Supercalender

Supercalender 

a machine for finishing paper—that is, increasing its surface smoothness, giving it luster and stiffness, and embossing it.

A supercalender consists of six to 12 metal and paper rolls, between which the paper web is threaded. The metal rolls are made of polished cast iron. The paper rolls are made by compressing paper disks stacked onto a steel core at pressures up to 45 meganewtons per sq m, or 450 kilograms-force per sq cm, after which the rolls are finished by turning and polishing. The Shore hardness of paper rolls used to calender printing papers is 36–40; the linear pressures produced in the finishing process are 100–350 kilograms-force per sq cm. The paper web travels through a supercalender at speeds of up to 900 m/min. Idler rolls, which reduce the tension on the paper in the calendering section, are used to prevent the paper from tearing in the machine.

Supercalenders are used primarily to finish printing and writing papers.

REFERENCE

Eidlin, I. Ia. Bumagodelatel’nye i otdelochnye mashiny, 3rd. ed. Moscow, 1970.

G. A. IVANOV