Molding continuous

Flow sheets for preparing the components of various monomer and oligomer reactant mixtures do not differ significantly from each other, although they may have different sets of reactors. The choice depends mainly on the physical and chemical properties of the initial components. Fig. 4.2 shows a flow sheet for obtaining continuously molded polyurethane elastomers. Fig. 4.3 illustrates an elementary flow sheet for a batch process unit for manufacturing moldings of epoxy resin or epoxy-based composites filled with quartz sand. 

As the mold rotates past the extrusion-injection die head, the melt flows onto the circumference of the mold and is forced by the melt pressure into the cavities. Enough additional melt is supplied to create the base strip at the same time. By the time the mold has completed about one-half a revolution, the plastic has been cooled and solidified. Mold temperature is controlled by an air plenum located about one-quarter of a revolution before the injection point the molded Velcro itself is cooled by another plenum ahead of the strip-ofFpoint. The airflow is adjusted to keep the nylon (usual plastic used) sufficiently warm and flexible so that the projections can pull free from the undercuts in the cavities without damage during strip-off See extruder injectionmolding, continuous mold zipper, velocity See calculus. 

ESA electrostatic assist ExCM extrusion continuous molding... 

World-Class Management is not a system or a procedure, it is a culture. It is a continually molding process of change and improvement. It is a competitive strategy for success. 

Pultrusion is a continuous molding process resembling the application of insulation to wire and cable (Figure 14.11). Typically, a glass fiber or fabric reinforcement is fed... 

To form hollow parts such as thin-walled bottles, the blow molding process (Figure 10.11) is used. Blow molding starts with a cylindrical hollow preform of smaller diameter called a parison which is first produced by extrusion in a continuous molding process, or by injection in an intermittent molding process. 

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