TALC IN RUBBER AND ADHESIVE INDUSTRY

   


In the rubber industry Talc is used for two purposes.One, as compounding material in the preparation of certain types of hard rubber, and the other, as a lubricant to prevent rubber moulds from sticking.



1. As A Compounding Material

·         Talc is hydrophobic in nature due to which it gets completely wetted by the rubber matrix allowing negligible permeability to gas, which would otherwise significantly reduce mechanical strength of the rubber.

·         Talc can be grounded to extremely fine particle size. Thus, it can integrate between the matrix without increasing the gap between the polymer chains.Further, its shape is platy and therefore high in surface area and it has high affinity for rubber matrix due to which it can interact with the matrix. Thus, Talc as filler is extremely effective in transferring applied stress from rubber matrix onto itself. This makes Talc an excellent rubber reinforcing agent, which improves mechanical properties of rubber such as resilience, toughness and tensile strength.

·         Talc has a flexible molecular structure. Thus, even under high load, it maintains the elasticity of rubber as it prevents the rubber from getting permanently compressed, thereby offering excellent compression resistance to the rubber product.

·         Talc reduces electrical conductivity of the final product.

·         Talc provides resistance against ultra violet rays.

·         Talc decreases rubber matrix viscosity thereby improving processing.

2. As A Lubricant

Talc’s smoothness and slipperiness make it an excellent lubricant. It is therefore dusted on the molds through which unvulcanized rubber is extruded to be shaped into wire, cables, tyres etc. This prevents the rubber from sticking to the mold.


TALC IN ADHESIVE INDUSTRY


Often, sealants and adhesives include powdered Talc in the formulation as a filler to reduce costs and increase the solids level. It adds to viscosity, contributes to opacity, oil absorption and whiteness and improves mechanical properties like sagging resistance and rheology.