Injection moldable thermoplastic materials

The physical properties of injection moldable materials vary from the soft flexibility of gum rubber to the brittleness of glass; temperature resistance varies from complete softening and dissolving in hot water to an ability to withstand a brief exposure to flame.  Costs vary from a few cents to several dollars a pound.

The decision as to which material to use for an application need not be a difficult one since over ninety percent of thermoplastic parts used are made from no more than a dozen basic materials.  Often a part can be successfully made from any one of a number of available materials.  Listed in this section are the most commonly used thermoplastics with a brief description of their most notable characteristics and uses.

• ABS
  ABS - A.B.S. is a copolymer - mixture of acrylic, butadiene, and styrene.
  
  
• Acetal
  Acetal - Parts which must maintain a springiness such as latches and snap catches are usually made of acetal since it strives to retain its molded shape.
  
  
• Acrylic
  Acrylic - This material has good optical clarity.
  
  
• Nylon
  Nylon - As any ardent fisherman will know, nylon is a tough material with a high resistance to abrasion.
  
  
• Phenylene Oxide
  Phenylene Oxide - This is a high-temperature resistant material used for electrical components such as switch holdings and junction boxes.
  
  
• Polycarbonate
  Polycarbonate - This material is extremely tough. Impact resistance is its real asset.
  
  
• Polyester
  Polyester - Polyester is dimensionally stable and has low moisture absorption.
  
  
• Polyethylene
  Polyethylene - Many food containers used in the home are polyethylene.
  
  
• Polypropylene
  Polypropylene - This is the lowest density common plastic.
  
  
• Polysulfone
  Polysulfone - Polysulfone is strong, rigid and has a very high heat-deflection temperature along with excellent electrical properties.
  
  
• Styrene
  Styrene - It has low resistance to chemicals and heat, will solvent bond easily.
  
  
• Urethane
  Urethane - The wear resistance of this material is often many times that of rubber compounds.
  
  
• Vinyl
  Vinyl - Most electrical wire coverings and plugs are made of vinyl.
  
  

Information provided by Morgan Industries Inc., plastic injection molding machines