Composite yarn comprising at least two bundles of coalesced elastic filaments and plurality of inelastic elements

Abstract

To provide elastic yarns that, when used in high elasticity garments, are not (or at least less) affected by breakage and slippage of the elastic yarns.SOLUTION: The present invention relates to a composite yarn (100) comprising at least two bundles of elastic filaments (101, 102) and a plurality of inelastic elements (103), wherein the bundles of elastic filaments (101, 102) comprise a plurality of elastic filaments (150) connected one to the other in a substantially continuous manner; each of the inelastic element (103) is chosen among an inelastic filament or a bundle of coupled inelastic filaments; and the bundles of elastic filaments (101, 102) and the inelastic elements (103) are connected to each other by intermingling.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to elastic yarns, and in particular composite elastic yarns. The yarns of the present invention are particularly useful in the manufacture of fabrics for highly elastic garments, such as jeggings and similar garments. [Background technology]

[0002] Elastane or spandex filaments and yarns are well known in the art and have been widely used in the textile field to produce elastic yarns and fabrics. Elastane filaments are produced by extruding a polyurethane polymer through a spinneret with several extrusion cells. Before the filaments leave the extruder, a certain amount of solid single filaments or strands are bonded together to produce a filament bundle having the desired count, i.e., the desired thickness. Thus, each filament bundle of elastane (spandex) is composed of many smaller individual filaments that are bonded together, i.e., adhered to each other by the inherent tackiness of their surfaces when they come into contact with each other in the manufacturing process. US Pat. No. 5,399,433 discloses a suitable manufacturing process for bonded multifilament bundles.

[0003] Bundles of elastane filaments are used to make yarns. It is known to produce elastic yarns by combining a single bundle of bonded elastane filaments with a plurality of substantially inelastic (or substantially instretchable) polyester filaments.

[0004] When these types of elastic yarns are used to manufacture highly elastic fabrics, several problems are observed. The main problem with this type of fabric is known as "elastane break" or "elastane slippage", i.e. the elastic yarns can break and be pulled inwards. This results in the elastic yarns slipping from the break into the fabric, especially in the edge areas of both the waist and crotch of the garment.

[0005] These problems can occur, for example, when sewing with overlock or folded seams, during dry scraping processes, when laundering in industrial washing machines, when drying in tumble dryers, or when laundering at home.

[0006] The '613 patent discloses a composite yarn having a filamentary core with at least one elastic control filament and at least one inelastic control filament. A fibrous sheath formed from spun staple fibers preferably surrounds the filamentary core over substantially its entire length. The at least one elastic control filament most preferably comprises spandex and / or lustole filaments. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Pat. No. 3,094,374 [Patent Document 2] International Publication No. 2008 / 130563 Summary of the Invention [Problem to be solved by the invention]

[0008] The object of the present invention is to solve the above-mentioned problems and to provide a yarn which is not (or is less) susceptible to elastic yarn breakage and "slippage" when used in highly elastic garments. [Means for solving the problem]

[0009] These objects are solved by one or more claims of the present invention.

[0010] An aspect of the invention relates to composite yarns, fabrics, articles and processes as set out in the independent claims, while preferred aspects are set out in the dependent claims.

[0011] According to one aspect of the invention, the composite yarn includes two or more elastic filament bundles and a plurality of inelastic elements. Among the elastic filament bundles (hereinafter also referred to as "elastic bundles") connected to each other, there are at least a first elastic filament bundle (hereinafter also referred to as "first elastic bundle") and a second elastic filament bundle (hereinafter also referred to as "second elastic bundle"). And each of the first elastic bundle and the second elastic bundle includes a plurality of elastic filaments connected to each other, i.e., connected, in a substantially continuous manner. The inelastic elements can be a plurality of different inelastic filaments or a bundle of a plurality of different inelastic filaments. The plurality of connected elastic filament bundles is preferably combined with a plurality of individual inelastic monofilaments. The initial bundles of elastic filaments and inelastic filaments are connected by twisting. The twisted connection provides a knot.

[0012] Thus, twisting is used to join elastic filament bundles and inelastic elements which, prior to twisting, were substantially separate elements.

