Hoechst Aktiengesellschaft

Hoechst Aktiengesschaft

Ingolf Jacob

Josef Geirhos

Burkhard Bonigk

Hans-Jurgen Strutz

Herbert Wellenhofer

Hans-Joachim Bruning

August Schneider

Eberhard Paulus

Bernd Schubert

Peter Kretschmer

Gerhard Kreuzer

Two-component loop yarns composed of core and effect filaments are made of synthetic polymers and comprise the following features. At least some of the effect filaments are made of polyester, and at least some of the effect filaments have a breaking extension of from 35 to 70%, preferably from 35 to 60%. Moreover, at least some of the effect filaments have a birefringence of from 100*10.sup.-3 to 150*10.sup.-3, in particular from 125*10.sup.-3 to 140*10.sup.-3, and at least some of the effect filaments have a hot air shrinkage of 200.degree. C. of from 3 to 14%, in particular from 5 to 10%. The effect filaments have a filament linear density of not greater than 1.5 dtex.

Two-component loop yarns, production thereof and use thereof as sewing

There is described a particularly gentle and fast process for heating and drawing yarns by passing them contactlessly through a heating apparatus at high speed. Polyester fibers have a tenacity index TI equal to or greater than 50 and a molecular orientation MO equal to or greater than 20 or a compliance COM equal to or less than 12 and a storage modulus index SMI equal to or greater than 100. The polyester fibers of the invention can be used in particular for reinforcing plastics or for producing dimensionally stable textile fabrics.

Process for drawing heated yarns, thereby obtainable polyester fibers,

There is described a tape comprising unidirectionally oriented reinforcing and thermoplastic fibers composed of yarns of reinforcing and/or thermoplastic fibers, the yarn density being about 5 to 20 yarns/cm of width and the yarns having a linear density of about 1000 to 3000 dtex, the matrix fibers having been locally incipiently or completely melted on at least one of the tape surfaces to form consolidation points. The tape is suitable as a starting material for producing composite materials.

Semifinished tape product comprising unidirectionally oriented

There is described an intermingled multifilament yarn comprising high modulus monofilaments made for example of aramid, carbon or glass and a process for producing this yarn. Conventional air intermingling is impracticable for high modulus yarns since they tend to break, because of their brittleness, which leads in particular to an appreciable reduction in the tenacity. The invention proposes carrying out the intermingling at elevated temperature--either by preheating the yarn or by heating the intermingling air. It is found, surprisingly, that, although the entanglement spacings are relatively low, the tenacity remains substantially unaffected and in some instances is even raised. The multifilament yarn produced by this process is noteworthy in particular for the low number of broken monofilament ends. The invention can also be applied to commingled yarns, yarns which are part high modulus filaments and part thermoplastic filaments.

Intermingled multifilament yarn comprising high modulus monofilaments

A gentle and fast process for heating yarns passing contactlessly through a heating apparatus. The process includes the steps of preheating a heat transfer has to a temperature above the desired final yarn temperature, feeding the preheated heat transfer gas to the yarn duct so that it impinges essentially perpendicularly on the moving yarn and along a length such that the yarn heats up to the desired elevated temperature within the heating apparatus. The present invention may be used for heating air jet textured yarns and for setting two component loops sewing yarns. The invention further relates to an apparatus for carrying out the process including a preheating means, a duct in the form of a tube drilled with holes, feed lines, and a distributor chamber enabling the heat transfer gas to impinge radially upon the outside of the yarn moving contactlessly in the duct.

Process for heat treating moving yarns and apparatus therefor

Two-component loop sewing yarn composed of core and effect filaments of high tenacity and low shrinkage made of synthetic polymers, having an ultimate tenacity of above 40 cN/tex, a thermoshrinkage at 180.degree. C. of below 8% and an ultimate tensile strength elongation of below 18%, has a total count of 200 to 900 dtex, its core filaments and effect filaments being in a weight ratio of 95:5 to 70:30 with the linear density of the core filaments being 8 to 1.2 dtex and that of the effect filaments being 4.5 to 1 dtex.

Two-component loop sewing yarn and manufacture thereof

There are described two-component loop yarns composed of core and effect filaments made of synthetic polymers, having a final tenacity of at least 30 cN/tex and a final linear density of less than 200 dtex and wherein the core and effect filaments each have a total linear density of in each case of less than 100 dtex. The yarns described are preferably useful as sewing yarns. They are obtainable by a process comprising the measures:

Low-denier two-component loop yarns of high strength, production thereof

There are described a process and apparatus for measuring the degree of filament intermingling of an intermingled multifilament yarn. The intermingled yarn is moved through a self-conveying fluid jet (air jet). The yarn substantially fills out the jet channel and emerges from the jet in a virtually tensionless state. Owing to the pressure difference at the jet outlet, noncohesive yarn zones expand explosively in the manner of a balloon. After expansion, the yarn passes before a sensor means, preferably an electronic camera, which detects the lightness differences or light diffraction phenomena due to the yarn filaments and sends as a function thereof a signal to a signal processing means. The method of measurement of the invention makes it possible to obtain very accurate information about the nature of the intermingling (spot type or continuous) and also about the geometry of intermingling (for example number and spacing of intermingling nodes in the case of spot type intermingling).

Process and apparatus for measuring the degree of filament intermingling

Method for measuring the degree of intermingling of yarns where an optical sensor is used to register intermingled and non-intermingled yarn sections, which comprises performing the measurement on a yarn which has been laid with no or low tension onto a moving support which transports the yarn past the optical sensor at a selectable, constant speed at a distance suitable for registering the yarn properties, and an apparatus for carrying out this method.

Measurement of degree of intermingling and measuring apparatus therefor

An intermingling nozzle for filaments and yarns is described. The intermingling nozzle comprises a reedlike side by side arrangement of alternate yarn channel and closing plates. In the yarn channel plate sides adjoining the closing plates, grooves are formed as yarn channels and perpendicularly thereto as blowing channels. The closing plates are rotatable with respect to the yarn channel plates, specifically between an open position, in which they give access to the yarn channels to allow yarns to be inserted, and a closed position, in which they cover up the yarn channels. The intermingling nozzle is suitable in particular for intermingling high-count yarns, for example for reinforcing fabrics and tire cords.

Intermingling nozzle

A yarn brake is arranged in the direction of the traveling yarn after the section where the yarn tension has to be kept constant, and the yarn tension is measured before this brake. The yarn is fed to and drawn off from the brake at a substantially constant speed. The control, contrary to the hitherto known processes, has to be carried out inversely, that is, for example, when the measuring feeler signals a rise in the yarn tension in the section to be controlled, the braking effect of the brake has to be increased until the set value of yarn tension in this particular section is attained again. Correspondingly, the braking effect has to be decreased when the yarn tension measured is too low.

Process for the control of yarn tension

To facilitate the introduction of running yarns into injector nozzles the cross section of the inlet openings of the said nozzles are enlarged before the yarns are laid in, the yarns are sucked into the enlarged openings and subsequently the openings are reduced to their initial dimensions. The injector nozzles are preferably used in jet stufferbox texturizing processes or with suction guns. Without special threading aids, yarns and threads supplied at high speed are sucked in automatically and conveyed into spaces under elevated pressure.

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Untermeitingen, Germany

Ingolf Jacob