In screen printing, the ink passes through the screen printing plate under a certain pressure by a moving squeegee, and is transferred to the substrate to form graphics. Therefore, various indicators of the scratch plate affect the printing effect. Due to the variety of substrate materials and the different conditions, they can be roughly divided into two types: plane and curved surfaces (including spherical surfaces). Therefore, the following factors should be considered when selecting a squeegee according to different substrates and the shape of the surface of the substrate. 

① Squeegee hardness The amount of ink transfer and the reproducibility of graphics and text are related to the hardness of the squeegee. Generally, when printing on hard printed matter, a soft squeegee can be used, so that the pressure applied during squeegee printing can make the The layout and the substrate are in full contact to improve the printing effect. On the contrary, when printing soft substrates, a hard squeegee should be used to make good contact between the layout and the substrate. The reason for the two is the same. Due to the wide variety of substrates and the different textures of the substrates, a harder squeegee is generally used for smoother substrates. On the contrary, a softer squeegee will be more ideal for printing. The squeegee will bend to a certain extent due to a certain pressure applied to it during scraping. Therefore, when using the squeegee, the bending fatigue and mechanical strength of the squeegee should be considered, and the squeegee should be required to have a certain elasticity. While scraping, the scraper will generate heat due to friction, and the hardness will change after the temperature rises. When selecting scraper materials, attention should be paid to selecting materials that are not easily deformed by heat. Generally, the hardness of scraper materials should be selected at Shore hardness 60. to 90 degrees as well.

②The abrasion resistance of the squeegee Because the squeegee is in direct contact with the screen printing plate, there is friction every time it is scratched (the number of prints in screen printing can reach tens of thousands). Therefore, the scraper is required to have good wear resistance, lubricity and certain mechanical strength, so that friction can be minimized when scraping to ensure the service life of the scraper.

③The solvent resistance of the scraper The scraper should be in contact with various inks and solvents during use, such as ethanol, gasoline, etc. The affinity of various rubber materials to solvents is also different. The scraper changes to varying degrees after contacting ink or solvent. It is common that the hardness of the scraper changes, and the volume expands and deforms after contacting the solvent. If the squeegee expands, the edge accuracy of the squeegee will be reduced, and the ink leakage will be uneven during printing, which will affect the printing quality. It is generally believed that rubber with high hardness has a large cross-linking density, and it is difficult for the molecules of ink and solvent to penetrate into the molecules of the rubber, so the expansion coefficient is small. When choosing a squeegee, it can be considered that on the premise of meeting the printing requirements as much as possible, in order to minimize the deformation, a rubber squeegee with higher hardness can be selected.