Due to the reasons such as the denseness of the screen, the brand of the photosensitive adhesive, and the light source, the exposure time will be inconsistent. This requires time to accumulate experience.
Here, we recommend a test method:
1. Prepare a stencil with good sensitized adhesive, and prepare a negative (there is preferably a large pattern and a thin line above). Stick the left end of the negative and the stencil with transparent tape (avoiding the negative and the screen) The position of the move)
2. Use a piece of red paper (red or black waxed paper, or red film - thin and light-blocking) between the film and the screen, covering the right three-fourths of the pattern, left One-fourth is exposed and after five minutes of exposure in the usual way, turn off the power
3. Move the red paper to the right by a quarter, that is, half of the film is covered and one half is exposed. After normal exposure for five minutes, turn off the power supply. ... and so on. Exposure four times. The four sections from left to right on the screen were exposed for 20 minutes, 15 minutes, 10 minutes, and 5 minutes, respectively.
4. Use the usual method to clean the screen, carefully observe which part of the effect is good, which time is used.
note:
1, you can also choose to move red paper from right to left
2, you can also choose to exposure for 1 second, 180 seconds, 300 seconds ... ...