls for that amount to be combined with the contents of other chambers for a fill.
Starch-based adhesive:An adhesive whose primary raw material is starch. Such adhesives may be simple starch and water blends or they may be heavily modified by being cooked with acids (dextrin adhesives) or alkalis (jelly gums) or by the addition of other modifying ingredients or synthetic polymers.
Static coefficient of friction:See coefficient of friction.
Static compression:The compressive load resulting from a static (nonmoving) load on a container or object. Warehouse loads are said be static-loads. See also compression strength and dynamic compression.
Straight-line configuration:A packaging machine configuration in which all actions are performed in-line with one another. Most typically, a conveyor transports the package from station to station and then stops while an action (for example, fill, close, label, code) is per formed. The start and stop nature of the process limits the production speed.
Stitching or Stapling:Application of metal fasteners to form the joint of fiber boxes or to close boxes. Stitches are machine-formed using wire drawn from a spool.Staples are pre-formed.
Stringer:The structural component of a pallet to which the deckboards are attached.
Stripping torque:The torque required to cause the threads of a screw closure to override the threads of the container. Stripping can occur because of improper dimensions in closure or container or because of excessive flexibility in the container or closure, among other reasons.
Styrene-acrylonitrile (SAN):A high-barrier plastic material also having good solvent resistance, used for molding bottles. The material’s cost limits its application to those requiring SAN’s specific property combinations. Barex (a polyacrylonitrile) is a commercially available variation of a SAN-type polymer.
Subtractive synthesis:The synthesis of various colors by the subtraction of selected wavelengths from an impinging white light.
Substrate:The material on which some action, such as printing, coating, adhesive bonding, and so on, is being performed.
Synthetic-emulsion adhesive:Any of a group of adhesives in which a water-insoluble synthetic polymer is treated so as to make it dispcrsable in water. The insol uble polymer exists as a small entity surrounded by a protective substance that is compatible with both water and the polymer. The most common packaging adhesive emulsions are based on poly(vinyl acetate).
Tack:In adhesives, the amount of stickiness or pull resistance experienced when one attempts to separate two substrates while the adhesive is still in a viscous or fluid state. Tack also refers to a comparable property in inks.
Tack range:The period of time during which an adhesive will remain in a tacky condition after application to an adherent. tamper-evident closureA closure system having an indicator or barrier to entry, which, if breached or missing, can reasonably be expected to provide visible evidence to consumers that tampering has occurred.
Tape:A narrow strip of cloth or paper, sometimes having a filler or reinforcement, coated on one side with an adhesive.
TAPPI:See Technical Association of the Pulp and Paper Industries.
Technical Association of the Pulpand Paper Industries (TAPPI):An industry association with many activities that affect the packaging industry. TAPPI issues standards for the testing and evaluation of paper and paperboard properties.
Tear propagation:The ability of a packaging material to continue to easily tear once the tear has been initiated. Some plastics, such as polyethylene, have no tendency to continue to propagate an initiated tear. Other plastics, even those that are normally resistant to initial tearing,will readily propagate a tear once one has been initiated.
Tear strength:The resistance of a material to tearing.
TE closure:See tamper-evident closure.
Temper:A metal property related to stiffness and hardness, and most usually quantified with a Rockwell hardness gauge.
Tensile modulus:See modulus a/elasticity.
Tensile properties:Properties determined by recording the stress-strain curve of a specimen as it is being pulled in tension. These include strength, elongation, and modulus of elasticity. (Reference method: ASTM D 882.)
Tensile strength:A material’s resistance to fracture when exposed to a force operating to extend, stretch, or pull apart.
Test Bursting Strength:The resistance of a material to bursting expressed in pounds per square inch. The test is made on a motor drive Mullen tester.
Test Compression:The application of pressure applied by two flat surfaces of machine to opposite face or a box, such as top and bottom, the two end or the two sides.
Test Drop:The resistance of a filled container to stocks caused by dropping in certain way (i.e. or corners, edge, faces, etc.) onto a solid surface. The test measure how well a container and its inner packaging (if any) will protect the contents against the handling encountered in shipping.
