Screen Printing Printing

General injection molding PP, POM and other polymers are screen printing. Screen printing is the same as screen printing, and the principle is similar. That is, the basic principles of screen printing are used to penetrate the ink, and the non-graphical part of the mesh does not penetrate the basic principles of ink printing. During printing, ink is poured onto one end of the screen printing plate, and a certain pressure is applied to the ink portion of the screen printing plate by the squeegee blade while moving toward the other end of the screen plate. The ink is pushed by the squeegee from the aperture of the graphic portion onto the substrate during the movement.

Indeed, in practical applications, although phenolic, alkyd, and other types of inks or coatings are easy to handle, their adhesion, hardness, and abrasion resistance are difficult to meet. The letter in your letter does not indicate what type of ink the polymer uses. So I can only recommend that you use acrylic inks, nitros, urethanes, or epoxy resins, etc. The type of ink or paint will have a very high adhesion.

PP and POM are non-polar molecular structures with high crystallinity and low surface tension. They do not have polar groups such as carbonyl groups, carboxyl groups, and hydroxyl groups in their molecular structures, and are therefore more suitable for networks. Edition printing. However, for polyolefin materials, in order to ensure the adhesion of the ink film, the plastic surface must be processed.

In general, there are two methods currently popular: One method is to increase the surface tension of plastic solids. The method is to use ultraviolet light to increase the molecular weight of the low molecular layer of the plastic surface and increase the tension of the solid surface in the presence of a photosensitizer. . Another method is to oxidize the polyolefin plastic surface molecules to generate polar groups such as carboxyl, hydroxyl, and carbonyl groups on the surface to increase the critical surface tension of the plastic surface and improve the adhesion of inks and coatings to plastic surfaces. Performance, can be used flame, chromic acid mixture, discharge oxidation, ozone oxidation and other treatment methods.

This step is very necessary and it cannot be canceled theoretically. The use of PP to treat water treatment processes is too complex and alternative methods can be considered for replacement, but this step of surface treatment is very necessary.