A
Acetate: Often used by plastic manufactures, acetate is a derivative of acetic acid.
Additive: A compound or substance added to a polymer plastic to improve and alter characteristics of a polymer.
Antiblock Agent: Additive incorporated in the film to prevent the adhesion between layers of film that are touching during the fabrication or use.
Antioxidant: An additive, when exposed to ambient air, inhibits the degradation and oxidation of material.
Antistatic Agent: Additive which renders a remote degree of electrical energy to plastics, permitting the dispersion of electricity.
B
Banbury Mixer: Used for mixing and compounding plastic material, while scattering reinforcing fillers within an absorbent resin system.
Barrier Resins: Polymers that have low absorption to gases.
Biaxial Orientation: A process of stretching a hot plastic film in different directions, which results in molecular orientation in two different directions.
Biodegradation: The process of reducing plastics by microorganisms while buried in the soil.
Blend: The mixing of polymer plastics with other polymer or copolymers.
Bloom: A lean and greasy film on the surface of a plastic film usually caused by the exudation of an additive.
Blown Film: A process that involves extruding a continuous thin walled tube of plastic material, and inflating the plastic material immediately after the plastic leaves the die. Air is trapped within the blow tube (bubble) between the die and collapsing rolls which converts it to lay flat plastic film to facilitate winding onto a roll. Blow film is a frequent process plastic manufacturer’s use.
C
Calcium Carbonate: A chemical compound filler and extender used in thermoplastics, commonly found in rock.
Coating: Plastic that has not been recycled commonly has coating of a substrate by extruding a thin film of molten polymer plastic and pressing it onto the substrate.
Centerfold: Folding plastic material along the length to obtain a two layered product.
Chill Roll: Frequently used in the plastics manufacturing industry, usually temperature controlled with circulating water, which cools a molten polymer web on contact before winding.
Color Concentrate: Is a plastic’s compound containing high pigment that is blended into base resin.
Copolymer: Polymers resulting from the polymerization reaction of two monomers that are chemically altered.
Corona Treat: The process by which the surface energy of a plastic film is increased in order to allow improved wet-ability and adhesion to inks, coatings and adhesives.
D
Degradation: Caused by exposure to heat, light, oxygen, or weathering, degradation is a destructive change in the chemical structure, physical properties, or appearance of plastic materials.
Density: Weight per unit volume of a substance.
Die: A steel block containing an orifice through which plastic is extruded, shaping the extrudate to the desired form.
Die Gap: Distance between the metal faces forming the die opening within the material.
Die Lines: Vertical or horizontal marks on the extrudate plastic and in the finished plastic product caused by contamination held up in the die land.
Differential Scanning Calorimetry (DSC): A method used to determine thermal histories of polymers.
Drawdown: Typically used by most manufacturers, the drawdown process is pulling the extrudate away from the die at a linear speed higher than that at which the melt is emerging from the die.
E
Elasticity: The processes of recovering original size and shape after deformation of the material.
Elongation: The stretching of material.
Erucamide: A fatty acid-based slip additive used in polyolefin resins to reduce friction.
Ethylene Vinyl Acetate (EVA): Copolymeric member of the polyolefin family derived from random copolymerization of vinyl acetate and ethylene.
Extrusion: Compacting and melting plastics and forcing them through an aperture in a perpetual fashion.
F
Foam: Process for producing plastic sheet or molded plastic articles with a cellular construction. Either a chemical or gaseous blowing agent is introduced into the polymer plastic melt while the plastic melt is being prepared in the extruder barrel. As the plastic melt exits the die, it expands a predetermined amount forming a cellular wall.
Flame Retardant: Used by recycled plastic and plastic material manufacturers, flame retardants are reactive compounds and additive compounds to render a polymer plastic fire resistant. Reactive compounds become an integral part of the polymer plastic.
G
Gauge: Thickness of recycled plastic or plastic film measured in decimal inches or mils.
Gloss: Brightness or luster of a plastic resulting from a smooth surface within recycled plastic and plastic material.
H
Haze: Cloudiness in plastic film that is measured as percent haze in plastic film. Five percent and below is considered high clarity in plastic.
Heat Sealing: Plastic manufacturers use this process of joining two or more thermoplastic films or plastic sheets by heating areas on the plastic, in contact with each other to the temperature at which fusion occurs. Plastic heat sealing is usually aided by pressure.