[0013] As mentioned above, each filament bundle contains a plurality (two or more) of elastic filaments that are bonded, i.e. connected, to each other in a substantially continuous manner (e.g. in a manufacturing step or by bonding, gluing or similar methods). By "substantially continuous" we mean that there is a continuous portion of the filaments that are connected to each other, although the connection between the filaments is not strict (e.g. as provided by twisting). Indeed, in the case of elastic fiber elements, it is known that a certain amount of filaments can be bonded (bundled) together to produce a desired thickness. For example, spandex yarns are known to be usually prepared as bonded filament bundles, because to prepare a multifilament bundle, i.e. a bonded filament bundle, elastane yarns can be composed of a plurality of smaller individual filaments that are bonded to each other.

[0014] The bundle is elastic: according to DIN 53820 part 2 it can be stretched from 50% to 1000% (as elongation at break).

[0015] Inelastic elements are "inelastic" because they have a smaller elongation at break than the elastic bundles, preferably less than 75%, more preferably less than 50%, when measured in the same test. Typically, inelastic elements have an elongation at break of 5% to 100% according to DIN ISO 2062.

[0016] The filaments of the same elastic bundle are connected in a substantially continuous manner, as this is done in the manufacturing steps mentioned.

[0017] As a result, in the claimed solution, there are at least two, preferably three or more, elastic filament bundles. They do not behave or move like a single element (which would therefore be at risk of breaking), but maintain a certain independence from each other, even when twisted with non-elastic elements. The elastic multifilament bundles are separated from each other, so that even if one bundle breaks during the sewing step or breaks due to stress, the remaining bundles of elastic filaments can still impart elasticity to the yarn. This fact gives a better resistance to stresses, and in particular in the above-mentioned situations, allows the damage to be limited to only a part of the elastic bundles (or to a part of the filaments of the bundles).

[0018] Preferably, the composite yarn consists essentially of the above-mentioned elastic bundles and inelastic elements. In particular, according to a preferred embodiment, the above-mentioned yarn is not used as the core of a core-sheath composite yarn, in other words, this yarn is not covered by a sheath of, for example, staple fibers.

[0019] According to one aspect of the invention, the composite yarn is comprised of elastic bundles and inelastic filaments.

[0020] As mentioned above, in preferred embodiments, there are three or more elastic bundles. In practice, embodiments of the present invention may include at least three elastic bundles, or at least five elastic bundles, or at least seven elastic bundles. Exemplary and preferred embodiments include two, and preferably between 3 and 22 elastic bundles.

[0021] In an embodiment of the invention, the composite yarn comprises, in addition to the above-mentioned bundles of elastic filaments, at least one, and preferably several, single elastic filaments, which can be obtained by avoiding the bonding of single filaments into bundles during their production.

[0022] As a general concept, the number and yarn count of the non-elastic elements are not limited. However, it is preferable that the total yarn count of the non-elastic elements is equal to or greater than the total yarn count of the elastic elements. In other words, it is more preferable that the weight ratio of the non-elastic elements in the composite yarn is greater than the weight ratio of the elastic elements in the composite yarn. In the resulting yarn, the elastic filaments can be 5% to 50% by weight of the resulting composite yarn.

[0023] Also, according to one aspect of the invention, the number of inelastic elements in the composite yarn is greater than the number of elastic bundles in the resulting yarn.

[0024] Further according to one aspect of the invention, each inelastic element comprises at least one polyester filament, and / or polyamide filament, and / or polyester copolymer, and / or polyamide copolymer.

[0025] The present invention is a composite yarn according to claim 1. The present invention also relates to a fabric, preferably a woven fabric, according to claim 13, and the present invention includes an article, preferably a garment, comprising the yarn according to one or more of the above-mentioned embodiments and the fabric according to claim 13.

[0026] Furthermore, the present invention relates to a method according to claim 15. This method for producing a composite yarn comprises the steps of providing a plurality of inelastic elements, each inelastic element being selected from a filament or a bonded filament bundle, providing two or more elastic filament bundles comprising a plurality of elastic filaments connected to each other in a substantially continuous manner, the elastic filament bundles being separate from each other, twisting the elastic filament bundles and the inelastic elements, and collecting the composite yarn obtained by the twisting step. The twisting is preferably performed by air jet twisting.

[0027] By using multiple bundles of bonded elastic filaments and multiple inelastic filaments and twisting them together at entanglement points or knots, a resulting yarn with no or very little slippage of elastane can be obtained, which can also be used as is without further processing.

