EP0341420B1 - Yarn and method for making it - Google Patents

Abstract

A yarn, in particular a sewing yarn, is described which has at least one first yarn component in the form of a core and at least one second yarn component fluidised with the first yarn component. The second yarn component is arranged predominantly in the outer region, based on the finished yarn. The fluidised yarn has between about 0.02% by weight and about 20% by weight of granular particles which are incorporated in the yarn cavities and/or arranged on the outside of the yarn. The granular particles have a particle diameter between about 4 mu m and about 400 mu m. A process for the production of the yarn is also described, in which at least one first yarn component is fluidised with at least one second yarn component in a turbulent fluid stream, the first yarn component being wet with an aqueous dispersion or suspension of the granular particles, the density of which is greater than 1 g/cm<3>. In a further process, a mist consisting of finely divided water droplets and granular particles, and/or a dust of the granular particles, is added to the fluid stream, the granular particles having a density > 1 g/cm<3>. A nozzle for carrying out the process is also described, which nozzle is provided with a fluidising chamber and an outlet orifice for the finished yarn, the fluidising chamber and the outlet orifice consisting of ceramic or having a ceramic covering. <IMAGE>

Description

The present invention relates to a yarn, in particular a sewing thread, with the features of the preamble of patent claim 1 and two methods for producing the yarn with the features of the preamble of patent claims 11 and 19.

Swirled yarns, which consist of at least two yarn components, one yarn component forming the core, which is also called the core, and the other yarn component forming the sheath, have long been known.

Typically, such intermingled yarns are produced by feeding the core material with a certain advance, for example between about 1% and about 5%, together with the sheath material to a nozzle and swirling it there by an air stream, the sheath material generally being compared to the core material with a much higher lead in the nozzle. In the nozzle, the air stream hitting the yarn causes the individual filaments of the soul and / or the sheath material, for example with the formation of loops, loops and. Like., Swirled and confused, so that the resulting finished yarn forms a closed yarn structure due to this swirling or confusion, without a twisting of the two components is necessary for this.

In addition, swirled single yarns (single constructions) are known which do not have the core-sheath structure described above. Here, the multifilament yarn consisting of individual filaments is fed to the nozzle with a certain advance. swirled over an air stream in such a way that the individual filaments are swirled or tangled with themselves, so that a yarn which is closed per se results.

In order to achieve, in particular, a uniform intermingling of the core material with the sheath material and a constant thickness of the finished yarn in the known method described above, it is common in intermingling methods to wet the core-forming first yarn component with water before intermingling. This is to prevent contamination of the nozzle by preparations and / or finishing agents which are detached from the water and thus removed from the yarn in front of the nozzle. In addition, the individual filaments of the first yarn component, which may or may not be glued together by the preparation and finishing agents, are to be spread out, so that a relatively open yarn group is fed to the nozzle, which can improve the uniformity and the swirling effect. However, the previously described wetting of the first yarn component with water can lead to difficulties in the known processes. These are expressed, for example, by the fact that the preparation or finishing agents are only dissolved or hydrated during the relatively short wetting process, so that they are subsequently swirled cause considerable difficulties in the nozzle, which are noticeable, for example, in smearing or in a deposit of the dissolved or hydrated preparations and additives on the inner walls of the nozzle. This in turn leads to the fact that the flow conditions of the air flow in the nozzle responsible for the intermingling of the yarns change constantly, which is expressed in an irregularly intermingled yarn and / or undesirable titre fluctuations. With such a thread, the mechanical-technological properties are then considerably deteriorated, which can be expressed, for example, in the case of a sewing thread in a reduced strength, a deterioration in the force-elongation ratio and / or in an increase in the frequency of thread breakage during sewing.

The present invention has for its object to provide a yarn of the type specified, which has a particularly low frequency of yarn breakage during processing.

This object is achieved by a yarn with the characterizing features of patent claim 1.

