Processing and production method of plastic bottle cap

Processing and production method of plastic bottle cap

    Plastic bottles have certain processing and production methods. The processing methods mainly include extrusion, injection molding, calendering, blow molding, compression molding, lamination, casting, etc. The plastic bottle is processed through blow molding, that is, the plastic is heated and melted and then pressed into a special blow mold. At the same time, there is high pressure inside the air to press the plastic onto the mold to form the final product shape. When it is exposed to external pressure, the internal stress of the bottle itself is inward. After the heating temperature reaches a certain level, the plastic will soften, and the resistance to internal stress will become smaller, so the bottle will become smaller.

   Plastic bottles have certain processing characteristics in processing and production, and are processed in a certain way to favor processing methods to ensure good quality and performance in production and processing. The following describes the processing characteristics of plastic bottles in different aspects:

Shrinkage

   The shrinkage of reinforced plastics is smaller than that of ordinary compression plastics. It is mainly composed of heat shrinkage and chemical structure shrinkage. The factors that affect shrinkage are primarily plastics. Generally, phenolic is larger than epoxy, epoxy phenolic, and unsaturated polyester, among which unsaturated polyester has the smallest shrinkage. Other factors that affect shrinkage are the shape and thickness of the plastic part. Thicker walls shrink more. Plastics containing fillers and glass fibers have a smaller shrinkage. Large volatiles content causes a larger shrinkage. The molding pressure is higher and the loading capacity is larger. Small shrinkage, hot mold release shrinkage is greater than cold mold release, insufficient curing shrinkage is large. The shrinkage rate of plastic bottles is one of the important factors affecting the use of plastic bottles. In use, the shrinkage rate of plastic bottles must be reduced to prevent important shrinkage phenomena in use and affect the actual use effect.

fluidity

   The fluidity of the reinforcing material is worse than that of ordinary compression molding materials. When the fluidity is too large, it is easy to cause resin loss and accumulation of glass fibers. If it is too small, the molding pressure and temperature will increase significantly. There are many factors affecting fluidity. To evaluate the fluidity of a certain material, specific analysis must be made according to the composition. Factors affecting liquidity.