EP0602489B1 - Sewing yarn made of synthetic and/or natural fibres - Google Patents

Abstract

Described is a sewing yarn made of synthetic and/or natural fibres. The ready-finished sewing yarn has a hairiness between 2.5 and 7.5, as measured with a UT3 Uster yarn uniformity tester.

Description

The present invention relates to a sewing thread made of synthetic and / or natural fibers.

Sewing threads are known in different designs. For example, EP 0 295 601 B1 describes a sewing thread which consists of at least two multifilament yarn components intermingled with one another. The previously registered and as yet unpublished German patent application P 42 15 212.7 is directed to a core yarn which has a multifilament core, this multifilament core being wound with a second yarn component to form the core yarn. German patent application P 42 15 016, also previously registered and not yet published, is directed to a sewing thread which consists of at least two multifilament yarn components twisted together.

In order to achieve the properties required for a sewing thread, in particular those properties which are required for the later use of the sewing thread, the above-mentioned prior art teaches that the differently constructed sewing threads always have a certain specific strength, depending on the construction of the sewing thread is between 32 cN / tex and about 85 cN / tex.

The present invention has for its object to provide a sewing thread made of synthetic and / or natural fibers, which has particularly good sewing properties.

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

The sewing thread according to the invention made of synthetic and / or natural fibers is distinguished by the fact that it has a defined hairiness (sh), which is between 2.5 and 7.5, measured with a Uster thread uniformity tester UT3.

It was surprisingly found that, in addition to the strength, the hairiness of the sewing thread has a decisive influence on its sewing behavior. This is attributed to the fact that an optimal sewing behavior is only ensured if a sewing thread has a certain roughness and friction in relation to sewing thread guide members on the sewing machine, the roughness and friction being decisively influenced by a given thread hair. So it could be determined from sewing tests that one smooth sewing thread, ie a sewing thread whose hairiness is less than 2.5, the stitch loops required for the sewing operation are not provided, since the loop is not or only incompletely formed with such a sewing thread. Furthermore, it is not possible with such a completely smooth sewing thread to build up a thread tension required for the sewing operation on the sewing machine between the actual sewing needle and a disc brake contacted by the sewing thread, so that such a smooth sewing thread with a hairiness of less than 2.5 does not sew without problems . On the other hand, it was found that a sewing thread with a hairiness of more than 7.5 hooked too quickly onto thread guide elements of the sewing machine, so that such a sewing thread with a high hairiness (more than 7.5) also led to considerable disturbances in the sewing process. If, on the other hand, the respective sewing thread has the above-mentioned hairiness between 2.5 and 7.5, such a sewing thread according to the invention has excellent sewing properties. These excellent sewing properties are particularly expressed in the fact that the breakage frequency during sewing is considerably reduced, so that even with multidirectional sewing at extremely high sewing speeds of up to 7,000 stitches / minute, tearing of the sewing thread does not occur. With the sewing thread according to the invention, compared to an identical sewing thread, but which has a different hairiness, it is possible to produce between 30% and 70% more buttonholes before the sewing thread according to the invention breaks. These improvements in sewing behavior in the sewing thread according to the invention are further attributed to the fact that the hairiness Sewing thread still gives a certain volume, so that due to the protruding hair (capillaries) air is entrained by the sewing thread during the sewing process, which in turn causes cooling of such elements (needle, guide elements, disc brake) of the sewing machine, which due to the high speeds the contact with the sewing thread is extremely heated, for example to temperatures above 500 ° C. The high thermal strength of the sewing thread according to the invention is also expressed in that when sewing attempts under extreme conditions, for example when sewing a five-layer body, compared to a conventional sewing thread, about 30% longer seams can be produced until the sewing thread according to the invention also melts .

A first embodiment of the sewing thread according to the invention provides that the sewing thread has a hairiness between 3.0 and 7.0. Such a sewing thread has the advantages already described to an increased extent, so that it is outstandingly suitable for all sewing operations.

