Absorbent textile article

Abstract

The invention relates to a knitted fabric made of at least one first and one second basic knitting thread, wherein the first of the two basic knitting threads comprises at least 90 wt.% of a cellulosic fiber and wherein the second of the two basic knitting threads comprises at least 90 wt.% of polylactic acid (PLA) fiber, wherein at least one surface of the knitted fabric has adjacent sections with closed raised borders, and wherein at least a part of the second basic knitting thread is provided on the closed raised borders.

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 to a multi-layer absorbent article containing the knitted fabric according to the invention.

[0002] In particular, the present invention provides a functional fabric 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 the moisture is quickly transported and quickly absorbed into the fiber / yarn, thereby quickly drying the surface of the textile fabric.

[0004] This is especially 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 pads.

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

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

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

[0008] Numerous textile fabrics with moisture management are available on the market. Most of the commonly used textile fabrics are manufactured on so-called two-face, two-thread circular knitting machines and therefore have a relatively high fabric weight.

[0009] Existing fabrics of this type are predominantly made of synthetic materials such as polyester and polyamide (type 100%), possibly in various blend ratios 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 fabrics has its advantages and disadvantages, which can have positive but also negative effects on comfort, function and static charge.

[0011] When cellulose fibers are used, these properties are significantly improved, which contributes to considerable wearing comfort.

[0012] Currently available products 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 products available on the market (washable or non-washable) are largely made of 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 required comfort for certain applications in underwear and sportswear.

[0014] As mentioned above, one area of ​​application for fabrics 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 known here, which can also be incorporated, for example, as inserts in underwear. These products have a top layer (cover layer) facing the moisture source (i.e., the body), which wicks away the accumulating moisture. Below this layer is a layer of absorbent material, such as the fabrics with moisture management described above.

[0016] Well-known products also feature blends of different materials. In particular, the top layer is often made 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, in particular lyocell fibers, are also known, for example from JP2000248465A, CN110747549A, CN111317318A and CN105029785A.

[0020] The object of the present invention is to produce a textile fabric for use in functional textiles, which eliminates the deficiencies described above occurring in the prior art.

[0021] It is said to offer excellent moisture management performance.

[0022] It should also be cost-effective, offer better comfort and sustainability to ensure that garments made from it meet all performance requirements for their intended uses.

[0023] In summary, there is a need for a fabric that has several of the following properties: Good moisture transport Strong and rapid moisture absorption Excellent washing properties Wearing comfort, especially softness Fast drying time Possibility of piece dyeing Low weight Sustainability

[0024] This object is achieved 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 having at least two layers, one of the two layers being the knitted fabric according to the invention. SHORT DESCRIPTION OF THE CHARACTERS

[0025] Figure 1 shows a schematic view of the surface of a knitted fabric according to the present invention with a honeycomb structure Figure 2 is a photograph of an inventive knitted fabric from above Figure 3 shows the pattern of a thread path for producing a preferred embodiment of the present invention according to the embodiment. Figure 4 is a photograph of the back of a knitted fabric according to the invention. Figure 5shows schematically a multi-layer absorbent article which contains the knitted fabric according to the invention as one layer. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention provides a knitted fabric comprising at least a first and a second basic knitting thread, wherein the first of the two basic knitting threads has a proportion of at least 90 wt.% of a cellulosic fiber and wherein the second of the two basic knitting threads has a proportion of at least 90 wt.% fiber made of polylactic acid (PLA), wherein at least one surface of the knitted fabric has adjacent sections each with closed raised boundaries, and wherein at least a part of the second basic knitting thread is provided on the closed raised boundaries.

[0027] The term "base knitting thread" refers to a type of thread that contributes to the structure of the knitted fabric. According to the invention, at least two such thread types are provided: one with a high proportion of cellulosic fiber and one with a high proportion of PLA fiber.

[0028] It is understood that to produce a knitted fabric, numerous threads must be passed through numerous knitting needles. According to the invention, at least some of these threads are formed from the first basic knitting thread and the second basic knitting thread.

[0029] If, for example (as in the embodiment below), the knitted fabric is formed from 12 threads, a part of these threads is formed from the first basic knitting thread, and another part of these threads is formed from the second basic knitting thread.

[0030] It has been found that 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 specific construction can provide a knitted fabric with excellent moisture management.

[0031] According to the invention, the knitted fabric has adjacent sections on at least one surface, each with closed, raised borders. "Closed raised borders" refers to structures that are raised relative to the rest of the surface and have a closed circumference, such as a circle or other closed geometric shapes.

[0032] 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.

[0033] In the following, this is also referred to as a “structured surface according to the invention”.

