1. Injection Molded Plastic

2. Injection Molding
 Injection Molding is the most
widely used technique for
fabricating thermoplastic
materials because it can
mass produce parts for
relatively low costs.
 Melted plastic is pressurized
and forced into a
prefabricated mold. There, it
is allowed to cool and will
take the shape of the mold as
it solidifies.

3. Thermoplastics used in
Injection Molding
 Polyethylene
 Polypropylene
 Polystyrene
 Poly(vinyl chloride)

4. Polyethylene
Polyethylene is used for everything
– Grocery bags
– Bottles
It’s structure is [-CH2-CH2-]
Not good for high heat applications

5. Polypropylene
 Polypropylene is not as versatile
 Can be used as a plastic or fiber
 It’s used mostly for applications like outdoor
carpet
 Also used for dishes

6. Polystyrene
 Polystyrene is a vinyl polymer
 It has a phenyl group every other carbon atom
 In plastic form it’s used for computer shells
 In foam form it’s commonly used for packing
boxes

7. Poly(vinyl chloride)
 Pvc is used for plumbing in homes
 Can withstand fire and water
 The chlorine atoms will inhibit combustion