Some Aspects of the Machine Design

The melting of the polyethylene is primarily accomphshed by the turning of the screw which converts mechanical (frictional) energy into heat, but the melting process is also aided by heating bands around the extruder 

Although the extrusion process that transports the molten polyethylene through the extruder barrel exerts some pressure on the plastic, this pressure is too low for the injection process, hence an injection process is required to fill the mold. 

The primary difference between injection molding machines is in the design of the injection process. In a plxmger-type design, a predetermined 

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