The yarn designed according to the invention, which is used in particular as a sewing thread, consists of at least one first yarn component designed as a core and at least one second yarn component intermingled with the first yarn component, the second yarn component being arranged predominantly in relation to the finished yarn in the outer region thereof. Grain-like particles are arranged in the spaces between the threads and / or on the outside of the thread. The grain-like particles have a grain diameter of between approximately 4 μm and approximately 400 μm. Your concentration is between about 0.02% by weight and about 20% by weight, each based on the weight of the yarn.

Surprisingly, it was found in the yarn according to the invention that the mechanical-technological properties and the processing behavior are considerably improved in comparison with a conventionally designed, equivalent yarn which does not have such granular particles. This is expressed, for example, in that the yarn strength is improved by approximately 15% compared to the standard yarn described above, while at the same time the elasticity is improved in the yarn according to the invention. In industrial sewing tests and in comparative laboratory measurements with respect to the thread-thread friction against each other, as will be described in more detail below in the exemplary embodiments, it was found that the thread break frequency of a conventional yarn with the same structure compared to the yarn according to the invention by a factor of between is about 3 and about 8 higher. This is attributed to the fact that the grain-like particles which are embedded on the outside of the finished yarn and / or in the yarn spaces and are arranged so as to be movable relative to the individual filaments of the yarn, the friction between the individual filaments of the yarn and / or the friction of the outer yarn regions on thread deflection elements, sewing needles, other thread systems or the like. As a result, the mechanical stress on the individual filaments and / or the entire yarn is reduced and, associated therewith, less heating of the yarn occurs, so that the significantly reduced tendency to thread breaks is explained. The yarn according to the invention also has a higher interlacing in comparison to a conventional yarn produced under otherwise the same conditions, to which the property improvements previously mentioned are also attributed. Depending on the chemical composition of the grain-like particles as well as their grain diameter and distribution in or on the yarn, these particles can contribute to the electrostatic charge reduce synthetic yarns, which in turn improves the processing properties of the yarn according to the invention.

In addition to the prior art described at the outset, it should also be noted that EP 0 136 727 A discloses a yarn which is used as a filler or sealing material. Here, the known yarn, which is a single multifilament yarn, has a filament number between 1,000 and 20,000 filaments. In order to produce such a yarn, EP 0 136 727 A suggests swirling the only multifilament starting material, the multifilament starting material being wetted with an aqueous dispersion of granular particles before the swirling. The grain-like particles used for this, however, have a grain size that varies predominantly between 0.1 μm and 1 μm. The known yarn thus differs from the previously described inventive yarn not only in its construction but also decisively in the number of filaments and the size of the grain-like particles.

A particularly suitable embodiment of the yarn according to the invention has granular particles in a concentration between about 0.2% by weight and about 0.4% by weight. Especially for yarns with a very fine titer, i.e. for yarns in a titer range between about 100 dtex and about 300 dtex, it has been shown that the aforementioned concentration range of granular particles is sufficient to achieve the desired improvement in processing properties, the increase in strength and the increase in elongation behavior. This is particularly true if the grain-like particles are predominantly or exclusively arranged on the surface of the finished yarn and if the diameter of the particles is approximately in a range between 10 μm and approximately 100 μm. For yarns with higher titers, i.e. Titers in the range between approximately 500 dtex and approximately 800 dtex may require higher concentrations of granular particles, these concentrations usually being in a range between approximately 0.5% by weight and approximately 4% by weight. For yarns that have a relatively large titer, i.e. a titer in a range between 800 dtex and approximately 1200 dtex, particle concentrations in the order of magnitude between approximately 5% by weight and approximately 15% by weight may be required in order to achieve the above-mentioned favorable properties, with all of the above-mentioned yarns, the particle concentration for the respective yarn depends on the number of filaments, the distribution of the particles over the yarn cross-section and the particle diameter.

Such embodiments have particularly good mechanical properties and advantageous processing behavior of the yarn according to the invention, in which the grain-like particles have a grain diameter of between approximately 20 μm and approximately 100 μm. Such relatively small particles are particularly effective in reducing the friction described above and also have good adhesion to the yarn, so that no unwanted dusting occurs when the yarn is processed.

