摘要:
Toughened thermoplastics are prepared by mechanically dewatering a water-moist elastomer component A containing up to 60% by weight of residual water and mixing the resulting dewatered elastomer component A' with a thermoplastic polymer B in an extruder, by a process in which the elastomer component A is fed to a twin-screw extruder which has corotating, in each case double-flight, screws and essentially includes, in the transport direction,a metering section in which the elastomer component A is fed to the extruder by a metering means,at least one squeeze section which serves for dewatering and contains at least one retarding element and in each case at least one associated dewatering orifice,at least one section provided with a conveying screw or at least one section provided with mixing, kneading or other plasticating elements or combinations of these elements,at least one section in which the thermoplastic polymer B is introduced as a melt into the extruder,at least one section provided with mixing, kneading or other plasticating elements or combinations of these elements,at least one devolatilization section which is provided with at least one devolatilization orifice and in which the residual water is removed as steam, anda discharge zone,the water emerging from the dewatering orifices being present partially or completely in the liquid phase, and the extruder being operated at a screw speed of from 50 to 600 min.sup.-1 and average shear rates of from 20 to 240 s.sup.-1.
摘要:
Toughened thermoplastics are prepared by mixing a water-moist elastomer component A containing up to 60% by weight of residual water with a thermoplastic polymer B and further polymers C and additives D in an extruder with mechanical dewatering of the elastomer component A, by a process in which the components A, B, C and D are fed to a twin-screw extruder which has corotating screws and essentially comprises, in the transport direction, at least one metering section in which the elastomer component A is fed to the extruder by a metering means, at least one squeeze section which serves for dewatering the component A and contains at least one retarding element and in each case at least one associated dewatering orifice, at least one section in which the thermoplastic polymer B is introduced as a melt into the extruder, at least one section provided with mixing, kneading or other plasticating elements or combinations of these elements, at least one devolatilization section which is provided with at least one devolatilization orifice and in which the residual water is removed as steam, and a discharge zone, the water emerging from the dewatering orifices being present partially or completely in the liquid phase, and the components C or D or mixtures thereof, together or separately from one another, being fed to one or more of the stated extruder sections, either together with the component A or B or mixtures thereof or separately from A and B.
摘要:
A process for preparing thermoplastics or polymer blends comprising (A) from 5 to 95% of a water-moist elastomer component containing up to 60% of residual water, (B) from 5 to 95% of a thermoplastic polymer, (C) from 0 to 95% of a further polymer, and (D) from 0 to 70% of additives, said process comprising mixing the components A to D in an extruder with mechanical dewatering of component A, wherein the extruder has at least two rotating screws and, in the conveying direction, is essentially composed of a metering section into which component A is fed, a squeeze section which serves for dewatering component A and contains a retarding element and an associated dewatering orifice which is present upstream of the retarding element by a distance corresponding to at least one screw diameter, a feed section in which the thermoplastic polymer B is introduced as a melt into the extruder, a plastication section with mixing or kneading elements, a devolatilization section with an orifice and in which the remaining water is removed as steam, and a discharge zone.
摘要:
Toughened thermoplastics are prepared by mechanically dewatering a water-moist elastomer component A containing up to 50% by weight of residual water and mixing the resulting dewatered elastomer component A' with a thermoplastic polymer B in a mixing unit, by a process in which the elastomer component A is fed to a twin-screw extruder which has corotating screws and essentially includes, in the transport direction,one unheated metering section in which the elastomer component A is fed to the extruder by a metering means,at least one unheated squeeze section which serves for dewatering and contains at least one retarding element and in each case at least one associated dewatering orifice,at least one section in which the thermoplastic polymer B is introduced as a melt into the extruder,at least one section provided with mixing, kneading or other plasticating elements or combinations of these elements,at least one devolatilization section which is provided with at least one devolatilization orifice and in which the residual water is removed as steam, anda heated discharge zone,and in which the water emerging from the dewatering orifices is present partially or completely in the liquid phase.
