Contents
Thermosetting Plastics
The plastic which are hardened by the heating is called as thermosetting plastics. This type of heating reaction is non-reversible.
The molecules of thermosetting plastics have a very strong binding force. The raw material of thermosetting plastics is available in liquid or solid form. These types of thermosetting plastics consume more time for polymerization.
Phenol formaldehyde
It is also called as bakelite. It is obtained by the reaction of phenol with formaldehyde. It is generally dark in color and has high strength, stability, and rigidity. It is easy to handle while casting. It is mainly used for making plugs, knobs, pulleys, bottle caps, tooling, etc.
Polyster resin
Polyster resin has low moisture and has very good electrical resistance. It is available in variety of colors. It is generally used to manufacture paper mat, TV parts and car bodies. Main drawback of this plastic is high cost.
Melamines
It has very good electrical and heat resistance. This melamines has good stability and low moisture absorption. Melamines are also called as melmac, melantine and plaskon. It is widely used moulded parts. It is generally used for making telephone sets, circuit breakers, switch panels and lighting fixtures.
Phenol furfural
It has good flowability at low moulding temperatures and sets quickly at correct temperatures. The phenol furfural has good resistance to moisture and electricity. Generally used for manufacturing brake linings, electrical parts and instrument cabinets.
Epoxy resins
The popular variety of epoxy resin is araldite. It has very good electrical and chemical resistance. It is generally available in the form of liquid. It has good resistance to wear and impact. The only disadvantage is that it is expensive. Tools and dies, jigs and fixtures, housing
Silicones
The main property of silicone is that it has a high resistance to withstand high temperature of up to 260°C and possess excellent dielectric strength at high temperatures. It is also used as water repellant in liquid state. These silicones can be compressed reinforced. It is generally used in coating, laminates, foam products and induction heating process.
Urea formaldehyde
It is obtained by the condensation of urea and aqueous formaldehyde. It cannot be cast but can withstand temperatures up to 77°C. It is generally used as adhesive and binding material. It is generally used is table ware, buttons, clock cases etc.
Alkyds
It is also known as oil-modified polyester. Alkyds are used in synthetic enamels and lacquers. It is used in solid from where high electrical and heat resistance are required. Used in manufacturing automobile parts.
Polyurethanes
It is mainly used for cushion in transportation seats for insulation and electronic equipment as a packing material.