Airflex EN421 vinyl acetate-ethylene copolymer Air Products Ethylene copolymers - emulsions (VAE, EVC) >> Vinyl Acetate Ethylene copolymers, VAE Airflex EN421 emulsion is a surfactant-stabilized, self-crosslinking, vinyl acetate-ethylene copolymer adhesive base. It is recommended for the formulation of heat-curing or self-curing adhesives. This product has the softness and flexibility typical of a vinyl acetate-ethylene copolymer adhesive base. Airflex EN421 emulsion’s self-crosslinking property provides excellent wet strength and good solvent resistance. In addition, Airflex EN421 emulsion resists discoloration on aging and leaves no residual odor in the finished product. Airflex EN421 emulsion is a higher Tg polymer than Airflex 420 emulsion. Airflex EN421 emulsion also has a higher viscosity range. Compounding Airflex EN421 emulsion thickens rapidly upon the addition of poly(vinyl alcohol), conventional cellulosic thickeners or certain polyacrylic thickeners. The curing time and temperature for Airflex EN421 emulsion depend on the substrate and the type of drying and curing equipment available. The degree of curing is enhanced by adding a dilute solution of acid catalyst such as sodium bisulfate, ammonium chloride or citric acid at a ratio of 0.5 to 1.0 parts catalyst per 100 parts of dry polymer. Applications: Airflex EN421 emulsion exhibits excellent adhesion to polyester, polypropylene, rayon, nylon and cellulosic fibers. It is, therefore, suitable for enduse applications such as flocking. The polymer can be applied by several methods including spraying, saturating or print bonding. Surfactant-stabilized, self-crosslinking, vinyl acetate-ethylene copolymer emulsion. Recommended for the formulation of heat-curing or self-curing adhesives. Has typical softness and flexibility of a vinyl acetate-ethylene copolymer adhesive base. Provides excellent wet strength and good solvent resistance. Provides good water resistance, moderate adhesion to glass, very clear film, moderate dry tack, and good flexibility. Adhesion to polyester, polypropylene, rayon, nylon and cellulosic fibers.