EP0569891A1 - Yarn and method for manufacturing a yarn - Google Patents

Abstract

There is described a yarn, in particular a sewing yarn, containing at least one multifilament yarn component which forms a core. This multifilament yarn component has been overwrapped with at least a second yarn component to form a core yarn. The at least one multifilament yarn component forming the core of the core yarn is a customary textile standard multifilament yarn. The tenacity of the spun core yarn varies between 32 cN/tex and 55 cN/tex, preferably between 37 cN/tex and 48 cN/tex. There is also described a process for manufacturing the core yarn. It involves overspinning at least one multifilament yarn component serving as the core with a second yarn component. The at least one multifilament yarn component forming the core is a partially oriented (pre-oriented) multifilament yarn (POY) which in its molecular structure corresponds to a textile standard multifilament yarn. The multifilament yarn forming the core is drawn in such a way that its tenacity varies between 60 cN/tex and 90 cN/tex, in particular between 71 cN/tex and 90 cN/tex.

Description

The present invention relates to a core yarn with the features of the preamble of claim 1 and a method for producing such a core yarn with the features of the preamble of claim 16.

Yarns and especially sewing threads are known in different constructions.

For example, EP B1 0 367 938 describes a two-component yarn which has at least one multifilament first yarn component, which is arranged in the interior of the yarn and which is referred to as the core material, and at least one second multifilament effect material enveloping the core material. Here, the two aforementioned multifilament yarns are intermingled with one another in such a way that the necessary thread closure is achieved by intertwining the two yarn materials results. In order to ensure the required yarn strength in this known intermingled yarn, such a filament yarn is used as the first yarn material, the specific strength of which is already very high as a starting material compared to a standard textile yarn. In other words, EP B 0367 938 thus teaches that a high-strength multifilament yarn is already used as the starting material.

In addition to the intermingled yarns described above, fiber yarns or threads are also known.

A yarn with the features of the preamble of claim 1 is described in DE-PS 24 36 997. Here, the known yarn has a multifilament core material, which is wound with a second yarn component to form a core yarn. The core material of the well-known core yarn consists of stretched and fixed multifilament fibers, the high-strength multifilament yarns previously described for the intermingled yarn usually also being used for this. These high-strength multifilament yarns are considerably more expensive than standard textile fibers.

The present invention has for its object to provide a core yarn of the type specified, which has an extremely high resistance to mechanical stresses at a particularly low manufacturing price.

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

The yarn according to the invention, which is also used in particular as a sewing thread, has at least one multifilament yarn component which forms a core. Here, the multifilament yarn component forming the core is wound with at least one second yarn component to form the core yarn. The core of the core yarn forming at least one multifilament yarn component is a conventional textile standard multifilament yarn, the spun core yarn having a specific strength between 32 cN / tex and 55 cN / tex, preferably between 37 cN / tex and 48 cN / tex.

The core yarn according to the invention has a number of advantages. It was surprisingly found that a core yarn of this type has the previously stated high strengths between 32 cN / tex and 55 cN / tex, in particular between 37 cN / tex and 48 cN / tex, although a core material is used to produce this yarn. which, in contrast to the prior art described above, is not a high-strength multifilament yarn but a common textile standard multifilament yarn. This in turn leads to the core yarn according to the invention being particularly inexpensive to produce. If the core thread according to the invention is used as a sewing thread, such a sewing thread is characterized in that it performs the usual sewing operations, for example multidirectional sewing or buttonhole sewing, even at extremely high sewing speeds of up to 7,000 stitches per minute without one Damage to the core yarn survives. Hereby it is explained that the core yarn according to the invention does not cause any sewing disturbances in the area of the ready-to-wear.

