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The difference between blow mold and plastic injection mold

update:29-04-2021
abstract:

Injection molding and blow molding are two processing t […]

Injection molding and blow molding are two processing techniques for mold products, but their processing techniques are different and each has its own characteristics. Simply put, the injection mold uses the "injection + pressure" mode, and the blow mold uses the "injection + blow" mode, and the injection molding is a solid core body, while the blow molding is a hollow core body. In addition, the mold made by the injection molding process has a gate section, and the mold made by the blow molding process has an uneven surface with a blow port.

The following editor will take you to understand in detail what is an injection mold and what is a blow mold? What is the difference between the two?

1. Injection mold

Injection molding is thermoplastic injection molding. This method is to melt the plastic material and then inject it into the film cavity. Once the molten plastic enters the mold, it will be cold-formed and processed into the desired shape. The shape is often the final product appearance, no other processing is needed. In addition, the injection molding process can well control the details, such as protrusions, ribs, threads and other parts can be formed in one step in injection molding.

2. Blow mold

Blow molding, also called hollow blow molding, is a rapidly developing plastic processing method. Its processing principle is as follows. Place the thermoplastic resin in the heated and softened state or the tubular plastic parison obtained by injection molding in the mold, and then inject compressed air after the mold is closed to inflate the plastic parison and adhere to the inner wall of the mold , Then after cooling and demoulding, finally get the desired hollow product.

It is worth mentioning that the manufacturing process of blown film is very similar in principle to blow molding of hollow products, but its production does not use molds, which is completely different from processing injection molds in this regard. From the perspective of plastic processing technology classification, the molding process of blown film is usually included in the extrusion process. According to the production method of the parison, blow molding can be divided into extrusion blow molding and injection blow molding. The newly developed ones include multilayer blow molding and stretch blow molding.