EP0086451A2 - False-twist textured yarn and method for producing it - Google Patents

Abstract

The invention relates to a yarn made from false-wire-textured, fully synthetic yarn components, in which the one component only has a crimp of less than 10%, and a method for its production, in which the yarn component with reduced crimp by using a false wire number reduced to 35 to 65% of the value according to Heberlein and optionally texturing temperatures of 120 to 180 ° C is obtained.

Description

The invention relates to a false twist texturing yarn and its manufacture by plying and optionally blowing two oppositely false twist textured yarn components.

A number of methods are known from the prior art for producing twist-neutral or non-twist-living yarns by folding two yarns textured in the wrong direction in opposite directions. In this context, oppositely false-textured yarns are to be understood as those yarns which, in the conventional false-wire texturing, were in a state of opposite high twist, that is to say they have temporarily undergone rotation in the S or Z direction. While false-twisted textured yarns that only consist of single filaments. exist, which were all turned up in the same direction, even after turning back, have a tendency to twist or twist, this is no longer the case when combining two oppositely textured textures, here the torques remaining after the false wire texturing generally cancel each other out. The folding of oppositely false-textured threads can be supported by intermingling the individual filaments of the various components, such as e.g. is described in DE-OS 17 10 639, or can also be achieved by a slight rotation of the plied yarns, but this is usually associated with a reduction in volume and elasticity.

Wird mit einer Falschdrahtzahl in der Nähe des Wertes der Heberlein-Formel gearbeitet, so werden allgemein ein optimaler Bausch und besonders gute Kräuselwerte der behandelten Garne bzw. Einzelfilamente beobachtet.Twist neutral yarns have also been used as blended yarns. from individual filaments from various raw materials poses. For example, DE-OS 22 48 556 proposes false-textured cellulose acetate yarns with corresponding yarns made of polyester, polyamide, etc., while in DL-PS 1 419 33 folds and blows polyamide and. Polyester yarn is described to achieve special coloring effects. With these twist-neutral yarns according to the prior art, care is taken to texture both yarn components under optimal conditions. For synthetic yarns, the optimal number of false wires, ie the number of temporarily applied twists per unit length during false wire texturing, can be estimated using the so-called Heberlein formula (see GB-PS 707 859):

If the number of false wires used is close to the value of the Heberlein formula, an optimal bulk and particularly good crimp values of the treated yarns or individual filaments are generally observed.

With friction texturing, on the other hand, it is not possible to give an exact indication of the temporarily applied rotation, as is the case, for example, with Arthur and Welle in J. Text. Inst., No. 2 (1960), M 66 ff. In industrial practice, the optimum text _u riereinstellungen, especially the D / Y-value, determined from the Kräuselwerten the textured yarns; Using complex measuring methods, it can be demonstrated that the rotation actually applied by the friction swirl device then again corresponds to the known Heberlein value.

Such a texturing process turns the smooth filament yarns into crimped, bulky yarns that can be processed into fabrics that have an appearance and volume that resembles fabrics made of staple fibers. However, the "synthetic" appearance, the handle and the case of such flat structures made of false-wire-textured synthetic yarns are still contested.

The loss of goods e.g. On the other hand, knits made from textured viscose filament yarns are described as silky and flowing. Until now, it has not been possible to get a corresponding loss of goods in textile fabrics from fully synthetic material.

There was therefore still the task of developing suitable textured filament yarns from fully synthetic individual filaments, which can be processed into textile fabrics which have the appearance, feel and fall of fabrics made of textured viscose filament yarns, but do not have to be produced using a complicated wet spinning technology and secondly do not have the low dimensional stability and the continuous shrinkage with every wash.

It has now surprisingly been found that false twist texturing yarns, which consist of two components of fully synthetic individual filaments, which have different twist tendencies, can then be processed into textile fabrics with properties not previously known if the individual filaments of one component have egg-reduced crimp (E) which is less than 10%, mostly less than 6% and preferably less than 3% and the individual filaments of the other yarn component have a normal crimp of more than 30%, preferably more than 50%. It is therefore necessary that the crimp values of the individual filaments of the two yarn compos differ significantly. Substituting the value of Einkräuselun ^g of false-normal component equal to 100%, the single filaments of the other component should exhibit only Einkräuselungswerte that amount below 35% based on the normaltexturierte component, preferably 1 to 20%. The individual filaments of the two components preferably consist of the same thread-forming substance, in particular of thread-forming polyesters.

