Cleaning cloth

Abstract

The invention relates to a cleaning cloth comprising a textile carrier material designed as a nonwoven fabric and an impregnation containing polyvinyl formal, wherein the textile carrier material comprises microfibers on at least one surface, preferably on both surfaces, and wherein the cleaning cloth comprises 45 to 90 wt.% textile carrier material and 10 to 55 wt.% polyvinyl formal, based on the total weight of the cleaning cloth.

Description

Technical field

[0001] The textile-physical properties of cleaning cloths can be controlled via the chemical and textile-physical properties of the fibers or filaments that make them up. The fiber or filament raw materials are selected according to the desired chemical or physical properties, such as their dyeability, chemical resistance, thermoformability, dirt absorption capacity, or adsorption capacity. The modulus and elongation properties of the fibers or filaments depend, among other things, on the material properties, which can be controlled by selecting the degree of crystallization and / or orientation and the cross-sectional geometry to influence the flexural stiffness, force absorption, or specific surface areas of the individual fibers or filaments.

[0002] For many applications, cleaning cloths must meet a variety of requirements that are often difficult to reconcile. For example, microfiber nonwovens should offer a long service life, good handling (especially when soaking, wringing, and wiping), good cleaning efficiency, good resistance to mechanical wear, and / or a specific water balance. State of the art

[0003] One way to combine various properties in a cleaning cloth is to combine different fiber types depending on the chosen manufacturing method (for example, as woven, knitted, or nonwoven fabric). Woven, knitted, or crocheted fabrics containing thicker fibers in combination with microfibers exhibit good durability and, at least initially, satisfactory performance characteristics. However, a disadvantage of these fabrics is that they are more complex to manufacture than nonwovens. Furthermore, knitted fabrics, in particular, have insufficient microfiber retention capacity. It has been found that after approximately 400 industrial washing cycles (according to DIN EN ISO 155797), the microfiber content is almost completely removed. This is reflected in a significant deterioration of performance characteristics such as handling, skin feel, cleaning efficiency, and water retention.

[0004] Nonwovens containing microfibers are significantly easier to manufacture compared to woven, knitted, or crocheted fabrics. Nonwovens are structures made of fibers of limited length (staple fibers), filaments (continuous fibers), or cut yarns of any type and origin, which have been joined together in some way to form a web (a fibrous nap) and bonded to one another in some way. Microfiber nonwovens generally exhibit excellent properties in removing dirt and in absorbing and releasing liquids, especially water. However, a disadvantage of known microfiber nonwovens is their limited durability, particularly with frequent washing in industrial cycles. This is reflected, for example, in the formation of holes in the nonwovens after approximately 200 industrial wash cycles.For applications in professional cleaning, these 200 wash cycles, for example with daily disinfecting laundry, mean a lifespan of less than one year.

[0005] Increasing the proportion of thicker fibers can theoretically improve the durability of nonwovens, as the chemical and mechanical stability of the individual fibers or filaments increases with their thickness. However, this comes at the expense of performance characteristics.

[0006] An increase in the proportion of fine fibers predictably leads to improved performance characteristics, including enhanced water absorption through the creation of a greater number of capillary spaces and a softer feel due to the reduced flexural stiffness of the individual fibers. However, such fabrics prove to be fragile when compared to conventional textiles in terms of tear resistance, pilling, and especially washability, particularly at high temperatures. The performance characteristics attributable to microfibers, in particular, deteriorate significantly over time.

[0007] A stress test of 400 wash cycles according to DIN EN ISO 155797 revealed a significant decrease in the basis weight of a PIE 16 nonwoven fabric (70% PET 0.2 dtex; 30% PA6 0.1 dtex, split and hydroentangled). Further analysis showed that the polyamide content had dropped from an initial 30% to as low as 10% by weight, while the PET content decreased less dramatically. This result was surprising because PET is known to be attacked by bases such as washing lyes, while polyamide is not. This finding can be explained by the fact that the finer polyamide filaments in the microfilament nonwoven fabric are more susceptible to the chemical and mechanical stresses of washing, as well as the high mechanical friction during drum drying, and are eventually removed as fiber breakage. This could also be due to the smaller fiber thickness compared to polyester.

