Bayer Aktiengesellschaft

Wolfram Wagner

Dieter Paulini

Peter R Nyssen

Dirk Berkenhaus

Wolfgang Anderheggen

Roland Vogelsgesang

Michael Bueb

Hans-Theo Van Pey

Ulrich Reinehr

Rolf-Burkhard Hirsch

Wolfgang Rellensmann

Michael Kraemer

Wolfgang Olges

Thomas Dragovic

Erich Hilgeroth

Peter Schmitz-Bastian

Rolf-Volker Meyer

Helmut Waldmann

Hans-Joachim Traenckner

Edgar Muschelknautz

Bernd Klinksiek

Kaspar Hallenberger

Ralf Miessen

Herbert Schmidt

Zoltan Kricsfalussy

Heinrich Steude

Helmut Ohse

Beatrix Frauendorf

Klaus Rall

Geert Christoph

Hans-Joachim Wollweber

Roger Nyssen

Harry Kubitzek

Wolfgang Backer

Robert Bruck

Peter Landen

Lothar Rupprecht

Arthur Langhans

Herbert Groschel

Gunther Hahn

Winand Hahn

Gunter Espanion

Gunter Haladuda

Karl-Heinz Schott

Gunter Bieber

Peter Widder

Siegfried Kulisch

Wolfgang 35e,uml/a/ Cker

The preparation of dimethyl carbonate by reaction of methanol, carbon monoxide and oxygen in the presence of Cu compounds is carried out in distillation units and the water of reaction is removed at least partially from the stripping region or the bottom phase.

Process for preparing dimethyl carbonate

Glass fibres which are distinguished by their greatly reduced carcinogenicity have an average fibre diameter of &lt;8 .mu.m, preferably &lt;3 .mu.m, with more than 10% of the fibres having a diameter of &lt;3 .mu.m. The types of glass used for producing these fibres are characterized by containing the following compounds in the proportions shown in mol %:

Glass fibres with improved biological compatibility

The invention relates to a process for the production of low-gel spinning solutions-surprisingly stable in their solution viscosity-of segmented polyurethane urea elastomers in highly polar solvents, such as dimethyl formamide or dimethyl acetamide, characterized by the use of multistage jet reactor, and to a multistage jet reactor.

Process for the production of viscosity-stable, low-gel highly

This invention relates to processes for the production of mono- and multifilaments and also staple fibers of multifilaments based on polyarylene sulfides, preferably substantially linear polyarylene sulfides and, more preferably, substantially linear poly-p-phenylene sulfide by melt spinning, multistage stretching and optionally crimping and setting. As a result of the treatment by blowing of air onto the stabilized spun filaments in the first stretching stages at temperatures .ltoreq.100.degree. C. (preferably in stretching baths, more particularly in boiling water), the chain molecules are oriented; the orientation and crystallinity required for high strengths is achieved by afterstretching (in hot air) at elevated temperature. The residence times in the first stage required for effective stretching in accordance with the invention can only be varied within relatively narrow limits in order subsequently to achieve the calculated orientations and effects, particularly high strengths, crystallinities and densities. Overly long residence times at temperatures above 100.degree. C. result in elongation of the material with no additional orientation and hence with an inadequate increase in strength. To increase crystallinity and strength in the production of mono- and multifilaments, multistage stretching may be followed by a thermal aftertreatment; in the staple fiber process, the material is additionally crimped, set (in the absence of tension) and cut. Where an aerodynamic crimping nozzle is used, as is preferably the case, stretching has to be carried out in accordance with the invention in such a way that the fibers are left with sufficiently high shrinkage which is important for crimping and subsequent processing. Crimping is improved by setting in the absence of tension. Relatively high-tensile fibers with sufficiently high residual crimping for subsequent processing are obtained. Textile-denier fibers (up to about 20 dtex) having hitherto unknown strengths of &gt;6 cN/dtex, preferably &gt;6.2 cN/dtex and, more preferably, &gt;6.4 cN/dtex are claimed.

Processes for the production of mono- and multifilaments and staple

Fibres, fibre webs or fibre aggregates made of polyphenylene sulphide (PPS) or of mixtures of PPS with other polymers are produced by a melt-spinning process where the melt filaments are drawn out and cooled down to below the melt temperature by a gaseous medium flowing essentially parallel thereto at sonic or supersonic speed, this simultaneous deformation and cooling giving rise to amorphous fine or extremely fine fibres (17) of finite length which are deposited to form a fibre web or fibre aggregate.