With regard to the distribution of the grain-like particles over the yarn cross section, it should be noted that both the embodiment of the yarn according to the invention, in which the particles are predominantly or exclusively arranged in the outer region of the yarn, and those embodiments in which the particles are evenly distributed over the yarn cross section are claimed . In particular, the last-mentioned embodiments are suitable for yarns which have a relatively high number of filaments, i.e. between about 80 filaments and about 200 filaments, have a relatively fine titer, for example between about 100 dtex and about 300 dtex. In the case of such yarns, it was found that the desired improvement in properties depends crucially on the fact that the friction between the filaments is effectively reduced, which is achieved by embedding the particles in the spaces between the filaments.

Another advantageous embodiment of the yarn according to the invention provides that the grain-like particles are embedded in a finish applied to the yarn. The finish supports the effect of the grain-like particles in reducing friction, while the finish improves the adhesion of the grain-like particles to the yarn or to the individual filaments processed therein. In addition, the avivage affects The mobility of the particles relative to the individual filaments or the yarn is only slight, so that the previously described positive properties of the particles are additionally reinforced in such an embodiment of the yarn according to the invention. With regard to the distribution of the finish, the same statements apply as were made above for the distribution of the particles.

Regarding the chemical composition of the finish, it should be noted that this can consist of the chemical compounds known per se. The carboxylic acid derivatives, phosphoric acid esters, paraffin hydrocarbons and / or organosilicon compounds should be mentioned here in particular.

As already mentioned above, the yarn according to the invention has a core-sheath structure, the core (core) made of a multifilament yarn, for example one with a titer between approximately 100 dtex and approximately 500 dtex, in particular with a titer between approximately 150 dtex and approximately 300 dtex. The number of filaments of such a core material can vary between approximately 50 threads and approximately 500 threads, in particular between approximately 100 threads and approximately 300 threads, depending on the particular field of use of the yarn. As a sheath, the core sheath yarn described above has one or more multifilament yarns, the titer and number of filaments of which correspond to approximately half the titer and the number of filaments of the core material. Of course, however, it is also possible to use a fiber yarn that is comparable in fineness to the multifilamant yarns described above.

With regard to the grain-like particles, there are basically those particles that have a certain hardness and resistance exhibit mechanical loads. Inorganic particles such as talc, kieselguhr and aluminum oxide are particularly suitable.

One embodiment of the yarn according to the invention, which contains titanium dioxide and / or barium sulfate particles, has particularly good mechanical properties and excellent processing behavior, since these substances have excellent resistance to mechanical stress.

The yarn according to the invention can be processed wherever a high mechanical load on the yarn occurs during processing and / or high strength and excellent elastic behavior of the yarn is required. In particular, the use of the yarn according to the invention as a sewing thread brings considerable advantages compared to a suitably designed conventional thread, as will be demonstrated below by the exemplary embodiments. Such a sewing thread preferably has the core / sheath structure described above.

In the case of dyed yarns in particular, there may be an accumulation of particles in the outer region of the yarn, since the yarn according to the invention is usually produced as described below and only afterwards is colored. When the yarn according to the invention is dyed, particles can accumulate in the outer yarn area, in particular in the case of very open yarns, but such an enrichment does not cause any undesirable side effects.

In addition to the intermingling, the yarn according to the invention can also have a twist, for example in the range between 1 twist / m and approximately 1000 twists / m, preferably between approximately 100 twists / m and approximately 600 twists / m. Such a twisted embodiment is particularly suitable for those uses in which the yarn is exposed to extremely high mechanical loads, as is the case, for example, with yarns used in large-scale manufacturing. In addition to the intermingling, the rotation also improves the yarn composite, while the particles preferably arranged on the outside of such a twisted yarn considerably reduce the friction occurring during processing, so that the yarn breakage frequency is significantly reduced.

The present invention is also based on the object of providing a method of the type specified, with which the yarns described above can be produced with special consideration of a uniform yarn titer.

According to the invention, this object is achieved by a method having the characterizing features of patent claim 11 and by a method having the characterizing features of patent claim 19.

