Calendering

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.

Plastics:   Polyvinyl chloride, acrylonitrile butadiene styrene, and to a lesser extent high-density polyethylene, polypropylene, and polystyrene.

Marks:   None.

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.