Process: Melted polymer is subjected to heat and pressure in an extruder then formed into sheet through a number of pairs of calendering rolls. The temperature and speed of the rolls influences the properties of the film. Calendering allows speciality surface treatments such as embossing or in-line lamination.
Introduced: Patented for processing potash in 1790. First used to coat fabrics in 1874.
Tooling cost: Medium.
Production volume: High.
Uses: Films and sheet that can then be heat welded to form a variety of products including raincoats, bags, and inflatable items (including dinghies). Laminated flooring.