Abstract: An improved dry spinning process for the production of polyurethane elastomer threads using superheated steam as the spinning medium, comprising(1) spinning polyurethane-urea elastomers prepared by chain lengthening of NCO prepolymers with diamine from a solution containing dimethylformamide or dimethylacetamide via a hot spinneret having a nozzle at not less than 100.degree. C. and at a spinning solution temperature in the nozzle of not less than 100.degree. C. into a heated spinning chimney at a chimney wall temperature of not less than 160.degree. C., while(2) introducing superheated steam into the spinning chimney at a temperature above 250.degree. C. as the spinning medium in an amount of at least 20 kg/h, if the chimney diameter is less than or equal to 28 cm, or if the chimney diameter is greater than 28 cm, in an amount of at least 20 kg/h increased by up to a factor H, wherein factor H is equal to the chimney cross-section/615 cm.sup.

Abstract: A process for the production of crimped filaments and fibers of acrylonitrile polymers of copolymers containing at least 40% by weight acrylonitrile units, by dry spinning from highly polar solvents, where the filaments are brought to extremely low solvent contents in the actual spinning tube by a minimum of superheated steam prepared in the absence of water at very high spinning tube temperatures and spinning gas temperatures, but are cooled to low filament temperatures in the spinning tube by application of water or aqueous finishes in a quantity equivalent to more than 10% by weight moisture. In this way, spun PAN filaments of good natural color are safely obtained, in which there is no washing stage and no drying stage. Acrylic fibers and filaments combining a vacuolestable structure with a very high degree of whiteness and gloss are thus obtained with densities of at least 1.180 g/cm.sup.3, giving shrinkage-free to high-shrinkage fibers, depending on the aftertreatment applied.

Abstract: In an improved crimping process, use is made of a stufferbox where(a) lid and/or floor are arranged movably and(b) in the working position, the distance between lid and floor at the inlet opening is smaller than the distance between lid and floor at the outlet opening.

Abstract: Thread bundles which are transported from top to bottom, can be wetted with liquids by means of a device consisting of a system releasing the liquid, conduits and a storage container as well as suitable transporting means for the liquid, whereby the system releasing the liquid has at least two slotted nozzles positioned one above the other and opposite each other, having a horizontal slot and whereby rods are attached at the slot ends which, seen from above, form an angle with the slot of from 100 to 170.degree., preferably from 115 to 160.degree..

Abstract: Extraordinarily low ranges of error, with respect to yarn adhesion and uniformity, in dry spinning yarns are achieved when the spinning gas in the upper part of the shaft blasts the yarns radially from the inside to the outside in an apparatus designed for this purpose, the velocity of the radial flow of gas, dirctly below the spinning nozzle, transverse to the running direction of the yarns and within a spacing of 10 mm from the nozzle, increasing from 0 to at least from 0.2 to 1 m/s.

Abstract: The conditioning of synthetic fiber material to produce perfect products with a low residual solvent content using comparatively small quantities of steam is carried out in a steam-tight conditioning apparatus consisting of several zones with a rotating perforated belt, using steam which has been superheated to temperatures of from 105.degree. to 150.degree. C., and the material having a residence time in the apparatus of more than 3 minutes.

Abstract: The conditioning of synthetic fiber material to produce perfect products with a low residual solvent content using comparatively small quantities of steam is carried out in a steam-tight conditioning apparatus consisting of several zones with a rotating perforated belt, using steam which has been superheated to temperatures of from 105.degree. to 150.degree. C., and the material having a residence time in the apparatus of more than 3 minutes.

Abstract: Threads, films or thread bundles which are transported from top to bottom, can be wetted with liquids by means of a device consisting of a system releasing the liquid, conduits and a storage container as well as suitable transporting means for the liquid, whereby the system releasing the liquid has at least two slotted nozzles positioned one above the other and opposite each other, having a horizontal slot and whereby rods are attached at the slot ends which, seen from above, form an angle with the slot of from 100.degree. to 170.degree., preferably from 115.degree. to 160.degree..

Abstract: The invention relates to a process for the production of hydrophilic filaments and fibers from filament-forming synthetic polymers by spinning a solution which, in addition to a suitable solvent, contains from 5 to 50% by weight, based on the solvent and solids, of a substance which is essentially a non-solvent for the polymer, has a higher boiling point than the solvent used and is readily miscible with the spinning solvent and with a liquid suitable as a washing liquid for the filaments, and subsequently washing this substance out of the filaments, wherein a suspension is initially prepared at room temperature from the solvent, the polymer and the substance, the suspension thus prepared is subsequently heated, left for at least one minute and at most 15 minutes at a temperature of at least 30.degree. C. and of at most 60.degree. C.

Abstract: The invention relates to a process for the recovery of acrylonitrile and other monomers from an aqueous polymer dispersion by continuous distillation in a thin-layer evaporator under reduced pressure, condensation of the evaporated monomers in a condenser under the same or similar reduced pressure and subsequent condensation or absorption respectively of the monomer vapors which have not been condensed in the condenser at a higher pressure.