[0008] Another way to combine seemingly contradictory properties in a single surface structure is to produce composites from two or more surface structures. For this purpose, the individual surface structures can be produced separately and then joined together using known joining methods such as sewing, gluing, or laminating.

[0009] Multi-component spunbond nonwovens exhibiting a titer gradient are also known. EP 1 619 283 A1 describes multi-component spunbond nonwovens consisting of at least two polymers forming interfaces with each other, originating from at least one spinning device with uniform spinneret openings, and hydrodynamically stretched, laid down in a sheet-like manner, and jointly bonded either as single layers or as a multi-component composite.

[0010] The invention is based on the objective of developing a cleaning cloth which offers good mechanical properties, in particular good long-term wash resistance with good performance characteristics, good thermophysiological comfort, pleasant skin feel and appearance, good water management (absorption and water release, preferably uniform) and good cleaning efficiency.

[0011] The invention also aims to provide a cleaning cloth with improved cleaning performance. Furthermore, the invention aims to provide a cleaning cloth with low pilling and shrinkage. Additionally, the invention aims to provide a cleaning cloth with improved wringability and drapability.

[0012] Ultimately, the invention aims to provide a cleaning cloth that can be produced using a simpler method. Description of the invention

[0013] These problems were solved by a cleaning cloth and a manufacturing process according to the invention.

[0014] The invention relates to a cleaning cloth comprising a textile carrier material designed as a nonwoven fabric and an impregnation containing polyvinyl formalin, wherein the textile carrier material comprises microfibers on at least one surface, preferably on both surfaces, and wherein the cleaning cloth preferably has a packing density of 30 to 1000 kg / m³, more preferably 75 to 500 kg / m³, and more preferably 100 to 200 kg / m³, as determined by the method disclosed in the description, and wherein the cleaning cloth comprises, based on the total weight of the cleaning cloth, 45 to 90 wt.% textile carrier material and 10 to 55 wt.% polyvinyl formalin. The inclusion of microfibers on both sides is advantageous because both sides exhibit very good cleaning properties.

[0015] The invention further relates to a method for producing such a cleaning cloth.

[0016] It has now been surprisingly determined that by impregnating a nonwoven textile substrate with polyvinyl formal, even with a supposedly lacking pore volume (open-cell structure), polyvinyl formal adhesion is achieved and the product properties are innovative and advantageous, while simplifying the production process.

[0017] The cleaning cloth according to the invention exhibits excellent wash resistance. This is surprising because it was previously assumed that high resistance required a PVA (polyvinyl alcohol) fiber to be coated or impregnated with a PVA solution. Due to the chemical similarity of the two materials, and also through the partial dissolution of the PVA surface of the fiber, a good chemical and mechanical bond is formed between the fiber and the microfoam. However, practical tests have now shown that a non-polyvinyl formal carrier material in the form of a nonwoven fabric can also form a good and, above all, wash-stable bond.

[0018] A further advantage of using polyvinyl formalin (PVF) is its inherent high absorbency due to its free OH groups. The hydrophilicity of PVF can be further enhanced by using it in microfoam form. This microfoam preferably has a pore size of less than 100 µm. Due to the fine pore structure of the microfoam, this material exhibits even higher hydrophilicity. Additionally, the PVF microfoam can largely or even completely encapsulate the microfibers of the textile substrate, thereby creating a stable mechanical bond between the substrate and the coating / impregnation. This is advantageous because the PVF microfoam itself does not adhere well to the hydrophobic microfibers of the substrate.

[0019] The advantages of using a polyvinyl formal impregnation are surprisingly retained when using a nonwoven textile substrate, where the textile substrate comprises microfibers on at least one surface.

