Extrusion process and single-, dual- or multiple-screw extruder
Patent 4959186 Issued on September 25, 1990. Estimated Expiration Date: 
September 22, 2008. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
September 22, 2008. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3224739 3253303 3256562 3459840 3577588 3632256 Apparatus and method for producing solid polymeric material from a dilute polymer solution Process for the continuous degradation of plastics Process and apparatus for vacuum treatment of viscoplastic materials Vent type extruder InventorsAssigneeApplicationNo. 247792 filed on 09/22/1988US Classes:264/102, To degas or prevent gas entrapment264/211.23, Plural screws, plural extruders, or plural stage extruder264/349, MISCELLANEOUS366/75, With specified vent means366/86, Intercommunication by conduit425/173, Means permitting visual inspection by operator425/203, With separate and distinct gas withdrawal chamber425/205, Serially arranged chambers each housing a kneading or mixing means425/215, WITH MEANS TO GATHER EXCESS OR REJECTED STOCK MATERIAL425/382.4Including restriction upstream of shaping orifice and downstream of primary pressurizing meansExaminersPrimary: Thurlow, JefferyAttorney, Agent or FirmForeign Patent References
International ClassB29C 047/76Foreign Application Priority Data1988-05-27 DEAbstractIn the case of the extruder, the thread of the screw, or that of the screws, is partly left-handed and partly right-handed, so that one part of the material to be processed is conveyed in direction A, while the other part is conveyed in the opposite direction B. The process is a degasifying-extrusion-process and the extruder is a degasifying extruder. The apparatus includes a reverse-degasifying assembly (7,22) at the end (8,19) of the screw (1,16), or screws (1,16), if the material to be processed is carried away from this end, and/or a reverse-degasifying assembly (41,52) at the location between the threaded sections of the screw (1,16) or screws (1,16), so that the material to be processed is carried away in opposite directions B and A. According to the invention, continuous operation is possible, no dead areas and break-away edges are formed, the reverse-degasifying assembly (7,22,41,52) is easily sealed off against any entry of oxygen, products sensitive to heat and oxidation, such as polyamide-66, may also be produced, without damage, in continuous operation, for example by synthetic-fibre extrusion spinning.Field of SearchTo degas or prevent gas entrapmentVACUUM TREATMENT OF WORK Plural screws, plural extruders, or plural stage extruder MISCELLANEOUS With separate and distinct gas withdrawal chamber Plural means being diverse, or parallel and intermeshing or concentric Serially arranged chambers each housing a kneading or mixing means Within or at forming means Within pressurizing chamber By modified screw helix STOCK PRESSURIZING MEANS OPERABLY ASSOCIATED WITH DOWNSTREAM SHAPING ORIFICE Plural orifices WITH MEANS TO GATHER EXCESS OR REJECTED STOCK MATERIAL Means permitting visual inspection by operator Agitator or kneader comprises means rotating about a horizontal axis Including restriction upstream of shaping orifice and downstream of primary pressurizing means With specified vent means Intercommunication by conduit | |
