ABSORBENT TEXTILES ARTICLE

Description

[0001] The present invention relates to a textile article in the form of a knitted fabric. The invention further relates to the use of the knitted fabric according to the invention in an absorbent article, as well as a multi-layered absorbent article which contains the knitted fabric according to the invention.

[0002] In particular, the present invention provides a functional surface structure with excellent moisture management.

[0003] The term moisture management refers to properties of a material, for example a fiber material or a textile fabric, in which moisture is quickly transported away and quickly absorbed into the fiber / yarns, thereby quickly drying the surface of the textile fabric.

[0004] This is particularly important for textiles that come into contact with the body or are worn close to the body, such as underwear or sportswear. These properties are also important for absorbent products such as sanitary pads.

[0005] It is highly desirable that textile surfaces used in this application also offer good wearing comfort, good moisture transport and absorption, and are aesthetically suitable for the tasks in terms of color, style and appearance.

[0006] It is known that cellulose fibers can offer better comfort compared to synthetic fibers. This is because cellulose fibers are hydrophilic and absorb moisture vapor and liquid water.

[0007] Textile fabrics must be able to maintain their appearance over a longer period of use and care. Therefore, a textile fabric should be washable, have good wash resistance, and exhibit minimal shrinkage.

[0008] Numerous textile fabrics with moisture management features are available on the market. Most common textile fabrics are produced on so-called double-sided, double-row circular knitting machines and therefore have a relatively high fabric weight.

[0009] Existing fabrics of this type predominantly consist of synthetic materials such as polyester and polyamide (type 100%), possibly in various mixtures with animal fibers such as wool (types 70 / 30%, 80 / 20%) and natural fibers such as cotton (types 50 / 50%, 67 / 33%).

[0010] Each of these well-known textile surfaces has its advantages and disadvantages, which can have a positive or negative impact on comfort, function, and static charge.

[0011] The use of cellulose fibers significantly improves these properties, contributing to considerable wearing comfort.

[0012] Currently available products on the market generally offer moisture management. However, in the case of washable products, there are still no solutions that allow the surface to dry quickly. Furthermore, the majority of products available on the market (washable or non-washable) are made from materials (especially plastic) that offer poor comfort and are not very sustainable.

[0013] These fabrics are also often stiff and heavy and do not offer the necessary comfort for certain applications in underwear and sportswear.

[0014] As mentioned above, one area of ​​application for surface structures with moisture management is textiles that come into contact with the body or are worn close to the body, such as underwear or sportswear.

[0015] Multi-layered products are available, which can also be used, for example, as inserts in underwear. These products have an outer layer (top layer) facing the moisture source (i.e., the body), which wicks away the accumulated moisture. Beneath this layer is a layer of absorbent material, such as the moisture-management fabrics described above.

[0016] Well-known products also feature mixtures of different materials. In particular, the top layer often consists of synthetic materials, which leave much to be desired in terms of comfort due to their lack of softness.

[0017] Polylactic acid (PLA) fibers are a relatively new type of fiber that can be obtained from renewable raw materials, especially corn.

[0018] The prior art describes the use of PLA fibers in articles intended to absorb moisture, for example in CN109674101A, CN205728232U, CN203168107U, CN103266498A, CN104432665A, CN204483087U, CN114086304A, CN111319328A and CN216453462U.

[0019] Textiles made from yarns containing a mixture of PLA and cellulose fibers, especially lyocell fibers, are also known, for example from JP2000248465A, CN110747549A, CN111317318A and CN105029785A.

[0020] JP 2005-154949 A, JP 2004-353155 A and CN 102 134 776 A each disclose knitted fabrics made of at least one first and one second yarn, wherein the first of the two yarns has a high proportion of a cellulosic fiber and wherein the second of the two yarns has a high proportion of at least 90 wt.% polylactic acid (PLA) fiber.

[0021] The object of the present invention is to produce a textile surface structure for the use of functional textiles, which eliminates the shortcomings described above in the prior art.

[0022] It is designed to offer excellent performance in terms of moisture management.

[0023] It should also be cost-effective, as well as offer better comfort and sustainability, to ensure that garments made from it meet all performance requirements for their intended uses.

