Abstract: The invention relates to a method for the treatment of waste containing polyamide comprising a) depolymerisation of the waste containing polyamide, whereby a caprolactam raw material (6) and a flow (3), comprising the secondary constituents and additives from the depolymerisation, are obtained, and b) leaching of the flow (3) at least once using an extracting agent.

Abstract: The invention relates to a system for producing endless molded bodies from a molding compound. For producing the endless molded bodies, spinning means are used comprising an extrusion head through which the molding compound is extruded to form endless molded bodies, a precipitating bath containing a precipitant, and an air gap between the extrusion head and the precipitating bath. After extrusion, the endless molded bodies are first passed through the air gap, and then through the precipitating bath. For facilitating control of the system, it is provided in accordance with the invention that the system comprises a control area arranged in front of the spinning means and accessible by the operating staff, and that the air gap is arranged freely visibly in a height freely defined by a central vision range of an operator standing upright in the staying area and looking substantially in a horizontal direction.

Abstract: Process of producing polytrimethylene terephthalate (PTT) by esterification of terephthalic acid (TPA) with trimethylene glycol (TMG) in the presence of a catalytic, titanium compound, precondensation and polycondensation. The esterification is effected in at least two stages, where in the first stage a molar ratio of TMG to TPA of 1.25 to 2.5, a content of titanium of 0 to 40 ppm, a temperature of 245 to 260° C. as well as a pressure of 1 to 3.5 bar are adjusted. In the at least one subsequent stage a content of titanium is adjusted which is higher than in the initial stage by 35 to 110 ppm. For generating the vacuum in the polycondensation and in the precondensation, there are used vapor jet pumps operated with TMG vapor.

Abstract: A method and apparatus for the steam misting of rectangular nozzles and spinning systems equipped therewith for producing polyamide filaments whereby the steam feed is conducted through a tube loop which is passed through the heating chamber of the spinning beam so that the steam is brought to the spinning temperature. Directly below the spinning beam and thus on the lower edge of the rectangular nozzle stack which is connected thereto, between the spinning beam and the after-heater, steam outlet bars are longitudinally applied. These steam outlet bars are equipped with a simple labyrinth for pressure equalization. The steam inlet is effected initially in each case centrally of the rectangular nozzle stack and transitions into an upwardly open and relatively broad distribution chamber along the rectangular nozzle stack. This vertical distribution chamber transitions into a horizontal and very small gap which is open into the spinning chamber at its mouth.

Abstract: The invention relates to a spinning device in which liquid polymer is guided through a polymer line with a first heating jacket to a spinning pump with a second heating jacket. From said spinning pump, the polymer is transported through several lines to spinning packets and extruded through spinnerts to form filaments. The lines that are connected downstream of the spinning pump, the spinning packets and the spinnerets are located in at least one spinning housing through which heating fluid flows. There is a distance of 5 mm between the spinning housing through which the heating fluid flows and the first and second heating jackets and the spinning pump, to obtain thermal decoupling. According to a method for heating the spinning device, vaporous heating fluid is guided out of a first reservoir into the spinning housing, and heating fluid is guided out of a second reservoir into the first and/or second heating jacket.

Abstract: The invention relates to a spinneret for spinning thermoplastics. Said spinneret comprises a central polymer inlet channel, a filter assembly (2), consisting of one or more filter plates of various filtration grades, a spinneret plate (3) and a housing (1) which receives and tightly surrounds the filter assembly (2) and the spinneret plate (3). The selection of suitable materials and tolerances for the individual parts of the spinneret enables the sealing effect to be achieved at operating temperature by the increased expansion of the internal components, in relation to the external housing.

Abstract: This invention relates to a continuous and efficient method for the manufacture of highly pure caprolactam suitable for the polycondensation of Polyamide 6 (polycaprolactam) from polyamide waste. In particular the invention relates to a method for the manufacture of caprolactam from waste containing polyamides, including the steps a) depolymerisation of the waste containing polyamides, whereby a caprolactam raw material and a flow containing secondary constituents or additives is obtained, b) at least one distillation of the caprolactam raw material, and c) at least one crystallisation of the caprolactam material obtained in step b), by which means caprolactam is obtained, whereby at least part of the caprolactam obtained in step c) with a permanganate number of <10000 sec. and a UV transmission of <85% is added to the waste containing polyamides before and/or during the depolymerisation.

Abstract: A cooling system for filament bundles, which are spun from polymer melt by at least two spinneret units (1) disposed one beside the other and are drawn off by a draw-off system (17), the filament bundles (3a, 3) being cooled in a three-part shaft (A, B, C) by an equidirectional air stream, and the cross-section of the individual shaft parts (A and B) tapering such that the flow rate of the air increases approximately to the same extent as the draw-off speed of the filament bundles (3a, 3).

Abstract: A process of producing a synthetic ultrafine endless yarn on the basis of polyester or polyamide in the range from 0.25 to 0.9 denier per POY filament by melt spinning at draw-off speeds between 2000 and 6000 m/min with a high spinning safety. To the polyester or polyamide a second immiscible amorphous polymer may be added in an amount of 0.05 to 5 wt %. One feature of the invention is the adjustment of a balanced temperature profile in the cross-section of the filament bundle before reaching the draft zone, as well as the suitable adaptation between snap-back length and the draft point of the filaments in the quench duct.

