Mesh adjustment fabric printing screen production note

1. Frame:

The most ideal net frame is made of aluminum alloy material, which is refined, smooth, and not warped.

2, screen:

Polyester mesh is better because of its stable strength. The mesh should be thick and fine, if it is too thin, the tension is poor, and the tension is not tight; if it is too thick, the mesh is small, and the opening rate is not enough, which will affect the ink permeability. Plain weave monofilament mesh, uniform warp and weft yarns, uniform mesh size. Colored wire mesh is better than white, and colored wire mesh can prevent random reflection.

3, stretch net:

The conditional stretcher can be used to stretch the net and measured with a tensiometer to ensure that the four plates have the same tension.

Manual stretching can also be used to achieve the required requirements. However, it is necessary to adopt a pull-over and adhesive-bonding method and use a manual pull-grip chuck to pull out a vertical and uniform tension screen. Regardless of the method used, it cannot be stretched very tightly at one time. It is necessary to adopt an incremental stretching method so that the screen has a certain extension process to ensure the stability of its tension.

4, the photosensitive adhesive requirements:

To choose high quality water resistant diazo sensitized plastic, gelatin, vinyl chloride, ternary nylon and other photosensitive adhesives are not suitable for making color tone screen printing plate. General color block printing plate uses domestic sensitized plastic, exposure time is about 4 ~ 8min, while the tone screen printing plate is exposed to ultraviolet light, time is 15 ~ 20s, with 40W10 fluorescent tubes, exposure time is only 50 ~ 70s, the photosensitivity of poor photosensitivity, adhesion is not strong in this short time simply can not be cross-linked curing, not degumming, that is not easy to develop or outlets are not fully.

The use of water resistant diazo photoresist has the following features:

(1) The glue liquid is milky white fish: it is light yellow croaker after adding photosensitizer, it is lavender after exposure, and its transparency is high. It is easy to align or adjust when printing;

(2) Delicate resin: Adhesion with the screen is very strong, generally coated, only need to be positive and negative once, it can be repeated without coating;

(3) High photosensitivity: The latitude of exposure time is large. It is immersed in water for 3 to 5 minutes with iodine lamp, easy to develop, and the dots are smooth and clear. After the second exposure, the printing rate will increase.

5, exposure, development:

The exposure table should be installed with the corresponding positioning card of the ink pad, set a good position, does not allow errors. During exposure, the positive film of the positive color separation film faces the surface of the sensitized film of the film, and it is pressed tightly to ensure that the photosensitive film and the negative film adhere to the exposure glass without any slight gap.

The exposure time depends on the sensitivity of the photoresist and the light source. Generally, the UV exposure is controlled within 15 to 20 seconds. With 40W10 fluorescent tube exposure control in 50 ~ 60s, magenta, yellow, cyan control in 70 ~ 75s.

Soak in fresh water for 3 to 5 minutes, then wipe with a sponge or spray with water. After the second exposure, the photosensitive adhesive is further cross-linked and cured to increase the resistance to printing.

Experience has shown that the yellow version of the screen angle is 90 °, prone to moiré, but this does not affect the printing effect, because the yellow version is a light color, first printing, after the last three editions of superimposition, the moiré natural elimination.