The first, basic variant of the method according to the invention is based on the basic idea that grain-like particles are added to the water with which the first yarn component is wetted before intermingling, the grain-like particles used here having a specific weight greater than 1 g / cm 3 and one Grain diameter between about 4 microns and about 400 microns, in particular between about 20 microns and about 100 microns. In the method according to the invention, this then leads to a turbulent fluid flow acting on the yarn in the nozzle, and there specifically in the swirl chamber, which, in addition to the fluid fed to the nozzle in each case, for example air or steam, has a turbulent particle flow from the defined large one contains grain-like particles, which increases the degree of intermingling of the individual filaments and causes the grain-like particles to be deposited in or on the thread, so that a sewing thread produced in this way has the advantages as described above for the thread according to the invention.

The process according to the invention has a number of further advantages. The core-jacket yarns produced by this process are characterized by a particularly uniform titer, which is attributed to the fact that the flow conditions in the nozzle are optimized and / or by the additional particle flow in the swirl chamber be evened out. In addition, the particle flow causes any matting of the first yarn component to be loosened, which in turn improves the yarn uniformity. The particle flow also prevents the deposit of loosened or lubricated preparations and additives in the nozzle, so that undesired and uncontrollable changes in the dimension of the nozzle due to deposits or lubrication do not occur in the process according to the invention during production, so that on the one hand the flow conditions in the nozzle can also be kept constant over a longer production period and on the other hand undesirable Knot formation and / or capillary or yarn breaks can be prevented. This has the effect that the yarns described above can be produced over a longer period of time without interruption and without the need to clean the nozzle, so that in the method according to the invention there is no significant downtime for cleaning the nozzle and / or reinserting it Yarns occur when yarn breaks occur. Overall, the method according to the invention thus permits the economical production of improved core-sheath yarns, this being evident preferably in improved mechanical-technological properties and in a higher mechanical strength of the yarns during processing.

Grain-like particles whose specific weight is between approximately 1 g / cm 3 and approximately 6 g / cm 3, in particular between approximately 2 g / cm 3 and approximately 4.5 g / cm 3, are preferably used in the process according to the invention, it being particularly advantageous has proven to vary the specific weight of the granular particles depending on the yarn to be processed. In general, this means that with increasing number of filaments of the yarn used and increasing titer of the individual capillaries, grain-like particles are used, the specific weight of which is in a range between about 3 g / cm³ and about 4 g / cm³, while for relatively fine-thread yarns with a rather lower filament count grain-like particles are preferred, which have a specific weight between about 1 g / cm³ and about 3 g / cm³.

The hardness of the particle particles used is also important for the desired effects. On the one hand, the granular particles should not be so soft that they are destroyed during the swirling and on the other hand they should still have a certain softness in order not to cause undesired capillary injuries and / or undesirable damage to the nozzle. Grain-like particles are usually used which have a hardness on the Mohs hardness scale of between approximately 1 and approximately 7, in particular between approximately 4 and approximately 6 1/2, but also the hardness, as already explained above for the density of the grain-like particles, depends on the yarn used and its number of filaments. Particularly in the case of yarns with a coarser single titer, ie a titer of the single capillary in the range between approximately 5 dtex and approximately 10 dtex, granular particles are used which have a relatively high value on the Mohs hardness scale, ie a value in the range between approximately 4 and is about 6 1/2. In contrast, in the case of starting yarns with very fine elementary threads, in which the titer of the single thread is between approximately 1 dtex and approximately 3 dtex, grain-like particles are used, the hardness of which, according to the Mohs hardness scale, lies in a range between approximately 1 and approximately 3 1/2 .

As already mentioned above, the grain size of the particles used can also vary in a range between approximately 4 μm and approximately 400 μm, in particular for the production of yarns with an average titer between approximately 300 dtex and approximately 600 dtex Grain diameters between about 20 microns and about 100 microns can be used. In general, it also applies here that in the case of the finer titers of the individual filaments and / or the finished yarn, particles with a grain size of between approximately 20 μm and approximately 50 μm are preferred, and in the case of the coarser titers of the individual filaments or of the finished yarn preferably also larger grain-like particles, for example, those in a range between approximately 150 μm and approximately 250 μm can be used.

