1. Material problems. There is moisture during the mixing, storage, and use of rubber materials. Moisture has not been eliminated, resulting in air bubbles or dampness due to weather changes.
Most of the reasons may be that there is a problem with the raw materials. We have experienced similar situations before, and it is good to change another batch of materials;

2. The mold vent hole is improperly set up or blocked, which will generate air bubbles.
The raw materials are in the rubber compound, and the air is wrapped inside the material, which causes the material and air to enter the mold together during the processing. If the mold is not equipped with an exhaust groove or the exhaust process is not set during processing, the air is easily trapped. Inside the mold, make the product produce bubbles or pores.

3, the production of rubber products, there are bubbles after vulcanization, may be a problem in the rubber formula, you can find technical people to adjust the formula.