Process and appts. for solvent-free adhesive coating plastics films - has heated adhesive, e.g. moisture curing polyurethane, extruded onto roll which is pressed against esp. discontinuous film to reduce overspill

摘要

Process and arrangement for adhesive coating plastics films. A solvent-free adhesive is used, esp. a reactive adhesive, solid at room temperature but brought to working viscosity by heating. The adhesive is esp. a moisture reactive polyethan (SIC) (polyurethane in text). A fixed die feeds heated adhesive to coat a rotating roll (5) which is then pressed against the moving film to coat the latter. USE/ADVANTAGE - Adhesive coating plastics films, esp. discontinuous lengths. Avoids expensive solvent disposal from solvent containing adhesives. Avoids temp. limitations in end-use of usual hot melt adhesives. Uses atmospheric moisture to give usable curing times, forming heat-, chemical- and solvent-resistant solid adhesive. Use of offset roll rather than direct extrusion avoids overspill, contamination and cleaning with discontinuous film lengths6