False-wire texturing yarns of this type can be obtained by plying and, if necessary, additionally blowing two counter-false-textured yarns, if the one yarn component is false-textured in the usual way under optimal conditions, i.e. So at optimal temperature and a false wire, which results approximately from the Heberlein formula given above, while the other yarn component is subjected to an opposite twist, which is only 35 to 65, preferably 40 to 55% of the optimal false wire for this component . Preferred embodiments of the method are the subject of the dependent claims.

Particularly attractive yarns result if the yarn component is textured with a reduced number of false wires at lower temperatures. The normal-textured component is preferably textured or stretch-textured at the usual temperatures of about 200 ° C, the yarn component with a reduced number of false wires, on the other hand, at 120 to 180 ° C. Particular preference is given to using identical yarn components as the starting material, but it is also possible to use different raw materials, titers , Profiles, etc. other effects can be achieved.

In the method according to the invention, the texturing parameters that go beyond the number of false wires and possibly the texturing temperature are selected in the usual range, as they are e.g. in the compilation by Scherzberg in "Melliand Textile Reports" (1966), issues 2 to 12.

The shingling of the yarns can take place at any time after the false-wire texturing, but preferably immediately after the false-wire texturing before winding on a bobbin of the texturing machine. The fold can particularly preferably be improved by swirling. This type of intermingling is usually carried out by using blowing nozzles, but care must be taken to ensure that the thread tension is sufficient to avoid the formation of loop yarns that are possible under these conditions.

The process is particularly simple and, in particular, provides homogeneous yarns if the two yarn components have been produced on immediately adjacent texturing points and, after passing through the swirlers, are folded and, if necessary, blown. Under these circumstances, it is usually not possible to run the texturing heater at different temperatures for the different yarn components. However, it is possible to shorten the dwell time of a yarn on the texturing heater by comparison with the dwell time of the normal component by using appropriate thread guide elements.

As already stated above, however, it is still possible to fan the yarn components at a later point in time, if necessary directly before entering the knitting machine, and to blow them if necessary. It is then necessary to ensure a constant infeed speed of the yarn components under a given tension, unless special infeed effects which are not the subject of this application are to be produced by different infeed speeds or infeed tensions.

If spindle twist sensors are used in the false wire texturing machines used, the number of false wires can be set exactly by the speed of the spindles. When using friction swirlers with multi-axis disc units, the number of false wires can preferably be determined by the center distance of the disc units.

Identical yarns are preferably used as the starting material for the process according to the invention. Drawn yarns from Cops can be false-wire textured, but so-called quick-spinning yarns such as those e.g. are described in DE-OS 22 11 843. When using such spun yarns, the yarn components are to be drawn simultaneously during the false twist texturing process.

Essential to the invention is the significantly different number of false wires of the two yarn components textured in opposite directions. The significantly reduced number of turns in the second component leads to crimping values (F 1) of less than 10%, mostly even less than 6% compared to crimping values of approximately 50% and more for the component with normal false wire number.

When using the yarns according to the invention, textile fabrics can be produced which are clear in their surface structure, their feel and their fall deviate from those made from simple false-wire-textured yarns or fabrics made from twist-neutral, fully synthetic textured yarns. For example, the loss of a circular knitted piece made of a dtex 76 f 24 x 2 yarn produced according to the invention is described by knitting specialists as silky, flowing and ground. This effect can be enhanced by using a suitable profile, such as a triangular profile. The loss of goods can best be compared to knitwear made from false-wire textured viscose filament yarns.

If knitted pieces are produced from the yarns according to the invention in double-relief, structure or modified plain weaves, the result is a plastic product appearance that could previously only be obtained from high-twisted viscose yarns.

The causes of these surface effects of knitted pieces could lie in a very fine loop and / or loop structure of the yarns according to the invention. Such a loop structure can be made visible with an extremely loose knitting. If, for example, a yarn according to the invention is knitted on a single-system knitting machine with an infeed tension of only 4 cN, then after the heat treatment of a washing or dyeing process, a fabric with a distinctive terry structure is obtained, which is explained in more detail in Example 1. This "terry structure" can be optimized by a suitable choice of the number of false wires and the texturing temperature. In the case of appropriately tied knitted pieces, this optimum also gives about the optimum of the change in the surface structure described above in the direction of viscose texturing yarn. The resulting improvements in the upper surface structure, 'in the grip and in the case, however, can only be qualitatively recorded subjectively. However, the formation of the terry structure of the knitted pieces examined allows an objective optimization.

