Principle of hollow blow mold for hollow blow molding machine

2019-04-30 17:02:24

The tubular plastic parison obtained by extrusion or injection molding of thermoplastic resin is heated (or heated to a softened state), placed in a split mold, and compressed air is introduced into the parison immediately after closing the mold to blow the plastic parison It is inflated and adhered to the inner wall of the mold, and is cooled and released to obtain various hollow products. The manufacturing process of the blown film is very similar in principle to the blow molding of hollow products, but it does not use a mold. From the perspective of classification of plastic processing technology, the molding process of blown film is usually included in the extrusion. The blow molding process of the blow molding machine began to produce low density polyethylene vials 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. Hollow containers can be up to several thousand liters in volume, and some have been computer controlled. Suitable plastics for blow molding include polyethylene, polyvinyl chloride, polypropylene, polyester, etc., and the resulting hollow containers are widely used as industrial packaging containers.

The hollow blow molding machine is a comprehensive hollow plastic hollow blow molding machine that combines the injection plasticizing mechanism of the injection molding machine with the blow molding and clamping mechanism of the hollow blow molding machine, and absorbs and exerts the respective advantages of the two machines.

The parison weight is high in repeatability, high in plasticizing ability, short in color change and refueling time, and high in strength of the fusion zone. Extrusion blown large hollow plastic hollow blow molding machine generally adopts the storage type machine head, the internal structure is complex, and there are many parts. Therefore, from the characteristics of the storage type machine head, there is inevitably long time for color change and refueling, and the measurement accuracy is not allowed. Disadvantages. The machine head of the large-volume hollow plastic blow molding machine separates the two functions of the storage material and the injection-extruded embryo in the squeezing blow molding machine of the hollow plastic hollow blow molding machine, and is completed by the injection plasticizing mechanism. In this way, the handpiece has the advantage that the continuous handpiece is easy to change color and refuel.