[0024] In summary, there is a need for a surface structure that exhibits several of the following properties: Good moisture transport, strong and rapid moisture absorption, excellent washability, comfortable to wear, especially softness, fast drying time, piece dyeing capability, light weight, sustainability

[0025] This problem is solved with a knitted fabric according to claim 1. Further aspects of the invention relate to the use of the knitted fabric as an absorbent article and / or as a component of an absorbent article for absorbing moisture from a moisture source, as well as an absorbent article with at least two layers, wherein one of the two layers is the knitted fabric according to the invention. BRIEF DESCRIPTION OF THE FIGURES

[0026] Figure 1 shows a schematic view of the surface of a knitted fabric according to the present invention with a honeycomb structure Figure 2is a photograph of a knitted fabric according to the invention from above Figure 3 shows the pattern of a thread path for the production of a preferred embodiment of the present invention according to the exemplary embodiment. Figure 4 is a photograph of the reverse side of a knitted fabric according to the invention. Figure 5 schematically shows a multi-layered absorbent article, one layer of which contains the knitted fabric according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention provides a knitted fabric according to claim 1.

[0028] The term "base yarn" is understood below to mean a type of yarn that contributes to the construction of the knitted fabric. According to the invention, at least two such yarn types are provided, namely one with a high proportion of cellulosic fiber and one with a high proportion of PLA fiber.

[0029] It is understood that numerous threads must be passed through numerous knitting needles to produce a knitted fabric. According to the invention, at least some of these threads are formed from the first and second basic knitting threads.

[0030] For example, if the knitted fabric is formed from 12 threads (as in the example below), some of these threads are formed from the first basic knitting thread, and another part of these threads are formed from the second basic knitting thread.

[0031] It was found that by the inventive arrangement of threads made of cellulosic fibers on the one hand and threads made of polylactic acid (PLA) on the other hand in a certain construction, a knitted fabric with excellent moisture management can be provided.

[0032] According to the invention, the knitted fabric has adjacent sections on at least one surface, each with closed, raised boundaries. "Closed raised boundaries" are understood to mean structures that are raised above the rest of the surface and have a closed perimeter, such as a circle or other closed geometric shapes.

[0033] According to the invention, at least a part of the second basic knitting thread (which contains the PLA fiber) is provided on these closed raised boundaries.

[0034] This is subsequently also referred to as a "structured surface according to the invention".

[0035] When – as will be explained in more detail later – this surface structured according to the invention faces a moisture source, it has been observed that the moisture is transported very quickly downwards into the knitted fabric. It is assumed that this is caused by the properties of the PLA fiber threads provided at the raised edges.

[0036] The cellulosic fiber, which according to the invention is a cross-linked lyocell fiber, in turn absorbs the moisture and can store it due to the hydrophilic properties of the cellulose fiber.

[0037] According to the invention, the entire surface of the knitted fabric consists of adjacent sections with closed raised boundaries.

[0038] Furthermore, the knitted fabric according to the invention has a honeycomb structure on the surface, wherein at least a part of the second basic knitted thread is provided on the raised boundaries of the honeycomb.

[0039] The production of knitted fabrics with such structured surfaces, featuring a honeycomb structure, is known to experts.

[0040] It is advantageous if the diameters D of the sections or the honeycombs have a ratio X to the height H of the raised boundaries, which is X ≥ 2, in particular 2 ≤ X ≤ 3.

[0041] The height of the raised edges can be limited, on the one hand, by the technical possibilities of incorporating raised sections into a knitted fabric. On the other hand, a certain minimum height of the edge relative to the diameter of the section is important to ensure that, depending on the application, moisture initially comes into contact with the knitted fabric practically exclusively at the raised edges and is then wicked away.

[0042] The ratio X can be up to 5 or even up to 10.

[0043] If the knitted fabric according to the invention is used in a multi-layered product, wherein a further textile layer, lying on the surface structured according to the invention, is arranged in the direction of the moisture source, the suitable ratio X ensures that the textile layer rests exclusively on the raised edges. This allows the moisture contained in the textile layer to be transported away quickly and completely.

[0044] The first basic knitting thread contains at least 90% by weight of a cellulosic fiber, which is a cross-linked lyocell fiber. This fiber may be mixed with a small proportion of other fibers in the thread, provided that this does not impair its intended function, in particular its ability to retain moisture.

[0045] In a preferred embodiment of the present invention, the first basic knitting thread consists essentially of the cellulosic fiber.

[0046] According to the invention, a cross-linked lyocell fiber is used as the cellulosic fiber. This fiber is able to absorb moisture.

[0047] It is known to crosslink lyocell fibers with crosslinking agents, making the lyocell fiber less susceptible to fibrillation.

