PMMA hardened plate, with a surface hardness of 4H, is a plastic material that is easy to deform and absorb water. When the humidity in the air reaches 80% and the temperature is above 23 ° C, the PMMA water absorption rate is 0.3% in 24 hours, which causes the expansion and changes of PMMA common in production. Therefore, the storage environment of PMMA hardened plates and PMMA lenses should be controlled at 18- The humidity is controlled between 26 ° C and 40-55%.

From March to September in the south, when the humidity in the air is generally greater than 80% and the temperature is higher than 23 ° C, customers are advised to pay attention to the following points:

  1. Pre-bake the PMMA hardened board before silk screen printing. The recommended baking temperature is 45 ° C and the baking time is 15-20 minutes. Its role is to absorb the moisture of PMMA hardened board to dry it out, in order to prevent the ink from growing or shrinking during the screen printing process.

  2. It is recommended to reduce the temperature of the last screen printing ink from 60 ° C to 55 ° C in order to reduce the deformation of the PMMA hardened plate.

3. After the PMMA hardened board is finished with silk screen baking, the board is prone to warp. Jianyi users replace the original protective film of PMMA hardened board as soon as possible after the silk screen is baked, and then cover the screen with a 15C cutting film and flatten it with a heavy object. After standing for 6-10 hours, the PMMA hardened plate will become flat.

4. Due to the high temperature and high humidity, the PMMA hardened board will expand, and the maximum expansion is 8C-15C. Users are advised to cut the product with a negative tolerance of about 8C to prevent it from failing to fit due to the oversized product.