Processing centrifugal casting

Centrifugal casting Process in which tubular products are fabricated through the application of resin and glass strand reinforcement to the inside of a mold that is rotated and heated. The process polymerizes the resin system. 

The Automatic processes are those such as pultrusion, filament winding, centrifugal casting and injection moulding. 

Although the polymerization of e-caprolactam was described above, there is no difference in principle from the process flow sheets for centrifugal molding of items from other polymers and oligomers. Nevertheless, in most cases, the high temperatures used in lactam polymerization are not required, and the flow sheet as a whole is simplified. In industrial practice, poly(methyl methacrylate) pipes,172 and sheets of polyurethanes and unsaturated polyesters are obtained by centrifugal casting. 

Hidber et al. [9] described the colloidal processing of wet-milled a-alumina suspensions by centrifugal casting from a 80 wt-% suspension at pH 4.3. The mean particle diameter of the a-alumina powder was 0.3 pm and the BET surface area 8.59 m /g. Nitric acid or ammonia was used for electrostatic stabilisation. Very dense ceramics could be obtained with relative densities up to 99.9%. 

Centrifugal Casting. Reinforcing fibers are distributed inside a circular mold. The mold is rotated, and liquid resin is distributed inside it to impregnate the fibers. Rotation of the assembly is continued inside an oven until it is cured. This process is used for making pipes, tanks, and hoops. 

There is a modified centrifugal casting process that produces continuous filament reinforced TP pipes/tubes with precise fiber placement and smooth internal and external surfaces. TPs such as nylon and polypropylene have been reinforced with fibers such as glass and carbon. Products such as automotive drive shafts and bearings have been fabricated with fiber volumes up to 60wt%. These tubes have very low rotational unbalances and tight tolerance of wall thickness (Chapter 15). 

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