Steps for screen printing in plastic parts
The printing accuracy required for screen printing signs is relatively high. Generally, advanced indirect, direct, and direct three photosensitivity methods are used.
1. Prepare the frame and photosensitive film: Clean the frame (Nylon wire with 220-260 mesh) with 10% aqueous sodium phosphate to remove oil stains. Wire mesh film is a kind of sensitizing glue with polyenol glue as the main body. The film is coated with gelatin as the main sensitizer on 0.12-0.06 mm transparent plastic film base. Millimeters, use a cloth to wipe the powder dirt on the film clean.
2. Exposure: Press the film and the bottom plate in the printing machine and expose them with a carbon lamp or a xenon lamp. The distance between the frame and the light source is 50-60 cm and the exposure time is 2-6 minutes.
3. Development: After exposure, place the film of the film on the plate, infiltrate the film with warm water for 1-2 minutes, spray with a water jet, and use water to go to the non-photosensitive part (graphic part) and print the film until it is developed. Clear graphics.
4. film: The exposure of the film surface of the film is attached to the screen, the label produced in the back of the film with a rubber board or other straight, gently scraping paste, so that the film and mesh contact firmly, immediately placed in the oven, at the temperature Baking for 8-12 minutes under the condition of 55±2 degrees, after drying, the mesh frame is fixed on the plate for test printing.
5. Stripping method: In the exposure, development process, found that the version is unqualified, immediately with warm water can be re-filmed film produced. If the plate is dry or it is removed after production for a period of time, use one part of industrial sodium hypochlorite and water and soak for 10-20 minutes. Or 5% sodium hydroxide aqueous solution heat treatment screen, you can remove the film.