V. Analysis of failures such as knife threads or string inks in printing
Knife, string ink and other phenomena often appear in the printing process. This phenomenon is also a comprehensive factor.
Ink mixed with dust, paper debris, dust and other debris accumulated under the scraper, high-speed printing can easily scratch the printing roller to produce ink, knife wire phenomenon.
The scraper has a fine knife edge, so that the scraping of the ink is not clean will produce a knife wire.
Because the printing plate is electrically engraved on the copper plated surface of the plate roller, and later it is used for the abrasion resistance and corrosion resistance of the enhanced platen printing, a layer of chromium is plated, and the chromium plating is generally 800 HV to 1000 HV. After the chrome plating process, the company has introduced a world-class MDC automatic polishing machine, which can automatically set more than 100 individual parameters, which can fully meet the different requirements of customers for polishing.
The above describes the plate-making polishing process. If the polishing process is poor during the plate making, or the surface of the chromium layer is rough, it may also cause the knife threading phenomenon. Another if the depth of the roller is too deep, the hardness at the corners of the pattern is very high, and it is easy to grind the blade and produce a knife wire.
The quality of the ink is not qualified, and the particles are too thick. It is very easy to form ink sticks under the scraper when printing, which results in the knife wire and ink stringing.