Bayer Aktiengesellschaft

Hermann-Josef Jungverdorben

Ulrich Reinehr

Toni Herbertz

Hans K Burghartz

Rolf-Burkhard Hirsch

Joachim Dross

Kurt Bernklau

Gunter Turck

Rolf B Hirsch

Alfred Nogaj

Hans Uhlemann

Christian Pieper

Peter Kleinschmidt

Hans K Burghart

Jakob Breuer

A process for dry spinning of synthetic polymers, in particular PAN threads containing more than 85 wt. % acrylonitrile in the PAN (co)polymer, with high spinning chimney capacities of at least 20 kg PAN solid per spinning chimney and hour, using superheated steam as the spinning gas and with in-chimney finishing with water or aqueous finishes.

Pan dry spinning process of increased spinning chimney capacity using

A process for the dry spinning of synthetic polymers, in particular polyacylonitrile fibres, from solutions in high polar solvents, such as dimethylformamide, which are heated to 100.degree.-150.degree. C. shortly upstream of the spinneret and spun there by spinnerets having a certain shape, and in the spinning cell the specific energy supply is at least 0.090 kWh per m.sup.2 of heated cell area, the cell is charged with at least 70 m.sup.3 (S.T.P.) of hot air per hour, and the filaments are treated in the lower part of the cell with water or aqueous preparations, so that the temperature of the filaments which leave the cell is decreased below 110.degree. C. Under these conditions, the unexpectedly high spinning cell outputs of at least 20 kg of PAN solid per spinning cell per hour can be achieved without yellowing or self-ignition of the filaments occurring.

Dry spinning process with hot air and with spinning cell outputs greater

In an improved crimping process, use is made of a stufferbox where

Stufferbox crimper and process for preparing crimped synthetic fibers

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..

Process for wetting thread bundles with liquids

A process for the production of acrylonitrile fibers and filaments having a precise cross-sectional profile in which filament-forming synthetic polymers are dry-spun from a solution having a viscosity of at least 120 falling bass seconds, measured at 80.degree. C., or a viscosity of at least 75 falling ball seconds, measured at 100.degree. C. Such solution is dry-spun through one or more nozzles. The nozzle hole are of the profile nozzles being less than 0.2 mm.sup.2 and the lateral width being less than 0.17 mm.

Processes for the production of dry-spun polyacrylonitrile profiled

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..

Device for wetting threads, films or thread bundles with liquids

Ready-for-dispatch highly shrinkable filaments and fibers made of acrylonitrile copolymers can be prepared in a continuous dry-spinning method in which:

Continuous dry-spinning process for highly shrinkable acrylonitrile

Polyacrylonitrile filaments having a residual solvent content of less than 5% by weight and a total linear density of over 100,000 dtex can be prepared without contact with an extracting agent for the spinning solvent by a process in which

Preparation of low residual solvent content polyacrylonitrile filaments

Hollow acrylonitrile fibres and filaments are prepared by dry spinning the spinning dope through a nozzle having loop-shaped nozzle orifices, the solution having a viscosity equivalent to at least 120 falling ball seconds, measured at 80.degree. C., or at least 75 falling ball seconds, measured at 100.degree. C., wherein the nozzle orifice area of the profiling nozzle is smaller than 0.2 mm.sup.2 and the maximum width of the sides of the loop-shaped nozzle is 0.1 mm and the overlap between the two ends of the sides of the loop-shaped nozzle forms an angle of from 10.degree. to 30.degree. measured from the center of the nozzle and wherein the spinning air acts on the filaments in a transverse direction to the filament take-off and the air direction forms an angle of from 80.degree. to 100.degree. with a straight line passing through the opening between the sides.

Dry-spun hollow polyacrylonitrile fibres and filaments and process for

Process for the production of dry-spun hollow polyacrylonitrile fibers

Hygroscopic filaments or fibers with a core-jacket structure of hydrophobic, filament-forming synthetic polymers having a water retention capacity of at least 10% and having uniform round to oval cross-sectional profiles are obtained by a dry-spinning process which comprises addition of a substance to the spinning solvent which

Process for producing cross-sectionally stable, hygroscopic fibers and

Hollow polyacrylonitrile fibers having a uniform closed cavity structure are obtained by dry-spinning filament-forming acrylonitrile polymers from a solution through a spinning jet comprising annular jet bores of the type shown in FIG. 1, the solution having a viscosity of at least 120 falling-ball seconds, as measured at 80.degree. C. or of at least 75 falling-ball seconds, as measured at 100.degree. C., the ring of the annular jet bores consisting of three, preferably equally large, ring segments at a distance from one another of at most 0.2 mm, the surface area of the jet bores of the profile jet amounting to less than 0.2 mm.sup.2 and the side width of the ring segments amounting to at most 0.1 mm, the spinning air acting on the filaments transversely of the direction in which they are taken off relative to the center of the spinning jet.

The invention relates to a process for the continuous production of synthetic non-discolored filaments and fibers from a filament forming synthetic polymer being difficultly soluble in an organic polar solvent particularly polyacrylonitrile polymers which process comprises preparing a suspension of said polymer and said solvent at room temperature and subsequently heating the suspension thus formed for at least 3 minutes to at least 130.degree. C., and filtering the clear spinning solution formed without intermediate cooling, homogenizing and spinning it immediately afterwards into filaments.

Continuous process for the production of filaments or fibers from

The invention relates to hygroscopic filaments and fibres of synthetic high polymers. The improved hygroscopicity compared with known synthetic fibres is due to the fact, that in a conventional dry-spun process a liquid is added to the spinning solvent which liquid has a higher boiling point than the spinning solvent used, which liquid is readily miscible both with the spinning solvent and water and which represents a non-solvent for the polymer to be spun.

Process for hygroscopic, fibres and filaments of synthetic polymers

The invention relates to dry-spun hydrophilic core-jacket filaments or fibres of a hydrophobic filament forming synthetic polymer. The filaments or fibres having a porosity of at least 50%, a water-retention capacity of at least 100% and a mercury density of at most 0.7 g/cm.sup.3. The invention also relates to a process for the production of these fibres and filaments.

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Grevenbroich, Germany

Hermann-Josef Jungverdorben