Pilot Coater Study of Typical Single and Double Coating Practices, 1993 Coating Conference Proceedings

Standard practice for manufacturing high quality coated papers has developed along two paths. These are single coated papers over a basestock incorporating a pigmented precoat, and double coated over a starch sized basestock.

Economic factors, such as raw materials cost, production losses, labor requirements and capital costs, as well as quality considerations such as brightness, smoothness and printability dictated which path individual paper producers have followed.

In order to compare these two paths on an economic and quality basis we designed a program to produce paper by single and double coating techniques using base paper from a single source. The coating was done on our pilot coater using common formulas and operating procedures.

The raw materials used to produce the sheets are presented to allow independent economic comparison. The quality data for the sheets produced are compared to show differences. The pilot coater and supercalender operating conditions are given to allow comparison with commercial equipment.