The concentration of the granular particles in the aqueous suspension or dispersion depends on the type of wetting of the first yarn component. If the first yarn component is wetted by immersion in an aqueous suspension or dispersion of the granular particles, the concentration is usually in a range between approximately 45 g granular particles / l and approximately 150 g particles / l, preferably a concentration range between approximately 30 g Particle / l and about 60 g particle / l is selected.

If, on the other hand, the aqueous dispersion or suspension of the granular particles is sprayed onto the first yarn component, then particle concentrations between about 10 g / l and about 200 g / l, preferably between about 50 g / l and about 150 g / l, are preferably used .

Another embodiment of the process according to the invention provides that surfactants and / or dispersing agents or suspending agents are added to the aqueous suspension or dispersion of the granular particles. The surfactants or dispersing and suspending agents known per se from textile chemistry can be used here, preference being given to using low-foaming products and / or the known antifoaming agents, for example based on organosilicon compounds. Particularly good results can be achieved with anionic surfactants or dispersing and / or suspending agents based on organic sulfates and sulfonates, for example alkyl sulfates, alkyl sulfonates and / or alkylaryl sulfates or sulfonates, the concentration of the above products preferably being in a range between 1 g / l and about 4 g / l.

In order to prevent undesired settling of the granular particles in the aqueous suspension or dispersion, the dispersion or suspension is constantly moved. This can be done, for example, by stirring the dispersion or suspension or by irradiating it with ultrasound waves. A particularly good distribution and a stable dispersion or suspension are obtained by generating a turbulent flow in the dispersion or suspension, which can be achieved very well, for example, by blowing in air.

In the method according to the invention, the yarn components are usually intermingled at a fluid pressure between approximately 6 bar and approximately 15 bar, preferably between approximately 8 bar and approximately 10 bar. Either steam or air can be used as the fluid, the latter leading to particularly good results. By using the particle flow consisting of the granular particles, it is possible in the method according to the invention in comparison to the conventional method, which only provides for wetting the first yarn component with water, to reduce the fluid pressure by about 20% to about 40% in order to to achieve the same degree of swirling with the same starting material. In the method according to the invention, this leads to a considerable reduction in costs, since the production costs depend crucially on the amount of air used, which is accordingly reduced in the same order of magnitude (approximately 20% to approximately 40%) in accordance with the above embodiment.

In a further, particularly advantageous embodiment of the method according to the invention for producing the core-sheath yarn described above, the yarn components of the starting material are fed to a nozzle and there through the turbulent fluid flow swirls, the fluid flow additionally having, for example, air and / or steam, also granular particles. This can be done in such a way that the fluid flow that is fed to the nozzle is either a mist consisting of finely divided water droplets with a diameter between approximately 40 μm and approximately 600 μm with granular particles dispersed or suspended therein, and / or one Dust of the granular particles alone is added, the granular particles having a grain size between approximately 4 μm and approximately 400 μm and in particular between 20 μm and 100 μm. Thus, in this embodiment of the method according to the invention, the granular particles are not supplied directly by the first yarn component, but rather by the fluid flows supplied to the nozzle, which leads to a further intensification of the intermingling of the yarns. As an explanation for this, it is assumed that in this embodiment of the method according to the invention, in comparison with the embodiments described above, in which the first yarn component is wetted with the particle-containing dispersion or suspension, the particles adhering to the yarn during the air or steam flow during the relatively short stay of the yarn in the nozzle does not have to be accelerated there, but instead granular particles are already supplied to the nozzle as accelerated particles. This in turn means that the pressure of the fluid flow and thus the fluid throughput per unit time can be reduced even further with a constant degree of swirling. In comparative measurements, it was found that in the case of such a method, in comparison with a conventional method in which no granular particles are used, the consumption of air could be reduced by about 40% to about 60%.