A first embodiment of the core yarn according to the invention has a multifilament yarn component forming the core, which has an intrinsic viscosity between 0.5 dl / g and 0.75 dl / g, in particular an intrinsic viscosity between 0.55 dl / g and 0, 63 dl / g. This is a multifilament polyester yarn component. The values of the intrinsic viscosity mentioned above reflect the molecular structure (molecular weight, chemical composition) of the polyester multifilament yarn used, the degree of condensation of the polymers also correspondingly increasing with increasing viscosity. The values given above refer to polymer solutions in dichloroacetic acid at 25 ° C.

With regard to the single-filament titer of the multifilament yarn component forming the core, it should be noted that in the core yarn according to the invention this single-filament titer varies between 0.6 dtex and 6 dtex, preferably between 1.5 dtex and 4 dtex.

The core yarn according to the invention in particular has a multifilament yarn (multifilament yarn component) as a core, the number of filaments of which varies between 16 and 300, preferably between 24 and 96.

Regarding the second yarn component, which is spun with the core, it should be noted that any yarn is suitable for this is that the soul adequately covers the outside. A fiber yarn made of polyamide 6, polyamide 6.6, cotton and / or in particular polyester fibers is preferably used as the second yarn component.

Embodiments of the core yarn according to the invention have a particularly high strength in which the second yarn component comprises at least one fiber yarn, the specific strength of which varies between 40 cN / tex and 70 cN / tex.

If the core yarn according to the invention has a fiber yarn as the second yarn component, the staple length of the individual fibers of the fiber yarn varies between 15 mm and 120 mm, in particular between 20 mm and 60 mm.

With regard to the individual fiber titer of the second yarn component present as fiber yarn, it should be noted that this varies between 0.6 dtex and 4 dtex, preferably between 0.8 dtex and 2 dtex.

Ein derartig ausgezwirntes Garn, das, wie bereits vorstehend beschrieben, mindestens zwei, vorzugsweise zwei bis vier, miteinander verzwirnte Coregarne umfaßt, kann insbesondere auch ausgezeichnet als Nähgarn eingesetzt werden, da ein derartiges Nähgarn beispielsweise ein multidirektionales Nähen oder ein Nähen von Knopflöchern mit hohen Stichdichten (bis zu 7.000 Stiche pro Minute) ohne Garnriß übersteht.A particularly suitable embodiment of the yarn according to the invention provides that the yarn comprises at least two, preferably two to four core yarns twisted together, each individual core yarn having the structure described above or below. The correspondingly twisted yarn preferably has a twist coefficient α between 120 and 180, the twist coefficient α being defined as follows:

Such a twisted yarn, which, as already described above, comprises at least two, preferably two to four, twisted core yarns, can also be used particularly well as a sewing thread, since such a sewing thread, for example, multidirectional sewing or sewing buttonholes with high stitch densities (up to 7,000 stitches per minute) without yarn break.

The yarns according to the invention described above have a total titer which is between 100 dtex and 1,400 dtex, preferably between 100 dtex and 600 dtex.

The mass ratio of core to second yarn component varies in the yarn according to the invention from 70% (mass of core) to 30% (mass of the second yarn component) to 30% (mass of core) to 70% (mass of the second yarn component).

In order to ensure a simple dyeing with a dye class of core material and at the same time the second yarn component, it is recommended that the yarn according to the invention have the same fiber substrate mentioned above both as core and as a second yarn component. Of course, however, it is also possible that the invention Yarn has different fiber substrates in the soul and as a second yarn component.

The present invention is also based on the object of providing a production method with which the yarn according to the invention described above can be spun particularly economically.

This object is achieved by a method having the features of patent claim 16.

The process according to the invention for producing the yarns described above provides that at least one multifilament yarn component serving as a core is spun with a second yarn component to form the core yarns. Here, a pre-oriented multifilament yarn (POY yarn) is selected for the soul-forming at least one multifilament yarn component, the molecular weight of the at least one pre-oriented multifilament yarn (POY yarn) corresponding to a textile standard multifilament yarn. This pre-oriented multifilament yarn (POY yarn) is drawn in such a way that its strength varies between 60 cN / tex and 90 cN / tex, in particular between 71 cN / tex and 90 cN / tex.

