Method for producing multilayer cloth article

Abstract

The invention relates to a method for producing a multilayer fabric article comprising at least one cleaning layer and a core layer, each layer containing cellulose and / or consisting entirely of natural fibers and / or regenerated fibers, the cleaning layer and the core layer being bonded to one another by means of a spunlace method.

Description

[0001] The present invention relates to a method for producing a multi-layered cloth product, in particular a disposable multi-layered cloth product, such as a disposable cleaning cloth.

[0002] Depending on their properties, the fabrics are used in a variety of ways, particularly in the cosmetic and hygiene fields, as well as in many cleaning applications. Depending on the desired application, which usually involves moist or wet conditions, the fabrics can be impregnated with an impregnating agent and packaged individually or in units of a predetermined number of fabrics, or the fabrics can be packaged in an unimpregnated state and, as required, removed from the package and then impregnated or moistened only when required.

[0003] Depending on the desired application of the cloth products, these cloth products may include several layers of nonwoven fabrics that may have the same or different compositions. In the case of disposable cleaning cloths for cleaning surfaces, it is well known that these cleaning cloths should include several layers of nonwoven fabrics that generally have different compositions. On the one hand, this ensures that the cleaning cloth is sufficiently strong, and on the other hand, using multi-layer nonwoven fabrics with different compositions, it can be ensured that, for example, the first layer achieves good liquid absorption, while the second layer achieves good liquid release.

[0004] For example, WO 02 / 36339 A2 describes a multi-layer pre-impregnated cleaning cloth in which at least two layers contain a mixture of hydrophilic and hydrophobic fibers. The cleaning cloth comprises at least one cleaning layer and a layer serving as a liquid reservoir.

[0005] A similar method for disposable multi-layer cleaning cloths is described in EP 1 212 478 A1. Preferably, the cleaning cloths are provided with antimicrobial properties by adding silver particles.

[0006] US 4298649A describes a multi-layer cleaning cloth consisting of several layers of polypropylene having different appearances, wherein the cleaning cloth contains a surfactant.

[0007] The disadvantage of this solution is that the cleaning cloth, as a disposable item, is not environmentally friendly due to its high plastic content.

[0008] A more environmentally friendly alternative is disclosed in WO 2018 / 017597 A1, which describes a disposable cleaning cloth having at least one layer. The composition of the individual layers should be fully compostable and biodegradable. The high PLA content ensures that the individual layers can be bonded together.

[0009] DE 10 2021 122 041 B1 describes a disposable multi-layer cleaning cloth with abrasive strips, comprising at least one cleaning layer and a core layer, both containing cellulose and consisting entirely of natural and / or regenerated fibers, wherein a scraping strip having a higher abrasive performance than the rest of the cleaning layer is arranged on or in the cleaning layer, and wherein the scraping strip contains hemp and also consists entirely of natural and / or regenerated fibers. The cleaning layer and the core layer and optionally further layers are preferably bonded to one another by microentanglement using ultrasonic motion.

[0010] Purpose of the invention

[0011] The object of the present invention is to provide an alternative method for producing a multi-layer environmentally friendly textile product, which method preferably overcomes the above-mentioned disadvantages known from the prior art and which is characterized in particular by a strong and non-chemical bond between the layers.

[0012] General Description of the Invention

[0013] The present invention solves the above-mentioned problem by the features of the claims and in particular by providing a method for producing a multi-layer textile product, which comprises at least one cleaning layer and a core layer, each layer containing cellulose and / or consisting entirely of natural fibers and / or regenerated fibers, wherein the cleaning layer and the core layer are bonded together by hydroentanglement.

[0014] Optionally, in the method according to the invention, one or more further layers, also consisting entirely of natural and / or regenerated fibers, are also hydroentangled to the cleaning layer and / or the core layer. In particular, the further layer can be a top layer consisting entirely of natural and / or regenerated fibers and hydroentangled to the side of the core layer facing away from the cleaning layer.

[0015] In the context of the present invention, a "cleaning layer" refers to a layer that provides good liquid release. This is the layer that directly contacts the surface to be cleaned during use. However, in more abstract terms, the cleaning layer can also be called a "first layer", which is why in this disclosure "cleaning layer" and "first layer" are used synonymously and interchangeably.

[0016] In the context of the present invention, a "core layer" refers to a layer that provides good liquid absorption, acts as a reservoir for the impregnating agent and transfers the impregnating agent to the cleaning layer. However, in more abstract terms, the core layer can also be called a "second layer", which is why "core layer" and "second layer" are used synonymously and interchangeably in this disclosure.

