Plastics Glossary
108 plastics and polymer industry terms explained in plain language.
A
ABS
Acrylonitrile Butadiene Styrene (ABS) is a thermoplastic terpolymer combining rigidity, toughness, and processability, widely used in automotive, electronics, and consumer goods applications.
materialAntiblock Agent
A fine particulate additive used in polymer films to prevent adjacent surfaces from adhering to each other by creating microscopic surface roughness and reducing contact area.
materialAntioxidant
Chemical additives that prevent polymer degradation by neutralizing free radicals and reactive oxygen species during processing and service life, maintaining material properties.
materialAntistatic Agent
Chemical additives incorporated into plastic resins to reduce static electricity buildup by increasing surface conductivity and preventing charge accumulation during processing and use.
materialAsh Content
The percentage of inorganic residue remaining after complete combustion of a plastic material at high temperature, indicating the level of inorganic fillers, additives, or contaminants.
testingASTM D1238
Standard test method for measuring melt flow rate (MFR) and melt volume rate (MVR) of thermoplastic materials under specified temperature and load conditions.
testingASTM D256
A standardized test method that measures the impact resistance of plastics using Izod impact testing, determining a material's ability to absorb energy during fracture.
testingASTM D638
Standard test method for determining tensile properties of plastics including ultimate tensile strength, yield strength, elongation at break, and elastic modulus using dumbbell-shaped specimens.
testingB
Back Pressure
The pressure buildup in the molten polymer stream upstream of a restriction point during processing, typically measured at the screw tip in injection molding or die head in extrusion.
processBarrel Temperature
The controlled temperature of heated zones along an extruder or injection molding machine barrel, critical for proper plastic melting, flow, and processing quality.
processBlow Molding
A manufacturing process that forms hollow plastic parts by inflating a heated plastic parison or preform inside a mold cavity using compressed air pressure.
processBlown Film
A continuous extrusion process where molten polymer is formed into a tubular bubble, inflated with air, and collapsed to create thin plastic film with uniform thickness and properties.
processC
Calcium Carbonate Filler
An inorganic mineral filler derived from limestone or chalk, commonly used in plastics to reduce costs, improve stiffness, and enhance processing characteristics.
materialCarbon Black
A fine carbon powder additive used in plastics to provide black coloration, UV protection, electrical conductivity, and reinforcement properties in polymer compounds.
materialCast Film
A film manufacturing process where molten polymer is extruded through a flat die onto a chilled casting roll, creating smooth, clear films with excellent optical properties and uniform thickness.
processCertificate of Analysis
A document provided by resin manufacturers that certifies a specific lot of plastic material meets stated specifications, including test results for key properties and quality parameters.
testingClamping Force
The force applied by the clamping unit of an injection molding machine to keep the mold closed during plastic injection and cooling, measured in tons or kilonewtons.
processCo-extrusion
A manufacturing process that simultaneously extrudes multiple polymer layers through a single die to create multi-layer products with distinct material properties in each layer.
processColor Measurement
Quantitative analysis of color characteristics in plastic resins using standardized instruments and methods to ensure consistent color matching and quality control.
testingCompression Molding
A molding process where preheated plastic material is placed in an open mold cavity, then compressed under heat and pressure until it conforms to the mold shape and cures.
processContract Pricing
A pricing mechanism where plastic resin suppliers and buyers agree to predetermined prices for specific volumes and delivery periods, typically lasting 3-12 months.
materialCoupling Agent
A chemical additive that improves adhesion and compatibility between polymer matrix and fillers or reinforcements by forming chemical bonds at the interface.
materialCrystallinity
The degree to which polymer chains are organized in an ordered, repeating three-dimensional structure, expressed as a percentage of the total polymer mass.
propertyD
Data Sheet
A comprehensive document provided by resin manufacturers that contains detailed technical specifications, properties, processing guidelines, and performance characteristics of a plastic material or grade.
materialDelta E
A standardized measurement of color difference that quantifies how much one color differs from another, expressed as a single numerical value using the CIE color space system.
testingDensity
The mass per unit volume of a plastic material, typically expressed in g/cm³ or kg/m³, used to identify resin types, calculate material costs, and predict processing behavior.
propertyDSC Analysis
Differential Scanning Calorimetry (DSC) is a thermal analysis technique that measures heat flow differences between a sample and reference as temperature changes, revealing thermal transitions.
