To achieve the purpose of screen printing, the choice of printing mesh is not determined by a single factor, we need to consider comprehensively. In general, the following four factors need to be considered.
1, the resolution of the image:the resolution of thin wire diameter and high mesh is high; the resolution of coarse wire diameter and low mesh is low.
However, it is not true that the higher mesh the better. Too high mesh will result in insufficient ink output in screen printing and incomplete or damaged prints. At the same time, under the same number of meshes, attention should be paid to the influence of the wire diameter.
The width or dot diameter of the finest lines that can be reproduced by the two sizes of wire mesh is: L>2d+w, d is the wire diameter, and W is the open Hole width, when d>W, the area of the open area of the screen is small and will affect the fluidity of the ink then cause the thread or mesh saw-tooth or imprinted, damaged.
In general, printing mesh with larger openings can reproduce higher resolution. Therefore, the following points should be noted when selecting a screen mesh:
A. The larger the value of mesh/wire diameter, the better
B. The smaller the contact area between the printing surface and the substrate, the better
C. In order to meet the resolution requirements, the wire diameter and opening width of the wire mesh must meet certain requirements.
D. To meet the printing requirements, the relationship between wire diameter and ultimate tension must be considered
2,Ink layer thickness and coverage rate: if the ink thickness and good coverage rate is required, thick and large mesh should be selected (HD class)
3, according to the surface of the substrate to choose the screen material: curved or undulating surface should use a good elastic nylon mesh, strong absorption of the surface should select a large amount of ink screen; smooth surface should use high tension wire mesh ,rough surface use low mesh screen; insulation surface should use electrostatic screen
4, ink performance requirements: According to the ink's performance to choose the right printing mesh.