1.Check the smoothness of the copper mesh. If the smoothness does not meet the requirements, then the use of copper mesh printing in the SMT printer will cause hole blocking.
2.Try to increase the pressure of the scraper. If not, try using a steel scraper. The steel scraper is easy to scratch the copper mesh, so try to use a rubber scraper. Whether it is a "steel scraper" or a "plastic scraper", it must be able to "scrape clean" the surface of the copper mesh, which is a prerequisite.
3.Add support at the bottom of the printed PCB board, slow down the printing speed, and adjust the pressure. It is also recommended that if conditions permit, the copper mesh should be cut into strips instead of round holes.