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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
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
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
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.
- Spring '14