In a preferred embodiment of the method described above, the fluid flow is supplied with a mist which is produced from an aqueous dispersion or suspension of the granular particles, the concentration of the granular particles preferably being between approximately 30 g / l and approximately 300 g / l between about 60 g / l and about 200 g / l. With regard to the particle size and the hardness of the particles, the same applies as described above for the embodiment of the method according to the invention, in which the first yarn component is wetted with the aqueous dispersion or suspension.

Compared to the supply of a dust to the fluid flow, the supply of a mist in which the particles are dispersed or suspended has the advantage that the mechanical stress on the yarn and the nozzle is reduced by the lubricating or sliding action caused by the water is, so that the supply of a dust to the fluid flow is preferably used when using particularly soft particles, when using special nozzles, which will be described below, and / or with relatively coarse-titer yarns.

Usually, the fluid flow between about 0.1 m³ / h and about 5 m³ / h, in particular between about 0.5 m³ / h and about 2 m³ / h, fog or dust of the composition described above, with such Processes of fluid flow (air or steam) in a range between about 4 m³ / h and about 15 m³ / h, preferably between about 5 m³ / h and about 8 m³ / h.

Of course, if a mist in which the granular particles are suspended or dispersed is fed to the fluid flow, it is also possible to add surfactants and / or To use dispersing or suspending agents, the surfactants or dispersing or. Suspension agents preferably have the chemical structure described above.

The nozzle used to carry out the method according to the invention has at least a first inlet opening for the yarn, a second inlet opening for the fluid flow, an outlet opening for the swirled yarn and a swirl chamber, at least the inner walls of the swirl chamber and the inner walls of the outlet opening being made of ceramic .

As has been found, ceramic in particular not only has the required hardness and resistance to the particle flow impinging in the swirl chamber and the outlet opening, but at the same time brings about a constant flow profile in the nozzle due to its closed surface, which leads to a particularly reproducible yarn. Of course, it is also possible to manufacture the nozzle as a whole from ceramic, which simplifies the manufacture of such a nozzle or to provide the corresponding nozzle parts with a ceramic surface.

In the previously described methods for producing the sewing thread according to the invention, it is described, inter alia, that the aqueous dispersion or suspension of the granular particles can be applied by spraying the thread with the dispersion or suspension or by immersing the thread in the dispersion or suspension. Of course, it is also possible to use a special wetting device for applying the aqueous dispersion or suspension, through which the yarn is passed. In this case, this wetting device has a wetting head which can be brought into contact with the yarn and via which the dispersion or suspension of the granular particles is applied to the yarn in a kind of popping technique. Such wetting devices are known and are widely used and are offered, for example, by the Heberlein company under the system name "HEMA-WET-DÜSE".

Advantageous developments of the yarn according to the invention and of the method according to the invention are specified in the subclaims.

The invention is explained below using an embodiment in conjunction with the drawing. The single figure of the drawing shows schematically the yarn according to the invention.

Shown in the figure is a yarn denoted overall by 1, which consists of a plurality of individual capillaries 2 which are intermingled. Here, the individual capillaries are either swirled together in a knot-like manner, as can be seen at the point denoted by 3. The yarn also has protruding loops 4 and confused areas 5. Grain-like particles 6 are arranged in the spaces between the individual capillaries 2 and are freely movable in a certain area relative to the individual capillaries. Particles 7 adhere to the outside of the yarn and, like the particles 6, can be moved within a certain range relative to the individual capillaries 2 or to the yarn 1 as a whole. The particles 6 and 7 shown in the figure are titanium dioxide particles with a grain size of 60 μm. Their concentration is 0.2% by weight, based on the weight of the yarn.

Embodiment 1

A sewing thread with a titer of 285 dtex is produced by interlacing a first thread component serving as a soul, which was a polyester multifilament thread with a titer of 180 dtex and an elementary thread count of 40 filaments. The first yarn component was interlaced with a second component (effect or sheath component), the titer of the second yarn component being 50 dtex with a number of filaments of 24 filaments. A conventionally designed, commercially available nozzle was used as the nozzle, which bore the type designation T341 and is offered by the Heberlein company.

