Screen Printing Failures and Countermeasures - Inking and Printing

Fourth, ink uneven

Ink film thickness is uneven due to a variety of reasons. In terms of ink, the ink is poorly formulated, or the normally formulated ink is mixed with ink. When printing, the ink expands and softens due to the effect of the solvent. Mesh hole is blocked, play the role of the plate, so that the ink can not pass.

In order to prevent such failures, the formulated ink (especially the old ink) should be screen-filtered before use. When you reuse a used plate, you must completely remove the old ink that has adhered to the plate. When the plates are stored after printing, they must be fully washed (including scrapers). If this is done as described above, accidents with ink unevenness will not happen.

If the tip of the squeegee is damaged, there will be a trace along the direction of movement of the squeegee. In particular, when printing transparent materials, there will be significant ink inconsistencies. Therefore, the front end of the squeegee must be well protected so that no damage occurs, and if it is damaged, it is necessary to grind it with a grinder.

The unevenness of the printing table also affects the uniform ink. The convex ink layer is thin, and the recessed ink layer is thick. This phenomenon is also called ink inhomogeneity. In addition, if the back surface of the substrate or the printing table adheres with dust, the above failure may occur.