EVA and PEVA are both acronyms for Ethylene Vinyl Acetate. Somehow the P for polyethylene was added to create the acronym "PEVA."
To make EVA copolymer, Vinyl Acetate Monomer or "VAM" is copolymerized, or conjoined with Ethylene monomer to make Ethylene Vinyl Acetate.
EVA copolymer is made in varying percentages from 2% EVA, 4% EVA, 6% EVA, 8 % EVA up to about 28 % EVA for blown film. If you order simply "EVA" it is too broad and not specific enough.
The percentage of EVA is critical because the greater the EVA component, the lower the melting point. This affects the EVA film performance properties. If you are RF welding, the more EVA is needed for response to RF frequencies. For low melt / total batch inclusion, the amount of EVA must be known to match with the desired melting point. EVA is popular for solar photovoltaic pv cell encapsulation, yet EVA film suppliers do not specify the percent of EVA in the film for solar panel manufacturers.
When ordering EVA film, be sure to specify the amount of EVA for consistent performance.