Other Plastics & Rubber Industry Terminology

Accelerated Weathering

Exposure testing that simulates years of sunlight, heat, and moisture in days or weeks (e.g., QUV or xenon-arc) to predict durability, colorfastness, and cracking of plastics and rubber.

"Run QUV accelerated weathering per ASTM G154 for 1000 hours"; "The TPE failed after 500 hours of xenon-arc"; "Accelerated weathering suggests we need a stronger UV stabilizer."

Antioxidant

Additives (e.g., hindered phenols, phosphites) that inhibit polymer oxidation during processing and service, preventing embrittlement, color change, and property loss.

"Add 0.2% phenolic antioxidant to improve thermal stability"; "Switch to a phosphite to protect during extrusion"; "Oxidative degradation decreased after we boosted AO levels."

Banbury Mixer

An internal mixer used to compound rubber at high shear, dispersing fillers, curatives, and oils efficiently.

"Banbury the batch to 160°C, then sheet on the mill"; "The Banbury mix cycle needs more ram pressure"; "Mixer rotor wear is causing poor filler dispersion."

Blow Molding

A process for making hollow parts by inflating a heated parison/preform inside a mold (extrusion blow, injection blow, stretch blow).

"Switch to EBM for the 1L HDPE bottle"; "Preform heating is critical in ISBM"; "Wall thickness control improved with parison programming."

Carbon Black

A reinforcing filler and black pigment that improves tensile, abrasion, and UV resistance, widely used in rubber and some plastics.

"Use N330 carbon black for tire treads"; "Carbon black raised conductivity to dissipate static"; "Higher loading increased hardness but reduced elongation."

Compounding

The process of blending polymers with additives (fillers, plasticizers, stabilizers, colors) to achieve target properties, typically in twin-screw extruders or internal mixers.

"Scale up the PP compound on a 58 mm twin-screw"; "The compound needs better pigment dispersion"; "We adjusted the recipe to meet UL 94 V-0."

Draft Angle

A slight taper on molded walls to aid ejection and prevent scuffing or sticking; typically 1–3 degrees for most thermoplastics.

"Add 2° draft on all ribs"; "The lack of draft is causing drag marks"; "Increase draft to reduce ejection force."

Durometer

A handheld instrument measuring Shore hardness (A/D) of elastomers and plastics; also used to refer to the hardness value.

"Target 70A durometer for the seal"; "Use a Shore D durometer for rigid TPU"; "Hardness drifted 5 points after aging."

Elastomer

Polymers with rubber-like elasticity and high elongation, including thermoset rubbers (EPDM, NBR) and thermoplastic elastomers (TPEs, TPU, SEBS).

"Choose an elastomer with low compression set"; "Switch from NBR to HNBR for heat resistance"; "The TPE elastomer overmolds well on PP."

Extrusion

Continuous shaping by forcing molten polymer through a die to make film, sheet, pipe, or profiles; also used for compounding.

"Profile extrusion speed is limited by cooling"; "Die swell is high on this LDPE"; "Switch to a grooved feed barrel to boost output."

FDA Compliance

Meeting U.S. 21 CFR food-contact regulations for materials and additives used in processing equipment, packaging, or parts that contact food.

"Pick a 21 CFR 177.1520 compliant PP"; "Migration testing confirmed FDA compliance"; "Supplier provided an FDA food-contact letter."

Fillers

Solid additives (e.g., talc, calcium carbonate, silica, glass fiber) used to modify cost, stiffness, density, thermal and electrical properties.

"Add 20% talc to stiffen PP"; "Silica filler improved rubber tear strength"; "Calcium carbonate lowered cost but reduced impact."

Gate

The location and geometry where molten polymer enters an injection mold cavity; influences fill pattern, weld lines, and gate vestige.

"Move the gate to hide the vestige"; "Use a submarine gate for automatic de-gating"; "Valve gate timing reduced jetting."

Glass Transition Temperature (Tg)

The temperature at which the amorphous regions of a polymer transition from glassy to rubbery; critical for brittleness, damping, and service limits.

"Below Tg the ABS is brittle"; "DMA showed a Tg of 105°C"; "Choose a TPU grade with lower Tg for flexibility at -20°C."

HDPE (High-Density Polyethylene)

A semi-crystalline polyolefin known for stiffness, chemical resistance, and good ESCR; widely used in blow-molded bottles and pipe.

"Switch to PE4710 for pressure pipe"; "HDPE gives better ESCR than PP here"; "We need bimodal HDPE for top-load strength."

Hot Runner System

Heated manifolds and nozzles that keep polymer molten inside the mold to eliminate cold runners and reduce scrap.

"Specify valve gates for better gate cosmetics"; "Hot runner balance improved fill"; "Material shear in the manifold caused degradation."