The invention will be further explained in the following examples. The influence of the reduced number of false wires for a component is shown. Another example shows the possibility of operational production of a yarn according to the invention and another example shows the influence of the texturing temperature on the structure of the texturing yarn according to the invention.

In the case of the values for tensile strength or elongation at break given in the examples, the fineness-related maximum tensile force or maximum tensile force elongation is to be understood in accordance with DIN 53 815, the values for cooking shrinkage or thermal shrinkage are in accordance with DIN 53 866, the values for crimping or crimping resistance determined according to DIN 53 840.

example 1

The following example shows the production of the texturing yarn according to the invention by plying two false-wire textured yarn components. A dtex 86 f 24, round, glossy, polyethylene terephthalate high-speed spun yarn was spun out as the starting yarn for both components, and was wound up at a spinning take-off speed of 3,000 m / min. The texturing draw ratio of these threads was 1: 1.5

The normal textured component, which was stretch textured in the usual way, was produced in compliance with the following parameters:

The D / Y value is the quotient of the circumferential speed of the swirler discs (disc) and the yarn speed (yarn). Three-axis friction swirlers from Barmag, Barmer Maschinenfabrik AG, each with three ^(R) KYOCERA ceramic disks, were used as swirlers.

The textile technology data of this normally textured yarn component were:

In this example, a row of twists is shown for the second, less false-textured component, the false-wire number of the second component being set precisely with the help of a bar spindle. Both components were then folded on the knitting machine and knitted in a loose setting. A tube knitting machine of type SBV-A 2 from Santoni was used for this purpose, which had an 8 pitch and a diameter of 3.5 "and 88 needles. The inlet tension was approximately 4 cN.

Bei dem anschließenden Verstricken wurde jeweils ein normaltexturiertes Garn und eine Komponente der Proben 1a bis 1d vor der Strickmaschine gefacht, wobei auf gleiche Einlaufgeschwindigkeit und Fadenspannung geachtet wurde.In the texturing, the draw ratio, as with the normal component, was 1: 1.5, the heater temperature was 200 ° C, the number of false wires was varied, the wrong wire was twisted in the Z direction, while the normal component was textured in the S direction. The number of false wires according to Heberlein is 3270 T / m.

In the subsequent knitting, a normally textured yarn and a component of the samples 1a to 1d were each fanned in front of the knitting machine, taking care of the same running-in speed and thread tension.

The knitted tubes obtained were then dyed under the following conditions:

The samples were then rinsed with water, spun and dried.

The knitted hoses obtained from the plied yarns showed a terry-like loop structure, which initially became more pronounced as the number of false wires in the second component increased. An optimum of this loop structure was obtained with the folded yarn using yarn component 1c, with a number of false wires, which was about 40% of the value which is calculated using the Heberlein formula. A further increase in the number of false wires of the second component, which forms the loops, led to the curling of the protruding loops and to an increasingly fine crimping of the individual filaments of this component.

Samples of the knitted tubes obtained with the samples 1a, 1c and 1d are shown enlarged in FIGS. 1 to 3. The formation of the loops structure can be seen on the outer edges of the knitted tubes. FIG. 1 shows the knitted tube which was obtained using the yarn component 1a. With this yarn component, only one false wire count of 750 T / m, corresponding to 22.9% of the theoretical value according to Heberlein, was observed. There are relatively few pronounced loops on the edge of the hose.

FIG. 2 shows the failure using component 1c with a number of false wires of 1360 T / m, corresponding to 41.5% of the Heberlein value. The loops are strongly developed and are arched from the main mass of the knit. In Figure 3, the sample 1d was processed together with the normal component. Component 1d has a false wire count of 1720 T / m corresponding to a value of 52.5% according to the Heberlein method.

In this pattern, the loops of the component with a small number of false wires no longer protrude far from the main mass of the goods, show curls and a finer crimp.

If the yarns are knitted from mixtures of the yarn component with normal false twist texturing and yarn components with a reduced false twist count under normal conditions, it can be seen that the desired special features of these textile fabrics change approximately parallel to the terry structure observed on the sample pieces.