[0034] When—as will be explained in more detail later—this inventively structured surface faces a moisture source, it has been observed that the moisture is very quickly transported downwards into the knitted fabric. This is suspected to be caused by the properties of the PLA fiber threads provided at the raised edges.

[0035] The cellulosic fiber, in turn, absorbs the moisture and can store it due to the hydrophilic properties of the cellulose fiber.

[0036] Preferably, the entire surface of the knitted fabric consists of adjacent sections with closed raised boundaries.

[0037] A particularly preferred embodiment of a knitted fabric according to the invention has a honeycomb structure on the surface, wherein at least a part of the second basic knitting thread is provided on the raised boundaries of the honeycombs.

[0038] The production of knitted fabrics with such structured surfaces, in particular with a honeycomb structure, is known to the person skilled in the art.

[0039] It is advantageous if the diameters D of the sections, in particular of the honeycombs, to the height H of the raised boundaries have a ratio X which is X ≥ 2, in particular 2 ≤ X ≤ 3.

[0040] The height of the raised borders may be limited, on the one hand, by the technical possibilities for providing raised sections in a knitted fabric. On the other hand, a certain minimum height of the border relative to the diameter of the section is important to ensure that, depending on the intended application, moisture initially comes into contact with the knitted fabric almost exclusively at the raised borders and is transported away.

[0041] The ratio X can be up to 5 or up to 10.

[0042] If the knitted fabric according to the invention is used in a multi-layer product, with another textile layer arranged on the structured surface according to the invention toward the moisture source, the appropriate ratio X ensures that the textile layer rests exclusively on the raised edges. This quickly and completely transports away the moisture contained in the textile layer.

[0043] The first basic embroidery thread contains at least 90% by weight of a cellulosic fiber. The fiber may optionally be mixed with a small proportion of other fibers in the thread, provided that this does not impair the intended function, namely, in particular, moisture retention.

[0044] In a preferred embodiment of the present invention, the first basic knitting thread consists essentially of the cellulosic fiber.

[0045] In principle, all cellulosic fiber types that are able to absorb moisture, in particular natural cellulose fibers such as cotton, or underivatized man-made cellulose fibers such as viscose fibers or lyocell fibers, can be used as cellulosic fibers.

[0046] The cellulose fiber is preferably a lyocell fiber.

[0047] The lyocell fiber is particularly preferably a cross-linked lyocell fiber.

[0048] It is known to crosslink lyocell fibers with crosslinking agents, making the lyocell fiber less susceptible to fibrillation.

[0049] Crosslinking agents for crosslinking lyocell fibers are described, for example, in WO 94 / 09191.

[0050] Surprisingly, it was found that a knitted fabric with a base yarn made of a lyocell fiber crosslinked with the crosslinking 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 lyocell fibers crosslinked in this way absorb moisture faster than other types of lyocell fibers.

[0051] The second base knitting thread contains at least 90% by weight of a polylactic acid (PLA) fiber. Again, the PLA fiber in the thread may optionally be mixed with a small proportion of other fibers, provided that this does not impair the intended function, namely, in particular, the wicking away of moisture.

[0052] In a further advantageous embodiment of the present invention, the second basic knitting thread consists essentially of the fiber made of polylactic acid (PLA).

[0053] 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 not a mixture of PLA fiber and elastane thread, but rather two threads joined together by the application of the elastane thread.

[0054] By applying an elastane thread to the second basic knitting thread, the latter becomes more stretchable and better suited for producing the raised borders provided according to the invention around, for example, honeycomb-shaped sections.

[0055] The elastane thread can, for example, be present in a quantity of approximately 10% by weight, based on the PLA fiber thread.

[0056] A further preferred embodiment of the present invention is characterized in that the proportion of second basic knitting thread in the raised closed boundaries is more than 50 wt.%, preferably 60 wt.% to 80 wt.%.

[0057] This ensures that there is a sufficient or predominant amount of PLA fiber in the raised areas of the knit to transport away the moisture that needs to be absorbed.

[0058] In a further preferred embodiment of the present invention, the knitted fabric is formed exclusively from the first and the second basic knitting thread (optionally with an addition of elastane thread).

[0059] In this embodiment, the knitted fabric consists essentially of fibers made from renewable raw materials.

[0060] 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 be 40 to 60 Nm, while that of lyocell fiber thread can be 60 to 70 Nm. The metric number Nm indicates how many meters of thread have a mass of 1 g.

[0061] A single-fabric, single-thread circular knitting machine can be used to produce the knitted fabric according to the invention. This allows a lower fabric weight to be achieved compared to some known fabrics.

[0062] The circular knitting machine is preferably used in conjunction with a finer machine gauge E28 (28 needles per inch) so that a further reduction in the weight of the fabric can be achieved.

