Example of extruded sheet (flexible) line:
As in film processing, co-extrusion can also be utilized to create multilayer structures. Use a coat-hanger, flexible-lip die with a 1 inch land and 30-40 mil lip opening (or at least 25% greater than the desired film thickness). All flow surfaces should be hard chrome-plated and highly polished (no dead zones, nicks or scratches). The face of the die should be tapered instead of square to permit a short die to shill roll air gap. Restrictor-bar dies are not recommended.
Cooling
Use standard 3-roll sheet-casting stacks with a 12-inch-minimum roll diameter for producing nip-polished high-quality film/sheet. The casting stack temperature and polish roll pressure should be balanced to eliminate sticking and maintain high-quality aesthetics. The surface roughness or RMS values of the sheet casting stack cooling rollers can have a highly polished, embossed or matte finish.
Finishing
Use sharp, rigidly mounted razor blades for trimming film edges. Use a winder with good tension control and a proximity lay-on roll. Use static reduction devices prior to winding or as needed throughout the line. | 