[0017] In the context of the present invention, a "top layer" refers to a layer that can act as a barrier layer. This additional layer can in particular be arranged on the side of the core layer facing away from the cleaning layer, which ensures that liquid is not released upwards, but only downwards. The top layer can also be called a "third layer", which is why in the context of the present disclosure, "top layer" and "third layer" are used synonymously and interchangeably.

[0018] According to the invention, the cleaning layer, the core layer, the optional top layer and the further optional layers contain natural fibers and / or recycled fibers. "Natural fibers" are understood to mean all natural fibers that can be used directly without further chemical conversion reactions. On the other hand, "recycled fibers" are fibers that have been produced from natural renewable raw materials using chemical processes. However, like natural fibers, recycled fibers also consist of 100% natural materials.

[0019] In the prior art, hydroentanglement is known only for the corresponding reinforcement of individual and loose fibers, i.e. it is known that nonwoven fabrics can be produced by hydroentanglement. However, in the context of the present invention, it has now surprisingly been found that hydroentanglement can also be used to combine already reinforced nonwoven fabrics with each other.

[0020] The term "nonwoven fabric" refers to a reinforcement made of fibers in which the fibers have formed strong bonds. Since hydroentanglement usually involves loose fiber webs that are hooked together by water jets and thus reinforced, one would not expect that hydroentanglement can also be used to bond already reinforced nonwoven fabrics, because these nonwoven fabrics no longer have enough loose fiber ends that have not already hooked onto other fibers.

[0021] However, experiments have been conducted to determine the suitability of ultrasonic bonding, needle punching and hydroentanglement for joining reinforced nonwoven fabric layers. These experiments have shown that hydroentanglement is in fact the most suitable method.

[0022] In the case of ultrasonic bonding, the problem that must be solved is that the ultrasonic frequencies generate heat, which leads to thermal bonding of the fibers. However, in the absence of thermoplastic polymers, this heat does not lead to melting and resulting bonding. Therefore, attempts are made to achieve better bonding by wetting the core layer. However, this is only partially successful because, although hydrogen bonds between the cellulose-containing layers are formed due to the introduced water molecules, these hydrogen bonds break down again on contact with the impregnation solution, so that the cloth loses its structural integrity.

[0023] Another method is to connect the cleaning layer, the core layer and the top layer by needle punching. Needle punching is a method in which needles are pushed into the fabric, transporting the fibers from the top to the bottom side. This connects the fibers and mechanically strengthens the fabric. However, in the present case, it was found that the core layer was severely damaged by the needle punching and knobs formed on the "puncture side". However, different compositions were selected for the individual nonwoven layers, which were then bonded by needle punching. However, either sufficient bonding could not be achieved or the resulting fabric had extremely poor sliding properties, which is why it is completely unsuitable for cleaning surfaces and, in particular, for use as a sweeping cloth.

[0024] On the other hand, by means of hydroentanglement, even in contact with an impregnating agent, an excellent bond with high elasticity and stability can be produced between the already highly reinforced nonwoven fabrics constituting the individual layers.

[0025] Therefore, the method for producing a multi-layer cloth product according to the invention is characterized in that a cleaning layer and a core layer and optionally one or more further layers, in particular a top layer, are formed, and for each of these individual layers, the fibers forming the layer are processed into a nonwoven fabric, i.e. reinforced, and the cleaning layer, the core layer and optionally one or more further layers are thus obtained in each case as separate nonwoven fabrics, and wherein the (reinforced) nonwoven fabric comprising the cleaning layer and the core layer and optionally one or more further layers, in particular the top layer, obtained in this way is then bonded to one another by hydroentanglement.

[0026] According to one embodiment, the fibers contained in the cleaning layer, the core layer and / or other layers are combined to form a nonwoven fabric by a manufacturing technology belonging to the "web forming" technology or the "web bonding" technology. Preferred processes belonging to the "web forming" technology are carding, air laying, wet laying, melt blowing and spun bonding. On the other hand, preferred processes belonging to the "web bonding" technology are calendaring, hydroentanglement, spunlace, needle punching and air-through bonding.

[0027] According to a preferred embodiment of the method of the invention, the cleaning layer is produced by combining / reinforcing hemp fibers and viscose fibers to form a nonwoven fabric, wherein the proportion of hemp fibers is preferably equal to or greater than the proportion of viscose fibers. Advantageously, the proportion of hemp fibers is about 50-70% by weight and the proportion of viscose fibers is about 30-50% by weight. The basis weight of the cleaning layer is preferably 40-60 g / m 2 , more preferably 50g / m 2 .

