EVA and PEVA are the same thing. EVA is short for " ethylene vinyl acetate ". Somehow "polyethylene" got added as a prefix to create the acronym PEVA. Both are words for the same copolymer. PEVA / EVA is a copolymer comprised of the monomers Ethylene C2H4 and Vinyl Acetate Monomer CH2=CHOOCCH3 conjoined to make the copolymer Ethylene Vinyl Acetate, or EVA for short.
Vinyl Acetate monomer cannot be mechanically mixed at the extruder. It is made at specific percentages by the resin companies.
EVA is used for many applications besides film. This discussion is only about EVA as it pertains to blown film.
EVA lowers the seal initiation temperature and melting point of PE film. In low percentages, it has been used for decades for enhanced sealability for bread bags (2% EVA ), ice bags (4% EVA) and frozen food packaging (usually 6% EVA). In higher percentages, more or less 20% EVA, it is used for low melt/total batch inclusion bags. It is a common practice to say the ostensible percent of EVA is one not made by a resin company.
The higher percentage EVA, the lower the melting point whether measured as DSC melting point or vicat softening point.
Higher percentage EVA’s are soft and tacky.
EVA has a pungent, apple vinegar odor which can transfer to foods especially dairy products.
While EVA is considered obsolete by many for packaging applications because metallocene offers faster hot tack, demand for EVA remains strong for PVC replacement and solar panel encapsulation.
For more in-depth discussion of EVA and PEVA, visit our blog posts :
EVA & PEVA
METALLOCENE vs. EVA