摘要:
Essentially dry materials are obtained by mechanically dewatering water-moist rubber, prepared by emulsion polymerization and precipitation, to give a compact material having a rubber content of at least 50%, by a process in which the previously dewatered rubber is fed to the feed section of a twin-screw extruder which has screws rotating in the same direction and possesses, in succession in the conveying direction, at least two back-up zones and two associated dewatering orifices, each of which may be provided with a retaining screw, and at least one kneading zone, one devolatilization zone and finally one discharge zone, which may be closed by a die lip, and the water separated off is discharged at the dewatering orifices in liquid form.
摘要:
Toughened thermoplastics are prepared by mechanically dewatering a water-moist elastomer component A containing up to 50% by weight of residual water and mixing the resulting dewatered elastomer component A' with a thermoplastic polymer B in a mixing unit, by a process in which the elastomer component A is fed to a twin-screw extruder which has corotating, in each case triple-flight, screws and essentially includes, in the transport direction, one unheated metering section in which the elastomer component A is fed to the extruder by a metering means, at least one squeeze section which serves for dewatering and contains at least one retarding element and in each case at least one associated dewatering orifice, at least one section in which the thermoplastic polymer B is introduced as a melt into the extruder, at least one section provided with mixing, kneading or other plasticating elements or combinations of these elements, at least one devolatilization section which is provided with at least one devolatilization orifice and in which the residual water is removed as steam, and unheated discharge zone, and in which the water emerging from the dewatering orifices is present partially or completely in the liquid phase.
摘要:
The present invention relates to a mixing apparatus at least composed of a screw-based machine S1 and a screw-based machine S2, where S1 has heating equipment, at least in the plasticizing and homogenizing zone, and where the outlet from S2 has been connected to the screw-containing barrel of S1, within the plasticizing or homogenizing zone of S1, a substantive feature of which is that the connection between S1 and S2 is brought about by a connector which has cooling equipment effective as far as the inner wall of the screw-containing barrel of S1, and to a process for preparing thermoplastically processable molding compositions, in particular additive masterbatches, from at least one thermoplastic component C1 and at least one component C2, where the melting point or decomposition temperature TMC2 of C2 is lower, by at least about 50° C., than the temperature THC1, which is the lower limit of the thermoforming range of C1, and where most of C2 is melted only after contact with C1.
摘要:
Semi-finished GMT sheet material of GMT recyclate in which more than 50% by weight of the glass fibers are more than 2 mm in length and which is produced by extruding GMT recyclate particles without significant comminution of the glass fibers.
摘要:
Polyolefins are thermomechanically degraded in a twin-screw extruder without a downstream degradation apparatus, at from 300.degree. to 550.degree. C. and from 1 to 100 bar and in average residence times of the reaction mixture of from 0.5 to 10 minutes, by a process in which the pressure in the twin-screw extruder is changed periodically or aperiodically with a fluctuation of from 0.5 to 30 bar. The novel process is particularly suitable for the degradation of polypropylene.
摘要:
Polymers essentially comprising units of the formula I ##STR1## in which R.sup.1 and R.sup.2 are hydrogen or methyl andR.sup.3 is hydrogen, C.sub.1 -C.sub.18 -alkyl, C.sub.5 -C.sub.12 -cycloalkyl, C.sub.6 -C.sub.10 -aryl or C.sub.6 -C.sub.10 -aryl-C.sub.1 -C.sub.4 -alkyl, it being possible for these radicals, with the exception of the C.sub.1 -C.sub.18 -alkyl radicals, to be up to trisubstituted by radicals selected from the group consisting of C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy and halogen, are prepared by reacting a polymer based on C.sub.1 -C.sub.20 -alkyl esters of acrylic acid, methacrylic acid or mixtures thereof with ammonia or a primary amine in an extruder, by mixing the ammonia or the primary amine by mixing intensively with a melt of the polymer to be reacted, at at most 250.degree. C., before the imidation is carried out, and are used for producing thermoplastic moldings, films or fibers.