Polymer & plastics trade glossary

Short, plain-English definitions of the terms you see every day in polymer trading and processing.

MFI (Melt Flow Index)

A measure of how easily a molten polymer flows, expressed in g/10 min under a set load and temperature. It is a key property used to choose a grade for injection, blow moulding or extrusion.

Polymer grade

A specific product variant of a polymer from a manufacturer, defined by properties such as MFI, density and additives — for example an injection-moulding PP homopolymer grade.

Lot / batch number

An identifier given by the manufacturer to a production batch. Tracking lots lets a business trace quality issues back to the source.

COA (Certificate of Analysis)

A document certifying the test results of a specific batch of a product against its specification.

SDS (Safety Data Sheet)

A standard document describing the hazards, safe handling, storage and emergency measures for a chemical product.

Landed cost

The total cost of getting goods into your warehouse: purchase price plus freight, insurance, customs duty, port, clearing and inland transport.

HSN code

The Harmonised System of Nomenclature code used under GST to classify goods. Plastics and articles thereof fall under Chapter 39.

E-way bill

An electronic document required under GST for moving goods above a threshold value, generated before transport begins.

Masterbatch

A concentrated mixture of pigments or additives in a carrier polymer, added in small amounts to colour or modify plastics.

Regrind

Plastic scrap that has been ground into flakes so it can be reprocessed.