PET Resin Supplier China | Bottle, Fibre & rPET Grades

How to compare PET grade families

Specify PET by route first — blowing, sheet or fibre — and by intrinsic viscosity second. The same base polymer serves all three, but the IV window and additive package differ.

Grade family	What it sets	Typical uses	Confirm before ordering
Bottle grade	IV and acetaldehyde set blowing behaviour	Water, CSD, juice bottles	IV in dL/g, AA limit, colour
Fibre grade	Lower IV, spin finish and tenacity	Staple fibre, filament yarn	IV, filterability, finish type
Sheet or APET	Crystallisation control, melt strength	Thermoformed trays, blisters	IV, anti-block, regrind ratio
Recycled PET	PCR share, input source, colour shift	Bottles, strapping, fibre	PCR percentage, GRS certificate
Copolyester	Slower crystallisation, clearer walls	Cosmetic jars, thick parts	Comonomer level, haze

Specifications to put in your RFQ

Intrinsic viscosity — the value in dL/g and the test method, because methods differ
Conversion route — injection stretch blow, extrusion blow, sheet extrusion or fibre spinning
Virgin or recycled — the PCR percentage you must declare, and whether it must be food-contact approved
Acetaldehyde and colour — AA drives taste in still water; colour is quoted as L, a and b values
Comonomer and additives — nucleation, reheat additive, oxygen scavenger, colourant masterbatch
Delivery form — bulk, octabin or bags, moisture-barrier packaging, dust limits, lot size

Documents to request before you pay

Certificate of Analysis for the lot: IV, acetaldehyde, colour, moisture at delivery
Technical Data Sheet for the grade code, with drying window and melt temperatures
Food-contact declaration against EU 10/2011 or the applicable FDA 21 CFR 177 citation
Recycled-content proof — a GRS or ISCC PLUS scope certificate, plus the recycling route behind any food-grade rPET claim
Migration test reports for overall and specific migration on the finished article, not the resin alone
REACH SVHC and RoHS statements, and a Safety Data Sheet

Drying, processing and common sourcing mistakes

Skipping crystallisation and drying. PET hydrolyses: wet resin loses IV in the barrel. Agree drying temperature, time and dew point, and crystallise amorphous pellets first.
Letting IV fall through reheat. Every drying and melting pass costs viscosity. Set a regrind ratio and re-test IV on the blown bottle.
Buying on price alone. Two offers at the same price can differ in IV, acetaldehyde and colour; only one will run on your blower.
Assuming any rPET is food grade. Food-contact rPET needs an assessed recycling process — see how the EU clears recycled PET.
Ignoring acetaldehyde for still water. AA migrates into the contents as a sweet off-taste; specify the limit.
Ordering resin when you need preforms. Weight, neck finish and IV are specified together — read what a blowing programme should specify.

Frequently Asked Questions

What does intrinsic viscosity tell a PET buyer?

IV tracks molecular weight and melt strength, so it decides whether a grade blows a bottle, extrudes a sheet or spins a fibre. Quote it with the test method.

Can recycled PET replace virgin resin in food packaging?

Only where the recycling process and the finished article both carry the required approvals. The EU rPET approval route sets out the steps.

How does PET compare with PP for packaging?

PET gives clarity, stiffness and gas barrier; polypropylene wins on heat resistance and hot-fill behaviour. See PP vs PET for packaging.

When should I pick PBT instead of PET?

PBT crystallises faster and moulds more predictably for hot service; PET is the choice for clarity and barrier. Compare them in PBT vs PET heat resistance.