Example 2

This example shows the production of a yarn according to the invention by the sole use of friction swirlers. Work was carried out on a stretch texturing machine that was equipped with three-axis friction swirlers from Barmag AG, each equipped with three friction discs made from ^(R) KYOCERA. The yarn was inserted into the twister in the usual way by unfolding one of the three axes. To transfer the lesser false wire to the second component, this yarn was textured with a half-open twister, ie with an increased center distance, while the first component was textured with a closed twister as usual. The distance between the three axes is 38 mm when closed and has been increased to 49 mm to transmit the low swirl. One thread each with normal false wire (completely closed twister) and reduced false wire (partially closed twister) were fanned after leaving the twister and swirled with the aid of a blowing nozzle. The starting yarns and all parameters not mentioned in the following table correspond to the information in Example 1.

The looped structure of the knitted tubes made from the obtained interlaced and interlaced yarn corresponded to those obtained from normal textured goods and sample 1c according to Example 1, the knitted fabrics in firm inclusion showed the desired viscose-like feel and fall.

Example 3

Fast spun fabric made of polyethylene terephthalate with the spin titer dtex 86 f 24, glossy, round served as the template for the texturing machine. The normal textured material was again made using a Friction swirl generator from Barmag, Barmer Maschinenfabrik equipped with three times three ^(R) KYOCERA disks. The material was given a Z-twist during stretch texturing, the heater length was 125 cm. The following values were also observed

The yarn or yarn component obtained showed the following test results

The second yarn component with a reduced number of false wires was textured wrongly with the help of a bar spindle in the S direction. The heater length was again 125 cm. Further setting data:

This yarn component showed the following test results:

Both yarn components were assembled on a knitting machine with 10 divisions and knitted together with very little tension. To the. ge washed knitting patterns, the thread textured with a lower number of false wires stands out in most stitches as a small loop and leads to the terry character described. If the sample pieces obtained are washed and dyed, a terry-like character of the textile fabric develops, as was shown in FIG. 2. When such combined false-wire-textured threads are knitted under conventional yarn tensions, flat structures are obtained which in turn have the desired viscose-like handle and drop.

In the setting data of Example 3, it is striking that here, in contrast to the results of Example 1, a false wire count of 1710 T / m, corresponding to 52.5 _{% of} the theoretical value according to Heberlein, has still resulted in a usable yarn component. The reason for this is that in this example the temperature of the heater has been reduced from usually 200 ° to 145 ° C. Under these conditions, the desired reduced crimp is achieved even at somewhat higher numbers of false wires than at higher temperatures.

Claims (11)

1. False wire textured yarn from two yarn components, which consist of fully synthetic single filaments and have different twist, characterized in that the single filaments of one component have a reduced crimp (E) which is below 10% and that the single filaments of the other yarn component have a crimp in have a known height of over 30%, preferably over 50%. 2. Texturing yarn according to claim 1, characterized in that the yarn component with reduced crimp has a crimp of the individual filaments of less than 6%, preferably less than 3%. 3. Texturing yarn according to claim 1 or 2, characterized in that the individual filaments of the two components have the same thread-forming substance. 4. Texturing yarn according to claim 3, characterized in that a polyester is used as the thread-forming substance. 5. A method for producing a false-twisted yarn by doubling and optionally additional blowing two oppositely falschdrahttexturierter yarns, characterized in that said one yarn component at full false twisting number corresponding to the Heberleinformel and the other with a false twisting number of 35 to 65, preferably from ₄ 0 to 55% of the theoretical number of false wires according to Heberlein is applied. 6. The method according to claim 5, characterized in that the yarn component is textured with a reduced number of false wires at a temperature of 120 to 180 ° C. 7. The method according to claims 5 or 6, characterized in that identical yarns are used as the starting material for both components. 8. The method according to claim 5 to 7, characterized in that undrawn fast-spun yarns are used as the starting material for both yarn components, which are simultaneously stretch-textured. 9. The method according to claims 5 to ₈ , characterized in that at least one of the yarn components is textured by means of false twist spindles. 10. The method according to claims 5 to 9, characterized in that the yarn components of multi-axis disc units are false wire textured, which have a different center distance of the discs. 11. The method according to claims 5 to ₁₀ , characterized in that the two components on adjacent texturing points a texturing machine is produced and after passing through the swirl device and optionally blown, and where appropriate the yarn component with the reduced number of false wires runs a shorter distance on the texturing heater than the false wire component with normal false wire number.

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