Abstract: An apparatus and a method for injecting a liquid dye into a polymer melt, which includes a metering pump with a metering inlet and a metering outlet. The metering inlet connects to a dye tank and the metering outlet connects to a polymer melt carrying component. To add the liquid dye to the polymer melt in the melt carrying component in a quantity that is as uniform and accurate as possible, the invention provides for connecting the metering inlet of the metering pump to a feed outlet of a feed pump, which connects with its feed inlet to the tank. With that, it is possible to generate a feed pressure at the metering inlet of the metering pump, which can be adapted to an injection pressure at the metering outlet of the metering pump.

Abstract: An apparatus and a method for injecting a liquid dye into a polymer melt, which includes a metering pump with a metering inlet and a metering outlet. The metering inlet connects to a dye tank and the metering outlet connects to a polymer melt carrying component. To add the liquid dye to the polymer melt in the melt carrying component in a quantity that is as uniform and accurate as possible, the invention provides for connecting the metering inlet of the metering pump to a feed outlet of a feed pump, which connects with its feed inlet to the tank. With that, it is possible to generate a feed pressure at the metering inlet of the metering pump, which can be adapted to an injection pressure at the metering outlet of the metering pump.

Abstract: An apparatus for mixing and advancing a polymer melt, which includes a mixer and a conveying device. The mixer comprises a tubular mixing shaft (outer shaft) and an inner mixing shaft (inner shaft). The tubular outer shaft is arranged in surrounding relationship with the inner mixing shaft. Both mixing shafts extend in cantilever fashion into a mixing chamber, and a passageway is formed at the front end between the mixing chamber wall and the free end of the outer shaft, so that the mixing chamber is divided into an inner mixing chamber (inner chamber) and an outer mixing chamber (outer chamber), which are interconnected via the passageway. A melt inlet and a melt outlet are arranged in such a manner that the melt flow advances through the inner chamber and the outer chamber in opposite directions.

Abstract: A method and an apparatus for spinning a multifilament yarn of a thermoplastic material, wherein the thermoplastic material is extruded through a spinneret to form a downwardly advancing filament bundle. The filaments then advance through a cooling device with two cooling zones. In the first cooling zone, an air stream is directed substantially transverse to the direction of the advancing filaments, and in the second cooling zone, cooling occurs by a cooling stream composed of a mixture of air and liquid, with the cooling stream flowing oppositely to the direction of the advancing filaments. The advancing filaments are gathered to form a multifilament yarn, which is then wound into a package.

Abstract: An apparatus and method for melt spinning polymeric yarns, wherein a main melt flow is generated by an extruder and supplied to a spin head. The spin head is enclosed in a heated spinning beam and comprises a mixer, a distributor pump and a plurality of spinnerets. A feed device generates a secondary flow which is supplied to the main melt flow for the purpose of additive admixture. The secondary flow and the main melt flow are combined inside the spinning beam.