The selection of the number of mesh for screen printing is based on the following factors
1. The ink used.
① general water-based ink for coarse screen printing mesh
(120-180 mesh / inch) (inch is the unit of length 1inch = 1000mil = 2.54cm = 25.4mm).
② solvent ink in the printing of advertising, electrical appliances, etc., the use of medium mesh screen printing mesh
③UV ink uses high mesh printing mesh (305-510 mesh/inch).
④ general ink pigment particles are relatively fine, the ink through the good, this ink can also be very good when using high mesh low through; and high pigment concentration of ink, despite the fine particles, but its permeability will be poorer.
2. Types of substrates.
① surface rough absorbent substrate, to achieve the best ink coverage rate, need more ink, and therefore the use of coarse printing mesh.
② smooth surface of non-absorbent substrates needs relatively less ink, so use a higher mesh screen.
3. Match the screen mesh with the original image.
Select a screen mesh sufficient for the image on the film, that is, to ensure that the finest image area has sufficient polyester screen yarn support. (A certain number of mesh screens can print out the finest line width is equal to the sum of the mesh aperture and screen diameter plus the polyester yarn weaving expansion of about 7%.