[0028] Exemplary, non-limiting embodiments of the present invention are described with reference to the following figures. [Brief description of the drawings]

[0029] [Figure 1] FIG. 2 is a schematic diagram of a portion of a composite yarn according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of an apparatus capable of producing the composite yarn shown in FIG. [Diagram 3] FIG. 3 is a schematic diagram of a twisting device that can be used in the apparatus shown in FIG. 2. [Figure 4] FIG. 2 is a schematic diagram of a garment obtained using a fabric containing the composite yarn shown in FIG. 1 continuously. [Diagram 5] FIG. 2 is a schematic cross-sectional view of a bonded elastic filament bundle. [Figure 6] FIG. 2 is a schematic cross-sectional view of three monofilaments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] The composite yarn 100 includes at least two bundles of elastic filaments (also referred to as "elastic bundles" as discussed above) 101, 102, namely at least a first elastic bundle 101 and a second elastic bundle 102.

[0031] For ease of visualization and explanation, two bundles of bonded elastic filaments 101, 102 are used for illustration. In different embodiments of the invention, more elastic bundles 101, 102 may be provided. According to embodiments of the invention, between 3 and 8 bundles of bonded elastic filaments are provided.

[0032] In a possible embodiment of the elastic bundle, it comprises two elastic filaments, for example 40D / 40D elastic filaments (elastane). In a further possible embodiment, the elastic bundle 101, 102 comprises four elastic filaments, for example 20D / 20D / 20D / 20D elastic filaments (elastane). In a further possible embodiment of the elastic bundle, it comprises seven elastic filaments, for example 10D / 10D / 10D / 10D / 10D / 10D elastic filaments (elastane), where "D" stands for denier.

[0033] The elastic filament bundles 101 and 102 have a count of 20 to 1000 denier, preferably 50 to 300 denier. The number of filaments bonded to each other is 2 to 200, preferably 4 to 150, more preferably 6 to 100.

[0034] The elastic filaments 150 are preferably elastomeric filaments, i.e., filaments that can be repeatedly stretched at room temperature to at least twice their original length, and immediately and forcefully return to approximately their original length upon removal of tension. According to one embodiment of the invention, the elastic filaments 150 are polyurethane filaments, such as elastane filaments.

[0035] The elastic bundles 101, 102 include a plurality of elastic filaments 150. The elastic filaments 150 are connected to each other in a substantially continuous manner.

[0036] The elastic filaments 150 may be connected to one another in a generally continuous manner by any known means.

[0037] The composite yarn 100 includes a plurality of inelastic elements 103. In the above-described embodiment, the inelastic elements 103 are part of a bundle of inelastic filaments. As a result, in the above-described embodiment, the inelastic elements 103 correspond to inelastic filaments. In a different embodiment, the inelastic elements can be a plurality of connected (e.g., bonded) inelastic subfilaments. The count of the inelastic filaments is lower than the count of the elastic filaments 150. The preferred inelastic filaments have a count of 0.5 to 3 denier.

[0038] The composite yarn 100 includes a plurality of inelastic elements 103, which may be single inelastic filaments or inelastic subfilament bundles.

[0039] Each source of filament bundles can have a different filament bundle count / denier, and in the final product, all the filament bundle count / denier combinations can be different, such as 40 denier + 30 denier.

[0040] The inelastic elements 103 are preferably monofilaments, i.e. single filaments, of partially oriented yarn (POY) as known in the art. The filaments of the inelastic elements 103 are preferably selected from polyester filaments and polyamide (nylon) filaments, or filaments made of polyester or polyamide copolymers. The inelastic filaments are preferably textured filaments.

[0041] Each elastic bundle can be stretched to a different level of draft ratio.

[0042] The inelastic element 103 may also include bicomponent filaments, such as PBT / PTT or PET / PTT or PET / PTMT bicomponent filaments.

[0043] The elastic bundles 101, 102 and the inelastic elements 103 are connected to one another at a number of points P by twisting to form the resulting composite yarn 100. As a result, in the resulting composite yarn 100, there is a portion of the first elastic bundle 101 that is not connected to the second elastic bundle 102 (i.e., between two subsequent connection points P), which can behave substantially independently with respect to the corresponding portion of the second elastic bundle 102. As mentioned above, to facilitate such independence, as shown, the elastic bundles 101, 102 are preferably fed to the twisting device as independent bundles, e.g., at least in an untwisted state.

[0044] Preferably, the twisting is performed by air jet twisting.

[0045] The composite yarn 100 is typically used to provide a fabric 200, preferably a woven fabric. One aspect of the invention relates to an article 300, typically a garment, comprising such a fabric 200. According to a possible embodiment, as shown in Figure 2, in the manufacturing process of the composite yarn according to the invention, the inelastic elements 103 are provided by one or more sources 1, for example one or more bobbins. According to the illustrated embodiment, a single source 1 provides a bundle of separate inelastic elements (i.e. inelastic filaments) 103.

