The document discusses structural foam molding and sandwich molding processes used for producing parts by injecting materials like metals and polymers. It highlights the design and performance benefits such as reduced weight, lower costs, and increased strength, while also outlining applications like tool boxes and electronic housings. Additionally, it describes the properties of skin and core materials involved in sandwich molding and various methods employed in these processes.

1. STRUCTURAL FOAM
MOLDING
AND
SANDWICH MOLDING

2. INJECTION MOLDING
To produce the parts by injecting a
material.
Performed with metals, ,
thermoplastic and thermosetting
polymer.

3. STRUCTURAL FOAM MOLDING
low pressure injection molding
 inert gas into the melted polymer
Reduces density and weight
Increases strength

4. Materials used
Thermoplastic material:
•Polycarbonate
•ABS
•Polyphenylene oxide-PPO
•Polybutylene terephthalate

5. Design Benefits
 Reduced part weight
Thick sections up to 5 inches
Lower cost tooling
Chemical and corrosion resistance

6. Performance Benefits
Increased strength to weight ratio
Chemical and corrosive resistance
Improved acoustical and electrical
insulation characteristics
Can be recycled and reused.

7. APPLICATIONS
•Tool boxes
•Trash cans
•Commercial laundry bins
•Pallets
•Replace wood,concrete,metals,fiberglass

10. SANDWICH MOULDING
Two or more polymers are injected one
after another through the same gate in
one or more cavities.
Core and skin material different or
same.
Also called as co-injection molding

11. PROCESS
INJECTION 1-FORM THE
SKIN MATERIAL
INJECTION 2- FORM THE
CORE
INJECTON 3-TO SEAL THE
GATE AND FINISH THE PART

13. PROPERTIES OF SKIN MATERIAL
Will be thin
Surface structure of the material.
Transparent material
Paintable surface
E.g.: glass, thermoplastics,
thermosets , sheet material , plywood

14. PROPERTIES OF CORE MATERIAL
Thick but will be lightweight.
Low density material
High bending stiffness.
Recycled material.
E.g. :PVC, polyethylene ,polystyrene ,
metal foams.

15. APPLICATIONS
• Door handles in car
industry(strengthening)
• Electronic housings
• Decks in ships
• In aerospace, making doors in airplane
• Antennas

16. METHODS:
Autoclave molding
Adhesive bonding
Liquid molding
Continuous lamination
Compression molding