Manual screen printing workflow

1, check the printing plate

Check the situation of the sealer of the printing plate, whether the plate has broken eyes, whether there is looseness between the plate and the bottom plate, whether the network spacing is proper, whether the printing rules are positioned correctly, and whether the multi-color printing has the phenomenon of no printing.

2, the choice of scraper

The length of the scraper should be slightly longer than the printed graphics. Different types of scrapers should be used for different substrates. The squeegee should have a certain degree of flexibility so as to improve the contact performance between the screen and the substrate and make the ink uniform. Squeegee is required to be smooth. If uneven sandpaper is used for flattening, scraper material can be made of 5mm acid resistant rubber.

3, printing material preparation

The preparation of printing materials should be based on the printed material and printing requirements to determine the type and composition, the key is to adjust the color, adjust the dryness, adjust the viscosity, and strive to adapt to the requirements of scraping. The printing material should be adjusted well before it is stored for one day to make its performance stable, except for adjusting the gold color. You should also check the presence of foreign matter in the print material to prevent it from being scratched.

4, cast printing material

The printing material generally falls in the initial position of the screen frame and the width of the doctor blade. The printing material in the frame cannot be placed too much and is added at any time to facilitate the control of the ink amount during the squeegee printing operation.

5, squeegee

1 The hand-held printing material is placed on a ruled platen, and the screen frame is put down, leaving a certain distance between the printing plate and the platen.

2 Hand-held squeegee presses against the wire mesh. When the squeegee blows, it should maintain an angle of 50-60°. The squeegee moves the squeegee at a certain speed so that the squeegee presses the printing material from the stencil hole of the stencil section. Leakage is printed on the substrate, and the screen rebounds after the scraping blade is separated from the substrate. Depending on the size of the printing area and the length of the squeegee, one-handed or two-handed squeegeeing operations may be adopted, but to control the amount of printing material, the printing plate layout must be scraped cleanly, and no printing material can remain on the graphic plate of the printing plate.

3 Raise the frame and remove the sheet from the platen.

6, scrub screen

During the printing process, when it is found that the imprint is blurry and the mesh is blocked, the printing plate must be scrubbed, and the positive and negative sides of the screen plate should be lightly rubbed with a degreasing cotton wool or a soft cloth, and the image and text should be scrubbed and then scrubbed elsewhere. The front and back sides of the printing plate must be cleaned and cleaned. The plugging mesh should be dredged and the solvent on the printing plate should be blotted out. The plate should also be cleaned after printing.

7, color printing

When used in color stencil printing, it is necessary to distinguish the ink levels. In general, the color should be printed first and the dark color should be printed first. After printing, the main printing should be performed first, and the printing should be arranged when printing the printing plate. The color version must be overprinted accurately, especially the first color version should be printed very accurately. In the case of a mixed-color squeegee, the mixed-color trajectory should be changed to change the form of the plate to facilitate squeegee printing.

8. Drying after printing

Drying should be done after each printing, but the drying in the middle of the two colors only requires that the next lane of printing does not contaminate the upper traces, and the final drying should also consider that the outer ink layer is dry enough to ensure the fastness of the ink layer. Some substrates are susceptible to expansion and shrinkage due to climate change. If overprinting is not timely, long periods of storage may cause overprinting. This should be noticed when drying.