Copolymer Composition
Aqueous dispersion binders formed by the emulsion copolymerization of vinyl acetate monomer and flexible ethylene gas under high pressure. Packaging converting plants utilize VAE adhesives for laminating plastic films, foil structures and difficult paperboard substrates. Ethylene acts as an internal plasticizer, lowering glass transition temperatures without the volatile emissions or migration risks of monomeric additives.
Increasing ethylene content produces flexible, tacky polymers with improved adhesion to non-porous polymeric surfaces. The copolymer chemistry operates as a waterborne liquid system, requiring water removal through absorption or evaporation to form a permanent bond.
Bonding Performance
Internal ethylene units disrupt polyvinyl acetate crystallinity, creating inherently flexible polymer chains that conform to smooth low-energy surfaces. VAE adhesives demonstrate superior water resistance and heat resistance compared to conventional homopolymer polyvinyl acetate formulations. High-speed folder gluers run these dispersions to bond difficult coatings, varnishes and metallized films at short compression dwell times.
The balanced viscoelastic profile yields high wet tack, fast setting speed and excellent creep resistance under mechanical package stress. Formulators blend specialized tackifiers, fillers or silane coupling agents to adapt the base emulsion for specific film-to-board lamination requirements.
Plasticizer Boundary
High ethylene proportions reduce tensile strength and increase pressure sensitivity, causing bond creep under sustained loads. Exposure to organic solvents or high temperature environments softens the copolymer matrix, leading to cohesive failure within the adhesive layer.
