EVA Resin Supplier China | Foam, Film & Solar Grades

Four buying routes for EVA resin

EVA is not one market. A foam midsole, a solar encapsulant film and a hot-melt adhesive share the copolymer backbone but are formulated, tested and priced on different evidence. Settle the route first; the grade follows.

Route	What changes	Evidence to request	Downstream
Foam, footwear	Crosslink system	Gel content, density	TPU, TPE
PV encapsulant	UV package, purity	Damp-heat, gel content	applications
Hot-melt, wax	Polarity, viscosity	Softening point	additives
Film, sheet, cable	Sealing, filler load	Migration, flame rating	film, packaging

Specifications to put in your RFQ

Route — foaming, lamination, extrusion coating, blown film or injection; say which
VA band — the level you need and the property it is there to deliver
Melt flow index — stated at the load used on your machine
Additive package — UV stabiliser, antioxidant, anti-block, slip, and whether crosslinker is compounded or dosed
Filler loading — none, talc, carbonate, or flame-retardant filler, with the target level
Compliance — food contact, REACH SVHC, RoHS, or a cable flame rating

Documents and compliance to request

Lot Certificate of Analysis giving measured VA content and melt flow, not nominal values
Technical Data Sheet for the exact grade code, with melt and residence limits
Gel content test result for any crosslinkable foam or encapsulant grade
Food-contact declaration against EU 10/2011 or FDA 21 CFR, matched to your contact food
REACH SVHC and RoHS statements plus SDS, and an IMDS entry for automotive supply
Ageing reports — damp-heat and UV exposure data from the film maker for photovoltaic use

Processing EVA: the failures that repeat

Overheating the melt. EVA can split off acetic acid when it is run too hot or held too long, which smells of vinegar and attacks vents and inserts. Agree melt and residence limits and vent the tool.
Pellets blocking in the bag. Soft, high-VA grades cake together in a warm container. Ask what anti-block is used, agree a storage temperature and run first-in-first-out.
Treating encapsulant film as commodity EVA. Photovoltaic grades carry a formulated package — peroxide or silane, UV absorber, antioxidant — and are not interchangeable with a general-purpose resin.
Skipping the gel content check. Without crosslinking, foam collapses and compression set suffers; test gel content per batch, not the grade name.
Assuming it dries like polyethylene. Polar grades pick up moisture differently; take drying from the datasheet.
Blending and regrinding without a trial. EVA is often blended with other polyolefins; confirm the ratio and set a regrind limit — see the regrind control guide.
Leaving UV behaviour to chance. Light-coloured foam yellows and chalks outdoors; specify a stabilised grade and a colour standard up front.

Frequently Asked Questions

Is EVA a plastic or a rubber?

It is a thermoplastic copolymer that processes like polyethylene — until you crosslink it. A crosslinked foam will not re-melt, which changes both its service behaviour and how scrap can be recovered.

Which VA level should I buy?

Do not shop on the number alone. VA moves flexibility, clarity and adhesion one way, and heat resistance, blocking and cost the other. Grade-by-grade windows are mapped in our EVA resin specifications guide.

Can one grade cover both foam and solar film?

Rarely. Foam grades are built around the blowing and crosslink system, encapsulant grades around purity, UV stability and lamination. Buy to the route, not to the resin family.

Why does the mould smell of vinegar?

Acetic acid released by thermal deacetylation, usually from excess melt temperature or long residence. Drop the temperature, shorten residence, check dead spots and improve venting.

When should I move off EVA?

For foam resilience and low-temperature behaviour compare POE elastomer; for durable footwear outsoles compare TPU or TPE; for high-heat duties start from engineering plastics.