With regard to the thread count of the sewing thread according to the invention, it should be noted that this thread count depends on the particular application of the sewing thread. Usually, the effective thread count of the sewing thread according to the invention varies between 150 dtex and 4,500 dtex, preferably between 180 dtex and 2,400 dtex, the hairiness values and thread counts specified above being determined on sewing threads such as those which are commercially available as sewing thread ready for sale. In other words, these are values that have been determined on the finished product, ie in particular on dyed, finished and ready-made sewing threads.

There are several possibilities with regard to the construction of the sewing thread according to the invention.

Thus, a first embodiment of the sewing thread according to the invention provides that the sewing thread according to the invention consists of a twisted fiber yarn, the twisted fiber yarn preferably being made from at least two and in particular from three yarn components, each yarn component being pre-twisted for itself. It has been shown here that in particular those yarn components can be used for the production of the sewing thread according to the invention with the above-mentioned hairiness, in which a twist factor α between 80 and 130 has been selected for the pre-twists.

Bezüglich des Drehungsbeiwertes α, der ausgewählt wird, um die vorgezwirnten Garnkomponenten dann unter Ausbildung des erfindungsgemäßen Nähgarnes, das ein gezwirntes Fasergarn ist, zu verzwirnen, ist festzuhalten, daß hier diese Zwirndrehung einen Drehungsbeiwert α zwischen 80 und 150 aufweist. Hierdurch ist es dann insbesondere möglich, ein erfindungsgemäßes verzwirntes Fasergarn zu erstellen, das die zuvor wiedergegebenen Haarigkeit, insbesondere eine Haarigkeit zwischen 2,5 und 7,5 und vorzugsweise eine Haarigkeit zwischen 3,0 und 7,0, besitzt.The rotation coefficient α is defined as follows:

Regarding the twist factor α, which is selected in order to then twist the pre-twisted yarn components to form the sewing thread according to the invention, which is a twisted fiber yarn, it should be noted that here this twist twist has a twist coefficient α between 80 and 150. This then makes it possible in particular to create a twisted fiber yarn according to the invention which reproduces the previously reproduced Hairiness, in particular a hairiness between 2.5 and 7.5 and preferably a hairiness between 3.0 and 7.0, has.

In a second possibility, the sewing thread according to the invention is in the form of a twisted core thread. Here, the twisted core yarn according to the invention has a core which consists of at least one multifilament core material, this core material being wound with a second yarn component, preferably fibers. This core yarn can then be provided with a twist twist, in which case the twist twist has a twist coefficient α which varies between 120 and 180. However, it is particularly suitable if the core yarn according to the invention consists of at least two, preferably up to four core yarn components, each core yarn component being pre-twisted for itself.

In order to achieve the hairiness mentioned at the outset, it is advisable to pre-twist the core yarn components here in such a way that the pre-twist has a twist coefficient α between 90 and 140.

Such pre-twisted core yarn components are then twisted together to form a core yarn, with a twist twist selected for this, the twist coefficient α of which varies between 120 and 180.

Multifile yarn components made of polyester are preferred for the core yarn construction shown above (Polyethylene terephthalate) is selected, the single filament titer of these multifilament soul components varying between 0.6 dtex and 6 dtex, in particular between 1.5 dtex and 4 dtex. The number of filaments of the multifilament yarn component forming the core is between 16 and 300, preferably between 24 and 96, while fibers are selected for the spinning component, the staple length of which is between 15 mm and 120 mm, in particular between 20 mm and 60 mm, the individual fibers have a single fiber titer between 0.6 dtex and 4 dtex, preferably between 0.8 dtex and 2 dtex.

