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.
摘要:
A method for making a silicic acid containing rubber base composition includes providing composition ingredients of rubber, silicic acid, silane and additional additives except for vulcanization ingredients. First and second mixers separate from each other are provided wherein the ingredients except for the vulcanization ingredients can be mixed. All of the composition ingredients are introduced into the first mixer except for the vulcanization ingredients simultaneously or at time intervals. The composition ingredients introduced into the first mixer are mixed to a composition. The composition formed in the first mixer is transferred directly into the second mixer without an intermediate storage thereof. The transferred composition formed in the first mixer is mixed at least almost to completion in the second mixer with the temperature lying in the temperature range of 130° C. to 180° C. at least over the greatest part of the dwell time of the composition in the second mixer wherein the silicic acid reacts acceleratedly with the silane.
摘要:
This invention relates to an extrusion method preparing polycarbonates from a solution of an oligomeric polycarbonate. A mixture of bis(methyl salicyl)carbonate (BMSC), BPA and a transesterification catalyst are first equilibrated at moderate temperatures to provide a solution of polycarbonate oligomer in methyl salicylate. The solution is then fed to a devolatilizing extruder, where the polymerization reaction is completed and the methyl salicylate solvent is removed. The solution comprising the oligomeric polycarbonate can also be pre-heated under pressure to a temperature above the boiling point of methyl salicylate and subsequently fed to a devolatilizing extruder equipped for rapid flashing off the solvent. The method provides polycarbonate with greater efficiency than the corresponding process in which unreacted monomers are fed to the extruder. Additionally, the method of the invention does not require the isolation of a precursor polycarbonate comprising ester-substituted phenoxy terminal groups.
摘要:
A process for producing an article of resin made from at least about 50% by weight of methyl methacrylate is provided, which comprises a step of melt-processing the resin with an extruder, wherein an oxygen concentration of a gaseous phase in a resin feed zone of the extruder falls within a range of from about 0.7% by volume to about 10% by volume. The article is excellent in curbing the coloring in melt processing.
摘要:
An aromatic polycarbonate extruder which is a twin screw extruder for kneading components into a molten aromatic polycarbonate, the extruder comprising at least one module consisting of a kneading unit, a material seal unit, a back kneading unit and a full-flight unit which are arranged from an upstream side to a downstream side and a method of kneading components into an aromatic polycarbonate by using the above extruder. The present invention can provide a kneading apparatus and method for producing an aromatic polycarbonate which has an extremely small content of foreign matter and is free from residence deterioration such as coloration, cross-linking or gelation when the aromatic polycarbonate is to be kneaded with various components.
摘要:
Polyethyleneterephthalate extrusion equipment of material in granule form, still humid, coming from both ground recovered products and also virgin material, comprising a chassis (29), containing a co-rotating, oil-thermoregulated extruder with two screws (31, 32), which comprises a first zone (A), equipped with an opening (34) where there is an aspiration hood (35) for a first “open top” degassing, a second zone (C) where there is at least one stack (37, 38) for a further degassing, between the two zones (A, C), there being a tight zone (B), and a carrying and loading zone (E) activated by the screws (31, 32). The description also relates to an extrusion process of polyethyleneterephthalate effected in a co-rotating twin-screw extruder which comprises in a first zone (A) an “open top” degassing phase, followed by a stack (37, 38) degassing phase, between the two phases there being a tight zone which does not deteriorate the material, followed by a carrying, loading and amalgamation phase of the molten material and a final pumping phase with the extrusion of polyethyleneterephthalate.
摘要:
A method of producing a polycarbonate or the like which is excellent in hydrolysis and heat stability such as a reduction in molecular weight at the time of molding and color retention and moldability such as releasability and transferability, rarely experiences residence deterioration such as coloring, crosslinking and gel formation and has an extremely small content of foreign matter by employing a special structure for an opening in the side surface of a horizontal cylindrical vacuum resin treating apparatus, supplying a molten polycarbonate into a unidirectional rotary intermeshing double-screw extruder under specific conditions, adding a specific agent under specific conditions and cleaning the inner surface of a production apparatus by a specific method.
摘要:
A method and apparatus for making pellets of wood meal compound according to the present invention is constructed in such a manner that synthetic resin material and wood meal material are supplied into a hopper (3) in a most upstream position, and kneaded in a long kneading section (6) having no side feeder (2), thereby to obtain pellets from mixed material having more uniform properties than in the prior art.
摘要:
A method for making a silicic acid containing rubber base composition includes providing composition ingredients of rubber, silicic acid, silane and additional additives except for vulcanization ingredients. First and second mixers separate from each other are provided wherein the ingredients except for the vulcanization ingredients can be mixed. All of the composition ingredients are introduced into the first mixer except for the vulcanization ingredients simultaneously or at time intervals. The composition ingredients introduced into the first mixer are mixed to a composition. The composition formed in the first mixer is transferred directly into the second mixer without an intermediate storage thereof. The transferred composition formed in the first mixer is mixed at least almost to completion in the second mixer with the temperature lying in the temperature range of 130null C. to 180null C. at least over the greatest part of the dwell time of the composition in the second mixer wherein the silicic acid reacts acceleratedly with the silane.
摘要:
Polyethyleneterephthalate extrusion equipment of material in granule form, still humid, coming from both ground recovered products and also virgin material, comprising a chassis (29), containing a co-rotating, oil-thermoregulated extruder with two screws (31, 32), which comprises a first zone (A), equipped with an opening (34) where there is an aspiration hood (35) for a first nullopen topnull degassing, a second zone (C) where there is at least one stack (37, 38) for a further degassing, between the two zones (A, C), there being a tight zone (B), and a carrying and loading zone (E) activated by the screws (31, 32). The description also relates to an extrusion process of polyethyleneterephthalate effected in a co-rotating twin-screw extruder which comprises in a first zone (A) an nullopen topnull degassing phase, followed by a stack (37, 38) degassing phase, between the two phases there being a tight zone which does not deteriorate the material, followed by a carrying, loading and amalgamation phase of the molten material and a final pumping phase with the extrusion of polyethyleneterephthalate.