Abstract: Techniques produce a multifilament thread from a polyamide melt. In this case, freshly extruded filaments are cooled and combined to form a thread. In order, in addition to low boil-off shrinkage, to achieve high strength, the thread is taken off at a take-off rate in the range from 3600 m/min to 4600 m/min, preferably from 4000 m/min to 4400 m/min, by a first godet group having unheated guide casings. Subsequently, the thread is fully drawn between the first godet group and a second godet group having heated guide casings. After drawing, the thread is heated to a thread temperature in the range from 140° C. to 200° C. under tension at the guide casings of the second godet group and relaxed. After relaxing, the thread runs in a contact-free manner through at least one free cooling section between the second godet group and a third godet group having unheated guide casings.

Abstract: Techniques produce a multifilament thread from a polyamide melt. In this case, freshly extruded filaments are cooled and combined to form a thread. In order, in addition to low boil-off shrinkage, to achieve high strength, the thread is taken off at a take-off rate in the range from 3600 m/min to 4600 m/min, preferably from 4000 m/min to 4400 m/min, by a first godet group having unheated guide casings. Subsequently, the thread is fully drawn between the first godet group and a second godet group having heated guide casings. After drawing, the thread is heated to a thread temperature in the range from 140° C. to 200° C. under tension at the guide casings of the second godet group and relaxed. After relaxing, the thread runs in a contact-free manner through at least one free cooling section between the second godet group and a third godet group having unheated guide casings.

Abstract: A method for melt spinning, stretching, and winding a multifilament thread to form an FDY-yarn as well as a device for performing the method are presented. Hereby, a plurality of filaments are first extruded from thermoplastic melt, cooled to a temperature below the glass transition temperature of the thermoplastic material, and gathered to form a filament bundle without adding a preparation fluid. The filament bundle is then drawn-off at a speed above 1,500 m/min., heated to have a temperature above the glass transition temperature of the thermoplastic material, and stretched at a drawing speed above 4,000 m/min. Preparation of the filament bundle with a preparation fluid and winding the thread to form a spool is then performed. The device has the preparation device arranged in a zone of the thread course between the drawing device and the winding device, in which the thread has a thread-running speed above 4,000 m/min.

Abstract: A method for melt spinning, stretching, and winding a multifilament thread to form an FDY-yarn as well as a device for performing the method are presented. Hereby, a plurality of filaments are first extruded from thermoplastic melt, cooled to a temperature below the glass transition temperature of the thermoplastic material, and gathered to form a filament bundle without adding a preparation fluid. The filament bundle is then drawn-off at a speed above 1,500 m/min., heated to have a temperature above the glass transition temperature of the thermoplastic material, and stretched at a drawing speed above 4,000 m/min. Preparation of the filament bundle with a preparation fluid and winding the thread to form a spool is then performed. The device has the preparation device arranged in a zone of the thread course between the drawing device and the winding device, in which the thread has a thread-running speed above 4,000 m/min.

Abstract: A process for the production and for the winding of one polyester yarn, preferably multi-filament yarn, which comprises at least about 85 weight %, in relation to the total weight of the polyester yarn, of polytrimethylene terephthalate (PTT) wherein said process is characterized in that filaments of said polyester yarn is heat-treated, before it is wound on a bobbin, at a temperature in the range of about 70° C. to about 180° C. The method of accomplishing this is by heating the godets that are used in the spinning part of the process, preferably the last pair of godets, to relax the yarns so that the yarn package will not shrink significantly during storage and/or transportation. It is thus possible to obtain at least one PTT yarn package with long-term stability during storage and which is insensitive against elevated temperatures during storage and transport.

Abstract: A melt spinning apparatus for spinning a synthetic yarn, wherein the yarn is formed by combining a plurality of filaments and wound to a package by means of a takeup device downstream of the spinning apparatus. Downstream of the spinneret, an inlet cylinder with a gas-permeable wall and a cooling tube are arranged. The cooling tube connects to a suction device such that an air stream forms in the cooling tube in the direction of the advancing yarn. This air stream assists the advance of the filaments and leads to a delayed cooling. To ensure adequate cooling of the filaments within the cooling zone, an air supply device is provided for generating an additional cooling air stream which flows in the axial direction of the cooling tube for cooling the filaments downstream of the inlet to the cooling tube.