A further, particularly suitable construction for the sewing thread according to the invention provides that the sewing thread is designed as a swirled thread, the production of such a thread being described in detail, for example, in EP 0 295 601 B1 mentioned at the beginning. Such a swirled sewing thread has at least one multifilament core material and at least one multifilament effect material, the swirled thread preferably being twisted with a twist factor α between 40 and 120, in particular between 50 and 80. In contrast to the previously described embodiments of the yarn according to the invention, in such a multifilament interlaced yarn there are no protruding capillaries which are only integrated on one side, since the interlaced yarn contains no fiber yarn component. Nevertheless, such a swirled yarn has constituents which are detected by the yarn uniformity tester UT3 and which therefore fall under the term hairiness in the sense of the present invention. These components are about loops and / or loops protruding from the thread of the sewing thread, which may cross themselves and which are usually integrated on both sides of the thread.

In particular, if the previously described intermingled sewing thread has, in addition to the above-mentioned hairiness between 2.5 and 7.5 and in particular between 3.0 and 7.0, those components whose number is between 65 and 200 per meter and which in a distance of at least 0.5 mm from the package and which can be detected by the optical measuring method described below, such a swirled sewing thread has excellent sewing properties. These are attributed to the fact that these additional components further increase the volume of the sewing thread, so that such a voluminous sewing thread entrains further air, which brings about additional cooling of the elements of the sewing machine which come into contact with the sewing thread.

Preferably, in the sewing thread according to the invention, at least 85%, in particular 95%, of the loops formed during swirling are not drawn together in a knot-like manner, so that this ensures that the sewing thread according to the invention also has the previously specified volume.

Another embodiment of the intermingled sewing thread according to the invention provides that here the intermingled sewing thread, which has the above-mentioned hairiness, consists of up to four multifilament soul materials and up to four multifilament effect materials.

Depending on the respective field of application, the multifilament core material has an elementary thread number between 20 and 500, preferably between 30 and 150.

With regard to the number of filaments of the multifilament effect material, it should be noted in the case of interlaced sewing threads that the filament number of the multifilament effect material corresponds to approximately 30% to 250% of the filament number of the core material. In other words, the multifilament effect material has an elementary thread number which corresponds to approximately one third to two and a half times the elementary thread number provided for the multifilament soul material.

Particularly good results in terms of sewing behavior can be achieved with such interlaced sewing threads in which the core material has a titer between 80 dtex and 1,200 dtex, preferably a titer between 100 dtex and 600 dtex.

Regarding the titer of the multifilament effect material, it should be noted that the titer is about 15% to about 40% of the titer of the multifilament soul material.

Particularly good properties with regard to the subsequent care of a part assembled with the sewing thread according to the invention are ensured if the sewing thread according to the invention, which, as already explained above, is the construction of a fiber thread, a wrapped core thread or a swirled sewing thread can have a thermal shrink at 180 ° C between 0.4 and 5% and / or in water at 98 ° C between 0.2% and 3%. This prevents the seams from pounding or contracting in any other undesirable manner when the finished part is subsequently treated.

In a particularly suitable embodiment of the sewing thread according to the invention, the thread has a sliding value that is between 90 cN and 250 cN, in particular between 140 cN and 225 cN. Here, the sliding value is determined according to a measuring method, as is explained in detail below in the embodiments of the sewing thread according to the invention.

With regard to the specific strength of the sewing thread according to the invention, it should be noted that the finished sewing thread, as it comes on the market, has a specific strength which is between 30 cN / tex and 80 cN / tex, in particular between 35 cN / tex and 50 cN / tex , varies.

With regard to the fiber substrate, it should be noted in the sewing thread according to the invention that polyester fibers, polyamide 6 fibers, polyamide 6.6 fibers and / or cotton fibers are used in particular for this purpose.

The above data on hairiness, yarn fineness, twist factor of twisting, the number of other components, the number of filaments, the shrinkage values, the specific strength and the glide values Unless otherwise stated in the text, all focus on the finished sewing thread as it is offered in stores.

