How Does Blowmoulding Work?

Blowmoulding moulding involves the processing of plastic pellets through a heated screw and barrel to heat the plastic to a molten state. The screw and barrel is similar to an auger arrangement where the material is pushed forward while the screw is rotating.

The molten material exits through the end of the screw and barrel via a diehead, which shapes the plastic into a cylindrical tube shape, which is called a parison.
When the parison is long enough, a mould with two separate halves is moved into position and closed around the parison. A knife then cuts the parison, and the mould is moved out of the way, to allow the parison to continue extruding for the next machine cycle.

A blowpin then enters the neck or opening in the mould, a blows the parison to the shape of the mould with compressed air, and the plastic is allowed to cool against the mould surface. While the plastic product is formed and allowed to cool, the next parison is processed through the screw and barrel, ready for the next cycle to begin.The tool then opens, and ejects the finished moulding.

The total cycle time taken to manufacture a plastic product from blowmoulding will depend on several different factors such as wall thickness of the plastic, and overall size of the component being moulded.

Items that are produced from blowmoulding can vary in size from small cosmetic containers up to large drums and tanks, and moulded parts range from consumer goods, food and beverage storage, automotive, and industrial uses.


Post time: 01-22-2017