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US 4,462,692 AGranted
Screw extruders
AssigneeFrenkel C-D Aktiengesellschaft
InventorPaul Meyer
Life of this patent
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AssigneeFrenkel C-D Aktiengesellschaft
InventorPaul Meyer
Estimating the term…
An extrusion apparatus having a barrel and a rotatable threaded screw coaxially positioned therein is disclosed. The apparatus includes an upstream inlet section having an opening therein for receiving material to be processed by the apparatus, a compression section downstream of the inlet section, and a mixing or plasticizing section downstream of the compression section. The interior surface of the barrel is provided with an undercut therein which intercommunicates the feed opening with the compression section and has a portion thereof which extends downstream in the compression section about the interior surface of the barrel with a continuously decreasing cross-sectional area. The undercut may be formed in a cylindrical insert carried within the barrel and, in an alternate embodiment, a second undercut cylindrical insert positioned about the first insert and rotatable relative thereto may be employed to vary the cross-sectional area of the undercut.
An extrusion apparatus having a barrel and a rotatable threaded screw coaxially positioned within said barrel, said apparatus including an upstream inlet section having an opening therein for receiving material to be processed by the apparatus, a compression section downstream of said inlet section, and a mixing or plasticizing section downstream of said compression section, characterized in that the interior surface of said barrel is provided with an undercut therein which intercommunicates said feed opening with said compression section of said extruder, and which undercut includes a portion thereof which extends downstream in said compression section about the interior surface of said barrel with a continuously decreasing cross-sectional area through substantially a complete 360.degree. turn about said screw.
An extrusion apparatus having a barrel and a rotatable threaded screw coaxially positioned within said barrel, said apparatus including an upstream inlet section having an opening therein for receiving material to be processed by said apparatus, a compression section downstream of said inlet section, and a mixing or plasticizing section downstream of said compression section, characterized in that the interior surface of said barrel is provided with a generally spirally oriented undercut therein which intercommunicates said feed opening with said compression section of said extruder, said undercut including a portion thereof which extends downstream in said compression section with a continuously decreasing cross-sectional area, said apparatus further including adjustment means carried by said barrel and cooperative with said undercut to selectively change the cross-sectional area of said undercut in said compression section thereby to change the compression ratio to be applied to material that is to be processed by said apparatus.
Dependencies are inferred from the claim text.