According to production technology, it can be divided into injection molded caps and compression molded caps; The production process of injection molding caps is as follows: the suction machine sucks the mixed material into the barrel of the injection molding machine, heats it inside the barrel to melt and plasticize, injects it into the mold cavity, cools and shapes it in the cavity, demoulds it, and then completes the production of injection molding caps through ring cutting and padding. The production process of compression molding cover is as follows: the suction machine sucks the mixed material into the barrel of the compression molding machine, heats it to a semi molten and plasticized state inside the barrel, quantitatively extrudes it into the mold cavity, closes the upper and lower molds, compresses and cools the molding, demoulds it, and then completes the production of compression molding cover through ring cutting and padding. Comparison: ⑴. Injection molded caps require the material to be heated to a molten flow state at a temperature of around 250 ℃; Pressure molding only requires heating to around 180 ℃, and the energy consumption of injection molding caps is higher than that of pressure molding caps; ⑵ The compression molding processing temperature is relatively low, the shrinkage is small, and the size of the cover is more accurate; ⑶ Inject all the mold cavities at once, and extrude one bottle cap material each time through compression molding. The extrusion pressure of compression molding is very small, while the pressure required for injection molding is relatively high The injection mold has a large volume, making it difficult to replace a single mold cavity; Each cavity of the compression molding is relatively independent and can be replaced separately The pressure molding capping machine is a specialized machine for bottle caps, with a demolding design specifically designed for bottle caps; Bottle cap injection molding machines are not specifically designed for bottle caps, so the pressure molded cap can be made into a bell mouth, with a high cap hanging rate, which users like to use.