[0020] The cleaning cloth has the following advantageous properties: High wash resistance. Surprisingly good adhesion of the PVA coating to hydrophobic polymer fibers. Less pilling after washing due to continuous filaments, limited shrinkage. High tensile strength due to continuous filaments and good elasticity ratio, stable edges, no ultrasonic edge cutting required. Surprisingly dense structure yet high water absorption capacity with superior durability, coarse fibers in the center and fine fibers on the outer edges. Excellent cleaning performance due to microfiber, even with a coated surface. Improved wringability and drapability. Faster drying product.

[0021] The manufacturing process offers the following advantages: More affordable supply, less dependence on non-EU countries. Simple material handling, stable intermediate product. The base material can be pre-colored without additional process chemicals (improved color transfer properties). Less PVA can be used without compromising product performance, thus enabling faster crosslinking, resulting in lower raw material consumption, higher line speed, and reduced energy consumption during drying.

[0022] The cleaning cloth according to the invention preferably has a packing density of 30 to 1000 kg / m³, more preferably 75 to 500 kg / m³, and more preferably 100 to 200 kg / m³. The packing density is calculated as the quotient of basis weight and thickness. The methods for determining the basis weight and thickness are described in the experimental section below.

[0023] By reducing the packing density, the average pore volume can be increased. In this preferred embodiment, the lower packing density is partly responsible for the surprising properties of the cleaning cloth according to the invention.

[0024] This packing density can be adjusted through standard process steps. Compared to the state of the art, mechanical compaction can be reduced, which is an exceptional approach for such processes. This increases the amount of coarse fibers and the pore volume in the center of the nonwoven fabric (density distribution), leading to improved water absorption and cleaning performance. The feel and texture can also be adjusted through modified process parameters and a blind softening process. Due to the lower packing density, the textile backing material, formed as a nonwoven fabric, can be impregnated with a higher amount of polyvinyl formalin, which has a surprisingly beneficial effect on the cleaning cloth's properties.

[0025] The cleaning cloth according to the invention comprises 45 to 90 wt.%, preferably 50 to 85 wt.%, particularly preferably 55 to 80 wt.% of textile backing material, based on the total weight of the cleaning cloth. Correspondingly, the cleaning cloth according to the invention comprises 10 to 55 wt.%, preferably 15 to 50 wt.%, particularly preferably 20 to 45 wt.% polyvinyl formal (PVF), based on the total weight of the cleaning cloth. The total weight of the cleaning cloth refers to the cleaning cloth after it has been washed with water and then completely dried.

[0026] In determining the proportions of the textile backing material and the polyvinyl formalin coating / impregnation, it has been shown that by appropriately selecting the proportions of textile backing material and polyvinyl formalin, cleaning cloths can be obtained in which the soft, textile feel of the backing material is at least partially retained, even though the polyvinyl formalin inherently loses softness when dry, resulting in a largely rigid cleaning cloth. The proportions of polyvinyl formalin defined above are optimal for a largely soft feel.

[0027] If the nonwoven fabric comprises microfibers on only one surface, in a preferred embodiment the impregnation containing polyvinyl formalin is located on the side of the microfibers. Preferably, the nonwoven fabric has microfibers on both surfaces.

[0028] The substrate material can be provided with a full-surface coating or impregnation, whereby the term "full-surface coating or impregnation" means that the average distance between areas coated with polyvinyl formalin and areas not coated with polyvinyl formalin is less than 5 mm. Thus, even with a "full-surface coating" as described above, the substrate material can still have areas not coated with polyvinyl formalin. An advantage of this embodiment is that the full-surface coating or impregnation strengthens the substrate material and thus increases its stability. Furthermore, due to the high proportion of hydrophilic polyvinyl formalin, the removal of large quantities of liquid from a surface to be cleaned can be achieved particularly effectively.Secondly, this ensures that only a thin, even film of liquid remains on the surface being cleaned after wiping. This allows for streak-free cleaning, especially on glossy surfaces, compared to, for example, a knitted, uncoated microfiber cleaning cloth.

[0029] It is conceivable that the coating or impregnation is present only on one side of the cleaning cloth. This configuration is advantageous because, in this case, hydrophobic dirt can be easily removed with the uncoated, hydrophobic side of the surface, and hydrophilic dirt with the coated, more hydrophilic side. According to a preferred embodiment of the invention, however, the coating or impregnation is present on both sides of the cleaning cloth, as this allows the advantageous effects of the invention to be utilized particularly well.