Test Revolving Drum:The resistance of a packaged item to stocks encountered by rotating inside a drum which is usually 7 feet in diameter and which has 6 feet faces. Baffles mounted in a standard design on the faces force the box to fall on different sides, edge and corners as the drum is rotated.
Thermoforming:A method of forming plastics in which a plastic sheet material is heated to a point where it is soft and formable. The sheet is then formed to the desired shape using vacuum, pressure, mechanical assists, or any combination of these.
Thermophilic:Describes a microorganism capable of tolerating and surviving elevated temperatures.
Thermoplastic:Any fully reacted polymeric material that can be repeatedly softened to a melt form and resolidified to a solid shape without significant change in properties. Structurally, thermoplastics are characterized by the absence of cross-linking between polymer chains. Most packaging polymers are thermoplastics.
Thermoplastic ink:An ink that can be softened by heating. Such an ink can be applied to a carrier web such as a release paper, and then transferred from the release paper by a heated die to the substrate to be decorated, as in heat-transfer printing.
Thermoset:A polymer that is typically made by a polymerization reaction that is not reversible and is characterized by a structure that has a high degree of cross-linking between polymer chains. In most packaging applications, a thermoset starts as a prepolymer (thepolymerization reaction is not complete) or as a mixture of reactive ingredients. The final polymerization takes place in the mold or use location.
Thixotropy:A property of a fluid whose apparent viscosity decreases with time to some constant value at anyconstant shear rate.
Thread (A-style):The common thread profile for glass bottles, having a generally semicircular cross section.
Thread (L-style):A thread profile for plastic finishes that will fit either metal or plastic closures. The crosssection profile is pyramidal with a 60 slope topped by a flat crest.
Thread (M-style):A thread profile for plastic container finishes to be used with plastic closures. The cross section is a buttress with a high load flank at a significantly lesser angle than the low-load flank. M-style threads are also known as buttress threads.
Threaded closure:A closure that is applied by engaging an incorporated thread with a matching thread on the container finish.
Tier:One layer of cases or packages on a pallet load. tin-free steel A plate that has been treated with chromium or chromium oxide to enhance corrosion resistance.
Tinplate:Steel sheet coated on both sides with a thin layer of pure tin. The tin acts to protect the steel and reduce the possibility of corrosion.
Tolerance:Permissible maximum and minimum deviation from the specified dimensions or qualities.
Tooling cost:The one-time cost of manufacturing tooling such as molds, cutting dies, fixtures, and so on that may be required for a proposed package.
Torque:A force causing rotation.
Torque loss:The loss of torque with time. Most commonly experienced with plastic closures, and due to the viscoelastic movement of molecules trying to reduce internal stresses.
Trade name:A name or term that is owned by registration of copyright that identifies the product or service of a company.
Trade term:Any word or phrase used within a trade or industry, generally having a meaning more specific than or at variance with common or dictionary usage.
Trap:In printing, inks may be overlapped slightly to ensure that no substrate shows through within the register variations of the printing press. Trapping is the ability of one ink to adhere to a previously, applied and still wet ink.
Triplewall board:A corrugated board construction composed of four linerboards separated by three fluted mediums. Triplewall board can be regarded as a substitute for lumber in many packaging applications such as bulk bins and packaging for machinery.
Tube-style carton:A carton consisting of four or more panels folded completely around to form a tube. The ends can be left open or can be closed by a variety of end-closure designs.
Tuck flap:A folding carton closure made by extending and scoring one major flap so that it will tuck over into the carton to form a closure.
Twin-wire formers:Papermaking machines that pump the furnish between two moving screens. An advantage of this method is that dewatering takes place from both sides of the sheet being formed.
Two Piece Slide:This style of box usually contains an inner scored sheet formed in a rectangle and tape, which in turn slides into second outer piece, which is also a taped tube. This then forms the container which, when set up by the customer is often used for express or UPS shipments.
Ultimate tensile strength:The tensile strength at which fracture occurs.
Ultrasonic sealing:A heat-sealing method accomplished by the application of ultrasonic frequencies (20 to 40 kHz) to the materials being sealed together. The vibration at the interfaces generates enough localized heat to melt and fuse hermoplastic materials.