testingE
Elongation at Break
The percentage increase in length of a plastic specimen at the point of tensile failure, measured from original length to final length before breaking during a tensile test.
propertyEPR Extended Producer Responsibility
A regulatory framework requiring manufacturers to take responsibility for the entire lifecycle of their plastic products, including collection, recycling, and disposal costs.
regulationEVA
Ethylene Vinyl Acetate (EVA) is a flexible thermoplastic copolymer known for its rubber-like elasticity, clarity, and excellent low-temperature performance.
materialExtrusion
A continuous manufacturing process where plastic resin is melted and forced through a shaped die to create products with uniform cross-sections like pipes, films, sheets, and profiles.
processF
FDA Food Contact
FDA approval certification for plastic materials intended for direct contact with food, ensuring compliance with safety regulations under 21 CFR Parts 174-178.
regulationFlame Retardant
Chemical additives incorporated into plastic resins to reduce flammability, slow flame spread, and improve fire resistance by interfering with combustion processes.
materialFlexural Modulus
A material property measuring a polymer's resistance to bending deformation, expressed as the ratio of applied stress to resulting strain in a three-point bending test.
propertyForce Majeure
A contractual clause that frees parties from liability when extraordinary circumstances beyond their control prevent them from fulfilling contract obligations in resin trading.
regulationFTIR Spectroscopy
An analytical technique that uses infrared light to identify chemical bonds and functional groups in plastic materials by measuring their unique absorption patterns.
testingG
Gel Permeation Chromatography
A chromatographic technique that separates polymer molecules by size to determine molecular weight and molecular weight distribution in plastic resins and polymers.
testingGlass Fiber Reinforcement
Short or continuous glass fibers added to polymer matrices to significantly increase mechanical properties like tensile strength, flexural modulus, and dimensional stability.
materialGlass Transition Temperature
The temperature range at which an amorphous polymer transitions from a rigid, glassy state to a flexible, rubbery state, marking a critical thermal property for processing and application performance.
propertyGPPS
General Purpose Polystyrene, a clear, rigid thermoplastic polymer with excellent transparency, dimensional stability, and ease of processing, commonly used in packaging and consumer goods.
materialH
HDPE
High-Density Polyethylene, a thermoplastic polymer made from ethylene with a linear molecular structure and density range of 0.941-0.965 g/cm³, offering excellent chemical resistance and durability.
materialHeat Deflection Temperature
The temperature at which a polymer specimen deflects a specified distance under a controlled load, measured according to ASTM D648 or ISO 75 standards.
propertyHIPS
High Impact Polystyrene (HIPS) is a modified polystyrene resin enhanced with rubber particles to improve impact resistance while maintaining good processability and dimensional stability.
materialI
Impact Modifier
Additive blended with polymers to improve impact resistance and toughness, particularly at low temperatures, by absorbing and dissipating impact energy through controlled deformation.
materialImpact Resistance
The ability of a plastic material to absorb energy and resist fracture when subjected to sudden mechanical shock or impact loading, typically measured using standardized tests.
propertyInjection Molding
A manufacturing process where molten plastic resin is injected under high pressure into a closed mold cavity, cooled, and ejected to form precise plastic parts.
processIntrinsic Viscosity
A measure of a polymer's molecular size and chain length in solution, expressed as the limiting viscosity number at infinite dilution, typically reported in dL/g or mL/g.
propertyISO 10993
International standard that evaluates the biological safety of medical devices, including testing requirements for plastic materials and components used in medical applications.
regulationISO 1133
International standard specifying test methods for determining the melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of thermoplastic materials under specified temperature and load conditions.
testingK
L
LDPE
Low-Density Polyethylene (LDPE) is a flexible, translucent thermoplastic polymer with a highly branched molecular structure, offering excellent chemical resistance and processability.
materialLet Down Ratio
The ratio of masterbatch concentrate to total polymer weight in a plastic formulation, typically expressed as a percentage or weight ratio for achieving desired additive levels.
processLLDPE
Linear Low-Density Polyethylene is a polyethylene copolymer with short-chain branching, offering superior strength, flexibility, and puncture resistance compared to LDPE.
materialLot Acceptance
A quality control process where incoming resin lots are evaluated against predetermined specifications before acceptance into inventory or production use.
testingM
Masterbatch
A concentrated mixture of pigments, additives, or fillers encapsulated in a carrier resin, designed to be diluted into base polymers during processing to achieve desired properties or colors.
