Лако-красочные материалы — производство

Because of their relatively high melt viscosities, the EVA hot melts need special manufac­turing equipment. For example, a Z-blade mixer such as a Baker Perkins or Winkworth with oil-heated jacketing is required. Mix temperatures are kept as low as possible (± 110° C) to keep bulk thick. The high-viscosity kneading action ensures rapid dissolution of EVA copolymer and resin. Fillers are easily dispersed and a homogeneous mix is achieved rapidly with this type of agitation. Upon completion, the molten product is extruded into ropes approximately 6 mm in diameter, which are cooled through a chilled water trough and then granulated into pellet form. Alternatively, hot-melt slugs are sup­plied where application equipment utilizes this form. It is essential to ensure that any residual moisture picked up during the cooling process is eliminated via an air-drying cyclone before packing.