Abstract: A process for the production and for the winding of one polyester yarn, preferably multi-filament yarn, which comprises at least about 85 weight %, in relation to the total weight of the polyester yarn, of polytrimethylene terephthalate (PTT) wherein said process is characterized in that filaments of said polyester yarn is heat-treated, before it is wound on a bobbin, at a temperature in the range of about 70° C. to about 180° C. The method of accomplishing this is by heating the godets that are used in the spinning part of the process, preferably the last pair of godets, to relax the yarns so that the yarn package will not shrink significantly during storage and/or transportation. It is thus possible to obtain at least one PTT yarn package with long-term stability during storage and which is insensitive against elevated temperatures during storage and transport.

Abstract: An apparatus and method for spinning a synthetic yarn, wherein a heated polymeric melt is extruded through a spinneret and the resulting filaments are combined and wound to a package by means of a take-up device located downstream of the spinneret. A cooling tube for the filaments is positioned below the spinneret, and an inlet cylinder which has a gas permeable wall is positioned between the inlet cylinder and the cooling tube. The cooling tube connects to an air stream generator in such a manner that an air stream develops in the cooling tube in the direction of the advancing yarn. The air stream is formed by a quantity of air that enters the cooling tube via the inlet cylinder, and the inlet cylinder is subdivided in the direction of the advancing yarn into several zones, each with a different gas permeability, for controlling the quantity of air entering the inlet cylinder. It is thereby possible to influence with advantage the precooling of the yarn and the formation of the air stream.

Abstract: A method and an apparatus for melt spinning a multifilament yarn from a thermoplastic material, wherein a spinneret extrudes the thermoplastic material to strandlike filaments, which are initially in liquid form and then cooled to cause their solidification. For purposes of cooling, the filaments are precooled in a cooling zone downstream of the spinneret in such a manner that the filaments do not solidify. Subsequently, the filament bundle advances by the action of a coolant stream directed in the direction of the advancing yarn into a tension zone and undergoes further cooling until the filaments solidify in a solidification zone within the tension zone. To maintain the location of the solidification zone within the tension zone in a predetermined desired range thereof, an adjustable cooling of the filaments within the cooling zone is provided.

Abstract: A method and an apparatus for producing a highly oriented yarn (HOY) wherein the yarn is withdrawn from the nozzle of a spinneret at a withdrawal speed of at least 6,500 m/min. The filaments forming the yarn are drawn during their solidification, so that a highly oriented molecular structure forms in the polymer. To withstand the withdrawal tension generated by the high withdrawal speed without overstressing the filaments, the filaments are assisted in their advance before they solidify such that prior to the solidification a tensile stress relief is effective on the filaments, and that during the solidification a reduced withdrawal tension is effective on the filaments while they are drawn.

Abstract: An apparatus and method for spinning a synthetic yarn, wherein a heated polymeric melt is extruded through a spinneret and the resulting filaments are combined and wound to a package by means of a take-up device located downstream of the spinneret. A cooling tube for the filaments is positioned below the spinneret, and an inlet cylinder which has a gas permeable wall is positioned between the inlet cylinder and the cooling tube. The cooling tube connects to an air stream generator in such a manner that an air stream develops in the cooling tube in the direction of the advancing yarn. The air stream is formed by a quantity of air that enters the cooling tube via the inlet cylinder, and the inlet cylinder is subdivided in the direction of the advancing yarn into several zones, each with a different gas permeability, for controlling the quantity of air entering the inlet cylinder. It is thereby possible to influence with advantage the precooling of the yarn and the formation of the air stream.

Abstract: A melt spinning apparatus and a method for spinning a synthetic yarn, wherein the yarn is formed by combining a plurality of filaments and wound to a package by means of a takeup device downstream of the spinning apparatus. Downstream of the spinneret, an inlet cylinder with a gas-permeable wall and a cooling tube are arranged. The cooling tube connects to a suction device such that an air stream forms in the cooling tube in the direction of the advancing yarn. This air stream assists the advance of the filaments and leads to a delayed cooling. To ensure adequate cooling of the filaments within the cooling zone, an air supply device is provided for generating an additional cooling air stream which flows in the axial direction of the cooling tube for cooling the filaments downstream of the inlet to the cooling tube.

Abstract: The invention relates to a cooling assembly for a fiber spinning machine, which forms a cooling zone for the fibers and has openings, through which a cooling fluid flows to the fibers. The cooling assembly is formed by a plurality of overlying annular elements. Arranged between the elements are spacers so as to permit air to flow between the elements into the cooling assembly.