1. The problem of the material, the rubber material has moisture in the process of mixing, storage, and use, and the moisture is not removed, resulting in bubbles or damp due to weather changes.
Most of the reasons may be problems with the raw materials. We have had similar situations before, so just change to another batch of materials;

2. Improper setting or blockage of mold vent holes will also produce bubbles, which are not properly drained when venting.
When the raw material is mixed, the air is entrapped inside the material, causing the material and air to enter the mold together during the processing. If the mold is not equipped with an exhaust groove or there is no exhaust process in the processing, the air is easily trapped Inside the mold, the product produces bubbles or pores.

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