The method according to the invention has a number of advantages. It should first be noted that the method according to the invention, using relatively inexpensive raw materials, leads to a high-quality yarn, in particular sewing thread, which is distinguished by the fact that it is used even under extreme sewing loads does not tear. In addition, a thread or sewing thread produced in this way has low residual shrinkage values, which can be found, for example, in cooking shrinkage values (water, about 98 ° C.) in the order of 1%, preferably less than 0.5%, and in hot air shrinkage values (160 ° C.) on the order of about 2%, preferably less than 1%. This in turn leads to the fact that when the yarn produced by the method according to the invention is used as sewing thread, there is no seaming when the assembled parts sewn with it are steamed, ironed or washed during later use.

Regarding the selection of the POY yarn (core material) described above, it should be noted that a polyester multifilament yarn is preferably selected for this, the intrinsic viscosity of which is between 0.5 dl / g and 0.75 dl / g, preferably between 0.55 dl / g and 0.63 dl / g. Thus, the polyester POY yarn described above is such a yarn whose chemical structure and in particular its molecular weight corresponds to a conventional textile standard multifilament yarn. The aforementioned intrinsic viscosities represent values which are measured in corresponding solutions of the polymer in dichloroacetic acid at 25 ° C.

In a particularly suitable embodiment of the method according to the invention, each pre-oriented multifilament yarn, which is preferably polyester POY yarn, is drawn in such a way that this multifilament yarn is stretched over feeds a delivery godet wrapped in the yarn at a first speed to a main stretching zone. The multifilament yarn is then withdrawn from the main drawing zone at a second speed via a take-off godet wrapped in the pre-oriented multifilament yarn, the second speed being 70% to 180%, preferably 100% to 160%, greater than the first speed. In this embodiment of the method according to the invention, the take-off godet is heated to a temperature between 160 ° C. and 240 ° C. Due to the previously described speed differences between the first speed and the second speed, a degree of stretching of 1: 1.7 to 1: 2.8, preferably a degree of stretching of, is thus in the main stretching zone, which is formed exclusively from the delivery godet and the withdrawal godet 1: 2.0 to 1: 2.6. Although these degrees of stretching are very high, surprisingly no filament breaks occur during such stretching, so that this stretching process is particularly insusceptible to faults. Furthermore, the tensile strengths of a multifilament yarn stretched in this way are extremely high, ie, depending on the pre-oriented multifilament yarn (POY yarn) used, they are in the range between 60 cN / tex and 90 cN / tex, in particular between 71 cN / tex and 90 cN / tex .

A further development of the previously described embodiment variant of the method according to the invention provides that the delivery godet is also heated to a temperature between 60 ° C. and 160 ° C., preferably to a temperature between 80 ° C. and 140 ° C. heats up.

In a further embodiment variant of the method according to the invention described above, heating is carried out in the main stretching zone, i.e. between the delivery godet and the take-off godet, the pre-oriented multifilament yarn to a temperature between 80 ° C and 180 ° C. This heating of the multifilament yarn in the main stretching zone is preferably carried out in such a way that a hot plate, an IR radiator and / or a laser are used for this purpose.

Regarding the time at which the pre-oriented multifilament yarn is heated in the main stretching zone and allowed to dwell at the aforementioned temperatures (80 ° C. to 180 ° C.), it should be noted that this residence time varies in particular between 0.01 s and 1 s.

In order to obtain the clamping points required for drawing in the main drawing zone in the previously described embodiments of the method according to the invention, the delivery godet and the take-off godet are looped with the pre-oriented multifilament yarn, as already described above. It has been shown here that particularly high strengths and particularly low shrinkage values of the stretched multifilament yarn result when the delivery godet and / or the take-off godet are looped 5 to 40 times, preferably 10 to 20 times, with the pre-oriented multifilament yarn. These wrapping values refer to Godets, the diameter of which vary between approximately 40 mm and 250 mm, preferably 80 mm and 120 mm.

