PC Resin Supplier China | Polycarbonate Pellets & Grades

How to compare polycarbonate grade families

Polycarbonate is specified by viscosity first, by its certification package second: two grades at the same melt flow behave very differently once one carries a flame-retardant package or a biocompatibility file. Pick the grade family from the end use, then tune the flow to your tool.

Grade family	What it delivers	Typical uses	Confirm before ordering
General-purpose / optical	Clarity plus impact strength acrylic cannot match	Lenses, light guides, machine guards, visors	Melt flow rate, haze, yellowness index
Flame-retardant	UL 94 V-0 or V-2, mostly non-halogenated today	Electrical enclosures, chargers, switchgear, battery housings	Rating at your thinnest wall, on the UL Yellow Card
UV-stabilised / glazing	Weatherable sheet, usually with a UV cap layer	Skylights, greenhouse glazing, sound barriers	Cap layer thickness, exposure warranty
Medical & food contact	Biocompatibility or food-contact clearance documented for the exact code	IV connectors, instrument handles, water bottles, dispenser tanks	ISO 10993 or USP Class VI evidence; EU 10/2011 or FDA 21 CFR 177.1580 declaration
Reinforced and blends	Glass fibre for stiffness, PC/ABS or PC/PBT for easier flow and lower cost	Structural brackets, power-tool bodies, automotive trim	Fibre loading, blend ratio, heat-deflection temperature

Specifications to put in your RFQ

Melt flow rate or viscosity grade — quote MFR at 300 °C / 1.2 kg (ISO 1133) and ask for the supplier's own grade code
Optical requirements — transmission, haze, yellowness index; say if the part is visible
Flammability target — the UL 94 rating and the thinnest wall, because a rating only holds at the thickness tested
Colour and finish — natural, clear, tinted or opaque, gloss or matte, plus painting or laser marking
End-use compliance — electrical, food, water, medical or automotive, with the market named
Conversion route — injection, sheet or profile extrusion, or blow moulding

Documents to request before you pay

Certificate of Analysis for the lot: MFR, notched impact, transmission for optical grades
Technical Data Sheet for the exact grade code, not the family brochure
UL Yellow Card showing the flammability rating at your wall thickness
Food-contact declaration against EU 10/2011 or FDA 21 CFR 177.1580 where the part touches food or water
Biocompatibility evidence (ISO 10993 or USP Class VI) tied to your sterilisation method
REACH SVHC and RoHS statements, plus a Safety Data Sheet in the buyer's language

Processing and common sourcing mistakes

Treating PC as a drop-in replacement for ABS or PMMA: drying, temperatures and shrinkage all differ
Skipping drying. PC is hygroscopic: moisture causes splay, bubbles and molecular-weight loss — agree dew point and residence time with your converter
Ignoring chemical compatibility. Ketones, esters, aromatics and strong alkalis stress-crack PC — check every adhesive, ink and gasket
Quoting a UL 94 rating without the wall thickness, then finding the certificate does not cover the real part
Forgetting UV protection outdoors, or overlooking residual stress before machining and plating

Frequently Asked Questions

What does polycarbonate do better than other clear plastics?

It keeps impact strength and heat resistance while staying transparent — hence guards, visors and lenses. Acrylic is clearer and cheaper but more brittle; PC vs PMMA clarity compares them for optical parts.

Which melt flow grade should I choose?

Let the part and process decide, then confirm with your converter. Thin-wall parts need higher flow; extrusion and blow moulding need higher viscosity. Quote a window.

Is PC suitable for food contact and water bottles?

Specific grades are, provided you hold the declaration for the exact code against EU 10/2011 or FDA 21 CFR 177.1580. Bisphenol-A based PC is restricted in some uses, such as infant bottles, in several markets — check destination rules.

Do I need a flame-retardant grade?

Only if the end product or its standard requires it. Electrical enclosures normally need UL 94 V-0 or better at the thinnest wall; flame-retardant grade selection walks through the trade-offs.

Why do PC parts crack after assembly or chemical contact?

PC is notch-sensitive and prone to environmental stress cracking, so sharp corners, tight inserts and incompatible solvents shorten service life. PC vs PP chemical resistance covers common media.