The Blow Moulding Process
The Blow Moulding Process is simple but an effective way to manufacture thoudsands of Plastic Bottles & Plastic containers for the packaging industry, including producing plastic parts for the industrial and technical industries.
How blow moulding works.
Air is blown into a thin walled plastic cylinder called the parison. The parison is formed by melted plastic material being pushed through an extruder.
When the parison reaches a certain length, the two halves of the mould close around the parison sealing it at the bottom. Compressed air is then used to inflate the parison to form the shape of the cavity inside the mould.
The plastic begins to cool and become firm, the mould opens, and the new container is removed.
Blow Moulding Glossary
Blow Pressure |
The air pressure used to form a hollow part by blow moulding |
Blow Rate |
The speed at which the air enters the parison during the blow moulding cycle |
Cavity |
Depression in a mould that forms the shape of the product to be moulded |
Cross Head |
A channel which changes the direction of the ‘melt’ from a horizontal flow through the extruder, to a vertical flow through an extrusion die to form the parison |
Cycle Time |
The period between a certain point in one cycle and the same point in the next |
Deflashing |
Covers the range of finishing techniques used to remove the flash (excess unwanted material) on a plastics moulding |
Extrusion |
The compacting of plastics material and the forcing of it through an orifice in a continuous manner |
Flash |
Extra plastics attached to a moulding along the parting line. It must be removed before the product is considered finished. |
Flash Line |
A raised line appearing on the surface of a moulding and formed at the junction of the mould faces |
Lip |
The outer edge of the top of a container, intended to facilitate pouring |
Mould Seam |
A vertical line formed at the point of contact of the mould halves |
Parison |
The hollow plastics tube from which the product is blow moulded |
Recycle |
Ground materials from flash and trimmings which, after mixing with a certain amount of virgin material, are fed back into the blow moulding machine |