Bayer Aktiengesellschaft

Chemische Werke Huls Aktiengesellschaft

Roland Vogelsgesang

Edgar Muschelknautz

Wolfram Wagner

Wolfgang Anderheggen

Eckhard Moller

Michael Kraemer

Bernt Kesper

Wolfgang Olges

Thomas Dragovic

Rolf Dhein

Wolfgang Ebert

Wilfried Haese

Hans-Rudolf Dicke

Heiko Herold

Walter Simm

Karl-Heinz Magosch

Hermann Brinkmeyer

Hans-Josef Behrens

Helmut Ohse

Gunter B Weber

Hans Westermann

Wilhelm Schiemann

Klaus Hachmann

Horst-Dieter Bures

Winand Hahn

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

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.

A process for the production of optical fibers based on aromatic polycarbonates wherein the polycarbonate fibres are coated with a plastic, the improvement which comprises

Optical fibres based on polycarbonate fibres, and a process for the

A fluid which flows through a distributing pipe and is distributed into several outlets branching from the distributing pipe may be displaced more rapidly by another fluid, for example when changing the color of spinning solutions, if the entire layer of fluid adjacent to the wall and located upstream of a chosen outlet is caused to flow out through this outlet.

Process and an apparatus for the distribution of fluids

The processing by shaping, in particular includes here the moulding, spinning, extrusion, compression and injection moulding of polymers. An electric field thereby influences the flowing polymer melt before and/or during and/or after shaping. The temperature of the melt is maintained at a value between the glass temperature and the isotropic point. Thermotropic liquid-crystalline polymers are used as starting product. Among these are, in principle, all polymers which have mesogenic groups in the main and/or side chain and which can be processed from the liquid-crystalline melt phase. The orientation distribution and thus also the mechanical properties of the end product can be purposefully regulated by the electric field.

Thermoplastic processing of thermotropic liquid-crystalline polymers

In order to conduct thoroughly pre-mixed hot gas into a ring spinning nozzle by a rotational flow in such a manner that sufficient quantities of hot gas are available for drying the filaments situated on the inside without causing backflow and without any significant movement of the filaments by turbulence, an annular chamber with tangential inlet is placed around the ring spinning nozzle. The internal wall of the chamber is separated from a circular chamber by equalizers in its upper region while on its underside it is separated from the spinning chamber by equalizers and metal gauzes at the level of the lower edge of the spinning nozzle. The circular chamber is also separated on its underside from the spinning chamber by equalizers and metal gauzes.

Process and apparatus for conducting the hot gas in the dry spinning

A flow-promoting device in combination with a heated box tray open at the top in a reaction and degasification column in which a viscous or highly viscous liquid is flowing from an inlet end to an outlet end of the tray and in which a heating tube register is located to be completely covered by the liquid. The tube register includes a plurality of heating tubes spaced from each other, and the flow-promoting device has a bottom heating unit for the box tray positioned outside and along the bottom of the tray, a siphon plate mounted on the tray at a liquid inlet end of the tray and closely in front of the tube register, with the siphon plate having a bottom end extending to the underside of the tube register, and a weir positioned at the liquid outlet end of the box tray. The weir has a top edge extending at least to the topside of the tube register, and the spacing of the weir from the tube register is larger than the spacing of the siphon plate at the inlet end from the tube register.

Open heated box trays having flow-promoting devices

In the production of polyesters by introduction of precondensates on to a first plate of a column reactor product quality is improved and operating time is increased in that spontaneous flash evaporation of the precondensate takes place in a so-called entry box, before the introduction on to the first plate of the column reactor, and in that separation of the liquid component from the gaseous component is subsequently carried out by centrifugal force in a so-called annular chamber.

Process for the production of polyesters

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Leverkusen, Germany

Roland Vogelsgesang