Process comparison
Extrusion blow moulding is the largest type of blow moulding method. It is also an earlier type of blow moulding method. It is suitable for blow moulding of PE, PP, PVC, PETG, thermoplastic engineering plastics, thermoplastic elastomers and other polymers and blends. It is mainly used to produce packaging containers, storage tanks and other industrial products.
The extrusion blow-moulding process starts with the extruder extruding the tubular embryo, and the material is extruded from the die after melting and plasticizing in the extruder; then, when the embryo reaches a predetermined length, a section of the tube embryo is intercepted and placed in the blow-moulding die while it is heated, and the die is closed and clamped at the same time; after that, the blown embryo blows the compressed air into the embryo through the blower nozzle, and blows the embryo into the mold. The precise shape of the forming cavity; finally, the product is removed by opening the mould.
Injection blow moulding is a blow moulding method which combines injection moulding with blow moulding. The bottom embryo was produced by injection moulding, and then transferred to blow moulds for blow moulding. Injection blow moulding begins with the production embryo, which is formed by injecting melt into the injection moulds with blow-core tubes, and then transferred to the blow moulds at blow-moulding stations through mechanical devices for blowing. Then the blow-moulds are closed and the compressed air is transferred from the mandrel stomata to the inner of the embryos, which are closely connected with the blow-moulding cavity under the action of air pressure. After cooling, the product is transferred to the demoulding station. Finally, the product is demoulded. At the demoulding station, the product is ejected from the mandrel or sent directly to the packaging station, and then it is produced in the next cycle process.