High-Density Polyethylene: This term is generally considered to include polyethylene plastic’s ranging in density from about 0.940 to 0.960 and over in recycled plastic and plastic materials.
Homopolymer: The result of the polymerization of a single monomer. In the plastic industry a homopolymer consists of a single type of repeating unit.
I
(no entry)
J
Jfold: The folding of a plastic film along the length of the plastic film to obtain a two layered product with one layer wider than the other.
K
(no entry)
L
Linear Polymer Plastic: A polymer plastic in which the monomeric units are linked together in linear fashion with little or no long chain branching.
Linear Low-Density Polyethylene: Includes polyethylene plastic’s ranging in density from 0.915 to 0.935.
Low-Density Polyethylene: This term used by plastic material manufacturers is generally considered to include polyethylene plastic’s ranging in density from about 0.915 to 0.925. In low density polyethylene plastic’s, the ethylene monomeric units are linked in random fashion, with the main chains having long and short side branches. This branching prevents the formation of a closely knit pattern, resulting in plastic material that is relatively soft, flexible and tough, and which will withstand moderate heat.
M
Masterbatch: A concentrated blend of pigment, additives, filler, etc. in a base polymer plastic. Plastic distributors commonly use this method.
Melt Fracture: Is a phenomenon of melt extrudate in which the surface of plastic appears rough or wavy upon exit from the die. Melt fracture may appear uniformly or only in certain sections of plastic material.
Melting Point: The temperature at which a resin in plastic changes from a solid to a liquid form of the plastic material.
Modulus of Elasticity: The ratio of stress to strain below the yield point of the plastic material.
Molecular Weight Distribution (MWD): The relative amounts of polymer plastics of different molecular weights that make up a specific polymer.
Mono layer: A homogenous film formed by pumping molten polymer plastic from an extruder through a die assembly to form a plastic film.
N
Neck-In: The difference between the width of the extrusion die opening and the width of the coating on the plastic substrate, in extrusion coating.
Nip: The V-shaped gap between a pair of calendar rolls where incoming plastic material is nipped and drawn between the rolls commonly used in the plastics industry.
O
Octene: A comonomer used in the production of linear low-density polyethylene plastics.
Oleamide: An ivory-colored powder used as a slip additive in polyolefin plastics.
P
Perforating: Processes used by plastic manufacture’s by which plastic film or plastic sheeting is provided with holes within the plastic material ranging from relatively large diameters for decorative effects to very small, even invisible, sizes on the plastic.
Permeation: The passage or diffusion of a gas, vapor, liquid, or solid through a barrier within the plastic material without physically or chemically affecting the plastic.
Permeability: Permeability is the property of a plastic material. Plastic manufacturers use this as a degree to which it allows permeation to occur.
Photodegradation: Degradation of plastics due to the action of light. In the recycled plastic and plastic material industry, most plastics tend to absorb high-energy radiation in the ultraviolet portion of the spectrum this generates in the formation of free radicals and causes degradative reactions in plastic materials.
Plastic Lamination: Bonding of a polymeric or non-polymeric plastic substrate to a polymeric plastic film using heat and pressure.
Plastic Material Pressure Roll: Commonly used by plastic distributors, in extrusion coating, a roll used to apply pressure to consolidate the substrate and the plastic film with which the plastic has been coated.
Plastic Orange Peel: An uneven surface texture of a plastic article or its finished coating somewhat resembling the surface of an orange.
Plastic Pellets: Plastic tablets of uniform size, consisting of resins or mixtures of resins with compounding additives which have been prepared for plastic molding operations by shaping by plastic extrusion and chopping into short plastic segments.
Plastic recycling: The process of recovering plastic scrap or waste plastic material and reprocessing the plastic material into useful recycled plastic products.
Plastic Slitting: The conversion of a given width of plastic film, or sheet to several various widths by means of knives.
Plastic Thermoforming: The process of forming a thermoplastic sheet into a three-dimensional plastic shape by clamping the sheet in a frame, heating the plastic to render it soft, then applying differential pressure to make the plastic sheet conform to the shape of a mold or die positioned below the frame in the plastic sheet.
Plastic Virgin Material: Any plastic compound or resin that has not been subjected to use or processing other than that required for the plastic compound or resin’s original manufacture.