[0048] Crosslinking agents for crosslinking lyocell fibers are described, for example, in WO 94 / 09191.

[0049] Surprisingly, it was found that a knitted fabric with a base yarn made of lyocell fiber cross-linked with the cross-linking agent described in WO 94 / 09191 (commercially available under the name "Lenzing ®< Lyocell A100") in combination with a base yarn made of PLA fiber has particularly advantageous properties: Firstly, it was found that such cross-linked lyocell fibers absorb moisture faster than other types of lyocell fibers.

[0050] The second base yarn contains at least 90% by weight of a polylactic acid (PLA) fiber. Again, the PLA fiber may be mixed with a small proportion of other fibers in the yarn, provided that this does not impair its intended function, in particular the wicking away of moisture.

[0051] In a further advantageous embodiment of the present invention, the second basic knitting thread consists essentially of the fiber made of polylactic acid (PLA).

[0052] An elastane thread can advantageously be applied to the second base knitting thread made of PLA fiber. In particular, the elastane thread can be plated onto the second base knitting thread. This is therefore not a mixture of the PLA fiber and the elastane thread, but rather two threads bonded together by the application of the elastane thread.

[0053] By applying an elastane thread to the second basic knitting thread, it becomes more stretchable and better suited for producing the raised borders provided for in the invention, e.g. honeycomb-shaped sections.

[0054] The elastane thread can be present, for example, in an order of approximately 10 wt.%, based on the thread made of PLA fiber.

[0055] According to the invention, the proportion of the second basic knitting thread in the raised closed boundaries is more than 50 wt.%, preferably 60 wt.% to 80 wt.%.

[0056] This ensures that a sufficient or predominant amount of PLA fiber is present in the raised areas of the knitted fabric to wick away the absorbed moisture.

[0057] In a further preferred embodiment of the present invention, the knitted fabric is formed exclusively from the first and the second basic knitted thread (optionally with an addition of elastane thread).

[0058] In this embodiment, the knitted fabric consists essentially of fibers made from renewable raw materials.

[0059] The fineness of PLA fiber thread can be coarser than that of cellulosic fiber thread, especially lyocell fiber. For example, the fineness of PLA fiber thread can range from 40 to 60 Nm, while that of lyocell fiber thread can range from 60 to 70 Nm. The metric number Nm indicates how many meters of thread have a mass of 1 g.

[0060] A single-surface, single-row circular knitting machine can be used to produce the knitted fabric according to the invention. This allows for a lower fabric weight compared to some known flat fabrics.

[0061] The circular knitting machine is preferably used in conjunction with a finer machine gauge E28 (28 needles per 2.54 centimeters or per inch) to achieve a further reduction in the fabric weight.

[0062] As mentioned, the formation of a honeycomb structure in a knitted fabric is known to those skilled in the art. It is merely necessary to take further precautions to ensure that the needles of a circular knitting machine, which carry the basic knitting yarn made of PLA fiber, are arranged or guided in such a way that at least a portion, and in particular a predominant portion, of the basic knitting yarn made of PLA fibers lies within the resulting raised boundaries of the honeycomb.

[0063] The further processing of the knitted fabric according to the invention can be carried out in a manner known per se by washing, heat fixing under tension and optionally dyeing.

[0064] The weight of the fabric, the construction, the knitting machine and the binding of the knitted fabric can each be chosen to produce a textile fabric with the style and properties required for the intended use.

[0065] The basic principle of the present invention can be implemented via a wide variety of bindings and / or constructions, insofar as the inventive mixtures of basic knitting threads and arrangements thereof are used.

[0066] In a further aspect of the present invention, the knitted fabric can be used as an absorbent article and / or as a component of an absorbent article for absorbing moisture from a moisture source. In this case, the surface of the knitted fabric structured according to the invention faces the moisture source when used.

[0067] This allows the advantages already mentioned above to be achieved. The PLA fiber threads within the raised, closed boundaries transport the liquid away from the moisture source to the wider areas of the knitted fabric, where it is absorbed by the threads containing absorbent cellulosic fiber, particularly lyocell fiber.

[0068] The present invention also relates to an absorbent article with at least two layers of textile material for absorbing moisture from a moisture source, characterized in that one of the two layers is a knitted fabric according to the invention and the surface of the knitted fabric structured according to the invention faces the moisture source when using it.

[0069] In a preferred embodiment, the article has a textile layer lying on the surface of the knitted fabric structured according to the invention.

