EVA film grades: low-VA film, sealant and cling resin by VA content and melt index

How VA content changes a film grade

Vinyl acetate breaks up the polyethylene crystals. As VA rises, the film gets softer, clearer and tackier, and it melts and seals at lower temperatures. The values below are typical published figures from one producer’s blown film data sheets, so the trend is easy to see. For all EVA uses by VA, see EVA by vinyl acetate content; for foam, see EVA foam resin. For LDPE and LLDPE film grades, see LDPE and LLDPE film grades.

Typical values from published producer data sheets (DSC peak melting and Vicat by ASTM D1525 or the producer’s own method). They are not specifications. Your grade’s data sheet and lot COA are what count.

VA and melt index by film product

Find your product, then compare your current grade with the window. Every melt index is at 190°C / 374°F and 2.16 kg (ASTM D1238). Several of these films are covered for LDPE and LLDPE on our film grade finder and the film converter page; this table covers the EVA layer only.

Windows are drawn from published producer film, coating and medical grade data sheets and are typical, not limits. Confirm against the data sheet for the grade you run, and let a chemist check any equivalent before you switch.

Seal initiation, hot tack and how EVA compares with mLLDPE, plastomers and ionomers

Seal initiation temperature falls as VA rises, because the polymer melts lower. That lets a packaging line run faster or seal through a thin layer of product. The tradeoffs are tack and heat: a high-VA sealant blocks more on the roll and softens sooner in hot fill or warm storage. Hot tack, the strength of a seal while it is still hot, is a separate number. Ask for seal strength (ASTM F88) and hot tack (ASTM F1921) at your dwell and pressure. We do not publish seal temperatures, because they depend on your sealer, structure and gauge. See heat seal failures.

General comparison. Grades within each family vary widely, so compare actual grade data and run seals on your own equipment. See metallocene PE and plastomers.

Slip, antiblock, blocking and odor

• More VA, more antiblock. EVA film tacks to itself more as VA rises. Published EVA film grades run from no additives to about 1% antiblock and several thousand ppm slip, with the highest levels in the higher-VA grades.
• Built in or by concentrate. Some grades come with slip and antiblock already added at stated ppm, and others are natural for you to dose. When you replace a grade, match the package or expect COF and blocking to change. See film blocking.
• Slip and lamination. Slip moves to the surface over hours to days, and it can weaken print and adhesive lamination bonds. Laminators often buy low-slip or additive-free sealant grades.
• Clarity. Antiblock raises haze, so clear sealant and display films often use low-antiblock or natural grades and add only what the winder and bagger need.
• Odor and taste. Overheated EVA breaks down and releases acetic acid, which smells of vinegar and can carry into food. Keep melt temperature within the grade sheet, keep residence short, and test odor on film, not only on pellets, if your customer runs sensory panels.

Processing temperature limits and blending with LDPE and LLDPE

EVA tolerates less heat than polyethylene, and higher-VA grades tolerate the least. Purge with LDPE before shutdown and do not leave EVA sitting hot in the barrel. Low-VA EVA blends easily with LDPE and LLDPE and runs on the same blown film lines. It is often added to LDPE or LLDPE for toughness, clarity, low-temperature flexibility or a lower seal temperature, and LLDPE adds strength to a softer EVA layer.

Our general EVA range of about 160–220°C / 320–428°F on the EVA page still applies to most molding and extrusion. Always use the limit on the sheet for your grade.

FDA 21 CFR 177.1350: what it covers

• No VA cap for basic EVA. The regulation does not set a maximum VA content for ordinary EVA copolymers. It covers the basic resin plus permitted optional additives, including erucamide slip and a fluoroelastomer processing aid at up to 0.2%.
• Extraction limit. The copolymer, extracted with the solvents and at the time and temperature conditions for the food type and use (from the tables in 21 CFR 176.170(c)), must yield no more than 0.5 mg per square inch of chloroform-soluble extractives.
• Maleic anhydride-grafted EVA. Allowed with no more than 11% VA, no more than 2% grafted maleic anhydride, a melt flow index of no more than 2.1 g/10 min, and no more than 17% of the polymer blend, with limits on some food types.
• Irradiated film. EVA film may be crosslinked by electron beam up to 150 kGy, which is common in shrink bags, and food-contact film may be gamma-irradiated at 5–50 kGy, with an extractives limit.
• What to ask for. The producer’s FDA letter for the exact grade and its conditions of use. Concentrates need their own letters, and the finished film is the converter’s responsibility. See what FDA compliance means.

Price drivers, packaging and supply

We do not post prices. Every quote is for a specific grade, quantity, package and ship-to city. See EVA price per pound, how resin is priced and the resin market notes for direction.

• Feedstocks. EVA is made from ethylene and vinyl acetate monomer (VAM). Low-VA film grades come off the same high-pressure reactors as LDPE, so they tend to follow the LDPE market more closely, and higher-VA grades carry more VAM cost.
• Competing demand. High-VA capacity is shared with solar encapsulant film and hot-melt adhesives, which can tighten higher-VA sealant grades when those markets are busy.
• Campaigns. EVA film grades are made in campaigns. A specific VA, MI and additive package may wait for the producer’s next run.
• Packaging. Large film plants take low-VA EVA by bulk truck (about 40,000–50,000 lb) or railcar (about 180,000–210,000 lb). Sealant layers and trials often come in gaylords (about 1,000–1,600 lb) or 55 lb (25 kg) bags, about 40–55 per pallet. Higher-VA pellets can block in a hot warehouse, so store them cool and use them first in, first out.

What to put on the RFQ

• VA content in percent, with the tolerance you accept.
• Melt index at 190°C / 374°F and 2.16 kg (ASTM D1238), nominal and range.
• Process and layer. Blown, cast or coating; monolayer or which layer of a coextrusion; and your blend with LDPE or LLDPE.
• Additive package. Slip type and ppm, antiblock type and ppm, antioxidant, or natural. Say if you need fluorine-free processing aids.
• Film targets. Seal initiation, seal strength (ASTM F88), hot tack (ASTM F1921), haze (ASTM D1003), dart (ASTM D1709) and COF (ASTM D1894) at a set age.
• Gel limit. How gels are counted and the limit you accept, especially for clear sealant and medical film.
• Food contact or medical. The producer’s FDA letter for the exact grade, any irradiation in your process, and medical-grade paperwork if the film is for medical use.
• Quantity and package. This order, yearly use, release size, and bags, gaylords, bulk truck or railcar. Send your ship-to city.
• COA values to check. VA content and melt index on every lot, and gel count if the grade lists it. Every prime lot from our suppliers ships with a COA.

Common questions

If your grade is not listed, tell us what you run. We source commodity, engineering and specialty resins.