Another, particularly suitable development of the previously described embodiment variants of the method according to the invention provides that a pre-stretching zone is arranged in front of the main stretching zone, as seen in the transport direction of the pre-oriented multifilament yarn (POY yarn). In other words, the pre-oriented multifilament yarn (POY yarn), which is preferably a polyester POY yarn, is first partially drawn in the pre-drawing zone and then finally drawn in the main drawing zone.

In the development of the method according to the invention described above, it is advisable to pre-stretch the pre-oriented multifilament yarn in the pre-stretching zone between 0.5% and 10%, preferably between 1% and 4%. the pre-oriented multifilament yarn is thus lengthened in the pre-stretching zone between 0.5% and 10%, preferably between 1% and 4%.

Regarding the pre-drawing or drawing speeds, it should be noted that the aforementioned high strengths and low shrinkage values can be achieved particularly economically and reproducibly if one selects take-off speeds that are greater than 300 m / min and preferably between 600 m / min and 1,200 m / min.

In order to produce a particularly low-shrinkage and drawn yarn by the previously described drawing process, another, particularly suitable development of the previously described process provides that, viewed in the direction of transport of the multifilament yarn, a relaxation zone is arranged behind the main drawing zone, in which the drawn multifilament yarn is heated to a temperature between 80 ° C and 240 ° C, preferably to a temperature between 140 ° C and 200 ° C, is heated. It has been shown here that such a relaxation zone further reduces the shrinkage values, in particular the cooking shrinkage value (water 98 ° C.) and the hot air shrinkage value (160 ° C.) of the drawn multifilament yarn. This is particularly true when the drawn multifilament yarn is introduced into the relaxation zone with lead, which is preferably between 0.5% and 10% and in particular between 1% and 3%.

The residence time of the multifilament yarn in the relaxation zone then varies depending on the respective transport speed of the yarn through the relaxation zone and is preferably 0.01 s to 1 s.

The selection of the multifilament yarn (POY yarns) used in the method according to the invention depends on the later use of the drawn yarn. POY multifilament yarns are preferably selected here whose single filament titer varies between 1 dtex and 12 dtex, preferably between 3 dtex and 8 dtex.

Regarding the titer of the pre-oriented multifilament yarn, it should be noted that this varies between 40 dtex and 2,000 dtex, preferably between 80 dtex and 1,200 dtex. The number of filaments of the pre-oriented multifilament yarn used is between 16 and 300, preferably between 24 and 96.

A further, particularly suitable embodiment of the processes described above provides that at least two, preferably two to four, of the core yarns produced by the processes described above are twisted together. The resulting thread has excellent properties as a sewing thread, as has already been described for the thread.

A variant of the previously described embodiment of the method according to the invention provides that each core yarn is first individually twisted and then the core yarns present as pre-twine are twisted. Here, one preferably selects a yarn twist, the twist coefficient α is between 90 and 140, the twist coefficient α being defined above for the yarn. The subsequent twist of the twist is preferably carried out at a twist factor α between 120 and 180.

One embodiment of the core yarn according to the invention has particularly good results with regard to sewing behavior, the hairiness (sh) of between 2.5 and 7.5, in particular varies between 4 and 7. These hairiness values relate to measurement results as determined by the known method with a Uster yarn uniformity measuring device, type UT3.

As has already been mentioned several times above, the process according to the invention preferably uses a multifilament polyester core and a polyester spinning component as the starting material (second yarn component), so that accordingly a core yarn results which consists entirely of polyester. Polyester in the sense of the present application is understood to mean polyethylene terephthalate.

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

The method according to the invention is explained in more detail below using an exemplary embodiment.

A polyester POY yarn was pre-stretched between a delivery plant and a downstream delivery godet so that it was 5% elongated. The temperature of the delivery godet was 100 ° C. The pre-drawn multifilament yarn was then drawn in a main draw frame which consisted exclusively of the aforementioned delivery godet and a take-off godet at a draw ratio of 1: 2.4. The temperature of the take-off godet was 160 ° C. The polyester multifilament yarn was 20 times the supply godet and 20 times the Deduction godet wound. Both godets had a diameter of 150 mm. The drawing speed was 600 m / min.