Air was fed to the nozzle as a fluid stream at a pressure of 10.5 bar, the air throughput being 8 m 3 / h. After intermingling, the yarn was drawn off at a speed of 500 m / min.

The first thread component of the sewing thread was wetted before immersion by immersing it in water, the immersion distance being about 2 cm.

After the intermingling, the conventionally produced and designated sewing thread No. 1 was dyed and finished according to the known methods and served as a reference material for the subsequent mechanical-technological measurements and for industrial sewing tests.

Embodiment 2

A No. 2 sewing thread was prepared under the conditions described above, the No. 2 sewing thread being treated with an aqueous suspension of 30 g / l barium sulfate before intermingling. The barium sulfate had a particle size of 80 μm. Otherwise, the manufacturing conditions corresponded to embodiment 1.

Embodiment 3

A sewing thread Mr. 3 was produced in accordance with working example 1, however, in deviation from this, the first yarn component was wetted with a dispersion of 60 g / l titanium dioxide with a particle size of 20 μm prior to intermingling.

In Examples 2 and 3, a consumption of 22 l / h of aqueous dispersion was found.

Embodiment 4

A sewing thread No. 4 was produced under the conditions described in exemplary embodiment 1, but in deviation from this the first thread component was not wetted with water before the intermingling. Instead, 15% by volume of a mist, which was prepared from an aqueous dispersion of 100 g / l barium sulfate, was added to the air stream.

The sewing threads 1 to 4 described above were first examined microscopically. It was found that the degree of interlacing of the sewing threads increased steadily from sewing thread No. 1 to sewing thread No. 4.

Comparative industrial sewing tests showed that the yarn break frequency when sewing yarns 2 to 4 was significantly lower compared to yarn 1 (conventionally produced yarn). An orientative, statistical evaluation of the frequency of yarn breakage showed that, based on the sewing thread, Mr. 1 the thread break frequency with sewing thread No. 2 was 20%, the thread break frequency with sewing thread No. 3 was 30%, and the thread break frequency with sewing thread No. 4 was 50% lower.

At the same time, the frequency of yarn breakage when rubbing sewing thread against sewing thread was determined on a specially developed measuring device. For this purpose, one end of the sewing thread was clamped in a clamp, then the sewing thread was placed in a loop, the loop over movable rollers was kept open and then the yarn was moved under a load of 50 g in such a way that a point-like abrasion of yarn on yarn occurred at the loop. The scouring tests were carried out until the yarn broke, the number of movement cycles until the break being measured.

The conventionally produced sewing thread 1 broke after 200 movement cycles. Sewing thread 2 broke at 450 movement cycles, while 3,600 movement cycles were required for sewing thread and 4,750 movement cycles for sewing thread were required to break.

Claims (25)

