Rotational molding particle shape

However, carbon black has been used with success as a filler in rotationally molded products. At concentrations of up to 2.5 wt% it improves the weathering resistance of the product. Since dimensional stability and the shape of articles would benefit Ifom the use of fillers and fibers, it is probable that they will start to be used in the future. When this happens, fillers will be introduced in a premixed form to assure homogeneous distribution (forces normal to the surface of product cannot cause the movement of particles towards the mold surface when particles are premixed with polymer). 

In this process the molds or cavities are charged with a predetermined quantity of resin powder (generally around 500 particle size) or liquid The mold halves then are clamped together and rotated biaxially in an oven where the resin melts and densifies into the shape of the mold Then the molds are slowly cooled by air and water in a cooling chamber, following which they are opened and the finished articles removed. 

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