Constituted of a number of fixed superimposed rollers, one of which can be adjusted in order to change the characteristics of the paper through changes in the level of compression. This process makes the paper perfectly flat and optimises the surface quality, allowing very high-quality printing. The two sides of the compressed paper are smooth and highly reflective, with the optimum quality being attained with super- calendered paper. Compressing paper reduces its porosity. This process is carried out in order to improve the aspect and the impermeability of the paper, as well as to improve the reflection of light on the inks.
Coating is applied in order to improve printing on the paper.
The coating, carried out in the paper machine, is generally applied on non-finished or rubbed paper. Its presence is harmful to the production process and needs to be eliminated. This process is only carried out when the end-product needs it, such as for printing and writing paper, for magazines, for cellulose wool, and for certain types of packaging. De-inking consists of separating the ink particles mechanically and through the use of soap to create bubbles. While fixing themselves on particles of ink, these bubbles float up to the surface of the vat and are then recovered.