[0028] According to another preferred embodiment of the method of the present invention, the core layer is produced by optionally using a bio-based binder and / or other plant fibers to bind / reinforce cellulose fibers, lyocell fibers and / or pulp to form a nonwoven fabric. For example, in the case of using a bio-based binder, only cellulose fibers can be used as the core layer and they are reinforced by an air-laid process to form a nonwoven fabric. In particular, its basis weight is about 120-140 g / m 2 Alternatively, for example, a wet process can also be used to reinforce the pulp and lyocell fibers in the nonwoven fabric, the proportion of pulp being in particular 65-85% by weight and the proportion of lyocell fibers being correspondingly 15-35% by weight. The basis weight of the core layer made of pulp / lyocell is preferably about 50-70 g / m 2 Alternatively, for example, other plant fibers can also be used to produce the core layer. In particular, this also applies to hemp fibers, which, however, also belong to the cellulose fibers already mentioned.

[0029] Optionally, in the method of the present invention, in addition to the cleaning layer and the core layer, a further layer consisting only of viscose fibers is produced by combining viscose fibers into a nonwoven fabric. This further layer is preferably used as the top layer.

[0030] According to a preferred embodiment, in the process of the invention, a nonwoven fabric layer having the following composition is produced (data in % by weight):

[0031] Top layer: 100% viscose

[0032] Cleaning layer: 70% hemp / 30% viscose

[0033] Core: 100% airlaid cellulose, bio-based binder

[0034] According to another preferred embodiment, in the process of the invention, a nonwoven fabric layer having the following composition is produced (data in % by weight):

[0035] Top layer: 100% viscose

[0036] Cleaning layer: 70% hemp / 30% viscose

[0037] Core: 80% pulp, 20% lyocell

[0038] According to another preferred embodiment, in the process of the invention, a nonwoven fabric layer having the following composition is produced (data in % by weight):

[0039] Top layer: 100% viscose

[0040] Cleaning layer: 100% CAC (Carded / Airlaid / Carded) cellulose

[0041] Core: 100% airlaid cellulose, bio-based binder

[0042] According to another preferred embodiment, in the process of the invention, a nonwoven fabric layer having the following composition is produced (data in % by weight):

[0043] Top layer: 100% viscose

[0044] Cleaning layer: 50% hemp, 50% viscose

[0045] Core: 100% airlaid cellulose, bio-based binder

[0046] According to another preferred embodiment, in the process of the invention, a nonwoven fabric layer having the following composition is produced (data in % by weight):

[0047] Top layer: 100% viscose

[0048] Cleaning layer: 100% viscose

[0049] Core: 100% airlaid cellulose, bio-based binder

[0050] In this context, it is noteworthy that even formulations containing 100% cellulose and viscose, respectively, in the cleaning layer provide excellent lubricity to the fabric, provided there is 3D embossing. In the absence of embossing, it has been necessary until now to include hemp in the cleaning layer to ensure adequate lubricity. However, it has been found that cleaning layers made of pure cellulose and viscose, respectively, show at least equal lubricity if the fabric has embossing.

[0051] Preferably, the cleaning layer, the core layer and optionally one or more further layers are hydroentangled in a device having at least two drums, wherein the layers to be bonded are treated with water jets, wherein the water jets in the first drum act on the layers to be bonded with a lower pressure than in the second drum.

[0052] Preferably, the water jets in the first drum are ejected from a plurality of nozzle strips, each nozzle strip of the first drum comprising a plurality of nozzles, wherein the water jets from each nozzle belonging to the same nozzle strip are ejected at the same pressure, and wherein the pressure of the water jets ejected from the nozzles belonging to different nozzle strips can be the same or different and in each case is between 10 and 80 bar. Preferably, there are three nozzle strips in the first drum, wherein the pressure of the water jets ejected from the nozzles of the first nozzle strip is preferably between 10 and 30 bar, wherein the pressure of the water jets ejected from the nozzles of the second nozzle strip is preferably between 30 and 60 bar, and wherein the pressure of the water jets ejected from the nozzles of the third nozzle strip is preferably between 60 and 80 bar.

[0053] It is also preferred that the water jets in the second drum are ejected from a plurality of nozzle strips, wherein each nozzle strip of the second drum comprises a plurality of nozzles, wherein the water jets are ejected from each nozzle belonging to the same nozzle strip at the same pressure, and wherein the pressures of the water jets ejected from nozzles belonging to different nozzle strips may be the same or different, and each pressure is between 30 and 100 bar, preferably between 60 and 100 bar, and more preferably between 90 and 100 bar.

[0054] Optionally, the second roller has a multi-section structure, in particular a 2D multi-section structure, to achieve embossing of the cloth product, thereby improving sliding.