In order to be able to produce sewing threads with the previously specified hairiness or a desired gliding value, there are several possibilities. The desired hairiness or a desired gliding value can be achieved, for example, by varying the pile length of the fibers used for the twisted fiber yarn, the twist coefficient of the pre-twisting or twisting and / or the type and amount of finishing agent applied. In the case of core yarns, a desired hairiness and a desired gliding value can be set by changing the stack length of the winding component, the degree of winding, the type and amount of finishing agent and the twist factor of the twist twist, while in the case of intermingled sewing threads, a desired hairiness and / or a desired one Sliding value can be adjusted by varying the tension ratios during the swirling and / or after the swirling and / or the type and / or the amount of the finishing agent applied. In addition, all yarns can also be sewn accordingly in order to set a desired hairiness and a specified gliding value.

As has already been mentioned several times above, the sewing thread according to the invention preferably has or consists of polyester multifilaments, polyester being understood in the context of the present application to mean polyethylene terephthalate.

Advantageous developments of the sewing thread according to the invention are specified in the subclaims.

The sewing thread according to the invention is explained in more detail below using two exemplary embodiments.

Embodiment 1

A sewing thread thread was spun, which had a fineness as a ready-to-sell thread of Nm 71.2. Here, the thread consisted of two pre-twisted core yarn components, each core yarn component having a multifilament polyester core (74 f 24), which was wound with a polyester staple fiber with a staple length of 38 mm. Each core yarn component was pre-twisted with a twist factor α of 120 and then twisted to form the sewing thread, the twist factor of the twist being 167.

The specific strength of the twisted core yarn described above was 42 cN / tex.

Embodiment 2

An air-entangled polyester sewing thread was produced, which as a ready-to-sell sewing thread had a titer of 291 dtex and an elementary thread count of 64. A method was used for this, as described in EP 0 295 601 B1 is. After the intermingling, the sewing thread was twisted, the twist factor α for the twisting being 70. The specific strength of the ready-to-sell sewing thread was 38 cN / tex.

The hairiness (sh) of the above-mentioned sewing threads was measured on a Uster thread uniformity tester of the type Uster UT3.

Furthermore, the hairiness of two comparison yarns, hereinafter referred to as "core yarn standard" and "LB yarn standard", was measured. Here, the comparison yarns mentioned above differed from the yarns according to working examples 1 and 2 in that these standard yarns had identical final strengths, but a spinning component was used in the "core yarn standard", which had a stack length of 24 mm, while the "LB standard yarn" was swirled with another advance of the effect component.

The results of the hairiness measurement are shown in Table 1 below: Table 1 material Hairiness (h) Embodiment 1 4.35 Embodiment 2 6.3 Core yarn standard 7.9 LB yarn standard 0.8 Furthermore, the components that protrude above 0.5 mm above the thread base of the sewing thread according to embodiment 2 and the LB standard thread were determined by an optical measuring method. The results of this optical measurement, in which the yarn was transported through the measuring device at 300 m / min with a pretension of 40 cN, are shown in Table 2. The measuring device used had a light barrier which was positioned exactly 0.5 mm above the yarn base, so that the components protruding from the yarn base could be measured by pulse counting. material Components / m, distance from the yarn base:> 0.5 mm Embodiment 1 193 LB yarn standard 55

Furthermore, the sliding value of the four finished yarns mentioned above was determined. A chromed disc brake was used to measure the sliding value. It consists of two tension discs that are pressed together by means of a coil spring. The spring pressure is adjusted with the aid of a test thread, the spring pressure being set so that the test thread shows a sliding value of 180 cN when it is transported between the two tension disks at a take-off speed of 2 m / min becomes. The test thread is a standardized yarn with an average effective strength of dtex 121.5 x 3.

