Glossary of plastics trading terms

The terms that appear in specifications, offers and shipping documents, explained in plain language.

Material properties

Intrinsic viscosity (IV): A measure of PET molecular weight, in dl/g. Higher IV means stronger melt and products; bottles typically need 0.76–0.84 dl/g, fiber 0.60–0.68 dl/g.
Melt flow index (MFI / MFR): Grams of polymer that flow through a standard die in 10 minutes at a set temperature and load. Low MFI suits film and blow molding; high MFI suits injection and fiber.
Density: Mass per volume in g/cm³. It separates HDPE (≥ 0.94) from LDPE and LLDPE (< 0.94) and affects stiffness.
Acetaldehyde (AA): A by-product in PET that can affect the taste of bottled water. Bottle-grade resin is typically ≤ 1 ppm.
Denier: Linear density of a fiber: grams per 9,000 meters. Fine spinning fibers are about 1.2–1.5 D; filling fibers 3–15 D.
HCS: Hollow conjugated siliconized polyester fiber, with spiral crimp and silicone finish for soft, high-loft filling.

rPET: Recycled PET, usually from post-consumer bottles, traded as flakes or pellets.
Hot-washed flakes: Bottle flakes washed in a hot caustic solution that removes glue, labels and contaminants more thoroughly than a cold wash.
SSP (solid-state polymerization): A process that raises the IV of PET or rPET pellets and lowers acetaldehyde for demanding applications.
PCR / PIR: Post-consumer recycled material comes from used products; post-industrial recycled material comes from production scrap.
Regrind: Plastic scrap that has been ground into small pieces but not re-pelletized.
Prime, off-grade, wide-spec: Prime meets the producer’s full specification; off-grade and wide-spec fall outside it and are sold as such, usually at a discount.

FCL: Full container load: one shipper’s cargo fills a whole 20′ or 40′ container.
Incoterms 2020: International Chamber of Commerce rules defining who pays freight and insurance and where risk passes between seller and buyer.
FOB: Free on board: risk passes when goods are loaded on the vessel at the port of shipment; the buyer pays the main freight.
CFR / CIF: Cost and freight / cost, insurance and freight: the seller pays the main freight (and insurance for CIF), but risk still passes at loading.
DAP: Delivered at place: the seller delivers to a named destination, ready for unloading; import duties remain with the buyer.
HS code: Harmonized System code used by customs worldwide to classify goods; national tariffs add more digits.
Bill of lading (B/L): Document issued by the carrier that receipts the cargo, evidences the contract of carriage and, when negotiable, represents title to the goods.
Free time, demurrage and detention: Days allowed to use a container at no cost; demurrage is charged inside the terminal after that, detention outside it.

TDS: Technical data sheet: the producer’s description of a grade and its typical properties.
COA: Certificate of analysis: test results of the specific lot being shipped.
SDS: Safety data sheet with handling, storage and safety information.
Letter of credit (L/C): A bank’s undertaking to pay the seller when compliant documents are presented.
CAD: Cash against documents: the buyer’s bank releases the shipping documents only after payment.