How does the electrostatic induction of the open type rotary screen printer causes it?
From an atomic point of view: all neutral materials, such as conductors and insulators such as plastics and paper, that is, atoms with a positive charge in each molecular structure merge with nearby negatively charged electron clouds when the material touches under friction After separation, the electronic device in the insulating layer material will mineral acid to the surface layer of the material. For example, middle school physics learns to rub a glass rod with satin. Static electricity is generated on the glass rod to attract the shredded paper. The surface layer of materials with reduced electronic devices is positive, and the surface layer of materials with unnecessary electronic devices added to electronic devices is negatively charged. If materials reduced for electronic devices make up negative charges and materials made with electronic devices make up positive charges, then The positive and negative charges of the two types of materials are in balance, and the two types of materials are neutralized.
In optical disk printing, in short, ink printing is a whole process of migrating printing ink to a printing process of the scraping working pressure based on the relative movement of the screen and the squeegee. The screen (metal screen) and the squeegee (polyurethane squeegee) are both conductors and insulators. In the screen printing, they scrape relative to each other on the part and rub against each other, especially when they are dried at low temperatures. The spread of positive charge to the surface of the printing process. Very insulating layer materials, such as the PC substrate for optical discs, the Pet plastic sheet on the touch switch, its name, the PVC used for identification and labeling, the PP and PE of plastic bottles, these are mainly conductors and insulators, in open type If you don't pay attention to static induction in the actual operation of a rotary screen printer, it will happen. For example, when designing printing inks for the decoration of silk-screen film keys, because the Pet base is behind the producer, the surface layer is affixed with a layer of PVC or another self-adhesive label film to protect its surface layer, so that it can be protected from scratches during cutting and packaging. But after cutting the material, the protective film should be removed before the screen printing. Some actual operating personnel peels off the protective film very quickly. If you don’t know, you have been peeling the film quickly. The protective film and the Pet film are fast. During the whole separation process, especially when the surface of the Pet sheet is dried under low temperature, the electrostatic induction is caused. As a result, the printing ink on the edge of the handwriting on the silkscreen has flying hairs, and the pile-like textured ink filaments are sunk on the fully transparent Pet plastic plate. Product quality problems have caused considerable doubts in the screen printing workshop of the membrane button company.
In the printing of ink, it is difficult to produce due to electrostatic induction, and the specific performance in the printing of ink is as follows:
1. After screen printing, the screen is printed, and the printing ink on the scratches is fluffy with the screen, and the problem of the "flying hair" like ink thread can be broken after the product workpiece is taken out.
2. When printing, the front and back colors of the printing ink and the edges of the pattern conflict with each other, which cannot be well matched, so that the printing ink cannot be printed in the middle of the two-color grinding.
3. In screen printing, the product workpiece sticks to the screen, especially at the screen position where the scraper moves to the end station
4. Printing process materials stick together
5. During the entire process of scraping, the printing ink is difficult to scrape on the screen, and the cake sticks together
6. The printing process material absorbs dust, and after the screen printing, it produces damage, black spots, and uneven surface.