[0070] The textile layer lying on the knitted fabric in the direction of the moisture source is preferably a woven fabric containing lyocell fiber. The fabric is preferably hydrophobic. In this embodiment, the article consists almost entirely of sustainable materials that are environmentally friendly and produced from renewable raw materials (lyocell, PLA).

[0071] It was found that a combination of a particularly hydrophobic fabric made of lyocell fibers and a knitted fabric according to the invention (viewed from the moisture source) underneath it excellently fulfills the requirement for moisture transport and moisture storage.

[0072] The moisture that initially collects on the lyocell fiber fabric is released under pressure (e.g., from body weight) into the PLA fibers in the underlying knit fabric and transported away by them. This results in an almost immediate and complete drying of the fabric made of hydrophobic lyocell fibers, especially when worn close to the body, while the moisture in the underlying knit fabric is almost completely absorbed by the lyocell fibers.

[0073] Instead of a hydrophobic fabric made of lyocell fibers lying on the knitted fabric according to the invention, fabrics or structures made of other, in particular hydrophobic, materials can also be used.

[0074] On the side of the knitted fabric according to the invention facing away from the moisture source, further layers can be provided. These can be additional layers of absorbent material (e.g., lyocell fibers) or membranes that seal the article to the outside.

[0075] The absorbent article according to the invention is washable and therefore reusable.

[0076] Accordingly, the present invention also relates to the use of the absorbent article according to the invention as an insert in a product worn close to the body, in particular in underwear.

[0077] The absorbent material can be sewn into underwear or sportswear in areas prone to moisture. It has been shown that the material quickly absorbs moisture while keeping the fabric next to the body dry.

[0078] Due to the special properties of the knitted fabric according to the invention, the absorbent article can be made significantly thinner and lighter than alternative existing solutions.

[0079] In another aspect, the present invention also relates to a product worn close to the body, in particular a textile, in which the absorbent article according to the invention is contained, in particular sewn in. Example of implementation

[0080] A knitted fabric was produced from the following two basic knitting threads in the following ratio: 72 wt.% of a first base knitting yarn made from a cross-linked Lyocell fiber of type LENZING™< Lyocell A100, ring-spun, with a fineness of Nm 68 / 1. 26 wt.% of a second base knitting yarn made from a PLA fiber, ring-spun, with a fineness of Nm 50 / 1.

[0081] Approximately 8% by weight of Dorlastan type elastane with a fineness of 22 dtex was applied to the second base yarn by plating. The total elastane content of the knitted fabric was approximately 2% by weight.

[0082] The knitted fabric was produced on a single-layer circular knitting machine with a gauge of E28 (28 needles per 2.54 centimeters or per inch) and electronic needle selection. However, it could also be produced on a mechanical single-layer circular knitting machine with at least three needle paths in the knitting cylinder (needle configuration 1-2-3-2), or on a single-layer circular knitting machine with four needle paths (needle configuration 4-1-2-3 or 1-2-3-4).

[0083] The yarn path for the production of the knitted fabric is in Figure 3 The threads labeled 1 to 5 and 7 to 11 are made of lyocell fiber. Threads 6 and 12 are made of PLA fiber (with an attached elastane fiber).

[0084] The knitting pattern shows, for example, that in system 12 (PLA fiber) the third knitting needle is pulled down, while in the subsequent systems 1 to 5 (Lyocell fiber) the third needle is not used. This results in a raised area where the thread is predominantly made of PLA fiber. The same applies to systems 6 (PLA fiber) and 7 to 11 (Lyocell fiber).

[0085] Figure 1 The figure schematically shows the honeycomb-structured surface of the knitted fabric produced according to this method and the invention. The raised, honeycomb-shaped boundaries are visible (light). The dark area between the boundaries is a flat knitted fabric.

[0086] Figure 2 shows a photograph of the knitting from above.

[0087] Figure 3 The image shows a photograph of the reverse side of the finished knitted fabric. The lighter threads (6, 12) are the threads made of PLA fiber.

[0088] In this specific embodiment, the height of the raised boundaries of the honeycomb was 1 mm and the width of the honeycomb was 5 mm (X = 5).

[0089] The raw material weight of the knitted fabric was 120 g / m².

[0090] The knitted fabric according to the invention was used as a layer in a multi-layered absorbent article.

[0091] The basic structure of the article is in Figure 5 schematically represented.

[0092] The uppermost layer 13, which faces the moisture source (e.g. the body) during use, is a hydrophobic fabric made of lyocell fibers.

