In terms of ink:
1. Improper selection of ink, ink should be replaced;
2. The ink dries too fast, choose slow-drying ink;
3. Ink viscosity is too high, choose low viscosity ink. Either the ink is poorly blended, or the normally blended ink is mixed into the ink skin. During printing, due to the effect of the solvent, it swells and softens, blocking the mesh that should be permeable to the ink, which acts as a plate film and prevents the ink from passing through. In order to prevent this kind of malfunction, the mixed ink (especially the old ink) should be filtered once with a net before use. When reusing a used printing plate, the old ink attached to the frame must be completely removed. When storing the printing plate after printing, wash it sufficiently (including the scraper). If the above requirements are followed, the uneven ink will not happen.
If the tip of the front end of the sharp board is damaged, there will be traces along the movement direction of the scraper. Especially when printing transparent objects, there will be obvious uneven ink. Therefore, the front end of the sharp board must be well protected to prevent damage. If it is damaged, it must be carefully polished with a grinder.
The unevenness of the printing table will also affect the uniformity of the ink. The convex ink layer is thin, and the concave ink layer is thick. This phenomenon is also called uneven inking. In addition, if there is dust on the back of the substrate or on the printing table, the above-mentioned failures may also occur. Another reason is that the screen printing plate of the screen printing machine is clogged, and the screen printing should be cleaned; the printing pressure of the screen printing machine is insufficient, and the printing pressure should be increased; the substrate is not processed well before the printing, and the substrate pre-processing should be strengthened.