[0046] The inelastic element 103 passes through a guide 3, for example a tube, and can then be drafted by a drafting means 2, for example one or more drafting rollers.

[0047] The inelastic element 103 can also be subjected to a heat treatment, for example by a heating element 4 followed by a cooling element 5, for example a heating and cooling chamber through which the inelastic element 103 passes. The temperature of the initial heating element 4 can be between 180 and 210°C.

[0048] A sensor 6 can be provided to verify if breakage of the inelastic element occurs during this process, thereby allowing monitoring and preventing further supply of the inelastic element from the source 1. A further sensor 7 can be provided to verify the tension of the inelastic element 103.

[0049] The elastic bundles 101, 102 are drawn from associated sources 11, 12. Preferably, each elastic bundle 101, 102 is drawn from a different source 11, 12. As a result, for at least a portion of their paths, the first elastic bundle 101, the second elastic bundle 102, and the inelastic element 103 move along different and separate paths.

[0050] The inelastic elements 103 and elastic bundles 101, 102 are then connected together at a number of connection points P by a twisting device 8, preferably an air jet twisting device.

[0051] As mentioned above, the twisting device provides multiple connection points P between the filaments of the resulting yarn. In particular, as is known, twisting provides multiple connection points P (knots) between the filaments 101, 103 of the resulting yarn. There are known methods and testers for measuring the number of entanglements / knots per meter of yarn.

[0052] As an example, in the ITEMAT+ "Interlace Test" by Textechno H. Stein, Moenchengladbach, DE (https: / / www.textechno.com), the yarn is passed between two cylinders at a given elongation to assess the number of twist points. At each twist point, an entanglement, or knot, of elastic and inelastic filaments is provided, which remains when the yarn is pulled or stretched, or which can be sensed by the testing machine in smooth yarns.

[0053] When tested on the same machine, when stretched by about 6.0%, the yarn according to the invention preferably has at least 50 connection points (i.e. knots) per meter, more preferably at least 80 connection points / knots per meter, and even more preferably at least 100 connection points / knots per meter. The preferred number of knots per meter is between 80 and 120.

[0054] According to a preferred embodiment, the inelastic elements 103 are overfed to the twisting device 8, preferably by a ratio of 1.2% to 7.0%.

[0055] Before twisting, the elastic bundles 101, 102 and the non-elastic element 103 can pass together through a drafting device 9, e.g. a drafting roller. Preferably, the draft of the drafting device 9 (applied to both the elastic bundles 101, 102 and the non-elastic element 103) is greater than the draft applied to the non-elastic element 103 by the drafting device 2 (located upstream of the drafting device 9). In particular, the draft applied to the drafting device 9 can be 1.5 to 1.8 times greater than the draft applied by the drafting device 2.

[0056] The draft of the elastic bundle 101 is preferably between 1.1 and 6.9, more preferably between 2 and 6, and even more preferably between 3 and 5. With respect to the inelastic elements 103, the draft is preferably less than 6, more preferably less than 5, and even more preferably less than 4. Furthermore, the elastic bundle 101 is preferably drafted less than the inelastic elements 103.

[0057] Additionally, the non-elastic element 103 may be textured by a texturing device 10 prior to connection with the elastic bundles 101, 102. Any suitable texturing device may be used, such as a friction disc device.

[0058] After twisting, a composite yarn is formed, in which the elastic bundles 101, 102 and the inelastic elements 103 are connected by twisting.

[0059] Further finishing processes may be performed, such as heat treatment by a heating chamber 16, and / or further drafting by one or more drafting devices 13a, 13b, and / or application of a finishing agent, such as oil or a similar substance, by a finishing device 14.

[0060] The composite yarn 100 is finally collected in a yarn collection element 15. Typically, the collected composite yarn 100 is wound on a bobbin.

