In the paper-making industry, on-line and off-line paper stock can be finished with a variety of pigment coatings.
The quality grades of the rubber on coater and coater backing rollers must be absolutely homogeneous. The surface must be free from impurities and be processed to a highly smooth finish.
Some application systems use a double roller process. The coater roller draws the pigment and transfers it to the paper. The paper is guided by the coater backing roller. In this case, the coater roller is normally harder than the coater backing roller.
More modern, faster application system normally use only one roller. The pigment is sprayed or applied by a sump between the paper and roller and a blade. When application is very rapid, a curtain coating system must be used.
In principal, a resilient coating roller cover must have excellent mechanical properties. It must be sufficiently “resilient” to avoid any negative impact on the blade control system. It must be resistant to abrasion and cutting to avoid chafing and cutting paper edges (causing microgrooves on the roller surface). And most importantly, it must have good “sheet release”.
Our quality grades:
- LÜRA 2503 green (90 Shore A / approx. 10 P&J) for double roller process as coater roller.
- LÜRA 2506 brown (70 Shore A / approx. 70 P&J) for double roller process as coater backing roller with excellent mechanical properties and good sheet release.
- LÜRA 2506 black (70 Shore A / approx. 70 P&J) for standard coats.
- LÜRA 2560/3 grey (70 Shore A / approx. 70 P&J) specially developed for high-speed systems, with excellent mechanical properties and extreme sheet release effect. Tears are minimised by a specially developed surface.