substances. The adhesion of dust and oil on the surface of the Screen Printing Mesh will totally affect the combination of the Screen Printing Mesh and the photosensitive glue, resulting in the quality of the screen printing plate. In order to ensure that the screen is tightly bonded to the photoresist, the screen is treated before the photoresist is applied. Screen pretreatment is an important process for making screen plates. There are two methods: physical treatment and chemical treatment.
Physical treatment: The purpose of this method is to polarize the surface of the screen to facilitate the bonding of the screen to the photoresist.
This method uses a pumice stone and a silicone carbide to be ground into a powder and mechanically treated the surface of the screen. The screen is treated with a silicone carbide powder having a powder particle size of 20 microns or less. After the treatment, the screen is washed with water and dried, then used for plate making.
Chemical treatment: Usually, phenol, cresol and phosphoric acid etchants are used before the plate making, and the surface of the synthetic fiber Mesh is treated to make the surface of the wire Mesh rough and achieve the purpose of tightly bonding with the photosensitive glue. However, phenol and cresol are used. And phosphoric acid etchants tend to damage the wire Mesh, so take care when performing chemical processing.
In addition to the polarization treatment of the surface of the screen, the screen can be degreased and cleaned with caustic soda, cleaning agent, etc. This method can effectively remove the oil stains, dust and other substances on the screen surface, so that the screen and the photosensitive glue Strong bonding. After washing with the above solvent, it should be rinsed with water. After drying, it can be used for plate making.
