Injection Molded Plastic

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Injection Molded Plastic

• By Dan Quates
• Material science 3344

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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.

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Thermoplastics used in Injection Molding

• Polyethylene
• Polypropylene
• Polystyrene
• Poly(vinyl chloride)

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Polyethylene

• Polyethylene is used for everything
• Grocery bags
• Bottles
• Its structure is -CH2-CH2-
• Not good for high heat applications

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Polypropylene

• Polypropylene is not as versatile
• Can be used as a plastic or fiber
• Its used mostly for applications like outdoor
  carpet
• Also used for dishes

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Polystyrene

• Polystyrene is a vinyl polymer
• It has a phenyl group every other carbon atom
• In plastic form its used for computer shells
• In foam form its commonly used for packing boxes

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Poly(vinyl chloride)

• Pvc is used for plumbing in homes
• Can withstand fire and water
• The chlorine atoms will inhibit combustion

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References

• Callister, Material Science and Engineering, 6th
  edition
• School of Polymers and High Performance
  Materials, The University of Southern
  Mississippi URL http//www.psrc.usm.edu/index.ht
  ml AA/EOE/ADAI