[0030] According to a further development of the invention, a printed pattern consisting of an abrasive agent, for example polishing particles, is applied to the side of the textile substrate that is coated or impregnated with polyvinyl formalin. The polishing particles can, for example, be formed from silica. These particles create a cleaning cloth with a mildly abrasive effect. The abrasive agent can be applied to the textile substrate in a wide variety of ways using a simple printing process. This allows for an additional cleaning effect as well as a decorative effect on the textile structure.

[0031] In one embodiment, the impregnation contains more than 50 wt.%, preferably more than 90 wt.%, polyvinyl formal by weight of the impregnation. In another embodiment, the impregnation consists of polyvinyl formal.

[0032] In one embodiment, the impregnation has a basis weight of 10 to 300 g / m², preferably 20 to 200 g / m², and more preferably 25 to 175 g / m², based on dried impregnation.

[0033] In a further embodiment, the cleaning cloth according to the invention has, in addition to the impregnation containing polyvinyl formalin, a coating containing polyvinyl formalin. In this embodiment, the coating is applied to the nonwoven fabric as a separate step after the impregnation. The impregnation is a penetrating treatment of the nonwoven fabric. During coating, a layer is applied without the coating agent penetrating the nonwoven fabric. The composition of the impregnating agent and the coating agent can differ from one another.

[0034] Depending on the intended use, the textile backing material can be made easy-care and / or flame-resistant. The fibers can be composed of polymers containing additives such as color pigments, permanent antistatic agents, fungicides, bactericides, acaricides, and / or additives influencing the hydrophilic or hydrophobic properties in quantities of up to 10% by weight.

[0035] The textile backing material can further contain colored fibers, whereby the coloring of the multi-component continuous filaments can be carried out by spin dyeing. The textile backing material of the cleaning cloth according to the invention comprises microfibers on at least one surface. Microfibers comprise staple fibers and continuous fibers.

[0036] In one embodiment of the cleaning cloth according to the invention, the microfibers are designed as microfilaments. Microfilaments are continuous filaments.

[0037] In a further embodiment of the cleaning cloth according to the invention, the microfibers are composite fibers that are at least partially split into elementary fibers. In a further preferred embodiment of the cleaning cloth according to the invention, the microfibers are composite filaments that are at least partially split into elementary filaments.

[0038] In one embodiment, the composite fibers or composite filaments comprise at least two thermoplastic polymers selected from the group consisting of polyacrylonitrile, polyamide, polycarbonate, polyester, polyetheretherketone, polyolefin, polystyrene, polyurethane and polyvinyl chloride.

[0039] In one embodiment, the composite fibers or composite filaments comprise (i) polyester and polyamide, preferably polyethylene terephthalate in combination with polyamide 6 or polyamide 66, or (ii) polyolefin and polyamide, preferably polypropylene in combination with polyamide 6 or polyamide 66.

[0040] In one embodiment, the composite fibers or composite filaments comprise 60 to 80 wt.% polyester and 20 to 40 wt.% polyamide, preferably 65 to 75 wt.% polyester and 25 to 35 wt.% polyamide, based on the total weight of the composite fibers or composite filaments.

[0041] In a preferred embodiment, the composite fibers or composite filaments comprise 60 to 80 wt.% polyester, of which at least 50 wt.% is recycled.

[0042] Recycled polymer materials can be distinguished from "virgin" polymer materials. Suitable processes are as follows: 1. Analysis of chemical composition. Recycled polymers typically contain impurities or additives that are characteristic of recycled polymers. 2. Molecular weight distribution. Recycled materials usually have different molecular weight distributions than virgin materials.

[0043] In one embodiment, the textile carrier material comprises more than 60 wt.%, preferably more than 70 wt.%, and more preferably more than 80 wt.% microfibers, based on the dry textile carrier material, i.e., without any moisture-retaining agents.