materialMaterial Safety Data Sheet
A comprehensive document providing critical safety and hazard information for chemical substances, including plastic resins, additives, and processing materials used in polymer manufacturing.
regulationMelt Compounding
A processing technique that mixes molten polymer resins with additives, fillers, or other materials to create uniform blends with enhanced properties or specific characteristics.
processMelt Flow Index
A measure of the ease of flow of thermoplastic materials under standardized conditions, expressed as grams of polymer extruded per 10 minutes through a specific die at controlled temperature and load.
propertyMelt Flow Rate
A measure of the ease of flow of molten thermoplastic polymer under standardized conditions, expressed as grams of material extruded per 10 minutes through a specified die.
propertyMelting Point
The temperature at which a crystalline polymer transitions from solid to liquid state, representing the point where molecular chains gain sufficient energy to overcome intermolecular forces.
propertyMoisture Content
The amount of water present in plastic resin, typically expressed as a percentage by weight, which must be controlled to prevent processing defects and maintain product quality.
propertyMolecular Weight
The average mass of polymer molecules in a resin, typically measured in Daltons or g/mol, which directly influences mechanical properties, processability, and end-use performance.
propertyMolecular Weight Distribution
The range and frequency of different molecular weights within a polymer sample, typically expressed as polydispersity index (PDI) or molecular weight distribution curve.
propertyN
P
PEEK
Polyetheretherketone (PEEK) is a high-performance semicrystalline thermoplastic polymer known for exceptional thermal stability, chemical resistance, and mechanical properties at elevated temperatures.
materialPEI
Polyetherimide (PEI) is a high-performance amorphous thermoplastic offering exceptional heat resistance, flame retardancy, and dimensional stability for demanding applications.
materialPET
Polyethylene terephthalate (PET) is a thermoplastic polyester resin known for its clarity, strength, and barrier properties, commonly used in bottles, containers, and textile fibers.
materialPHA
Polyhydroxyalkanoates (PHA) are biodegradable thermoplastic polymers produced by bacterial fermentation, offering sustainable alternatives to conventional plastics.
materialPLA
Polylactic Acid (PLA) is a biodegradable thermoplastic polyester derived from renewable resources like corn starch or sugarcane, widely used in sustainable packaging and 3D printing applications.
materialPlasticizer
A chemical additive that increases the flexibility, workability, and ductility of polymers by reducing intermolecular forces and lowering the glass transition temperature.
materialPolyamide 6
A semicrystalline thermoplastic polymer formed by ring-opening polymerization of caprolactam, known for its excellent mechanical properties, chemical resistance, and processability.
materialPolyamide 66
A semi-crystalline engineering thermoplastic made from hexamethylenediamine and adipic acid, known for excellent mechanical properties, chemical resistance, and high temperature performance.
materialPolycarbonate
A thermoplastic polymer known for exceptional impact resistance, optical clarity, and high-temperature performance, commonly used in engineering applications requiring toughness and transparency.
materialPolypropylene Copolymer
A thermoplastic polymer created by copolymerizing propylene with small amounts of ethylene or other α-olefins, offering improved impact resistance and clarity compared to PP homopolymer.
materialPolypropylene Homopolymer
A thermoplastic polymer made from propylene monomer units only, offering high chemical resistance, low density, and excellent processability for rigid applications.
materialPost Consumer Recycled
Plastic resin material derived from products that have completed their intended use cycle by consumers and have been collected, processed, and remanufactured into new plastic pellets.
materialPost Industrial Recycled
Recycled plastic material derived from manufacturing waste and scrap generated during industrial production processes, before the product reaches consumers.
materialPPS
Polyphenylene Sulfide (PPS) is a high-performance engineering thermoplastic known for exceptional chemical resistance, thermal stability, and dimensional stability at elevated temperatures.
materialProcessing Aid
Chemical additives that improve polymer flow, reduce processing temperatures, eliminate melt fracture, and enhance manufacturability without significantly affecting final product properties.
materialProp 65
California's Proposition 65 requires businesses to provide warnings about significant exposures to chemicals known to cause cancer, birth defects, or reproductive harm in products sold in California.
regulationPTFE
Polytetrafluoroethylene, a high-performance fluoropolymer known for exceptional chemical resistance, low friction, and non-stick properties, operating at temperatures from -200°C to 260°C.
materialPVC
Polyvinyl Chloride (PVC) is a thermoplastic polymer made from vinyl chloride monomers, available in rigid and flexible formulations depending on plasticizer content.
