This document discusses different types of blow molding processes used to make hollow plastic parts. It describes injection blow molding, stretch blow molding, and extrusion blow molding. Injection blow molding uses preforms made via injection molding and is used for small, high-volume products. Stretch blow molding also uses preforms but stretches them using a core rod and is used for bottles and jars. Extrusion blow molding extrudes a hollow plastic tube called a parison then air is pumped in to shape it in a mold, used for containers. The document outlines design considerations, advantages, disadvantages, applications, and examples of blow molding processes and products.

1. Prepared by :
1)Muhammad Amir Bin Awang Jaafar
2)Siti Zulaikha Bt Mohd Rosli
3)Nor Ajuar Bt Abdullah
4)Nani Shajieha Bt Zawawi
Prepared for :
Encik Muhd Syahrir Bin Ahmad

2. INTRODUCTION
 Blow molding is a process used in making
hollow plastic part.
 The first two people who are known to have
used the blow molding process ; Enoch
Ferngren and William Kopitke. In 1938, they
produced a blow molding machine, which
they then sold to the Hartford Empire
Company, kicking off the commercial use
of blow molding.
 There are three main types of blow
molding: injection blow molding, stretch
blow molding, and extrusion blow molding.

3. INJECTION BLOW MOULDING
 This process is used for making
glass and plastic products, such as
single serving bottles and small
medical devices, in high volume.

4. STRECHING BLOW MOULDING
 This process begins with a preform
being made as done in the injection
method. The preforms are then
heated up, usually with infrared
heaters. Then it is blown with high
pressure air using metal blow molds.
The preform is stretched using a core
rod. This process is generally used
when making bottles, jars, and other
containers.

5. EXTRUSION BLOW MOULDING
 This process sees plastic melted and
extruded into a hollow tube called a
parison. The parison is then enclosed in
a cooled metal mold. Air is then pumped
into the parison, causing it to take the
desired shape. After a cooling period,
the part can then be ejected from the
mold.
 This process is used for making things
like milk and dairy containers, shampoo
bottles, and hollow industrial pieces.

6. CONT..
 Extrusion blow molding :
1) In continuous extrusion blow
molding, the parison is continuously
extruded, with individual parts being
cut out
2) Intermittent extrusion blow molding,
a machine injects melted plastic into
the parison part by part.

7. DESIGN CONSIDERATION
 Wall thickness should be as uniform as possible to
facilitate rapid moulding cycle time, conserve material
and avoid uneven moulding cooldown resulting in
distortion.
 Where the end is a bottle , and the neck portion must
have thicker wall than adjoining body, the body wall
thickness should not exceed 2:1 ration.
 The draft angle should be perpendicular to the mould
tool open direction.
 This wall allow easy removal of the moulded part.
 Sharp corner should be avoided , design wall features
with radii transitions. The larger the radii the better.

8. ADVANTAGES OF BLOW
MOULDING
 Complex hollow elastomeric parts can moulded.
 Flash free
 Core less
 With sequential material construction.
 With multiple layers of like materials.
 With integrated components.
 In sizes that ranges from very small to very large.
 No time needed for core ejection.
 Rapid cooling.
 Low parts weight due to thin walls.
 Less expensive mould.
 Reduced assembly cost.
 Good dimensional precision.
 Minor product weight variation.
 Minimal trimming operations.

9. DISADVANTAGES OF BLOW
MOULDING.
 Environmental disadvantages
effecting.
 Process and material limitation.
 Inability to produce bottles with
calibrated neck finishes.
 Machines typically dedicated to a
narrow range of sizes.
 Trimming required.

10. APPLICATION AND EXAMPLE
OF BLOW MOULDING
 Pharmaceutical Bottles

11. Cont..
 Polypropylene Bottle.

12. Cont..
 Toys

13. EXAMPLE OF DESIGN.

14. Cont..

15. Cont..

16. PROCESS OF BLOW
MOULDING
 INJECTION BLOW MOULDING

17. Cont..
 STRECHING BLOW MOULDING

18. Cont..
 EXTRUSION BLOW MOULDING

19. CONCLUSION
 Blow moulding is a manufacturing
process for production of hollow-form
plastic products. Process of blow
moulding have the effects on bottle
weight, bottle dimensions and machine
output. Specifically, high screw speed, low
melt temperature, and short vent time
results in the increasing of bottle weight
and thickness. High screw speed, high
melt temperature, large die swell and thin
bottle thickness lead to high shear rate.

20. THE END…
QUESTION AND
ANSWER
SESSION.