[0044] The basis weight of the textile backing material is not limited. In one embodiment, the textile backing material has a basis weight of 50 to 400 g / m², preferably 80 to 280 g / m², and more preferably 100 to 200 g / m². The determination of the basis weight is given below in the experimental section.

[0045] In one embodiment, the cleaning cloth according to the invention has a thickness of 0.5 to 2 mm, measured as explained below.

[0046] The textile backing material of the cleaning cloth according to the invention is designed as a nonwoven fabric. Examples of suitable nonwoven fabrics are mechanically formed nonwovens (those formed from filaments taken from cards or carding machines and laid on top of each other to form nonwovens, or formed directly by these carding machines, e.g., carded nonwovens or dry nonwovens, cross-laid nonwovens, random lay nonwovens), aerodynamically formed nonwovens (those formed from fibers by means of an airflow on an air-permeable substrate, e.g., dry nonwovens, meltblown nonwovens or meltblown nonwovens; spunbond nonwovens; spunbond-meltblown nonwovens-spunbond nonwovens), hydrodynamically formed nonwovens (e.g., wet-spunbond nonwovens) and electrostatically formed nonwovens (e.g., microfiber nonwovens or nanofiber nonwovens).

[0047] In a preferred embodiment, the nonwoven fabric is a spunbond nonwoven. Spunbond nonwovens are formed from fibers spun from polymer melts passing through dies and drawn by cold air and / or mechanical means, by direct lay-up. After bonding, they are referred to as spunbond nonwovens. The terms spunlaid nonwovens, or for the bonded nonwovens, spunlaid or spunbonded nonwovens, are in use. The nonwovens are composed exclusively of filaments or continuous fibers.

[0048] In one embodiment, the nonwoven fabric and the microfibers are made of different materials. In a preferred embodiment, the nonwoven fabric and the microfibers are made of the same materials.

[0049] In one embodiment of the cleaning cloth according to the invention, the nonwoven fabric comprises at least a first layer and a second layer, wherein the mean titer of the fibers forming the second layer differs from the mean titer of the fibers forming the first layer, preferably wherein the mean titer of the fibers forming the second layer is greater than the mean titer of the fibers forming the first layer.

[0050] In one embodiment of the cleaning cloth according to the invention, the nonwoven fabric comprises at least a first layer, a second layer and a third layer, wherein the second layer is arranged between the first layer and the third layer and the mean titer of the fibers forming the second layer differs from the mean titer of the fibers forming the first and third layers.

[0051] In one embodiment of the cleaning cloth according to the invention, the mean titer of the fibers forming the second layer is greater than the mean titer of the fibers forming the first and third layers.

[0052] These embodiments are explained in more detail below. The explanations apply equally to filaments and fibers.

[0053] According to one embodiment, the filaments of the first fiber component are at least partially intertwined with the fibers of the second fiber component across layers ("tentacle effect"). This effect can be achieved, for example, by first forming a layer composite ABA or even larger layer composites, such as a layer composite ABABA, from initially unbonded or only pre-bonded nonwovens of the first and second fiber components, and then performing a splitting or bonding step for the entire layer composite.

[0054] In this process, the fine filaments or fibers of the first fiber component, obtained during splitting, are distributed in the Z-direction, i.e., in the direction of the cross-section of the nonwoven fabric. This distribution can encompass several layers and leads to a particularly strong bond between the individual layers. Practical tests have shown that the finer the elementary filaments are, the further they are transported into the other layers.

[0055] According to a preferred embodiment, the first fiber component comprises melt-spun composite filaments laid down to form a nonwoven. According to the invention, the term "filaments" refers to fibers that, unlike staple fibers, have a theoretically unlimited length. Composite filaments consist of at least two elementary filaments and can be split and solidified into elementary filaments by conventional splitting processes, such as water jet needling. The composite filaments of the first fiber component are preferably at least partially split into elementary filaments. The degree of splitting is advantageously more than 80%, more preferably more than 90%, and particularly 100%.

