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Why is it difficult to demould blow molded products?
Blow molding, also known as hollow molding, is a manufacturing process for forming hollow plastic parts: it was initially used to form glass bottles. Generally speaking, there are three main methods of blow molding: extrusion blow molding, injection blow molding, and injection stretch blow molding. The blow molding process begins by melting plastic and forming it into a parison, or in the case of injection and injection stretch blow molding (ISB) preforms). A parison is a tubular plastic piece with a hole in one end through which compressed air can pass. It is a molding method that uses gas pressure to inflate the thermoplastic plastic closed in the mold into a hollow product, and is used to manufacture hollow products.
1 Answers
23-12-22
If the injection pressure is too high, the finished product will be over-saturated, causing the plastic to be pressurized into other gaps, causing the finished product to get stuck in the mold cavity and difficult to demould, and it is easy to cause mucous membrane when taking it out. As for mold problems, if the feed port is unbalanced, the finished product will be prone to sticky film when it is demoulded. At this time, improvements must be made to the mold. When the demoulding resistance caused by the tight hold of the plastic hole plug is too high, it is also effective to suppress molding shrinkage by increasing the holding pressure and mold temperature.
