Extrusion Coating of Thermoplastic Films
topic
Extrusion coating machines melt polyethylene, polypropylene, or ionomer resins at 250 to 320 degrees Celsius in single or twin screw extruders and extrude them through a flat film die directly onto moving substrate webs at speeds of 100 to 500 metres per minute, with the hot polymer melt bonding to the substrate surface by thermal adhesion as it cools on a chilled pressure roll nip, applying coating weights of 10 to 100 grams per square metre in a single pass.
Role
Provides the most productive and economical thermoplastic coating method for high-volume waterproof, barrier, and heat-sealable textile and paper products by converting resin pellets directly into a continuous bonded coating layer without solvent, water, or adhesive intermediates, with extrusion coating being the dominant technology for agricultural films, food packaging laminates, and waterproof fabric production at the production speeds required for commodity technical textile economics.