Process Encyclopaedia
Blow moulding
Overview |
Process Details |
Materials and Shapes |
Economics |
Typical Products |
Links |
Overview
Blow moulding is most commonly a batch process used to produce simple drinks bottles. Clever design of the blank allows the screw top and base of bottles to be thicker than the walls.
Process details
Materials and shapes
- Used for simple, thin-walled, hollow products - mainly bottles
- Used with thermoplastics, mainly PET.
- Good, smooth surface finish can be readily achieved.
- Depending on how the hollow blank (parison) is made, scrap can be negligible.
- There is a variant which is continuous and used to produce thin-walled tubes which can be slit to make cling-film or plastic bags.
Economics
- The production speed is limited by opening and closing the mould, so automation is normally used.
- Production rates from a few hundred to a few thousand per hour can be achieved.
- The tooling and machines are moderately expensive (£10,000 - £100,000).
- Moulds may need to be replaced after about 100,000 uses.
- Only used for high volume products with batch sizes of 100,000+.
Typical products
Bottles and containers up to 0.5 litre