The hottest way of screen printing

Printing method

generally, injection molded PP, POM and other polymers are printed in another way. Plate printing is the same as silk printing, and the principle is also similar. The door structure corresponding to the single arm structure is the basic principle of printing by using the silk printing plate, that is, the ink is penetrated into the graphics and text part of the hole, and the ink is not penetrated into the non graphics and text part of the hole. When printing, pour ink into one end of the screen printing plate, apply a certain pressure on the ink part of the screen printing plate with the scraping scraper, and move towards the other end of the screen printing plate at the same time. The ink is squeezed onto the substrate by the scraper from the hole of the image and text part during the movement

indeed, in practical applications, although phenolic, alkyd and other types of inks or coatings will help customers choose the most suitable materials for their projects, and the operation is simple, their adhesion makes them have good compatibility with resins, and their hardness and wear resistance are difficult to meet the requirements. The type of ink used in the polymer is not stated in your letter. So I can only suggest that you use acrylic, nitro, polyurethane or epoxy inks or coatings, which will greatly improve the adhesion

pp and POM are non-polar molecular materials with high crystallinity and low surface tension. There are no polar groups such as carbonyl, carboxyl and hydroxyl in their molecular structures, so they are more suitable for printing. However, for polyolefin materials, in order to ensure the adhesion of ink film, the plastic surface must be treated

generally speaking, there are two popular methods at present: one method is to improve the surface tension of plastic solids. The method is to increase the molecular weight of the low molecular layer on the plastic surface by using ultraviolet light in the presence of photosensitizers, so as to improve the surface tension of solids. Another method is to oxidize the molecules on the surface of polyolefin plastics and generate some polar groups such as carboxyl, hydroxyl and carbonyl groups on the surface, so as to improve the critical surface tension of the plastic surface and the adhesion of ink and paint to the plastic surface. Flame, chromic acid mixture, discharge oxidation, ozone oxidation and other treatment methods can be used

this step is very necessary and cannot be cancelled in theory. As for the PP treatment water treatment process adopted by your company, it is complex, and other methods can be considered to replace it, but the step of surface treatment is very necessary