Screen printing mesh selectionIn the process of screen printing, plate making is the key link, the first step in screen making process is the choice of screen printing mesh, which is related to the pros and cons of the screen and production efficiency. The following is
In the process of screen printing, plate making is the key link, the first step in screen making process is the choice of screen printing mesh, which is related to the pros and cons of the screen and production efficiency. The following is to share the screen printing mesh selection matters.
1. screen printing mesh mesh count guide selection:
Need to consider the following three factors used in the ink:
①General water-based ink is suitable for thicker screen mesh(125-180 mesh/inch)(inch is the length unit 1inch = 1000mil = 2.54cm = 25.4mm); ②Solvent ink in advertising, electrical appliances, etc printing, choose middle mesh count screen mesh (196-420 mesh/inch); ③UV ink needs to choose high mesh count screen mesh(355-457 mesh/inch); ④pigment particles of general inks are relatively fine, good ink through ability, this type ink even using high mesh screen can also be very good pass through, but the ink with high concentration, though it has fine particles, its permeability still relatively poor.
The type of substrate:
Rough surface of the absorbent substrate, to achieve the best ink coverage rate, needs more ink quantity, so needs to use the thicker screen mesh, ② smooth surface of non-absorbable substrates, the amount of ink needed is relatively small, so choose to use the higher mesh count screen mesh.
Screen printing mesh mesh count matches the original image guide:
Choose a mesh count sufficient for the image on the plate to ensure adequate screen support for the thinnest image area. (A certain mesh screen can print the smallest line width equal to the sum of aperture and wire diameter together with the 7% of the expansion when screen weaving. Such as 180 mesh/inch screen printing mesh, mesh aperture: 23μm，wire diameter: 30μm, the print smallest line width=23+30+（23+30）×7%≈57μm. it shows that the 180 mesh/inch screen printing mesh can only print the lines of 57 microns. There is also a formula is screen printing mesh can print the roughness of the smallest point (or line)
2. Screen printing mesh wire diameter selection: must consider two aspects, ①tensile strength of the screen printing mesh ② elaborate degree of the original image.
When has same mesh count, the larger the wire diameter, the tensile strength, abrasion resistance, corrosion resistance are stronger, the greater the thickness, the opening area (aperture ratio) the smaller. When the origin size of the original image is 2 times the wire diameter, branches may fall on the screen, the dot loss of high light area is heavy. When the origin size of the original image is 3 times the wire diameter, any part of the mesh screen can get enough support, shadow mesh screen can also get enough openings area.
3. Use screen printing mesh should pay attention to following questions:
Uneven weaving; uneven screen mesh thickness; cost of choosing the screen printing mesh; pay attention to the moire; In halftone screen, screen printing cloth will also affect the level of moire.