Surface printing principle and adhesion enhancemen

The surface printing principle of PP and other materials and the enhancement of adhesion

high nickel circuit has high requirements for material purity, oxygen content, humidity, cleanliness and so on. Generally, injection PP, POM and other polymers are printed by plate. Plate printing is the same as silk printing, and the principle is also similar, that is, the basic principle of using silk printing plate, that is, the holes in the image and text parts are permeable to ink, and the holes in the non image and text parts are impermeable to ink. When printing, pour the ink into one end of the screen printing plate at a speed of 0.5mm/min, apply a certain pressure on the ink part of the screen printing plate with a 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 are easy to operate, their adhesion, 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, which are mostly primary products of packaging materials. The method is to use ultraviolet light to increase the molecular weight of the low molecular layer on the surface of the broken plastic 8) sample in the presence of photosensitizer, so as to improve the surface tension of the solid. 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

specific treatment methods also need specific analysis of specific problems