Clay as a Filler in the Thermoplastic Compounding

The addition of fillers and additive in plastic is well recognized to impart desired properties to the virgin plastic such as improvement of mechanical and thermal properties as well as of cost(1). There are, however, some adverse effects upon using such fillers, for example, toughness and ultimate elongation of polymers often suffer with the addition of fillers. A practical interest originated from the addition of clay minerals as polymers fillers to enlarge their potential and actual applications. Almost any powdered material can be used as a filler, the common ones being obtained from natural deposits. Of the several hundred fillers used, those which find spread use are the various grades of CaCO3, quartz and silica flours, talc and various clay.(2) Kaolinite has been used as a filler for thermoplastics. Kaolinite is characterized by small grain size and plate shape. These properties are useful in the production of a compound with high strength and electrical insulation. The advantages of using clay as filler in plastics are in the producing a smooth surface finishing, low water absorption and improving the mechanical properties while increasing the chemical and weathering resistances(3).