Composite manufacturing processes

Hand lay up, pre-preg, pressure molding, vacuum bagging, filament winding, pultusion, spray method, sheet molding, bulk molding and resin transfer molding

1. BY,
SANGEETHA B

2. Composite Manufacturing Processes
Thermoset composites
Short fiber reinforced
Continuous fiber reinforced
Prepreg
resin transfer
Thermoplastic composites
Commingle
Impregnated

3. Composite Manufacturing Processes
Processes:
Hand Lay-up
Pre-preg forming
Pressure molding
Vacuum bagging
Filament winding

4. Composite Manufacturing Processes
Processes:
Pultrusion
Spray method
Sheet molding
Bulk molding
Resin transfer molding

5. Hand lay-up

6. Hand lay-up
Advantages:
low cost tools
versatile: wide range of products
Disadvantages:
time consuming
easy to form air bubbles and disorientation of fibers
inconsistency

7. Prepreg forming
Advantages:
orientation of fibers can be changed
consistent
high productivity
Disadvantages:
continuous process needs more customers
limited shelf life
delamination

8. Pressure molding
Advantages:
wide range of shapes
integrate parts
consistency
structural stability
relatively simple
Disadvantages:
high cost of machine
time consuming to heat up, cool down and curing
expensive molds (strong materials required)
no intricate parts
large volume of products

9. Vacuum bagging
Process

10. Vacuum bagging
Advantages:
simple design
any fiber/matrix combination
ok with cheap mold material
better quality for the cost
Disadvantages:
cannot be heated up too much
breeder clothe has to be replaced frequently
low pressure (760 mm Hg the most)
slowest speed
inconsistency

11. Filament winding

12. Filament winding products
Compressed air tanks
High-pressure CO2 tanks and bottles
Water softener systems
Rescue air tanks
Sail boat masts
Compressed Natural Gas tanks
Defense/Aerospace systems
Lightpoles

13. Filament winding
Advantages:
using existing textile processes.
quick, easy to handle package.
parts can have huge size.
Disadvantages:
spinning speed is limited due to resin penetration
and splashing, traveler speed and yarn breakage.
curing by heat is not easy to apply.
shape of the products limited (only cylindrical
possible).

14. Pultrusion

15. Pultrusion
Advantages:
Automated processes.
High speed.
Versatile cross-sectional shape.
Continuous reinforcement.
Disadvantages:
Die can be easily messed up.
Expensive die.
Mainly thermoset matrix.

16. Spray method

17. Spray method
Advantages:
Continuous process
Any materials can be used as mold.
Error can be corrected by re-spraying.
Disadvantages:
Slow.
inconsistency.
No control of fiber orientation.
Only one side finished.
Environmental unfriendly.

18. Sheet molding

19. Sheet molding
Advantages
High productivity thus inexpensive
consistency
Disadvantages
low volume fraction.
Only board can be made.

20. Bulk molding

21. Bulk molding
Advantages
Highest volume fraction for short fiber reinforced
composites (50%)
Good mechanical properties
Finish can be applied
Inserts and attachments possible
Disadvantages
High temperature and high pressure
Random fiber orientation
Cannot be used for intricate parts
Staple fibers only.

22. Resin transfer molding
http://www.plastech.co.uk/Mtrtm.html

23. Resin transfer molding
Advantages
Components will have good surface finish on both sides
Selective reinforcement and accurate fiber management is achievable
Ability to build-in fiber volume fraction loadings up to 65%
Uniformity of thickness and fiber loading, uniform shrinkage
Inserts may be incorporated into moldings
Tooling costs comparatively low
Uses only low pressure injection
Low volatile emission during processing
Ability to produce near net shape moldings
Process can be automated, resulting in higher production rates
Ability to mould complex structural and hollow shapes
Low resultant voids
Ability to achieve from 0.5mm to 90mm laminate thickness
Disadvantages
waste some material (spill)
curing time long
hard for intricate parts