Shortly after the introduction of the multi-colour printing presses, monochrome printing units were also introduced, which over the years have found their way into a wide range of applications, such as wallcovering printing, hard floor production, technical paints, artificial leather production, and last but not least: as a single color printing presses.
Screen coating equipment (Fig. 23.1) consists of the following parts:
• Screens are seamless, perforated nickel sleeves. The degree of perforation is indicated by the so-called mesh number, which indicates the number of holes per linear inch.
• Scrapers, installed in the screen, serve as supply and distribution pipes for the slurry. Scraper blades mounted on this pipe push the paste out of the screen walls.
• Whisper blade smoothes applied coatings.
The amount of paint used is determined by four factors:
• Choice of mesh
• Squeegee pressure: the angle formed between the scraper and the screen (the smaller the angle, the higher the added value.)
• Viscosity of slurry
• Regarding the drawdown blade setting of the counter pressure roller
Figure 23.1 Screen coater. 1: Network; 2: Scraper; 3: Screen; 4: Whisper Blade; 5: Scraper.