[0093] The knitted fabric 14 according to the invention is provided below.

[0094] The item can be sewn into underwear or sportswear, for example, and consists almost entirely of sustainable materials that are environmentally friendly and made from renewable resources. Comparative tests with state-of-the-art absorbent products.

[0095] The moisture absorption of the multilayer absorbent product according to the invention was compared with multilayer products of the prior art: Comparison product 1 was a conventional disposable sanitary pad (period pad made of cellulose and PVC). Comparison product 2 was period underwear / washable sanitary pad with a top layer of PVC and cotton and an absorbent layer of plastic material underneath. Applying moisture to the absorbent article according to the invention:

[0096] When moisture (water) is applied to the absorbent article, the moisture does not initially penetrate the absorbent article due to the nature of the hydrophobically treated lyocell fibers in the top layer of the fabric.

[0097] However, when pressure is applied, a sudden penetration into the uppermost layer of fabric and through it into the underlying knitted fabric according to the invention can be observed.

[0098] After a very short time, all the moisture has passed through the top layer and been absorbed by the knitted fabric according to the invention. The top layer, closest to the body, is largely dry. Comparative trials:

[0099] In comparison with the reference product 1 (disposable sanitary napkin), which absorbs moisture very quickly, it was found that the reusable and sustainable product according to the invention has a practically equally good absorption effect.

[0100] In comparison with the comparison product 2 (period underwear made of plastic materials), a practically equally good and even faster absorbency (the surface dries faster) was also observed.

[0101] The absorbent article according to the invention, which - with the exception of the small proportion of elastane fibers - is composed entirely of fibers from renewable raw materials, is therefore at least equivalent to conventional products made partly from synthetic materials, or in some cases even superior.

Claims

1. A knitted fabric made from at least a first and a second base knitting yarn, - wherein the first of the two base knitting yarns comprises at least 90 wt.% of a cellulosic fiber, and - wherein the second of the two base knitting yarns comprises at least 90 wt.% of a fiber made from polylactic acid (PLA), - wherein at least one surface of the knitted fabric comprises adjacent sections, each with closed raised boundaries, and - wherein at least a portion of the second base knitting yarn is provided on the closed raised boundaries, wherein the proportion of the second base knitting yarn in the raised closed boundaries is more than 50 wt.%, preferably 60 wt.% to 80 wt.%, wherein the entire surface of the knitted fabric consists of the adjacent sections with closed raised boundaries and the knitted fabric is present in a honeycomb structure, wherein at least a portion of the second base knitting yarn is provided on the raised boundaries of the honeycombs, characterized in that the cellulosic fiber is a lyocell fiber and that the lyocell fiber is a cross-linked lyocell fiber.

2. A knitted fabric according to claim 1, characterized in that a ratio X of a diameter D of the sections to a height H of the raised boundaries lies at X ≥ 2, in particular 2 ≤ X ≤ 3 .

3. A knitted fabric according to one of the preceding claims, characterized in that the first base knitting yarn consists essentially of the cellulosic fiber.

4. A knitted fabric according to one of the preceding claims, characterized in that the second base knitting yarn consists essentially of the fiber made from polylactic acid (PLA).

5. A knitted fabric according to any of the preceding claims, characterized in that an elastane yarn is applied to at least a portion of the second base knitting yarn.

6. A knitted fabric according to claim 5, characterized in that the elastane yarn is plated onto the second base knitting yarn.

7. A knitted fabric according to one of the preceding claims, characterized in that it is formed exclusively from the first and second base knitting yarns, optionally with an addition of elastane yarn.

8. Use of a knitted fabric according to any of the preceding claims as an absorbent article and / or as a component of an absorbent article for the absorption of moisture from a moisture source, wherein the surface of the knitted fabric, which has the sections with raised closed boundaries, faces the moisture source during use.

9. An absorbent article comprising at least two layers (1, 2) of textile material for the absorption of moisture from a moisture source, characterized in that one of the two layers (2) is a knitted fabric according to any one of claims 1 to 7, and that the surface of the knitted fabric, which has the sections with raised closed boundaries, faces the moisture source during use.

10. An absorbent article according to claim 9, characterized in that the article comprises a textile layer (1) resting on the surface of the knitted fabric, which has the sections with raised closed boundaries.

11. Use of an absorbent article according to any of claims 9 and 10 as an insert in a product worn close to the body, in particular in underwear.