Polyethylene: Used in the plastics industry, polyethylene is a family of resins obtained by polymerizing the gas ethylene of plastic.
Polymer Process Aid (PPA): Additives incorporated into plastic material as a modifier to aid in the extrusion of plastic materials.
Polyolefin: The class of polymer plastics, made by polymerizing relatively simple olefins.
Polypropylene: A tough, lightweight, rigid plastic made by the polymerization of high-purity propylene gas in the presence of an organometallic catalyst. Plastic manufactures do this at low temperatures and pressures.
Q
(no entry)
R
Reinforced Plastics: Plastic manufactures use reinforced plastics which are molded, formed, or shaped into plastic parts. These plastic materials consist of resins to which reinforcing fibers, mats, fabrics, etc., have been added before the forming operation of the plastic product.
Resin: An organic substance commonly used by plastic manufactures, of natural or synthetic origin in plastic material characterized by being polymeric in nature.
S
Screen: Woven metal screens are installed across the flow of plastic in an extruder in plastic manufactures. Supported by a breaker plate, the screens strain out contaminants and increase back pressure.
Sheeting: Sheets are distinguished from films in the plastics industry only according to the thickness. Plastic sheeting is most commonly made by extrusion, casting, and calendaring in the plastics industry.
Shelf Life: The length of time over which a product, such as plastics, will remain fit for use during storage under specific conditions.
Slip Agent: Provides surface lubrication for plastic material following the processing of plastics. Compounded into the plastic, the additive gradually migrates to the surface of the plastic where it reduces the coefficient of friction of the plastic product.
Specific Heat: The amount of heat required to raise a specified mass in plastic by one unit of a specified temperature, usually expressed as Btu/lb/°F. or cal/g/°C in plastic.
Stabilizer: Ingredient used in the formulation of some polymer plastics to assist in maintaining the physical and chemical properties of the compounded plastic materials.
Static Eliminators: Mechanical devices frequently used by plastic material manufactures, for removing electrical static charges from plastic articles.
Stearamide: A slip additive used by most plastic product distributors, in polyolefin's.
Stress: The force producing or tending the plastic material, to produce deformation divided by the area over which the force is applied to the plastic material.
Surface Tension: A method generally used in plastic materials, is a fluid in contact with a plastic surface exhibits phenomena, due to molecular attractions, which appears to arise from a tension in the plastic surface of the fluid.
T
Tack: The stickiness of an adhesive, measurable as the force required to separate an adherent from it by viscous or plastic flow of the adhesive.
Tackifier: A substance such as a resin ester which is added to synthetic resins or elastomeric adhesives to improve the initial and extended tackiness of the plastic film. This substance is commonly used in the plastics industry by most manufacturers.
Talc: A natural hydrous magnesium silicate, used frequently as filler such as steatite, talcum, mineral graphite in plastic materials.
Tear Resistance: Consistently used by plastic manufacturers, resistance of a material, such as plastic material, to a force acting to initiate and then propagate a failure at the edge of a test specimen.
Tensile Strength: The maximum tensile stress sustained by the specimen before failure in a tension test by plastic material and plastic product distributors. The cross-sectional area used is that of the original specimen, not at the point of rupture.
Thermoplastics: Resins or plastic compounds which, in their final state as finished plastic articles, are capable of being repeatedly softened by an increase of temperature and hardened by a decrease of temperature within resins or plastic compounds.
Thermosets: Resins or plastic compounds which in their final state as finished resin or plastic articles are substantially infusible and insoluble.
Transition Temperature: The temperature at which a polymer of the plastic changes from (or to) a viscous or rubbery condition to (or from) a hard and relatively brittle one.
Treater: Equipment and process generally used by plastic manufacturers used to render a surface of inert plastics, such as polyethylene plastic.
U
(no entry)
V
Vapor Barrier: A layer of plastic material through which water vapor will not pass in plastic material.
Vicat Softening Point: The temperature at which a flat-ended needle of 1 square millimeter circular or square cross section will penetrate a thermoplastic specimen to a depth of 1 mm under a specified load using a uniform rate of temperature rise. (ASTM D-1525-58T).
W
Wrinkle: A plastic surface imperfection in plastic films that has the appearance of a crease or wrinkle in plastic material.
X
(no entry)
Y
Yellowness Index: A measure of the tendency of plastics to turn yellow upon long-term exposure to light or heat.
Z
(no entry)
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