A thermal treatment (hot plate) was provided behind the take-off godet, the drawn multifilament yarn being introduced into the thermal aftertreatment with a lead of 3%. The temperature of the thermal aftertreatment was 180 ° C., the residence time was 0.5 s.

At the outlet of the thermal aftertreatment, the drawn polyester multifilament yarn, which had a total denier of 138 dtex and a filament number of 30, was wound up.

The stretched polyester multifilament yarn described above was spun to form a core yarn with a polyester staple fiber (single fiber titer 1.3 dtex, staple length 38 mm). After spinning, the spun core yarn had a twist coefficient α of 105.7 and a titer of Nm 49.

Two of these core threads produced in this way were twisted together to form a sewing thread, the twisted thread having a twist factor α of 153.5.

After dyeing and finishing, the sewing behavior of the sewing thread described above was checked. It was found here that this sewing thread, which consisted of two core threads twisted together, had excellent sewing behavior showed, which was expressed in that the sewing thread did not tear when multidirectional sewing at up to 7,000 stitches per minute or when buttonhole sewing.

Claims (36)

Yarn, in particular sewing thread, with at least one multifilament yarn component forming a core, which is wound with at least a second yarn component to form a core yarn, characterized in that the core of the core yarn forming at least one multifilament yarn component is a customary standard textile multifilament yarn and that the specific The strength of the spun core yarn varies between 32 cN / tex and 55 cN / tex, in particular between 37 cN / tex and 48 cN / tex. Yarn according to claim 1, characterized in that the multifilament yarn component forming the core has an intrinsic viscosity between 0.5 dl / g and 0.75 dl / g. Yarn according to claim 2, characterized in that the multifilament yarn component forming the core has an intrinsic viscosity between 0.55 dl / g and 0.63 dl / g. Yarn according to one of the preceding claims, characterized in that the multifilament yarn component forming the core consists of polyester. Yarn according to one of the preceding claims, characterized in that the multifilament yarn component forming the core has a single filament titer between 0.6 dtex and 6 dtex, preferably a single filament titer between 1.5 dtex and 4 dtex. Yarn according to one of the preceding claims, characterized in that the multifilament yarn component forming the core has a filament number between 16 and 300, preferably a filament number between 24 and 96. Yarn according to one of the preceding claims, characterized in that the second yarn component is a fiber yarn made of polyester, polyamide-6, polyamide-6.6 and / or cotton fiber. Yarn according to one of the preceding claims, characterized in that the second yarn component comprises at least one fiber yarn, the specific strength of which varies between 40 cN / tex and 70 cN / tex. Yarn according to one of the preceding claims, characterized in that the second yarn component has a fiber yarn with a staple length of the individual fiber between 15 mm and 120 mm, in particular between 20 mm and 60 mm. Yarn according to one of the preceding claims, characterized in that the second yarn component has a fiber yarn, the fibers of which have a single fiber titer between 0.6 dtex and 4 dtex, preferably between 0.8 dtex and 2 dtex. Yarn according to one of the preceding claims, characterized in that the yarn comprises at least two, preferably two to four, twisted core yarns. Yarn according to claim 11, characterized in that the twisted yarn has a twist coefficient α between 120 and 180. Yarn according to one of the preceding claims, characterized in that it has a total titer between 100 dtex and 1,400 dtex, preferably a total titer between 100 dtex and 600 dtex. Yarn according to one of the preceding claims, characterized in that it has a mass ratio of core to second yarn component of 70% to 30% to 30% to 70%. Yarn according to one of the preceding claims, characterized in that the core material and the second yarn component consist of the same fiber substrate. A process for producing the yarn according to one of the preceding claims, in which at least one multifilament yarn component serving as a core is spun with a second yarn component to form a core yarn, characterized in that a pre-oriented multifilament yarn (POY.) Is