Extremely fine polyphenylene sulphide fibres

Processes for the production of mono- and multifilaments and also staple fibers of multifilaments based on polyarylene sulfides by melt spinning, multistage stretching and setting. As a result of the treatment by blowing of air onto the stabilized spun filaments in the first stretching stages at temperatures .ltoreq.100.degree. C., the chain molecules are oriented; the orientation and crystallinity required for high strengths is achieved by afterstretching at elevated temperature. The residence times in the first stage required for effective stretching can only be varied within relatively narrow limits in order subsequently to achieve the calculated orientations and effects. Overly long residence times at temperatures above 100.degree. C. result in elongation of the material with no additional orientation and hence with an inadequate increase in strength.

The polymer granular melt (1) is whirled out of a rotating nozzle head (6) through a plurality of exit holes (24) with fibre formation (32) and the fibres formed (9) are deposited on a collecting surface (12) in web form (15). This polymer melt is introduced into the nozzle head (6) under a preliminary pressure of 1 bar to 200 bar, preferably 1 bar to 50 bar. Furthermore, the fibres (32) are deflected by a high-speed gas stream (7, 8) in a radial direction at a radial distance of 10 mm to 200 mm from the exit holes (24) and, in the course of being deflected, are simultaneously drawn and stretched. The melt streams (32) exiting from the exit holes (24) can be additionally drawn by gas streams (26, 34) exiting in the vicinity of the exit holes (24) at the nozzle head (6) with a predominantly radial component before coming under the influence of the axial deflecting gas stream (7, 8).

Production of very fine polymer fibres

A compressing chamber (7) for directed crimping consists of step-shaped bars (8) by way of increasing outwards in length.

Device for crimping large filament groups

For the purpose of conveying slivers the latter are fed over constructional units (15) which are situated behind each other in a staggered maner from injector (8), in a pipe (16) including a guide means (17) by means of an air supply, and subsequently carried further by mechanical means.

Conveying of filament bundles over long conveying sections

Filament cables are crimped and the crimp cake of the filament cable obtained is passed over a gas permeable screen plate while gas flows to the bottom of the cake from flow through the screen plate so that the cake can be moved over the plate without making contact therewith or with reduced contact force and can be treated during its residence over the screen plate.

Process for treatment of filament cable

The streams of melt issuing from the melt outlet apertures (18) at the bottom of a melting crucible (14) are broken up into fibers in a drawing nozzle by means of a blast medium directed substantially parallel to the streams of melt. The blast medium is produced by a pressure gradient in the drawing nozzle and sucked in at the drawing nozzle inlet (7). In the drawing nozzle (16), the flow velocity is reduced in a downstream diffuser after the drawing process. The blast medium is supplied in the form of a hot gas between the underside of the crucible and the top edge (15) of the drawing nozzle from opposite broadsides of the melt distributor (14) in excess to the total quantity of gas stream sucked in at the drawing nozzle inlet (7). The hot gas consists of a mixture of combustion gases and air and is at a temperature from 600.degree. C. to 1500.degree. C., preferably from 800.degree. C. to 1400.degree. C. The flow velocity of the hot gas is adjusted to a value below 100 m/s, preferably 50 m/s, in the region (13) between the drawing nozzle (16) and the melt distributor (14). Gas burners (1) provided for producing the hot gas are arranged with their combustion chambers (3) situated laterally between the melt distributor (14) and the top edge (15) of the debiteuse. The combustion chambers (3) are connected by bores (6) to air chambers which are under an excess pressure. In the combustion chambers (3), the combustion gases are homogeneously mixed with the air introduced.

Process and apparatus for the production of very fine mineral fibers, in

A method for sealing a passage (2) in a wall (3) for the unsupported transport of continuously accumulating tows (1), in which the pressure difference on both sides of the wall (3) is compensated by an additional gaseous medium (5).

Sealing of apparatus with continuous product transport

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.

Process for conditioning synthetic fiber material

The treatment of a filament cable in a device into which it is introduced, in which it is crimped, treated with a gas, and withdrawn, characterized by the fact that the cable is crimped using a crimping device which is operated gas-dynamically, which has been mounted into the front face of a device for the treatment of the cable with a gas, and is thus introduced into this device in the manner of a sluice, and is folded using a slide with an S-shaped section onto a gas-permeable, horizontally transporting base as a crimping cake, is treated there with the gas, and is finally withdrawn from the device.

Process for the treatment of a filament cable

Process and an apparatus for conditioning synthetic fiber material

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Dormagen, Germany

Wolfram Wagner