materialPVDF
Polyvinylidene fluoride, a specialty fluoropolymer offering exceptional chemical resistance, high purity, and excellent mechanical properties for demanding applications.
materialR
REACH Regulation
European Union regulation requiring Registration, Evaluation, Authorization and restriction of CHemicals to ensure safe use of chemical substances in products including plastics and polymers.
regulationRegrind
Recycled plastic material created by grinding and reprocessing plastic scrap, runners, sprues, or rejected parts back into usable pellets or flakes for manufacturing.
materialResin Grade
A specific classification of plastic resin that defines its molecular structure, properties, and intended applications, typically designated by manufacturers with alphanumeric codes.
materialResin Pricing Index
A standardized benchmark that tracks price movements of plastic resins over time, typically weighted by volume and market significance to provide industry pricing reference points.
materialRheology
The study of how polymers flow and deform under applied stress or strain, measuring viscosity, elasticity, and flow behavior during processing and use.
testingRoHS Directive
European Union regulation restricting the use of hazardous substances in electrical and electronic equipment, including specific limits on lead, mercury, cadmium, and other toxic materials.
regulationRotational Molding
A hollow plastic forming process where polymer powder is placed in a mold, heated while rotating on multiple axes, allowing material to coat mold walls and fuse into seamless parts.
processS
Screw Design
The engineering configuration of extruder and injection molding screws, including geometry, channel depth, compression ratio, and mixing elements to optimize polymer processing performance.
equipmentShore Hardness
A standardized measurement of a material's resistance to indentation, commonly used to characterize the hardness of plastics, elastomers, and rubber compounds.
propertySingle Use Plastic Directive
EU regulation (EU 2019/904) restricting the production, marketing, and use of certain single-use plastic products, requiring extended producer responsibility and promoting alternatives.
regulationSlip Agent
A processing additive that reduces the coefficient of friction between polymer surfaces, improving material flow and preventing blocking in films and molded parts.
materialSpot Market
A trading system where plastic resins are bought and sold for immediate delivery at current market prices, as opposed to long-term contracts with predetermined pricing.
materialSVHC Substance of Very High Concern
Chemical substances identified under REACH regulation as posing serious threats to human health or environment, requiring authorization for use in concentrations above 0.1% w/w.
regulationT
Talc Filler
A naturally occurring magnesium silicate mineral used as an inorganic filler in plastic resins to reduce cost, improve dimensional stability, and enhance mechanical properties.
materialTensile Strength
The maximum stress a plastic material can withstand while being stretched before breaking, measured in PSI or MPa and determined through standardized testing methods.
propertyTGA Analysis
Thermogravimetric Analysis (TGA) is a thermal analysis technique that measures weight loss of a material as a function of temperature or time, used to determine decomposition temperatures and filler content.
testingThermoforming
A plastic processing technique where heated thermoplastic sheets are formed into specific shapes using vacuum, pressure, or mechanical force against a mold surface.
processTitanium Dioxide
A white, inorganic pigment and additive (TiO2) used in plastics to provide opacity, whiteness, and UV protection. Essential for achieving bright white colors and opacity in polymer applications.
materialTPE
Thermoplastic Elastomer - a class of copolymers or polymer blends combining rubber-like elasticity with thermoplastic processability, allowing repeated heating and cooling cycles.
materialTPU
Thermoplastic Polyurethane, an elastomeric polymer combining flexibility of rubber with processability of thermoplastics, offering exceptional abrasion resistance and elasticity.
materialTPV
Thermoplastic vulcanizate (TPV) is a rubber-plastic blend where vulcanized rubber particles are dispersed in a thermoplastic matrix, combining rubber elasticity with thermoplastic processability.
materialU
UL 94 Flammability
UL 94 is a fire safety standard that classifies plastic materials based on their burning behavior and flame spread characteristics in controlled laboratory conditions.
testingUV Stabilizer
Chemical additives that protect polymers from degradation caused by ultraviolet radiation, preventing chain scission, color changes, and mechanical property loss in plastic materials.
materialV
Vicat Softening Point
The temperature at which a flat-ended needle penetrates 1mm into a polymer specimen under specified load and heating rate, indicating the material's softening temperature.
propertyVirgin Resin
Plastic resin that has never been processed or used before, manufactured directly from raw petrochemical feedstocks without any recycled content or contamination from previous applications.
material