Difference Between Pad Printing Ink And Silk Screen Ink: Different printing processes have different requirements for inks. Appropriate supplementary ingredients must be added to the inks to make them easier to use in specific situations. For example, offset printing inks have high viscosity and good water resistance, and gravure printing inks are relatively thin, good fluidity; screen printing ink must have good permeability.
In terms of the suitability of substrates, screen printing has great advantages. Especially in the non-formal plastic hardware electronics and direct consumer goods industries, screen printing has gained widespread praise. However, there is no universal printing method in the world, and screen printing is no exception. In the field of industrial printing with small areas and irregular substrate surfaces, screen printing has encountered real troubles, and this trouble gave birth to the birth of pad printing technology. It can be said that although pad printing technology and screen printing are quite different, they involve extremely similar industrial fields.
The earliest pad printing ink was replaced by silk screen ink, and practice has proved that there is nothing absolutely unsuitable. However, there must be differences in the suitability of inks used in different printing environments. For example, pad printing ink, users do not require it to have the permeability of screen printing ink, but they will require it to have better thixotropy and surface drying to ensure that the transfer process from steel plate to plastic head and substrate is more accurate. Using dedicated pad printing ink will undoubtedly make it easier to improve printing quality.
It is worth noting that screen printing inks and pad printing inks are completely universal, but additives need to be added to change the printability. So when there is no special pad printing ink, you can use silk screen ink instead.
There are many printing materials for silk screen and pad printing, and it is impossible to replace it with one ink. In order to fully adapt to the market, ink manufacturers must produce a variety of inks.
We can simply divide the printing materials into the following types:
1. PP and PE, in the plastics family, PP and PE are two materials with a very large amount. First of all, they have good physical properties and good chemical resistance. Most solvents can't help them, so they are widely used in coatings, cosmetics, plastic films, and electrical products. But this is also the reason why they are difficult to print because their constituent molecules are non-polar molecules. At present, the printing of these two materials generally adopts pre-press processing methods, and the more common methods are flame processing and high frequency processing.
Combined with pre-press treatment, there are many types of inks that can be used on the surface of PP and PE. What we are discussing here are solvent inks. For UV inks, pre-press processing is also necessary. There is no UV ink that is free of processing. It should be said that in the current printing technology field, it is difficult to achieve stable quality control for printing on PP and PE materials.
2. Some polar materials such as ABS, PC, PVC, PS, AS are easy to print. Most of these materials can be printed without pre-press processing, and this part of the ink is the strength of all manufacturers.
3. Substrates such as glass, metal, ceramics, etc., do not have any absorption properties on the surface. Inks made according to conventional methods are difficult to work. In most cases, two-component inks are used.