Ultraviolet (UV):A region of the electromagnetic spectrum just shorter in wavelength than the visible portion, with wavelengths between 0.01 and 0.4 micrometer.
Undercut:In plastic molding, a shape that cannot be directly removed from the mold without the need to incorporate mold parts that need to be moved out of the way to release the part. Undercuts significantly increase tooling cost.
Unit dose:A single containment package that holds one discrete pharmaceutical dosage form.
Unit load:The assembly of multiple containers into a single combined load that can be handled more efficiently by machinery. The load is usually stabilized by binding it with strapping, tying, stretch-wrapping, or other means to form a single unit. Also called a unitized load.
Universal Product Code (UPC):A 10-digit, machine-readable, numeric code that uniquely identifies products. The first 5 digits (the manufacturer’s identification number) identify the manufacturer or organization control ling the product label. The second 5 digits (the item code) identify individual items within the company or organization controlling the product label.
Unscrambler:A machine for sorting and aligning containers or packaging components so that they can be fed in an oriented and orderly fashion into the next piece of equipment in the line.
Urea plastic:A thermoset plastic made by the poly merization of urea and formaldehyde.
Urethane:A polymeric material made by the reaction of any of a group of isocyanates with any of a group of multifunctional glycols. Depending on the participating monomers, urethanes can be made that have a wide range of properties (for example, thermoplastic, thermoset, rigid, elastic, cellular, and so on).
Use temperature:The temperature at which a product will be used. The temperatures that a package will be exposed to during use are one of the considerations when selecting appropriate materials. For example, some plastics become brittle at freezer temperatures and would not be appropriate for freezer applications.
UPC:See Universal Product Code.
UV coating:Coatings that consist of monomeric substances and a photoinitiator that are polymerized in the presence of ultraviolet light.
Vacuum filling:The filling of containers with low-viscosity liquid product by drawing a vacuum on the sealed container. Vacuum filling requires the ability to form a good seal across the container finish and a container with sufficient rigidity that it will not collapse or distort under vacuum. Vacuum filling is readily adaptable to fill-to-level requirements.
Vacuum forming:A thermoforming method in which the softened plastic sheet is pulled into conformity with the mold by a vacuum.
Vacuum metallizing:See metallizing.
Vacuum packaging:A method of packaging where the air is withdrawn from the primary package. The usual objective of vacuum packaging is to remove atmospheric oxygen, which is implicated in most product degradation. Vacuum packaging when using flexible packaging materials also reduces volume.
Vacuum snap back:A method of thermoforming in which the softened plastic sheet is first extended by mechanical stretching and then pulled back into conformity with the mold by an applied vacuum.
VDF- Variable Depth Folder:This is exactly like the OPF except additional scores are provided so the box can be folded down to one of several depths. It is often used by record album distributors who can use the same box to ship one or several albums to their customers by taking advantage of the varying depth of the container.
Vertical form-fill-seal (VFFS):A form-fill-seal machine in which the roll-fed flexible packaging material is unwound and shaped while traveling vertically up and down through the machine’s operating stations. A VFFS machine occupies less floor space than a horizontal form-fill-seal machine, but it has the disadvantage of having a single point through which filling or other open-package functions can be performed.
Vibration:Regular movement about a fixed reference point. The number of movements per second is reported as hertz (Hz), and the distance to either side of the reference point is the double amplitude. Vibrations are present in all methods of transport and can be a source of damaging input. vibrational damage can be regarded in two broad categories: (1) Damage due to relative motion of one part against another,most commonly observed as scuffing or abrasion. (2) Damage due to resonance conditions, which may be observed as a range of physical damage. The greater proportion of damage occurs in the frequency ranges of 3 to 30 hertz.
Vibratory feed filler:A method of moving product through a filling or transport system by inducing a vibration in a sloped tray at about the resonance frequency of the product. In effect, the product periodically becomes momentarily weightless, and in this state will descend the feed tray slope for a short distance.
