Bottle is a container that can hold liquid or solid, which can be seen everywhere in our life, including medicine bottle, cosmetics bottle and beverage bottle. Due to the rapid development of the petroleum industry, human beings invented high molecular polymer, which is commonly known as plastics. Since then, our bottle materials have changed from single glass or ceramics to various kinds of plastics. Drawing lessons from the long history of glass container blowing process, the extrusion or injection molding plastic mold in relativistic state is placed in the blowing mold, and the mold is inflated by a certain pressure of compressed air to make it close to the cavity wall. After cooling and setting, the mold is demolished to obtain the plastic hollow products with the same shape as the cavity. This is the hollow blow molding process we are familiar with.
Common blow molding processes include extrusion blow molding, injection blow molding and stretch blow molding. Extrusion blow molding, extruding molten material by extrusion device, placing extrusion embryo in blow molding mold for blowing, demolding and taking out products after cooling and setting; In injection blow molding, the bottom mold is first injected, then transferred to the blow mold to blow, cooled and shaped, and then demoulded to take out the product; Stretch blow molding is to produce the mold embryo by extrusion or injection, put it in the blow mold, stretch it axially with the drawing rod, blow it horizontally, then cool it to shape, and finally demould the product.
In the production of the same product, injection blowing and extrusion blowing have inherent advantages, such as no flash, no waste, accurate size, high production efficiency of three-step method, three working positions working at the same time, no need to wait in neutral position; With the conveyor belt, the testing equipment can directly enter the packaging station, with a high degree of automation. Therefore, a conclusion can be drawn: in the range of packaging bottles, the injection blowing process can improve the production efficiency and reduce the production cost.