VA Content, Solubility and Tack

Vinyl acetate (VA) is the polar segment in an EVA copolymer. Raising the VA level changes the material from a waxy, near-polyethylene character toward a soft, polar, rubber-like polymer. Two consequences matter most to formulators.

Solubility

As VA climbs, EVA dissolves more readily in polar and aromatic solvents. A grade like Evatane 40-55 (40% VA) gives clear, low-viscosity solutions in esters, ketones and aromatic solvents — essential for solvent-based laminating adhesives and inks where a clean solution is required.

Tack

Higher VA also increases surface tack and affinity to polar substrates such as aluminium foil, PET and treated films. This improves wetting and initial grab in pressure-sensitive and heat-seal systems.

Trade-Offs

• Higher VA lowers crystallinity, so heat resistance and stiffness drop.
• Lower VA grades stay stiffer and more chemical-resistant.
• The right VA is a balance between solubility/tack and thermal limits.

For soluble, high-tack systems, high-VA grades such as Evatane 40-55 are the natural choice.