used as the at least one multifilament yarn component forming the core Yarn) is selected, the molecular structure of the pre-oriented multifilament yarn corresponding to that of a standard textile multifilament yarn, and that the multifilament yarn (POY yarn) is drawn such that its strength is between 60 cN / tex and 90 cN / tex, preferably between 71 cN / tex and 90 cN / tex, varies. Process according to Claim 16, characterized in that a polyester POY yarn is selected whose intrinsic viscosity is between 0.5 dl / g and 0.75 dl / g, preferably between 0.55 dl / g and 0.63 dl / g, varies. Method according to one of claims 16 or 17, characterized in that the pre-oriented multifilament yarn is fed at a first speed to a main stretching zone via a delivery godet wrapped in the yarn and withdrawn from the main stretching zone at a second speed via a withdrawal godet wound around the yarn, the second speed 70% to 180%, preferably 100% to 160%, greater than the first speed, that the stretching in the main stretching zone is carried out exclusively between the delivery godet and the take-off godet and that the take-off godet is heated to a temperature between 160 ° C. and 240 ° C. Process according to Claim 18, characterized in that the delivery godet is heated to a temperature between 60 ° C and 160 ° C, preferably to a temperature between 80 ° C and 140 ° C. Process according to Claim 18 or 19, characterized in that the pre-oriented multifilament yarn is heated to a temperature between 80 ° C and 180 ° C in the main stretching zone. A method according to claim 20, characterized in that a hot plate, an IR radiator and / or a laser is used to heat the multifilament yarn in the main stretching zone. Process according to Claim 20 or 21, characterized in that the pre-oriented multifilament yarn is heated in the main stretching zone between 0.01 s and 1 s. Method according to one of claims 18 to 22, characterized in that the delivery godet and / or the take-off godet are looped with the pre-oriented multifilament yarn 5 to 40 times, preferably 10 to 20 times. Method according to one of claims 18 to 23, characterized in that a pre-stretching zone is arranged in front of the main stretching zone, seen in the direction of transport of the multifilament yarn. Process according to Claim 24, characterized in that the multifilament yarn is pre-drawn in the pre-stretching zone between 0.5% and 10%, preferably between 1% and 4%. Method according to one of claims 18 to 25, characterized in that the pre-stretching and / or the stretching is carried out at a take-off speed greater than 300 m / min, preferably at a speed between 600 m / min and 1,200 m / min. Method according to one of claims 18 to 25, characterized in that, viewed in the direction of transport of the pre-oriented multifilament yarn, a relaxation zone is arranged behind the main drawing zone, in which the drawn multifilament yarn is heated to a temperature between 80 ° C and 240 ° C, preferably to a temperature between 140 ° C and 200 ° C, heated. A method according to claim 27, characterized in that the drawn multifilament yarn is introduced into the relaxation zone with a lead. A method according to claim 28, characterized in that stretched multifilament yarn is introduced into the relaxation zone with a lead of between 0.5% and 10%, preferably 1% and 3%. Method according to one of claims 16 to 29, characterized in that a yarn is selected as the pre-oriented multifilament yarn, the individual filament titer of which varies between 1 dtex and 12 dtex, preferably between 3 dtex and 8 dtex. Method according to one of claims 16 to 30, characterized in that the pre-oriented multifilament yarn has a total denier between 40 dtex and 2,000 dtex, preferably between 80 dtex and 1,200 dtex. Method according to one of claims 16 to 31, characterized in that the pre-oriented multifilament yarn has an elementary thread number between 16 and 300, preferably between 24 and 96. Method according to one of claims 16 to 32, characterized in that two to four core yarns are twisted together. A method according to claim 33, characterized in that first each core yarn is twisted and then the core yarns are twisted. A method according to claim 34, characterized in that the yarn twist is carried out at a twist coefficient α between 90 and 140. A method according to claim 34 or 35, characterized in that the twisting is carried out at a twist factor α between 120 and 180.