There are several reasons for bubbles in pepper balls:During the manufacturing process of the pepper ball mold, the gas in the mold cavity can't be exhausted due to the tight joint between the upper mold and the lower mold, and it is trapped in the middle of the pepper ball to form bubbles. The improvement method is to start with the mold, exhaust the mold well, and basically solve the problem of bubbles in the middle of the pepper ball caused by poor exhaust of the mold.There are bubbles in the middle of the pepper ball caused by the injection molding machine, and the injection speed is adjusted too fast. When injection molding, the plastic material quickly rushes into the cavity, and the air in the cavity cannot be quickly discharged outside the mold, forming trapped air, resulting in bubbles in the middle of the pepper ball.The vacuum bubble generated in the middle of the pepper ball is also a kind of bubble. The main reason for the vacuum bubble is that the temperature is too high during injection molding, and the plastic decomposes at high temperature in the injection molding machine. The decomposition process will also produce certain gas, which will be injected into the pepper ball cavity with the rubber compound to produce bubbles. The solution to this vacuum bubble is also very simple, that is, the problem of plastic ball vacuum bubble can be completely solved by lowering the temperature of the injection molding machine and preventing the material from decomposing in the injection molding machine.The bubbles produced by pepper balls depend on the water content of the materials, and the water absorption rate of various plastic materials is different. If the plastic raw materials are not fully dried and injected directly, this water will be injected into the cavity of the plastic ball mold together with the melted material to form bubbles. The solution is to fully dry the plastic raw materials before injection.