Impact Modifier

Additives (e.g., SEBS, MBS, core-shell rubbers) that increase toughness and reduce brittle failure, especially at low temperatures.

"Add 10% AIM to toughen PVC"; "SEBS improved impact but lowered stiffness"; "Consider an acrylic core-shell for UV stability."

Injection Molding

A cyclic process that injects molten polymer into a mold, then cools and ejects parts; critical variables include melt temperature, pressure, and cooling time.

"The press needs 200 tons clamp force"; "Tune V/P switchover to reduce flash"; "Cycle time dropped 3 seconds after cooling optimization."

Jetting

A surface defect where a high-velocity polymer stream snakes or folds in the cavity, causing wavy lines and weak spots.

"Relocate the gate to mitigate jetting"; "Raise melt and mold temperatures"; "Use a tab gate to slow the stream."

Just-in-Time (JIT)

A lean manufacturing approach that synchronizes deliveries and production to minimize inventory, WIP, and lead time.

"Shift to JIT with supplier-managed Kanban"; "JIT cut our resin inventory by 35%"; "Line stoppages drop when JIT signals are reliable."

Kaizen

Continuous improvement methodology that engages teams to make incremental changes in safety, quality, delivery, and cost.

"Run a kaizen to reduce purge time"; "Kaizen blitz shortened changeover by 40%"; "Daily kaizen boards track scrap reduction."

K-Value (PVC)

A measure related to the degree of polymerization/molecular weight of PVC resin; affects viscosity and mechanical properties.

"Select K67 for rigid profiles"; "Higher K-value improved impact but raised processing torque"; "Spec calls for K65–67 PVC."

LCA (Life Cycle Assessment)

A standardized method (ISO 14040/44) to quantify environmental impacts from raw materials through end-of-life.

"LCA shows 30% lower CO2 with PCR content"; "We’re modeling cradle-to-gate impacts"; "Use LCA to support an EPD for the product."

Liquid Injection Molding (LIM)

A process for liquid silicone rubber (LSR) using metered two-part systems injected into a heated mold for fast cure and precise parts.

"LIM enables flashless medical seals"; "Install a static mixer at the metering unit"; "Optimize cure at 180°C for the LSR grade."

Masterbatch

A concentrated mixture of pigments or additives in a carrier resin, later let down into base polymer during processing.

"Use a 40% TiO2 color masterbatch at 2% LDR"; "Switch to a compatibilizer masterbatch"; "Masterbatch improved dosing consistency."

Melt Flow Index (MFI)

A measure of melt viscosity (g/10 min) under specified load/temperature (ASTM D1238), used for quality control and processing selection.

"Pick PP with MFI 12 for thin-wall molding"; "MFI drifted out of spec on last lot"; "Higher MFI improved flow but reduced impact strength."

NBR (Nitrile Butadiene Rubber)

A copolymer rubber known for oil and fuel resistance; acrylonitrile content drives polarity and temperature performance.

"Use 33% ACN NBR for better fuel resistance"; "NBR seals hardened at low temperatures"; "Consider HNBR for heat and oil."

Nylon (PA)

Engineering thermoplastics (PA6, PA66, etc.) with high strength and temperature resistance; moisture uptake affects properties and dimensions.

"Dry PA66 to <0.2% moisture before molding"; "Glass-filled PA boosted stiffness"; "Condition PA6 parts before testing."

OEM (Original Equipment Manufacturer)

A customer that integrates supplied components into final products; often sets specifications, approvals, and PPAP requirements.

"We’re an approved OEM supplier for seals"; "Submit PPAP to the automotive OEM"; "OEM spec mandates REACH and RoHS compliance."

Overmolding

Molding a second material over a substrate (insert or first-shot part) to add grip, seal, or functions; adhesion/compatibility are critical.

"Overmold TPE onto PP handle"; "Use a primer for rubber-to-metal overmold"; "Two-shot overmolding eliminated assembly."

Plasticizer

Low-molecular-weight additives that increase flexibility and lower Tg/processing temperature, common in PVC and rubber (phthalates, adipates, bio-based).

"Switch to DOTP to be phthalate-free"; "Plasticizer migration caused fogging"; "Increase plasticizer for 60A hardness target."

Polypropylene (PP)

A semi-crystalline thermoplastic with good chemical resistance and low density; available as homo, random, and impact copolymers.

"Use impact copolymer PP for toughness"; "Nucleated PP cut cycle time"; "PP warpage improved with mold temp control."

Quality Management System (QMS)

A formal set of policies and procedures (e.g., ISO 9001) to ensure consistent quality, traceability, and continuous improvement.