Viscoelasticity:The behavior of a material is classed as elastic it” after deformation due to an applied stress the material returns to its original size (providing the material’s yield point has not been exceeded). A material that flows and deforms permanently when under stress is said to exhibit viscous flow. Some materials, plastics, for example, exhibit elements of both behaviors and are said to be viscoclastic. Elastic behavior tends to be relatively time independent, while viscous flow is time dependent. A plastic that is quickly bent and released will exhibit primarily elastic behavior. The same plastic bent (stressed) to a new shape and held there for a period of time will become permanently deformed.
Viscosity:A measure of a fluid’s resistance to flow. Water would be classed as a low-viscosity fluid, while a syrup would have a high viscosity. Viscosity is measured in centipoise or pascal/seconds.
VOC:See volatile organic compounds.
Volatile organic compounds (VOCs):Any organic substance that can be evaporated at ambient or process conditions. In packaging these come primarily from solvents used for preparing inks, adhesives, and coatings, as well as from various solvent-based cleaning agents. The release of VOCs into the atmosphere can pose serious health and environmental hazards, and their release is restricted by law. There is a trend toward reducing the use of VOCs or, when they need to be used, toward eliminating the discharge of released vapors into the atmosphere.
Volumetric filling:A method of measuring and filling free-flowing products of consistent density. The product is measured by, filling a calibrated cup or flask to an exact level and then dispensing the product into the container.
Water activity:A measurement, abbreviated Aw and expressed as a decimal, that indicates the relative humidity at which a food or other substance will neither gain nor lose moisture. A food with an Aw of 0.30 would neither gain nor lose moisture at a relative humidity of 30%. Since typical relative humidity is most commonly higher than 30%, such a product would have a tendency to gain moisture under most ambient relative humidity conditions. A suitable moisture-barrier package would likely be required.
Water resistance:The resistance of a packaging material to deterioration or change when in contact with water.
Water-vapor transmission rate (WVTR):The actual rate of water-vapor transmission used to compare watervapor barrier materials. The rate is expressed in a variety of units. (Reference test methods: ASTM D 895, D 1251, D 3079, D 3199, D 4279, and E 96.)
Wax Impregnation:The wax impregnation of linerboard and medium materials in-line on the corrugator with saturating waxes protect them from wetting out during exposure to wet packaging environment.This characteristic helps to retain the containers’ compression performance.
Web:Paper, film, foil, or other flexible material as it is unwound from a roll and passed through a machine.
Weight of Facings:(minimum combined of corrugated board).This is the summation of weight per thousand square feet of all facings the board structure excluding the weight of coating and excluding the weight of the corrugating medium and the corrugating adhesive.
Wet-bond laminating:A laminating process in which an applied adhesive, including any volatile solvents or ingredients, is pressed between the two substrates to be laminated. Since the adhesive still contains volatiles that must be allowed to escape, at least one of the laminate materials must be porous.
Wet-end treatments:Treatments or additives to papers and paperboards that are done to the paper furnish or to the formed web prior to being passed through the dryers.
Wet out:To form a molecule attraction to a substrate. The ability of an applied adhesive substance to form a chemical bond with a substrate depends on its compatibility with the substrate. The individual adhesive molecules must have at least as much attraction for the substrate molecules as for other adhesive molecules. Where this happens, the fluid adhesive will flow out over the substrate in an even film, and the adhesive (or coating) is said to wet out the substrate. Where adhesive molecules have greater attraction to themselves than for the substrate, the adhesive will bead up into droplets and not wet out the substrate surface.
Wet strength Linerboard:Should be used where wet Mullen and wet tear specifications exist or anywhere there is a need for just a wet strength liner. Some examples are packaging of poultry, beef, pork, fish, semi-wet or wet produce.
Working creases:The creases at which a folding paperboard canon is knocked down flat for shipment to the customer.
WVTR:See water-vapor transmission rate.
Yield:The amount of product that can be produced from a given weight of material. Most packaging raw materials are sold by weight. However, because of density differences, the same weight of similar materials can produce different amounts of finished product. For example, the yield for a plastic resin used for film manufacture might be expressed as the number of square meters of film that could be made from 1 kilogram of the material (square inches per pound.) In other instances, the yield might be expressed in terms of volume per unit weight, or the actual number of physical objects per unit weight.
Yield point:That point beyond which the stresses applied to a material will cause permanent deformation.