[0056] To achieve a sufficient stabilizing effect, it is advantageous if the proportion of elementary filaments in the first fiber component, based on the total weight of the nonwoven fabric and as a sum across all composite layers, is at least 20 wt.%. Practical tests have shown that particularly high wash resistance combined with good performance characteristics can be achieved when the proportion of these elementary filaments is between 20 wt.% and 60 wt.%, and especially between 30 wt.% and 50 wt.%, based on the total weight of the nonwoven fabric.

[0057] With regard to the individual layers of the nonwoven fabric, it is advantageous if the proportion of the elementary filaments of the first fiber component in the respective layer A, for example in an outer layer A or in an inner layer A, is 80 wt.% to 100 wt.%, preferably 90 wt.% to 100 wt.%, in particular 100 wt.%, in each case based on the total weight of layer A.

[0058] With regard to the long-term performance characteristics (pilling, abrasion and wash resistance), it is advantageous if at least one outer layer, but preferably both outer layers of the nonwoven fabric, are formed by layers A.

[0059] In principle, it is conceivable that the individual layers A contain additional fibers besides the first fiber component. However, particularly good performance characteristics are obtained if at least the outer layers A consist entirely of elementary filaments of the first fiber component.

[0060] An advantage of using composite filaments as a starting material for producing elementary filaments is that the titer of the resulting elementary filaments can be easily adjusted by varying the number of elementary filaments contained in the composite filaments. The titer of the composite filaments can remain constant, which is advantageous from a process engineering perspective. A further advantage of using composite filaments is that the ratio of thicker to thinner filaments in the nonwoven fabric can also be easily controlled by varying the degree of splitting of the composite filaments.

[0061] Practical trials have shown that nonwovens with particularly high wash resistance combined with good performance characteristics can be obtained when the average titer of the elementary filaments of the first fiber component is between 0.01 and 0.1 dtex, particularly between 0.03 and 0.06 dtex. Elementary filaments with this titer can be obtained, for example, by splitting composite filaments with a titer of 0.02 to 6.4 dtex, preferably between 0.06 and 3.8 dtex.

[0062] The elementary filaments can have a circular segment shape, a nubby shape, or a multilobal shape in cross-section.

[0063] Preferably, the nonwoven fabric according to the invention is one in which the composite filaments have a cross-section with an orange-segment-like or "pie" multi-segment structure, wherein the segments can contain different, alternating, incompatible polymers. Hollow-pie structures are also suitable, which can also have an asymmetrically axially extending cavity. Pie structures, in particular hollow-pie structures, can be split particularly easily.

[0064] With regard to the first fiber component, the orange segment or pie arrangement advantageously has 2, 4, 8, 16, 24, 32 or 64 segments, particularly preferably 16, 24 or 32 segments.

[0065] The proportion of the first fiber component in the nonwoven fabric is preferably at least 40 wt.%, more preferably from 40 wt.% to 60 wt.%, in particular from 45 wt.% to 55 wt.%, in each case based on the total weight of the nonwoven fabric.

[0066] To achieve easy splitting, it is advantageous for the composite filaments to comprise filaments containing at least two thermoplastic polymers. Preferably, the composite filaments comprise at least two incompatible polymers. Incompatible polymers are defined as those polymers that, in combination, do not bond, bond only conditionally, or bond poorly. Such a composite filament exhibits good cleavage into elementary filaments and results in a favorable strength-to-weight ratio.

[0067] Preferably, incompatible polymer pairs such as polyolefins, polyesters, polyamides and / or polyurethanes are used in such a combination that pairings that do not adhere, only adhere to a limited extent or are difficult to adhere to are obtained.

[0068] The polymer pairs used are particularly preferably selected from polymer pairs with at least one polyolefin and / or at least one polyamide, preferably with polyethylene, such as polypropylene / polyethylene, polyamides / polyethylene or polyethylene terephthalate / polyethylene, or with polypropylene, such as polypropylene / polyethylene, polyamides / polypropylene or polyethylene terephthalate / polypropylene.

[0069] Polymer pairs containing at least one polyester and / or at least one polyamide are particularly preferred.

