Direct drive by means of clutch with either ac or dc

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Unformatted text preview: and to reduce vibrations Drive motor- turns the screw and provides power for operation. Extruder power capacity- key characteristic on extruder Power increases as polymer output increases barrel diameter increases screw length increases requirements for high output at high polymer temperature Thrust bearing is mounted on the screw near where the screw attaches to the linkage. It prevents the screw from moving backwards and absorbs the thrust of the screw as it turn against the resistance of the resin. L\D ratio5-34 Maximum 20 for elastomers More than 20 for thermoplastics. Hopper Hopper Barrel Barrel Screw Screw Extruder screw Function conveying resin through extruder imparting mechanical energy to melt the polymer mixing ingredients together building pressure to push resin through die Type Single screw Twin-screw Length/diameter (L/D) ratio: Length of flighted portion of the screw to the inside diameter of the barrel. L/D is a measure of the capability of the screw to mix and melt materials. High L/D ratios indicate good mixing and melting capabilities, e.g. 32:1 Sheet Extrusion • Sheet extrusion is a technique for making flat plastic sheets from a variety of resins Sheet Sheet Extrusion Applications Within the building and construction industries, sheet extrusion is used for a variety of applications. One of the main uses of extruded PS sheet is for thermal insulation materials for walls, roofs, and under floors. In the automotive industry, sheet is currently used to produce interior trim, panels, and dashboards. Foamed polyolefin sheet, both cross-linked and noncross-linked, is also used in automotive applications. There are a number of other applications where thermoformed sheet plays a significant role. These include the manufacturing of luggage, refrigerator liners, and shower units. Profile/Pipe Profile/Pipe Extrusion This process is used to manufacture plastic products with a continuous cross-section such as; drinking straws, plastic Pipes and profiles. Blown Blown Film Extrusion (Film Blowing) Blown film extrusion is the process by which most commodity and specialized plastic films are made for the packaging indust...
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This document was uploaded on 03/14/2014.

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