[0063] As mentioned, the formation of, for example, a honeycomb structure in a knitted fabric is known per se to those skilled in the art. It is merely necessary to ensure that the needles of a circular knitting machine, which carry the base knitting thread made of PLA fibers, are arranged or guided in such a way that at least a portion, in particular a predominant portion, of the base knitting thread made of PLA fibers lies in the resulting raised boundaries of the honeycomb.

[0064] The knitted fabric according to the invention can be further processed in a manner known per se by washing, thermosetting under tension and, if necessary, dyeing.

[0065] The fabric weight, construction, knitting machine and weave of the knitted fabric can be selected to produce a textile fabric with the style and properties required for the intended use.

[0066] The basic principle of the present invention can be implemented over a wide variety of weaves and / or constructions, as long as the mixtures according to the invention are used as basic knitting threads and arrangements thereof.

[0067] In a further aspect of the present invention, the knitted fabric according to the invention can be used as an absorbent article and / or as a component of an absorbent article for absorbing moisture from a moisture source

[0068] The surface of the knitted fabric structured according to the invention faces the moisture source during use.

[0069] This allows the aforementioned advantages to be achieved. The PLA fiber threads located in the raised, closed borders transport the liquid away from the moisture source into the wider areas of the knitted fabric, where it is absorbed by the absorbent cellulosic fiber threads, especially the lyocell fiber.

[0070] The present invention also relates to an absorbent article having 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 in use.

[0071] In a preferred embodiment, the article has a textile layer lying on the surface of the knitted fabric structured according to the invention.

[0072] The textile layer lying on top of the knitted fabric facing the moisture source is preferably a fabric containing lyocell fibers. The fabric is preferably hydrophobic. In this embodiment, the article is made almost exclusively from sustainable materials that are environmentally friendly and made from renewable raw materials (lyocell, PLA).

[0073] It has been found that a combination of a particularly hydrophobic fabric made of lyocell fibers and a knitted fabric according to the invention lying underneath (seen from the moisture source) excellently meets the requirement for moisture removal and moisture storage.

[0074] The moisture that initially collects on the lyocell fiber fabric is released under pressure (e.g., due to body weight) into the PLA fiber threads in the underlying knit, where it is transported away. It has been shown that this results in an almost complete drying of the close-fitting fabric made of hydrophobic lyocell fibers, for example, while the moisture in the underlying knit is almost completely stored by the lyocell fiber threads.

[0075] 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.

[0076] Additional layers can be provided on the side of the knitted fabric according to the invention facing the moisture source. These can be additional layers of absorbent material (e.g., lyocell fibers) or membranes that seal the article to the outside.

[0077] The absorbent article according to the invention is washable and can therefore be used multiple times.

[0078] 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.

[0079] The absorbent article can be sewn into underwear or sportswear, for example, in areas where moisture may occur. It has been shown that the article can quickly absorb moisture while the fabric adjacent to the body remains dry.

[0080] 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.

[0081] In a further aspect, the present invention thus also relates to a product worn close to the body, in particular textile, in which the absorbent article according to the invention is contained, in particular sewn in. Example

[0082] A knitted fabric was made from the following two basic knitting threads in the following ratio: 72 wt.% of a first base knitting yarn made of a cross-linked lyocell fiber of the LENZING™< Lyocell A100 type, ring-spun, with a fineness of Nm 68 / 1. 26 wt.% of a second base knitting yarn made of a PLA fiber, ring-spun, with a fineness of Nm 50 / 1.

[0083] The second base knitting thread was coated with approximately 8% by weight of elastane of the "Dorlastan" type with a fineness of 22 dtex. The elastane content of the entire knitted fabric was approximately 2% by weight.

[0084] The fabric was knitted on a single-surface / single-point single jersey circular knitting machine in gauge E28 (28 needles per inch) with electronic needle selection. However, it could also be produced on a mechanical single-surface / single-point single jersey circular knitting machine with at least three needle tracks in the knitting cylinder (needle pattern 1-2-3-2), or on a single-surface / single-point single jersey circular knitting machine with four needle tracks (needle pattern 4-1-2-3 or 1-2-3-4).

[0085] The thread path for producing the knitted fabric is in Figure 3The threads labeled 1 to 5 and 7 to 11 are the lyocell fiber threads. Threads 6 and 12 are the PLA fiber threads (with applied elastane fiber).

[0086] In the knitting pattern, for example, it can be seen 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). Figure 1 This diagram shows a schematic of the honeycomb-shaped surface of the knitted fabric produced according to this process. The honeycomb-shaped, raised borders are visible (light). The dark area between the borders is a flat knitted fabric. Figure 2 shows a photograph of the knit from above. Figure 3shows a photograph of the back of the finished knitted fabric. The lighter threads (6, 12) are the PLA fiber threads.