[0070] Polymer pairs with at least one polyamide or with at least one polyethylene terephthalate are preferred because of their conditional adhesiveness, and polymer pairs with at least one polyolefin are particularly preferred because of their poor adhesiveness.

[0071] Particularly preferred components include polyester, preferably polyethylene terephthalate, polylactic acid, and / or polybutylene terephthalate, on the one hand, and polyamide, preferably polyamide 6, polyamide 66, or polyamide 46, on the other hand, optionally in combination with one or more other polymers incompatible with the aforementioned components, preferably selected from polyolefins. This combination exhibits excellent cleavage. The combination of polyethylene terephthalate and polyamide 6 or of polyethylene terephthalate and polyamide 66 is particularly preferred. The proportion of the second fiber component in the nonwoven fabric is preferably at least 30 wt.%, more preferably 40 wt.% to 60 wt.%, and particularly 45 wt.% to 55 wt.%, in each case based on the total weight of the nonwoven fabric.

[0072] It is conceivable that the respective layers B contain additional fibers besides the second fiber component. Advantageously, the respective layers B contain fibers of the first fiber component in addition to the second fiber component. These could have been introduced from layers A into layer B, for example, during consolidation and / or splitting. This can result in a higher degree of interlocking between the layers and thus greater strength.

[0073] The type of fibers in the second fiber component is generally not critical, provided they have a density of 0.1 to 3 dtex. The fibers in the second fiber component can be selected from the group consisting of filaments, staple fibers, threads, and / or yarns. Here, staple fibers, in contrast to filaments which have a theoretically unlimited length, are understood to be fibers with a limited length, preferably from 20 mm to 60 mm.

[0074] The fibers of the second fiber component can consist of a wide variety of materials. Polymers are particularly suitable, especially plastics, particularly those already discussed above in relation to the first fiber component, but also natural materials.

[0075] The selection of fibers for the second fiber component is best determined by the specific applications for which the nonwoven fabric is intended. Filaments have proven suitable for many applications. These can be mono-component filaments and / or composite filaments.

[0076] Preferably, the fibers of the second fiber component, like the filaments of the first fiber component, are present at least partially as composite filaments and are at least partially split into elementary filaments. In this case, at least some of these elementary filaments have a titer of 0.1 to 3 dtex. Most preferably, all of these elementary filaments have this titer. Such elementary filaments can be obtained by splitting composite filaments with a titer of 0.2 to 24 dtex.

[0077] Another advantage of using composite filaments is that the titer of the individual elementary filaments can be easily adjusted by varying the number of elementary filaments contained in the composite. Furthermore, the ratio between thicker and thinner filaments in the nonwoven fabric can be controlled by varying the splitting ratio. Practical tests have shown that particularly good pilling properties can be achieved when the splitting ratio of the composite filaments is set to at least 60%, preferably at least 70%, and even more preferably to 80% to 100%.

[0078] A further advantage is that, in this embodiment, the nonwoven fabric can preferably be consolidated by a joint splitting of both composite filament components, for example by water jet bonding. This method allows for a particularly intensive interlocking of the elementary filaments formed during splitting across layers, so that the resulting composite nonwoven fabric has particularly good durability.

[0079] The type and structure of the composite filaments can correspond to those discussed above for the first fiber component. Preferably, the composite filaments of the second fiber component consist of 2, 4, 8, or 16 elementary filaments, and particularly preferably of 4 or 8 elementary filaments.

[0080] Alternatively, the fibers of the second fiber component can be monocomponent filaments and / or a mixture of composite filaments with monocomponent filaments.

[0081] Preferably, the average titer of the filaments of the first fiber component is significantly lower than the average titer of the fibers of the second fiber component. However, practical tests have shown that for achieving high strength and good performance characteristics, it is advantageous if the fibers of the second fiber component have an average titer that is no more than 30 times, preferably no more than ten times, the average titer of the filaments of the first fiber component.

[0082] It has proven particularly advantageous if the ratio of the average filament titer of the filaments of the second fiber component to the average filament titer of the filaments of the first fiber component is between 6 and 16, preferably between 8 and 12. Nonwovens with such a ratio have been shown to exhibit particularly high delamination resistance.

