摘要:
An extrusion-molding machine according to the present invention comprises: a screw having a blade portion for extruding a molding material, the screw disposed in a tightly-closed space; and a die for molding an extruded molding material, wherein the space is maintained in a reduced-pressure atmosphere, and a high-hardness coat layer is formed at least on the blade portion.
摘要:
The invention relates to a device (1) for extruding thermoplastic material, having an extruder housing (22) in which an extruder screw (22) driven by a drive device (23) is supported rotatably about the axis thereof, said housing comprising an intake opening (24) to which a plastic material feeder (3) is connected, said feeder comprising at least one air inlet opening (36), wherein the extruder housing (22) comprises at least one vapor outlet opening (41) upstream of the intake opening (24) and an air/vapor path (28) is defined from the intake opening (24) to the vapor outlet opening (41).
摘要:
The invention relates to a vented extruder (1) for the devolatilization of a polymer material. The vented extruder (1) encompasses at least one drive (4), at least one gearbox (5), at least one rotatably driven extruder screw (3), at least one first material feed (6) and at least one extrudate outlet (13). A feature of the vented extruder (1) according to the invention is that the drive, encompassing drive (4) and gearbox (5), has been provided in the region of that end of the extruder screw (3) that is downstream in relation to the direction of conveying of the polymer.
摘要:
A processing installation for devolatilization of polymer melts comprises a first extruder and a second extruder arranged downstream thereof in a direction of conveyance. The first extruder comprises several rotatably drivable first shafts which are provided with first treatment members and several devolatilization zones with associated devolatilization ports. Correspondingly, the second extruder comprises several rotatably drivable second shafts which are provided with second treatment members and several second devolatilization zones with associated devolatilization ports. The first treatment members have an external diameter which is smaller than or equal to that of the second treatment members. A devolatilization unit is arranged in a transfer zone which interconnects the extruders. The devolatilization unit comprises a perforated plate and a clearance arranged downstream in the direction of conveyance. A control unit is configured in such a way that when the processing installation is operated, the speed of the second shafts is lower than the speed of the first shafts. The processing installation allows a high devolatilization performance and a high polymer throughput to be achieved at the same time. A throttle is arranged in the transfer zone upstream of the devolatilization unit when seen in the direction of conveyance, with the position of the throttle being adjustable by means of the control unit.
摘要:
The invention relates to an apparatus for extruding thermoplastic material, comprising an extruder screw (2) which is mounted in a housing (1), comprises a plasticizing section (P) on the inlet side, a degasification section (E) upstream of an outlet section (A), a flow arrester (S) between the plasticizing section (P) and the degasification section (E) with a screw section with a counter-rotating delivery flight (3), and at least one flow channel (5) bridging the flow arrester (S) and containing a melt filter (4). In order to reduce the driving power of the extruder screw (2) it is proposed that a sleeve (7), which encompasses the screw (6) and is mounted in the housing (1) in a rotationally fixed manner, is associated with the screw section that forms the flow arrester (S), and the screw (6) in the screw section of the flow arrester (S) has a smaller screw diameter in relation to the plasticizing section (P) and preferably also to the degasification section (E).
摘要:
An extruder with a housing comprising parallel, partially inter-engaging bores and screws disposed therein is used when applying a method of feeding powdery bulk materials into such an extruder. A solid transport of powdery bulk material takes place in an inlet zone disposed downstream of a feed opening wherein said inlet zone is partially filled. The inlet zone is provided with at least one gas-permeable wall portion wherein a layer of bulk material is created on said wall portion, thereby preventing bulk material from passing through, The gas-permeable wall portion is connected to a vacuum source and to a pressure gas source. Furthermore, the gas-permeable wall portion has an inner wall which is set back with respect to the wall of the bores, thereby forming a gap with a partially annular cross section wherein a layer of the bulk material is formed in the gap.
摘要:
A mixing degree adjusting device comprises a pair of spacer members arranged at a position sandwiching both round sectional portions of a pair of screws from both sides in the aligning direction of the pair of screws, and a pair of drawing members arranged as a position sandwiching both the round sectional portions from both sides in the orthogonal direction that is orthogonal to the aligning direction. The spacer members are movable between an adjusting position opposing to the round sectional portions, and a retracting position, when the screws are extracted from the barrel, for retracting to the outside until the passage of the screws is accepted. Opposing portions opposing to the round sectional portions at the time of moving to the adjusting position are formed in a substantially linear shape extending in parallel with the orthogonal direction seen from the axial direction of the screws. The drawing members are movable in the direction approaching to and retracting from the round sectional portions along the opposing portions in an area intervening between the opposing portions of both the spacer members at the time of moving to the adjusting position, and when the screws are extracted from the barrel, retractable to the outside until the passage of the screws is accepted.
摘要:
An extruder comprises a displacement part with a housing, inside of which at least one screw shaft is housed and which is provided, at one end, with a material entry opening for the material to be processed and, at the other end, with a material outlet opening for the processed material, and with an intermediate opening between the material entry opening and the material outlet opening for discharging gas from the displacement part. A material retaining device is connected to said intermediate opening and has at least one screw shaft inside an intermediate housing. This screw shaft extends from the intermediate opening to a gas discharge opening in the intermediate housing and conveys material entering the intermediate housing back into the displacement part. To this end, the screw section of the screw shaft facing the displacement part has a direction of thread that returns into the displacement part, and the screw section of the screw shaft facing away from the displacement part has an opposite direction of thread.
摘要:
Polycarbonate is prepared by reactive extrusion on a reactive extruder. A method incorporates the steps of introducing a polycarbonate oligomer, an activated carbonate, and a transesterification catalyst to the extruder through a feed section. The extruder has a feed section, a polycarbonate exit section, and a reaction section between the feed section and the polycarbonate exit section. The reaction section has one or more devolatilization units, wherein each devolatilization unit incorporates an array of vent-conveying sections and conveying sections arranged in a configuration of: (C V C)x(V)n, and/or (V C V)x(C)n. (V) is a vent-conveying section, (C) is a conveying section, x is 1 or more, and n is 1 or 0. The extruder screw in the vent-conveying sections and the conveying sections in each devolatilization unit have conveying elements or conveying elements and mixing elements and no elements that create a melt seal in the devolatilization unit. The method further includes the step of extruding the reaction components at a temperature in a range between 100° C. and 500° C., wherein during the extrusion of the reaction components, activated carbonate residue is removed through the vent-conveying sections.
摘要:
A method of separating a polymer-solvent mixture is described wherein a polymer-solvent mixture is heated prior to its introduction into an extruder comprising an upstream vent and/or a side feeder vent to allow flash evaporation of the solvent, and downstream vents for removal of remaining solvent. The one-step method is highly efficient having very high throughput rates while at the same time providing a polymer product containing low levels of residual solvent.