[0087] In this specific embodiment, the height of the raised boundaries of the honeycombs was 1 mm and the width of the honeycombs was 5 mm (X = 5).

[0088] The raw material weight of the knitted fabric was 120 g / m 2< .

[0089] The knitted fabric according to the invention was used as a layer in a multi-layer absorbent article.

[0090] The basic structure of the article is in Figure 5 shown schematically.

[0091] The uppermost layer 13, which faces the moisture source (e.g. the body) during use, is a hydrophobic fabric made of lyocell fibers.

[0092] The knitted fabric 14 according to the invention is provided underneath.

[0093] The article can be sewn into underwear or sportswear, for example, as an insert and is made almost exclusively from sustainable materials that are environmentally friendly and made from renewable raw materials. Comparative tests with state-of-the-art absorbent products.

[0094] The moisture absorption of the multi-layer absorbent products according to the invention was compared with multi-layer products of the prior art: Comparison product 1 was a conventional disposable sanitary pad (a period pad made of cellulose and PVC). Comparison product 2 was a period underwear / washable sanitary pad with a top layer made of PVC and cotton and an underlying absorbent layer made of plastic material. Applying moisture to the absorbent article according to the invention:

[0095] 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 fabric layer.

[0096] However, when pressure is applied, a sudden penetration into the uppermost fabric layer and through this into the underlying knitted fabric according to the invention can be observed.

[0097] After a very short time, all the moisture has permeated 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 tests:

[0098] In comparison with the comparison product 1 (disposable pad), which absorbs moisture very quickly, it was found that the reusable and sustainable product according to the invention has a practically equally good absorbency.

[0099] In comparison with the reference product 2 (period underwear made of plastic materials), a practically equally good and even faster absorbency (the surface dries faster) was also observed.

[0100] 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, therefore proves to be equivalent or in some cases even superior to conventional products made of partly synthetic materials.

Claims

1. A knitted fabric comprising at least a first and a second basic knitting thread, - wherein the first of the two basic knitting threads has a proportion of at least 90% by weight of a cellulosic fiber and - wherein the second of the two basic knitting threads has a proportion of at least 90% by weight of fiber made of polylactic acid (PLA), - wherein at least one surface of the knitted fabric has adjacent sections each with closed raised boundaries, and - wherein at least a part of the second basic knitting thread is provided on the closed raised boundaries.

2. Knitted fabric according to claim 1, characterized in that the entire surface of the knitted fabric consists of adjacent sections with closed raised borders.

3. Knitted fabric according to claim 2, characterized in that it is in a honeycomb structure, wherein at least part of the second basic knitting thread is provided on the raised boundaries of the honeycombs.

4. Knitted fabric according to one of the preceding claims, characterized in that a ratio X of a diameter D of the section to a height H of the raised boundary is X ≥ 2, in particular 2 ≤ X ≤ 3.

5. Knitted fabric according to one of the preceding claims, characterized in that the first basic knitting thread consists essentially of the cellulosic fiber.

6. Knitted fabric according to one of the preceding claims, characterized in that the cellulosic fiber is a lyocell fiber.

7. Knitted fabric according to claim 6, characterized in that Lyocell fiber is a cross-linked lyocell fiber.

8. Knitted fabric according to one of the preceding claims, characterized in that the second basic knitting thread consists essentially of the fiber made of polylactic acid (PLA).

9. Knitted fabric according to one of the preceding claims, characterized in that an elastane thread is applied to at least part of the second basic knitting thread.

10. Knitted fabric according to claim 9, characterized in that the elastane thread is plated onto the second basic knitting thread.

11. Knitted fabric according to one of the preceding claims, characterized in that the proportion of second basic knitting thread in the raised closed boundaries is more than 50 wt.%, preferably 60 wt.% to 80 wt.%.

12. Knitted fabric according to one of the preceding claims, characterized in that it is made exclusively from the first and second basic knitting threads.

13. Use of a knitted fabric according to one of the preceding claims as an absorbent article and / or as a component of an absorbent article for absorbing moisture from a moisture source, wherein the surface of the knitted fabric having the sections with raised closed boundaries faces the moisture source during use.

14. Absorbent article with at least two layers (1, 2) of textile material for absorbing moisture from a moisture source, characterized in that one of the two layers (2) is a knitted fabric according to one of claims 1 to 12 and that the surface of the knitted fabric which has the sections with raised closed boundaries faces the moisture source when in use.

15. Absorbent article according to claim 14, characterized in that the article has a textile layer (1) lying on the surface of the knitted fabric which has the sections with raised closed boundaries.

16. Use of an absorbent article according to any one of claims 14 to 15 as an insert in a product worn close to the body, in particular in underwear.

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