The results of the sliding value measurement are shown in Table 3 below. Table 3 material Sliding value in cN Embodiment 1 125 Embodiment 2 149 Core yarn standard 275 LB yarn standard 70 The sewing behavior of the four sewing threads mentioned above was examined. For this purpose, the sewing threads were sewn on an industrial sewing machine with a stitch density of 6,000 stitches / min in a multidirectional direction until a thread break occurred. The results shown in Table 4 represent mean values from 10 measurements / yarn. material Sewing behavior 6,000 stitches / minute m until the thread breaks Embodiment 1 broken off after 2,000 m, no yarn break Embodiment 2 broken off after 2,000 m, no yarn break Core yarn standard after 800 m of yarn break LB yarn standard no perfect seam possible

Claims (21)

1. A sewing thread, comprising synthetic and/or natural fibres, characterized in that said sewing thread provides a hairiness between 2,5 and 7,5, as measured with an Uster-yarn regularity tester UT3.
2. The sewing thread according to claim 1, characterized in that said sewing thread provides a hairiness between 3,0 and 7,0.
3. The sewing thread according to claim 1 or 2, characterized in that said sewing thread provides an effective yarn fineness between 150 dtex and 4500 dtex.
4. The sewing thread according to any of the preceding claims, characterized in that said sewing thread is a twisted spun yarn or a twisted core spun yarn.
5. The sewing thread according to claim 4, characterized in that said sewing thread comprises at least two yarn components, each of which yarn components is pre twisted.
6. The sewing thread according to claim 5, characterized in that each yarn component of the spun yarn provides a value of twist α for the pretwist between 80 and 130.
7. The sewing thread according to claim 4 or 5, characterized in that said twisted spun yarn has a ply twist with a value of twist α between 80 and 150.
8. The sewing thread according to claim 5, characterized in that each of the yarn components constituting the plied core spun yarn provides a value of twist α between 90 and 140 for the pretwist.
9. The sewing thread according to claim 4 or claim 8, characterized in that said twisted core spun yarn has a value of twist α between 120 and 180.
10. The sewing thread according to one of the claims 1 to 3. characterized in that said sewing thread is an intermingled yarn, comprising at least one multifile core material and at least one multifile effect material, said intermingled yarn being twisted to a plied yarn with a value of twist α between 40 and 120, preferably 50-80.
11. The sewing thread according to claim 10, characterized in that said sewing thread comprises between 65 and 200 yarn elements per meter which extend more than 0,5 mm from the yarn base.
12. The sewing thread according to one of the claims 10 or 11, characterized in that at least 85%, preferably 95%, of the loops being formed during the intermingling procedure are not drawn to knots.
13. The sewing thread according to one of the claims 10 to 12, characterized in that said sewing thread comprises up to four multifile core materials and up to four multifile effect materials.
14. The sewing thread according to one of the claims 10 to 13, characterized in that said multifile effect material provides a number of elementary filaments between 20 and 500, preferably between 30 and 150.
15. The sewing thread according to one of the claims 10 to 14, characterized in that said multifile effect material comprises a number of elementary filaments, which is 30 % to 250 % of the number of elementary filaments of the core material.
16. The sewing thread according to one of the claims 10 to 15, characterized in that said core material provides a titre between 80 dtex and 1,200 dtex, preferably between 100 and 600 dtex.
17. The sewing thread according to one of the claims 10 to 16, characterized in that the titre of the multifile effect material is about 15% to about 40 % of the titre of the multifile core material.
18. The sewing thread according to one of the preceding claims, characterized in that said sewing thread possesses a heat shrinkage at 180 °C between 0,4% and 5% and a boiling shrinkage in water (98°C) between 0,2 % and 3%.
19. The sewing thread according to one of the preceding claims, characterized in that said yarn possesses a specific strength between 30 cN/tex and 80 cN/tex, in particular between 35 cN/tex and 50 cN/tex.
20. The sewing thread according to one of the preceding claims , characterized in that said sewing thread consists of polyester fibres, polyamide 6.-fibres, polyamide 6.6-fibres and/or cotton fibres.
21. The sewing thread according to one of the preceding claims, characterized in that said sewing thread provides a slip friction value between 90 cN and 250 cN.