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Learn about polymer sourcing

30 terms covering polymer technology, food-contact regulation, commercial mechanics, and logistics, written for procurement teams who need the working answer fast.

Technical

Melt Flow Rate (MFR / MFI)

Mass of polymer extruded through a standard capillary in 10 minutes under specified load and temperature. Inverse proxy for molecular weight. Higher MFR = easier flow, lower mechanical strength.

Polyethylene Density Classification

PE families divided by density: LDPE 0.910–0.940, LLDPE 0.915–0.935, MDPE 0.926–0.940, HDPE 0.941+. Density correlates with crystallinity, stiffness and barrier.

Vicat Softening Point

Temperature at which a flat-tipped needle penetrates 1 mm into a specimen under load. Useful proxy for upper service temperature.

Homopolymer vs Copolymer

Homopolymers polymerise a single monomer (e.g. PP-H = pure propylene). Copolymers add a second monomer (PP-R random, PP-B impact) for clarity, toughness or processing.

Random vs Block (Heterophasic) Copolymer

Random copolymer disperses comonomer evenly along the chain (clarity, lower modulus). Block / heterophasic uses a separate rubber phase for impact (PP-B).

BOPP vs CPP Film

Biaxially-oriented PP (BOPP) is stretched in MD and TD for stiffness, clarity and barrier. Cast PP (CPP) is unoriented; softer, better seal initiation.

Color Masterbatch

Concentrated pigment carried in a polymer matrix (typically PE for PE applications, PP for PP). Dosed at 1–4% to natural resin during processing.

Polymer Additives Overview

Antioxidants (Irganox), UV stabilisers (HALS), nucleators, anti-blocks, slips, antistatics, flame retardants. 0.05–5% addition typical. REACH-restricted lists update twice yearly.

Regulation

ISO 1133 (MFR Test Method)

International standard for melt mass-flow rate (MFR) and melt volume-flow rate (MVR). Specifies temperature, load (e.g. 230 °C / 2.16 kg for PP) and equipment.

ISO 178 (Flexural Properties)

Three-point bending test for flexural modulus and strength of plastics. Reported in MPa.

ISO 180 (Izod Impact)

Pendulum impact test on a notched or unnotched specimen. Reported in kJ/m². Distinguishes brittle GPPS from impact-modified HIPS or ABS.

EU 10/2011 Food Contact Regulation

Plastic Materials and Articles Regulation. Lists permitted monomers and additives, sets specific migration limits (SML) and requires Declaration of Compliance (DoC) along the supply chain.

FDA 21 CFR 177.1520

US FDA olefin polymers food-contact regulation. Common reference for PP and PE compliance even in EU-sold products targeting US-market exposure.

REACH and Polymers

Polymers themselves are exempt from REACH registration but their monomers, additives and compounds are not. SVHC list updated twice yearly affects PVC plasticisers, flame retardants and stabilisers.

PPWR (EU Packaging Regulation)

Packaging and Packaging Waste Regulation, in force from 2024. Mandates minimum recycled content (rPET 25% 2025, 30% 2030), design-for-recycling by 2030, reuse targets.

Mechanical vs Chemical Recycling

Mechanical: shredding, washing, extrusion preserves the polymer chain. Chemical: depolymerisation back to monomer (e.g. PET glycolysis, PE pyrolysis) produces virgin-equivalent output.

GRS / RecyClass / ISCC Plus

Voluntary certifications proving recycled or sustainable content claims. GRS for textile fiber, RecyClass for packaging, ISCC Plus for mass-balance bio/chemical recycled.

Bio-PE vs Recycled PE

Bio-PE (e.g. Braskem I'm Green) is virgin polymer made from sugarcane ethanol, chemically identical to fossil PE. Recycled PE comes from end-of-life material. Different sustainability arguments.

Commercial

Prime vs Near-Prime vs Off-Grade

Prime: full-spec with CoA. Near-prime: minor spec deviation, batch-tracked, 10–25% discount. Off-grade: out-of-spec, sold without CoA at 30–50% discount; quality varies widely.

Virgin vs Recycled Polymer

Virgin: directly from monomer polymerisation. PCR (post-consumer recycled) and PIR (post-industrial recycled) recover end-of-life material; food-contact rPET via EFSA-listed processes.

Polymer Pricing and Monomer Linkage

PE/PP track ethylene/propylene contract prices (ICIS monthly). PVC follows ethylene + chlorine. PET tracks paraxylene + MEG. Margin spread = polymer minus monomer cost.

Oil Price Impact on Resin Prices

Naphtha cracking dominates EU olefin supply, so Brent crude price moves filter to PE/PP within 4–8 weeks. US-imported PE follows ethane/Henry Hub gas pricing instead.

Producer-Direct vs Distributor vs Trader

Producer-direct contracts require minimum annual tonnage. Distributors break bulk and offer credit. Traders work the spot market for prime, near-prime and off-grade lots.

Spot Market vs Contract Pricing

Contract: monthly negotiation tied to monomer index, typically 60–85% of EU demand. Spot: lot-by-lot, usually 5–20% above or below contract reflecting near-term tightness.

NACE Codes for Plastics

NACE 20.16 Manufacture of plastics in primary forms. NACE 22.21 Manufacture of plastic plates, sheets, tubes and profiles. NACE 22.22 Plastic packaging goods. Used to identify customer industries.

Certificate of Analysis (CoA)

Per-batch document listing tested properties (MFI, density, moisture, ash, color) against grade specification. Required for prime material; absent on off-grade.