The plastic box for Tool Set is mostly made from Blow Molding.
The tubular plastic parison obtained by extrusion or injection molding of thermoplastic resin is placed in the split mold while it is hot (or heated to a softened state). After the mold is closed, the compressed air is immediately introduced into the parison to make the plastic parison inflate and cling to the inner wall of the mold. After cooling and demoulding, various hollow products are obtained. The manufacturing process of blown film is very similar to that of hollow products in principle, but it does not use molds. From the perspective of classification of plastic processing technology, the molding process of blown film is usually included in extrusion. Blow molding process was used to produce low-density polyethylene bottles during the Second World War. In the late 1950s, with the birth of high-density polyethylene and the development of blow molding machines, blow molding technology was widely used. The volume of hollow containers can reach thousands of liters, and some production has been controlled by computers. The plastics suitable for blow molding include polyethylene, polyvinyl chloride, polypropylene, polyester, etc. the resulting hollow containers are widely used as industrial packaging containers.