Introduction of blow molding process

The blow molding process is also a common production process for plastic products. Like extrusion and injection molding, it has a wide range of applications and can produce a variety of products. Today, let's learn about the process, advantages and disadvantages and application scope of the blow molding process.

I Blow molding process

In blow molding, the molten thermoplastic raw material extruded from the extruder is added into the mold, and then by blowing air into the raw material, the melted raw material expands under the action of the air, and is attached to the wall of the mold cavity, and then cooled, solidified and cooled. into the desired product shape.

The blow molding process can be divided into film blow molding and hollow blow molding.

Film blowing: Extrude the molten plastic into a cylindrical thin tube from the annular gap of the die of the extruder head, while blowing compressed air into the inner cavity of the thin tube from the central hole of the die to inflate the thin tube to a diameter Larger tubular film, coiled after cooling.

Hollow blow molding: The secondary molding technology of blowing the rubber-like parison closed in the mold cavity into a hollow product with the help of gas pressure is a method of producing hollow plastic products. According to the different manufacturing methods of the parison, hollow blow molding includes extrusion blow molding, injection blow molding, and stretch blow molding.

II the advantages of blow molding

The wall thickness of the blow-molded product is uniform, the waste generated is few corners, and the weight difference is small, so it is more suitable for mass production of small blow-molded products, and also suitable for the production of large-capacity blow-molded barrels.

III the application of blow molding

Film blow molding is mainly used to make plastic thin molds; hollow blow molding is mainly used to make hollow plastic products bottles, packaging barrels, watering cans, fuel tanks, cans, toys, etc.