Blow molding and injection molding are two kinds of injection mold processing technologies for mold products. Although there is only one word difference between blow molding and injection molding, they are two methods of plastic product molding, and the molding conditions and raw material conditions are also different. So do you know the difference between injection mold processing and blow mold processing?
First, let's introduce the concept of blow molding. Blow molding, also known as hollow blow molding, is a rapidly developing plastic processing method. Tubular plastic parison obtained by extrusion or injection molding of thermoplastic resin is placed in a split mold while the plastic parison is heated to a softened state, compressed air is introduced into the parison immediately after the mold is closed, so that the plastic parison is blown and tightly adhered to the inner wall of the mold, and various hollow products which are desired are obtained after cooling and demoulding.
The manufacturing process of blown film is very similar to blow molding of hollow products in principle, but it does not use a mold, which is completely different from processing injection mold. From the perspective of classification of plastic processing technology, the forming process of blown film is usually included in extrusion. However, according to the parison manufacturing method, blow molding can be divided into extrusion blow molding and injection blow molding, and the newly developed are multi-layer blow molding and stretch blow molding.
The concept of injection mold processing is thermoplastic plastic injection molding. This method is to melt plastic material and inject it into the film cavity. Once molten plastic enters the mold, it is cold-pressed into the desired shape. The resulting shape is often the final product and no further processing is required before installation or use as the final product. Moreover, many details, such as protrusions, ribs and threads, can be formed in one-step injection molding operation in the injection mold processing. The following figure is the processing and forming diagram of the injection mold of the traveling crane recorder.
The above understanding of the concept between the two, in fact, the main difference between the blow mold processing and the injection mold processing is the difference in products. Blow molding is a product formed by using gas, and the products that need injection molding are generally used to make thicker products. Blow molding is different, because the product is thinner and more transparent, and its slight defects are obvious. Therefore, the requirements are relatively high, and blow molding has some requirements on the toughness and stretchability of raw materials. The products for processing the injection mold are thicker, and the requirements are relatively lower, and the requirements for raw materials are also lower.
