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US 4,053,143 AGranted
Screw for use in an extruder
AssigneeToray Industries, Inc.
InventorsAkira Hosokawa, Yukifusa Miyazaki, Yoshio Yada, Yasuo Kitamura, Masasi Takeda
Life of this patent
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Abstract
There is provided a screw for use in an extruder comprising a melting section and a metering section and a decompression section therebetween so that the head pressure profile along the longitudinal direction of the extruder is higher than atmospheric pressure and has an inflection point, with the result that a high melting performance is attained and a high extrusion stability is ensured even at a high extrusion rate.
Claims1
A screw for use in a non-vent type extruder and having a diameter D, comprising:
- a feed section having a channel depth h.sub.1 at a rear end thereof;
- a melting section subsequent to said feed section, having a channel depth gradually decreasing along a forward direction from said value h.sub.1 to a value h.sub.2 ;
- a decompression section subsequent to said melting section, having a channel depth increasing from said value h.sub.2 to a value h.sub.3 and gradually decreasing to a value h.sub.4 ;
- and a metering section subsequent to said decompression section, where the channel depth has a constant value of h.sub.4 ;
- where h.sub.1 >
- h.sub.3 >
- h.sub.4 >
- h.sub.2 ;
- ##EQU1## and where 1.5>
- (h.sub.4 /h.sub.2 )>1.15.
7 more elements
Dependencies are inferred from the claim text.