Calendering process

 


Calendering, process of smoothing and compressing a material (notably paper) during production by passing a single continuous sheet through a number of pairs of heated rolls. The rolls in combination are called calenders. Calender rolls are constructed of steel with a hardened surface, or steel covered with fibre; in paper production, they typically exert a pressure of 500 pounds per linear inch (89 kilograms per centimetre). Coated papers are calendered to provide a smooth, glossy finish.

Calendering is also widely used in the manufacture of textile fabrics, coated fabrics, and plastic sheeting to provide the desired surface finish and ...

the processing of materials (fabric, paper, orrubber) on a calender. In the production of paper, calenderingis done on machine calenders installed at the end of the dryingsection of a paper machine or on separate supercalenders. Paper processed on a supercalender is called calendered or glossy pa-per; paper that has been passed through a machine calender andhas a lower gloss is called machine-finished paper. The smooth-ness produced by calendering depends on the type of rollers (itis greater with the combined use of cast-iron and paper rollers), their temperature (smoothness increases under heating), the pa-per composition and moisture content (paper with greater kaolin content calenders better), and the pressure between the calenderrollers. In the production of rubber, calendering is used for manufacturing sheet rubber in various thicknesses, for plasticiz-ing and heating rubber stock, and for rubberizing fabric. Intextile manufacturing, calendering is used for packing cotton, linen, and jute fabrics, adding luster to them, and applying em-bossed patterns.