Screen pulling steps: screen frame cleaning -- level checking -- coating adhesive layer -- screen pulling -- tension measurement -- coating adhesive -- off screen, edge sealing -- storage

Job description:

1. Due to the repeated use of the mesh frame, the residual viscose, gauze and other sundries around the mesh frame must be removed, so as not to affect the adhesion between the mesh and the mesh frame.

2. Place the mesh frame on the platform (horizontal) to check whether the mesh frame is deformed. If it is deformed, it shall be leveled.

3. Clean and evenly apply a layer of glue without hardener on the joint surface between the undeformed screen frame and the screen yarn to enhance the adhesion between the screen yarn and the screen frame after the screen is pulled.

4. After the first gluing for about 10 minutes, place the screen frame on the screen pulling table, and adjust the relative position and height

5. Select the mesh, loosen the clamping mouth around, lay the mesh flat on the frame, and then clip the mesh evenly into the clamping mouth without wrinkles. Note that there should be loose mesh at the four corners, the clamping mouth must be locked, and there should be no gap between the clamp and the clamp (for example, automatic frame lifting and manual mesh pulling).

6. Mesh tension: 26 for the first time, 24 for 5 minutes; The second tension is 28, and the tension is 26 after standing for 5 minutes; The tension is 32 for the third time and 30 for 5 minutes; For the fourth time, the tension of 5 points shall be corrected to 32, and the gluing tension shall be 30 after standing for 20 minutes; The lower screen tension is 28 after 15 minutes of glue curing, and the screen plate can be made after standing for 72 hours (one meter × One meter automatic production line uses screen plate as an example). Longitudinal and transverse synchronous pulling, brush glue when pulling to the required tension. The tension of common mesh yarn is (30 ± 2N for 100T, 110T and 120T) (35 ± 2N for 77T and 51T) (50 ± 2N for 24T)

7. Evenly brush the adjusted glue over the joint surface of the screen frame and the screen yarn with a small brush. Do not drop the glue into the middle of the screen plate. After the glue is dried for 8 minutes, the scraper glue can be used to press and paste the incomplete joint on the gluing surface for about 10 minutes. After the glue is completely dried (the open air dryer should be used to strengthen the drying), it can be removed from the screen.

8. Use a paper cutter to remove the excess screen yarn around the screen, and indicate the date, mesh and tension when lowering the screen (to observe the tension change) on the screen frame. In order to prevent the penetration of screen washing water (white water), seal the inner corner of the screen frame with red glue, and then seal it with waterproof tape above the interface between the screen frame and the screen yarn to prevent the penetration of liquid medicine.

2、 Bask in a net

1. Washing the screen: remove the grease (new screen) with the grinding paste, remove the graphics (old screen) with the ghost paste, remove the screen slurry and blue oil with the desizing powder, wash the debris with white water, wash the screen with the detergent, and finally wash it with a high-pressure water gun, and finally clean it with pure water.  

2. Drying: -- The set temperature of the oven should be less than 48 ℃.

3. The method of using the film: clean the net and then clean it with pure water once. Select the water film according to the project film patching pattern by about 20%, press one end of the water film with a triangle ruler on the net, and then slowly scrape it up with a triangle ruler, then gently press it with a rubber spatula, and wipe the excess water with a towel to dry.

4. Use photosensitive glue (screen paste): dry the screen plate and then apply photosensitive glue. Use a scraper box to scrape the screen onto the net. The screen printing green oil needs to be starched three times, (about once every 10 minutes or more) and other anti-corrosion inks for screen printing need to be starched twice. The screen printing strippable glue (blue glue) is first applied with 50 micron water film to tear off the film, then applied with screen paste twice, scraped three times each time, and dried after starching.

5. Selection of screen yarn: generally, the line includes screen printing of character ink, 120T, 100T, 110T screen yarn for corrosion resistant ink (green oil, base oil, surface oil), 51T carbon paste (carbon oil), and 77T screen printing photosensitive line for strippable ink (blue glue) 24T screen printing and heat curing ink.

6. Film selection: 18K water film is used for the line (it is easy to get uneven on the net without photosensitive adhesive, such as burrs (dog teeth)), photosensitive adhesive (screen paste) is used for other anti-corrosive inks (green oil, base oil, surface oil), and 50 micron water film is used for carbon paste (carbon oil)

7. Paste the required engineering graphics film on the selected position of the screen, and place it on the light blaster for light blasting. The time is selected (3000W spotlight). The circuit is generally 60-80 seconds, the green oil is 80-100 seconds, the bottom character oil is 40-60 seconds, the carbon oil and blue glue are 350-400 seconds

8. Flush the screen with pressurized water and dry it.

9. After the screen board is made, use the screen sealing glue (blue oil) to scrape the screen sealing glue on the screen where the screen is not covered by film or photosensitive glue, and then dry it.

10. Check and repair the screen, write the completion date and corresponding numbers, and record and store them.

3、 Storage

The screen frame can be self-made or purchased. It should be stored in the same environment as the screen printing environment to prevent deformation. At the same time, the tension of the screen should be tested before screen printing, and the graphics can be inspected with a photographic negative.

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