"Audit the QMS against ISO 9001"; "QMS CAPA closed the nonconformance"; "Control plans are part of our QMS."

REACH Compliance

Conformance with EU chemicals regulation covering registration, authorization, restriction, and SVHC communication.

"Product is REACH registered for 1–10 tpa"; "No SVHCs above 0.1% w/w"; "Submit SCIP dossier for the article."

Rheology

Study of flow/viscosity behavior under shear and temperature; guides processing (extrusion, molding) and formulation.

"Rheometer shows shear-thinning behavior"; "Match viscosity curves for overmolding"; "High melt elasticity caused die swell."

SBR (Styrene-Butadiene Rubber)

A general-purpose synthetic rubber with good abrasion resistance; used in tires, footwear, and industrial goods (emulsion or solution grades).

"Use SBR for tread wear resistance"; "Blend SBR with NR to balance properties"; "Solution SBR improved rolling resistance."

Shore Hardness

A scale (A, D, etc.) for hardness of elastomers and plastics; measured with a durometer and reported as, e.g., 70A or 80D.

"Specify 85A Shore for grip"; "Hardness drifted from 70A to 75A after aging"; "Use Shore D for rigid TPU."

Thermoplastic Elastomer (TPE)

A family of elastomeric materials that process like plastics (SEBS, TPU, TPO, COPE) and can be recyclable.

"Select a 60A SEBS TPE for soft touch"; "TPE bonds well to PP in overmolding"; "Switch to TPO for weatherable fascia."

Thermoset

Polymers that irreversibly crosslink during curing (e.g., vulcanized rubber, epoxies) and cannot be remelted.

"Rubber is a thermoset after vulcanization"; "B-stage the epoxy before final cure"; "Thermoset silicone holds shape at high temperatures."

UL 94 Flammability

A plastics flammability rating system (HB, V-2, V-1, V-0, 5VA/5VB) specifying burning behavior under test.

"We need UL 94 V-0 at 1.5 mm"; "Add FR package to reach 5VA"; "UL cards show our material’s rating."

UV Stabilizer

Additives (HALS, UV absorbers) that protect polymers from ultraviolet degradation, reducing yellowing, chalking, and cracking.

"Add HALS to the TPO capstock"; "UV package extended outdoor warranty"; "Switch to UV-absorber for clear PC."

VOCs (Volatile Organic Compounds)

Organic emissions from materials and processing that affect air quality and odor; managed via formulation and capture/abatement.

"Reduce VOCs by switching plasticizer"; "Test per VDA 278 for VOC and FOG"; "Install carbon adsorption to control emissions."

Vulcanization

The crosslinking process for rubber using sulfur, peroxides, or other systems to achieve elasticity, strength, and set resistance.

"Optimize cure time on the rheometer curve"; "Use sulfur donor for faster vulcanization"; "Peroxide cure improved heat aging."

Warpage

Distortion of molded parts due to differential shrinkage, cooling, or fiber orientation; mitigated via design and process changes.

"Increase mold temp to reduce PP warpage"; "Add ribs to control deformation"; "Moldflow predicts sink and warp zones."

Weld Line

A line where two melt fronts meet and knit; often a mechanical weak point and cosmetic defect.

"Shift the gate to move the weld line"; "Raise melt temp to improve knit strength"; "Valve gating reduced weld line visibility."

XRF (X-ray Fluorescence)

A non-destructive elemental analysis technique used to screen materials for restricted substances (e.g., RoHS metals, halogens).

"XRF shows no lead or cadmium"; "Use XRF for incoming resin checks"; "XRF flagged bromine in a recycled batch."

Yellowing Index (YI)

A metric (e.g., ASTM E313) indicating the shift toward yellow of a material’s color over time or after exposure.

"YI increased after UV exposure"; "Add UV absorber to control YI"; "Pre-dry PC to prevent processing yellowing."

Young’s Modulus

The tensile modulus (stiffness) of a material, typically measured per ASTM D638 or ISO 527; crucial for structural design.

"Glass fiber raised PA6 modulus to 7 GPa"; "Target modulus of 300 MPa for the TPE"; "DMA gives a temperature-dependent modulus curve."

Ziegler–Natta Catalyst

Catalyst systems used in polyolefin production that control tacticity and molecular weight distribution (e.g., isotactic PP).

"Switch to Ziegler–Natta PP for better stiffness"; "Catalyst choice impacts MWD"; "Metallocene vs Ziegler–Natta affects clarity and toughness."

Zinc Oxide

An activator in sulfur-cured rubber formulations and a UV-blocking additive in plastics; also aids heat conductivity.

"Increase ZnO to speed cure"; "Use non-staining ZnO in white rubber"; "ZnO helped UV resistance in the PVC compound."