[0061] In one embodiment, substantially no further yarns, rovings or similar fibrous elements are added to the composite yarn 100 during this manufacturing process, so that it can be used in a form essentially including elastic bundles 101, 102 and inelastic elements 103 as a yarn for manufacturing fabrics, particularly woven fabrics 200, for articles 300 such as garments. [Explanation of symbols]

[0062] 1 Source 2 Draft device 3 Guide 4 heating elements 5 Cooling Elements 6, 7 Sensors 8 Twisting device 9 Draft device 10 Texture imparting device 11, 12 Source 13a, 13b Draft device 14 Finishing Equipment 15 Yarn collection elements 16 Heating Chamber 100 Composite Yarn 101, 102 Elastic bundle (filament bundle) 103 Inelastic Elements 150 Elastic Filament 200 Fabric (woven) 300 Articles (clothing) P Connection Point

Claims

1. A composite yarn (100) comprising two or more elastic filament bundles (101, 102) and a plurality of inelastic elements (103), The elastic filament bundle (101, 102) includes a plurality of elastic filaments (150) connected to each other, The inelastic element (103) comprises a plurality of inelastic filaments and / or at least a bundle of inelastic filaments; A composite yarn (100), characterized in that said elastic filament bundles (101, 102) and said inelastic elements (103) are connected to each other by twisting.

2. 2. The composite yarn (100) according to claim 1, characterized in that the inelastic elements (103) are heat-treated via a heating element (4) before being twisted with the elastic filament bundles (101, 102).

3. A composite yarn (100) according to claim 1 or 2, characterized in that it consists essentially of elastic filaments (101, 102) and said inelastic elements (103), which are joined by twisting.

4. 4. The composite yarn (100) according to any one of claims 1 to 3, characterized in that each said inelastic element (103) comprises at least one polyester filament and / or polyamide filament.

5. 5. The composite yarn (100) according to any one of claims 1 to 4, characterized in that it comprises more than 50 entanglement points per meter, more preferably more than 80 entanglement points per meter, most preferably more than 100 entanglement points per meter, preferably up to 150 entanglement points per meter.

6. The composite yarn (100) according to any one of claims 1 to 5, characterized in that the elastic filaments (101) are preferably drafted at 1.1 to 6.9, more preferably at 2 to 6, and even more preferably at 3 to 5.

7. 7. The composite yarn (100) according to any one of the preceding claims, characterized in that the draft of the inelastic elements (103) is between 1.01 and 6, preferably less than 5, and most preferably less than 4.

8. 8. The composite yarn (100) according to any one of claims 1 to 7, characterized in that the draft of the inelastic elements (103) is smaller than the draft of the elastic filaments (101).

9. The composite yarn (100) according to any one of the preceding claims, characterized in that the inelastic elements (103) are textured.

10. 10. The composite yarn (100) according to any one of claims 1 to 9, characterized in that the inelastic elements (103) preferably comprise bicomponent filaments selected from PET / PTT, PBT / PTT, PET / PTMT.

11. 11. The composite yarn (100) according to any one of the preceding claims, characterized in that it comprises at least three elastic filament bundles (101, 102), preferably at least five elastic filament bundles (101, 102).

12. 12. The composite yarn (100) according to any one of the preceding claims, characterized in that the elastic filament bundles (101, 102) have a count of 2 to 1000 denier, preferably 10 to 100 denier.

13. 13. The composite yarn (100) of any one of claims 1 to 12, further comprising, in addition to the combined elastic filament bundles, at least one, preferably a plurality of single elastic filaments that are twisted with the inelastic element (103).

14. A fabric (200), preferably a woven fabric, comprising the composite yarn according to any one of claims 1 to 13.

15. An article (300), preferably a garment, comprising the fabric (200) according to claim 14.

16. a. providing a plurality of inelastic elements (103) comprising a plurality of filaments and / or bonded filament bundles; b. providing at least two elastic filament bundles (101, 102) that are separate from one another and that include a plurality of elastic filaments (150) connected to one another; c. twisting said elastic filament bundles (101, 102) and said inelastic elements (103), preferably by air jet twisting; and d. collecting the composite yarn (100) obtained by said twisting step.

17. 17. A method for producing a composite yarn (100) according to claim 16, characterized in that the inelastic element (103) is heat treated via a heating element (4) before being twisted with the elastic filament bundles (101, 102).

18. 18. A method for producing a composite yarn (100) according to claim 16 or 17, characterized in that no further yarns, or rovings, or slivers are added to the composite yarn (100) between steps c and d.

19. A method for producing a composite yarn (100) according to any one of claims 16 to 18, characterized in that it comprises a step of imparting texture to the inelastic elements (103).

20. A method for producing a composite yarn (100) according to any one of claims 16 to 19, characterized in that in step c, the inelastic elements (103) are overfed, preferably by a proportion of 1.2% to 7.0%.

21. A composite yarn obtainable by the process according to any one of claims 16 to 20.

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