[0055] Due to the hydroentanglement of the cleaning layer, the core layer and optionally one or more other layers, these layers are bonded to each other, thereby obtaining a multi-layer cloth product. Then, it is optional to dry at a temperature above 150°C, in particular above 170°C, and particularly preferably at a temperature between 175 and 200°C. The drying step is preferably carried out in a multi-drum dryer, in which the multi-layer cloth product is not only dried but also pressed. As an alternative or supplement to the above-mentioned drying at a temperature above 150°C, the drying step can also involve applying ultrasound to the cloth product to dry it by the generated kinetic energy.

[0056] The features of the invention disclosed in the above description, the examples and the claims are essential for the implementation of the various embodiments of the invention, both individually and in any combination.

Claims

1. A method for producing a multi-layer fabric product, the multi-layer fabric product comprising at least one cleaning layer and one core layer, each of the at least one cleaning layer and one core layer containing cellulose and / or consisting entirely of natural fibers and / or regenerated fibers, wherein: The cleaning layer and the core layer are bonded to each other by hydroentanglement.

2. The method for producing a multi-layer fabric product according to claim 1, characterized in that Optional one or more further layers, also consisting entirely of natural and / or recycled fibers, are also bonded to the cleaning layer and / or the core layer by hydroentanglement.

3. The method for producing a multi-layer fabric product according to claim 1 or 2, characterized in that: The cleaning layer, the core layer and the optional one or more other layers are formed by processing the fibers contained in each of the cleaning layer, the core layer and the optional one or more other layers into a non-woven fabric and thereby obtaining the cleaning layer, the core layer and the optional one or more other layers as non-woven fabrics, and wherein the cleaning layer, the core layer and the optional one or more other layers thus obtained as non-woven fabrics are then bonded together by a water entanglement method.

4. A method for producing a multi-layer textile product according to any one of the preceding claims, characterized in that The cleaning layer is formed by combining hemp fibers and viscose fibers to form a nonwoven fabric, wherein the proportion of the hemp fibers is greater than the proportion of the viscose fibers.

5. A method for producing a multi-layer textile product according to any one of the preceding claims, characterized in that The core layer is formed by combining cellulose fibers, lyocell fibers and / or pulp, optionally using bio-based binders and / or other plant fibers to form a nonwoven fabric.

6. A method for producing a multi-layer textile product according to any one of the preceding claims, characterized in that In addition to the cleaning layer and the core layer, other layers consisting only of viscose fibers are formed by combining viscose fibers into a nonwoven fabric.

7. A method for producing a multi-layer textile product according to any one of the preceding claims, characterized in that The fibers comprising the cleaning layer, the core layer and / or the other layers are combined to form a nonwoven fabric by a method independently selected from the following groups, wherein the group includes air-laid method, wet-laid method, hydroentangled method, carding method, calendaring method, melt-blown method, spunbond method, air-permeable bonding method, needle-punched method, spunbond method and DRC method.

8. A method for producing a multi-layer textile product according to any one of the preceding claims, characterized in that The cleaning layer is hydroentangled with the core layer and the optional one or more further layers in a device having at least two rollers, in which the layers to be bonded are treated with water jets, wherein the water jets in the first roller act on the layers to be bonded with a lower pressure than the water jets in the second roller.

9. The method for producing a multi-layer fabric product according to claim 8, characterized in that The water jets are ejected from a plurality of nozzle strips in the first drum, each nozzle strip in the first drum having a plurality of nozzles, wherein the water jets from the nozzles belonging to the same nozzle strip are ejected at the same pressure, and wherein the pressures of the water jets ejected from the nozzles belonging to different nozzle strips can be the same or different, and in each of the aforementioned cases the pressure is between 10 and 80 bar.

10. The method for producing a multi-layer fabric product according to claim 8 or 9, characterized in that: The water jets in the second drum are ejected from a plurality of nozzle strips, each nozzle strip in the first drum having a plurality of nozzles, wherein the water jets from each nozzle belonging to the same nozzle strip are ejected at the same pressure, and wherein the pressures of the water jets ejected from the nozzles belonging to different nozzle strips may be the same or different, and in each of the aforementioned cases the pressure is between 30 and 100 bar.

11. The method for producing a multi-layered fabric product according to any one of claims 8 to 10, characterized in that: The cleaning layer, the core layer and the optional one or more further layers are bonded to one another as a result of the hydroentanglement process and thereby the multi-layered cloth product is obtained.

12. The method for producing a multi-layer fabric product according to claim 11, characterized in that The multi-layered fabric product is subsequently dried at a temperature above 150° C. and / or by ultrasound.

13. The method for producing a multi-layer fabric product according to claim 12, characterized in that The drying step is carried out in a multi-drum dryer in which the multi-layered cloth product is dried and pressed.