What is the reason for the pinhole phenomenon in the silk screen printing process of the Automotive Wiring Harness Protection Sleeve?

Silk screen printing is a link that often needs to be touched when printing LOGO or pattern characters on the protective cover of the automobile wiring harness. The silk screen printing area is relatively small, and once pinholes appear, it will be very obvious. For those in the Automotive Wiring Harness Protection Sleeve industry, when the screen printing of the Automotive Wiring Harness Protection Sleeve has defective pinholes, if the quality inspector fails to find the improvement in time, they will put it in the oven to bake, which means that batches of finished products will be scrapped. But even if it is discovered by the quality inspector during this period, rework in batches will also increase the cost of silk screen printing. Therefore, for screen printing operators, self-inspection must be done at all times, and quality inspectors must conduct spot checks at any time to find various defects in time and improve them.

1. The unevenness of the surface of the Automotive Wiring Harness Protection Sleeve
The quality of the Automotive Wiring Harness Protection Sleeve is not well controlled during the molding process, resulting in tiny pinholes on the surface of the Automotive Wiring Harness Protection Sleeve, especially in white, translucent or transparent colors, it is difficult to find pinholes. For the pinhole problem on the car harness protective cover, if the position of the pinhole is just at the silk screen character, then the position of the pit cannot absorb the silk screen ink, forming a hollow area, which is the silk screen pinhole. In response to this problem, first observe whether the pinholes on the surface of the car harness protective cover are serious. If it is a slight one, you only need to polish it with fine sandpaper to print it. If the pinholes on the surface of the car harness protective cover are serious, it can only be scrapped. deal with!
2. The screen printing screen is not cleaned
During the silk screen printing process, the screen is not cleaned and screened directly. Part of the ink is adsorbed on the mesh and solidified to block the mesh. A position blank forms a pinhole. It is troublesome to solve this situation. Use a cloth strip dipped in a little ink thinner to slowly wipe the mesh until the blockage is cleaned up. In the process of cleaning the screen, it should be gentle and not too violent, otherwise it is easy to wipe off the photosensitive adhesive other than the characters, and the whole screen printing screen will be scrapped!
3. The working environment is not clean or the surface of the Automotive Wiring Harness Protection Sleeve is dirty
The screen printing environment is not clean or the surface of the Automotive Wiring Harness Protection Sleeve is dirty, causing debris to be adsorbed at the position of the screen printing characters and causing pinholes. In this case, you only need to clean the surface of the screen or the car harness protective cover.