1. A yarn, in particular sewing thread , with at least one core yarn component and at least one second yarn component intermingled with the first yarn component, said second yarn component being mainly present as the jacket of said yarn,
   wherein the yarn (1) comprises between about 0,02 % by weight and about 20 % by weight of granular particles (6,7), which are arranged in the yarn gaps and/or at the outside of the yarn (1), and said granular particles (6,7) possess a granule diameter between about 4 µm and about 400 µm.
2. The yarn according to claim 1, wherein said yarn comprises about 0,2 % by weight to about 0,4 % by weight granular particles (6,7).
3. The yarn, according to claim 1 or 2, wherein the granular particles (6,7) possess a granule diameter between about 20 µm and about 100 µm.
4. The yarn, according to one of the preceding claims, wherein the granular particles (6,7) are embedded in the yarn gaps and are spread homogeneously over the cross section of the yarn.
5. The yarn according to one of the preceding claims, wherein the granular particles are embedded in a spin finish or a preparation.
6. The yarn according to one of the preceding claims, wherein the first yarn component is a multifilament yarn and the second yarn component is one multifilament yarn or several multifilament yarns, in particular two to four multifilament yarns.
7. The yarn according to one of the preceding claims, wherein the first yarn component is a multifilament yarn with a titre between about 100 dtex and about 1000 dtex, preferably between about 100 dtex and about 600 dtex.
8. The yarn according to one of the preceding claims, wherein said yarn comprises a number of elementary filaments between about 40 and about 500, preferably between about 50 and 150.
9. The yarn according to one of the preceding claims wherein said yarn contains inorganic granular particles (6,7), in particular talcum, silicon dioxide, aluminium oxide, titanium dioxide and/or barium sulphate,
10. The yarn according to one of the preceding claims wherein said yarn provides a twist between about 1 twist /m and about 1000 twists /m, in particular between about 100 twists /m and about 600 twists /m.
11. A method for manufacturing the yarn according to one of the preceding claims wherein at least one first core yarn component is intermingled with at least one second yarn component, which is intended as a jacket, in a turbulent fluid stream, said first yarn component being wetted with water before being intermingled, wherein said yarn is a sewing thread and said first yarn component is wetted with an aqueous dispersion or suspension of granular particles, the specific weight of which is larger than 1 g/cm³ and the granule diameter of which is between about 4 µm and about 400 µm, in particular between about 20 µm and about 100 µm.
12. The method according to claim 11, wherein the first yarn component is wetted by dipping into the aqueous dispersion or suspension.
13. The method according to one of the claims 11 or 12, wherein an aqueous dispersion or suspension is used, which contains the granular particles in a concentration between about 5 g/l and about 150 g/l, preferably between about 30 g/l and about 60 g/l.
14. The method according to claim 11, wherein the first yarn component is sprinkled with the aqueous dispersion or suspension of the granular particles.
15. The method according to claim 14, wherein an aqueous dispersion or suspension is used, which contains the granular particles in a concentration between about 10 g/l and about 200 g/l, preferably between about 50 g/l and about 150 g/l.
16. The method according to claim 14 or 15, wherein between about 1 % by weight and about 50 % by weight, preferably between about 5 % by weight and about 30 % by weight of the aqueous dispersion or suspension is sprinkled onto the first yarn component.
17. The method according to one of the claims 11 to 16, wherein a turbulent stream is generated in the aqueous dispersion or suspension .
18. the method according to one of the claims 11 to 17, wherein surfactants and/or dispersing agents are added to the aqueous dispersion or suspension.
19. The method for manufacturing the yarn according to one of the claims 1 to 10, in which one first core yarn component is intermingled with a second yarn component intended as a jacket in a turbulent fluid stream, wherein said yarn is a sewing thread, and a mist, comprising water droplets with a diameter of between about 40 µm and about 600 µm and granular particles, and/or a dust of granular particles, is supplied to the fluid stream, said granular particles showing a specific weight greater than 1 g/cm³ and a granule diameter between about 4 µm and about 400 µm in particular between about 20 µm and about 100 µm.
20. The method according to one of the claims 11 to 19, wherein the granular particles provide a hardness according to Mohs between 1 and 6 1/2, preferably between 3 and 5.
21. The method according to one of the claims 11 to 20, wherein the granular particles possess a density between 1,5 g/cm³ and 6 g/cm³, preferably between about 3 g/cm³ and about 5 g/cm³.
22. The method according to one of the claims 11 to 21, wherein the yarn components are intermingled with another at an air pressure between about 6 bar and about 15 bar, preferably between about 8 bar and about 10 bar.
23. The method according to claim 19, wherein a mist is supplied to the fluid stream, which mist is generated from an aqueous dispersion or suspension of the granular particles, said granular particles being present at a concentration of between about 30 g/l and about 300 g/l, in particular between about 60 g/l and about 200 g/l.
24. The method according to claim 19 or 23, wherein the mist is added to the fluid stream at between about 0,1 m³/h, in particular between about 0,5 m³/h and about 2 m³/h.
25. The method according to claim 19, wherein a dust is supplied to the fluid stream between about 0,1 volume % and about 15 volume %, in particular between about 0,2 volume % and about 1 volume %.

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