All credit goes to the creators, my colleagues.

1. Blow Moulding

2. What is Blow Moulding?
Blow Moulding (Blow Forming) is a manufacturing process by which, hollow plastic
parts are formed.

3. Process Material
Blow moulded parts can be formed from a variety of thermoplastic materials,
such as:
oLow Density Polyethylene (LDPE)
oHigh Density Polyethylene (HDPE)
oPolyethyleneTerephthalate (PET)
oPolypropylene (PP)
oPolyvinylChloride (PVC)

4. Types of Blow Moulding
1. Extrusion Blow Moulding
2. Injection Blow Moulding
3. Stretch Blow Moulding

5. Components in Blow Moulding
Preforms of different shapes

6. Basic Process
• A parison of hot plastic resin, in a tube-like shape, is formed.This is
called a ‘preform’.
• A pressurized gas, usually air, is used to expand the hot preform and
press it against the cavity.The pressure is maintained until the
plastic cools.

7. Process in Detail
• The process begins with melting down the polymer, into a parison.
• The parison is then clamped into a mould and air is pumped in.
• Gas pressure inside pushes the tubular boundary of the parison until
it takes the shape of mould.
• Once the polymer has cooled, mould is opened and part is ejected.

9. Extrusion Blow Moulding
In EBM, plastic is melted and extruded into a hollow tube (a parison).
This parison is then captured by closing it into a cooled metal mold.Air
is then blown into the parison, inflating it into the shape of the hollow
container, or the part.

10. Injection Blow Moulding
• Injection stage
Molten polymer is injected into a heated preform mould.The preform consists
of a fully formed neck with a thick tube of polymer attached.
• Blowing Stage
The preform is passed to the hollow, cooled blow mould. Compressed air is blown
into the preform, inflating it and forcing it against the mould.
• Ejection
The blow-formed polymer is allowed cool, then removed from the mould. Cleaning
and testing are carried out.

11. Stretch Blow Moulding
Preform is first made with injection moulding. In SBM process,
preforms are heated (using IR heaters) and then blown using high
pressure air into various shapes, inside metal moulds.

12. Advantages of Blow Moulding
• Well suited for low or high production rates.
• Mould costs are comparatively low, due to lower pressure.
• Quick product revisions for increased flexibility.
• Tooling is less expensive than other mouldings.
• Price per part is less than that in Rotational Moulding.

13. Disadvantages of Blow Moulding
• Products are not biodegradable most times.
• Process and material limitations.
• Extrusion moulding has longer cooling times than injection
moulding.
• It is not possible to mold in holes, except after the moulding.

14. Blow Moulding Applications
o Milk Bottles
o Pharmaceutical Bottles
o Antifreeze Bottles
o GarbageCans
o Drums
o FuelTanks
o Ice Chests and Coolers

15. Thank you!