EVA in the Plastics & Footwear Industry: Structure, Specs, and Why Artifactus Chooses Premium Foam

EVA in the Plastics & Footwear Industry: Structure, Specs, and Why Artifactus Chooses Premium Foam 1) What EVA Actually Is Ethylene–vinyl acetate (EVA) is a random copolymer of ethylene and vinyl acetate (VA). Adjusting VA% tunes crystallinity and softness: higher VA lowers crystallinity, raising flexibility and resilience—key for comfort foams. EVA is typically crosslinked (peroxide or radiation) before foaming to lock in cell structure and prevent collapse. Closed-cell foam morphology is standard in footwear midsoles and clogs, giving buoyancy, water resistance, and cushioning. Crosslinking during foaming is crucial for stable cells and rebound. 2) Key Physical & Mechanical Specs (typical footwear-grade EVA foam) - Density: ~0.10–0.35 g/cm³ for foams used in footwear; neat EVA ~0.95 g/cm³ before foaming. - Hardness (Shore C/Asker C): Soft to medium for comfort clogs; tuned by VA% and crosslinking. - Compression set / shape recovery: Low compression set—f...