Abstract: The production of linear polyester by the interchange of ester radicals or esterification and polycondensation of multivalent alcohols with multivalent carboxylic acids takes place by means of catalysts. In order that the catalyst features the lowest possible content of catalytically active metal compound, the carrier substance that forms the heterogeneous phase comprises particles of the finest grain and of porous structure and features a surface of great inner, reactive and/or coordinated centers, whereby a catalytically active metal compound is adsorbed in the pores.

Abstract: The present invention provides a copolyester fiber consisting of a copolyester with primarily C2-4 alkylene terephthalate units and a process for producing these copolyester fibers. The copolyester contains more than 4 wt % up to 12 wt % poly(C2-4 alkylene glycol) units and 60 to 260 ppm pentaerythritol units and/or a total of 150 to less than 2500 ppm carboxy methylene phosphonic acid units and/or carboxy ethylene phosphonic acid units polymerized into it.

Abstract: The present invention comprises a method of producing polyester transesterification of at least a dicarboxylic acid dialkyl ester or esterification of at least a dicarboxylic acid with at least a diol and subsequent precondensation and polycondensation in the presence of the usual catalysts, whereby the polycondensation and optionally the esterification take place in the presence of an additional carbon containing co-catalyst, preferably activated charcoal with a specific surface area of more than 500 m2/g and an average grain size of less than 2 &mgr;m.

Abstract: The invention provides a sealing element for spinning systems used for spinning polymer melts, wherein the sealing element seals the transition between a polymer melt conducting melt channel of a permanently mounted component and a melt channel of a removable, interchangeable component. The sealing element consists of a cylindrical and externally smooth hollow object with an axial bore for passage of the melt, which hollow object is inserted into a fitting socket hole in the interchangeable component and is made of a material with a higher thermal expansion coefficient than that of the surrounding material of the interchangeable component.

Abstract: The present invention provides a process for mixing additives into a polymer melt steam, wherein a substream is removed from the polymer melt stream, mixed with additives, and then fed back into the polymer melt stream. In this process, the unmixed substream is sent as a single substream or in a maximum number of n−1 additional substreams directly to one up to a maximum number (n−1) of pump gear wheels of a planet wheel pump with n pump gear wheels. The additives are simultaneously supplied directly without mixing to at least one pump gear wheel of the planet wheel pump, and the substream mixed with the additives is removed from the planet wheel pump centrally at the inlet of the planet wheel pump and fed into the polymer melt stream.

Abstract: The invention provides a reheater door of a spinning device, which door is constructed so as to facilitate relatively easy access to the spinning nozzle plate as well as enable suction removal of vaporizable compounds and prevention of substantial cooling even when the door is open.

Abstract: The present invention comprises a process for the recovery from a reaction mixture of cellulose carbamate produced by conversion of cellulose with excess urea in an inert organic liquid reaction carrier, wherein the reaction mixture is treated with added water under heat, then the liquid phase is separated as much as possible on a filter, the cellulose carbamate remaining on the filter is washed with water, optionally pre-dried and, if desired, dried and recovered, and the organic reaction carrier is recovered by phase separation from the combined liquids.

Abstract: The invention is an apparatus for spinning solutions of cellulose carbamate by extruding the solution through a spinneret into a precipitation bath, coagulating the cellulose carbamate fibers thus formed and drawing off the fibers by mechanical means, where the fibers are enveloped from the outlet of the spinneret to the outlet of the precipitation bath in a stream of precipitating medium flowing in the same direction, where the velocity of flow of the precipitation medium where the fibers exit the spinneret (plane X1) amounts to 0.1 to 0.8 times the draw-off speed of the fibers, and the velocity of flow of the precipitation medium where the fibers exit the precipitation bath (plane X3) amounts to 0.96 to 1.1 times the draw-off speed of the fibers.

Abstract: The invention comprises an injector for feeding additives into a polymer melt stream. The injector comprises a body with a curved surface and a longitudinal axis having an inlet opening for the additives in the upper portion, opening into a channel running along the longitudinal axis and having a 90 degree deflection to a side injector outlet and having two groove-shaped recesses in the outer wall arranged parallel to the channel on both sides at the level of the injector outlet.

Abstract: The present invention comprises a multiway valve for fluids, consisting of an inlet line (1), a connector housing (9), basic valve bodies (2, 3) and additional valve bodies (25, 26, 26') branching off from the connector housing (9), with each of the valve bodies (2, 3, 25, 26, 26') having a valve housing (10) designed as a guide cylinder with a lateral discharge outlet (4) opening into the respective outlet line (5), with a valve spindle (13, 13a) movable in the axial direction within the guide cylinder with a valve head (12, 12a) engaging in a valve seat (6) in the connector housing (9) in the closed position of the respective valve body, as well as the use of this multiway valve.The basic valve bodies (2, 3) have a valve head lantern (17, 18) in the form of a straight cylinder (17) with an attached, straight cylinder (18) cropped at an inclined angle.

Abstract: The invention provides a process and device for the spinning of polyamides including transporting vapor through at least one round spinning nozzle casing (5) using an exhaust device (14, 15) that is positioned under at least one round spinning nozzle plate (10).In this process, the vapor is injected tangentially into the upper portion of the applicable spinning nozzle casing (5) and is conducted downward through at least one helical groove (7), which is arranged along the exterior of the applicable spinning nozzle unit (6). The vapor at the lower end of the spinning nozzle unit (6) is conducted against a circular, horizontally positioned groove (8), where it undergoes a change in the direction of flow toward the spinning nozzle plate (10).