1. Paper manufacture and calendering

Most papers and boards are calendered. The main purpose of calendering is to improve the paper's appearance and printability by modifying its surface finish. However, calenders can also be used to regulate the profiles (thickness, humidity...) of the paper sheet in the cross direction.

There are different types of calender depending on the nature of the rolls, the number of nips (the area where the web is pinched between two calender rolls is often called a "nip" in papermaking parlance) and the positioning in the papermaking line (in-line, following the paper machine or coater, or off-line). The type of calender is determined by the type of paper being manufactured. The calendering parameters (pressure, speed, temperature, paper humidity) are then adapted to obtain the properties required for its use (see