Q. What are the ingredients of moulding components?
Ans. Polymer Additives: One or more of the following materials are added to the polymers, either before or during polymerization, to make them processable plastics.
1. Catalysts or Accelerators: They are also known as hardeners. They are the catalysts which are added to accelerate the chemical reactions during polymerization of plastics.
2. Fillers: These are the materials added to synthetic resins to dilute them in order to reduce their consumption. They also increase their bulk and thus, reduce the material cost. Many of them, specially when they are finally distributed help in increasing strength, stiffness and thermal resistance of the plastics. Materials added for this purpose include clay, tale, wood flour, mica, quartz, alumina, carbon black, calcium carbonate, asbestos or glass fibers etc.
3. Modifiers: These are the chemicals added to plastics for changing the properties of the base resin. Some of them help in providing mechanical properties as well.
4. Plasticisers: They are the chemicals added for either softening the resin of forming temperature or to improve their toughness of the finished stage and to impart flexibility to their finished products. A plasticiser is normally a fluid of high molecular weight.
5. Stabilisers: Their addition to plastics help in preventing deterioration due to the action of heat and light.
6. Initiators: They help in initiation starting the reaction i.e. polymerization. H2O2 is commonly used for this purpose.
7. Dyes and pigments: They are the colouring agents, added to impart different colours and shades to plastics.