Reasonable selection of screen
according to the nature of the substrate and the requirements of the selection of suitable screen
Because screen printing has the characteristics of a wide range of substrate, its substrate species, the characteristics of the substrate materials are also different.So in the selection of screen should be based on the substrate material to choose.
When the substrate for textiles, such as cloth, scarf, bag, etc., can choose nylon wire mesh;When printed for postcards, wallpaper, calendar, etc., can choose the thick nylon wire network;When the substrate is glassware, metal container, wood, ceramic, plastic products, toys, you can choose monofilar nylon mesh, thin polyester mesh, stainless steel wire mesh;When the substrate for integrated circuit, semiconductor components, insulation cloth, television components, etc., can be used polyester mesh, stainless steel mesh.This selection can also be said to be based on the different screen has different properties.
Substrate surface roughness, screen selection is not the same.When the substrate surface is rough, the general use of a low mesh screen.Such as leather, canvas, foam thin sheet, wood printing, due to the substrate surface rough, ink absorption is strong, so to use a low mesh, to ensure that enough ink through.Printed matter of different USES, the final printing effect of the requirements are not the same, general quality requirements of printed matter, can use a lower mesh screen;Quality requirements of higher prints, such as line precision to high, to choose a higher mesh screen.
the selection of screen should pay attention to the problem
1. Screen appearance
To choose a good appearance, woven uniform, the same thickness, smooth surface of the screen.If the screen is damaged, such as does not affect the printing, can make the damaged part avoid the part of the text and text.Screen between the wire and wire spacing is not uniform, will cause aperture changes and affect printing ink transfer, ink film thickness will be different.If the screen weaving uneven only appear in the local, use should be as far as possible to avoid this part, do not affect the printing quality.Jumping wire will also affect the quality of printing, refers to the weaving of a silk in the middle of the break, forming a few centimeters of falling off state, if you do not pay attention to it can not be found, this defect will also affect the quality of printing.Silk diameter thickness is not uniform, so that the screen thickness is different, so that printing ink thickness is different, affecting the quality of printing.The surface of the screen should be smooth, especially the polyester monofilament is sprayed by a spinneret.This process produces silk with a fairly smooth and uniform surface.
The two characteristics of silk and screen printing are diameter d and strength.The diameter of the silk determines the thickness of the screen.If the silk is polyester, the screen thickness is 2d or less (about 1.8d).Screen thickness is one of the decisive factors of ink film thickness.The strength of a single wire is determined by its tensile strength and diameter.And the strength of the wire mesh is the strength of the wire mesh and the number of wire mesh unit length.
2. Screen permeability
Select the screen to consider the screen permeability.If the middle tone with high transparency of ink, pigment particles
Fine, ink through good, the use of high mesh screen ink can also be very good through:
General plastic ink through better: special purpose ink, pigment concentration of ink, although fine particles, but its relatively poor through.So according to different ink to choose different mesh screen.
3. Screen cost
Screen selection also needs to consider the cost of the screen, in order to meet the printing requirements, as far as possible to choose a lower price screen.
Selection of screen for plate making, as far as possible from a comprehensive consideration.