[0083] As explained above, the alternating arrangement of layers of fibers with high and low fiber titers is advantageous. A particularly preferred arrangement is one in which the fiber layers with high titers are at least partially penetrated by filaments from the fiber layers with low titers ("tentacle effect"). This provides maximum protection for the inner, coarser filaments, which have lower stability due to their lesser intertwining, from the outer, finer filaments, which have good stability due to their high degree of intertwining with themselves and with the coarser filaments. At the same time, the outer, finer filaments, which inherently have a higher tendency to pill due to their lower mechanical strength and stiffness (fibers can be more easily detached from the composite by mechanical stress), are better anchored within the overall structure of the nonwoven fabric.This can be achieved in particular through the aforementioned "tentacle effect", which better integrates them into the adjacent layers with filaments of larger titer.

[0084] Against this background, it is advantageous if at least part of the nonwoven surface is formed by elementary filaments with a titer of less than 0.1 dtex. Accordingly, it is advantageous for at least one, preferably both, of the nonwoven surfaces to be formed by elementary filaments with a titer of less than 0.1 dtex to at least 50%, preferably 60-100%. The structure and composition of the surface can be determined, for example, by SEM imaging.

[0085] The placement of fine filaments on the outer surface of the nonwoven fabric has the advantage of mechanically stabilizing internal threads or filaments of any kind, but especially the coarse fibers of the second fiber component. At the same time, the surface of the nonwoven fabric is characterized by advantageous performance properties as well as a pleasing appearance and feel.

[0086] The formation of the alternating arrangement of coarse and fine fibers in the composite nonwoven fabric according to the invention can be achieved, for example, by separately producing layers containing filaments of the first fiber component and layers containing filaments of the second fiber component, and then joining them together in the desired arrangement. The layers can be joined using known joining methods such as sewing, gluing, laminating, and / or mechanical needling, with the individual layers optionally being bonded together. Bonding the layers is particularly simple using water jet bonding of the composite filaments contained in the nonwoven fabric. The layers can also be pre-bonded separately before bonding.

[0087] Preferably, both the fibers of the first and second fiber components are composite filaments that are at least partially split into elementary filaments. In this case, the nonwoven fabric is preferably consolidated by a joint splitting of both composite filament components. This can be achieved, for example, by first forming a layered composite of nonwovens of the first and second fiber components and then consolidating them, for example, by water jets. This procedure allows for a particularly intensive interlinking of the elementary filaments formed during splitting across layers, so that the resulting composite nonwoven fabric has particularly good durability.

[0088] To achieve a high degree of interlacing, it is advantageous for the degree of splitting, particularly of the first fiber component, to be as high as possible. Against this background, the proportion of the respective elementary filaments of the first or second fiber component in the layers is advantageously more than 80 wt.%, and even more preferably 85 to 100 wt.%.

[0089] In a particularly preferred embodiment, all layers A contain at least partially split Pie 24 filaments, Pie 32 filaments, and / or Pie 64 filaments. It is also conceivable that all layers B contain at least partially split Pie 8 filaments or Pie 4 filaments. An arrangement is also conceivable in which one or more layers B contain Pie 8 filaments and other layers B contain Pie 16 filaments and / or Pie 4 filaments.

[0090] As explained above, it has proven particularly advantageous to arrange the layers such that layers B, containing the fibers of the second fiber component, are located in the interior of the nonwoven fabric, while layers A, containing the filaments of the first fiber component, are at least positioned on the surface of the nonwoven fabric. In this arrangement, the outer cover layers with their fine filaments can surprisingly and effectively protect the inner layers despite their low fiber density and resulting mechanical sensitivity. This, as explained above, leads to the formation of a particularly stable layered composite and good long-term performance characteristics.

[0091] This effect can possibly be attributed to the fact that the fine filaments obtained during splitting are distributed in the Z-direction, i.e., in the direction of the cross-section of the nonwoven fabric, during the consolidation step. This distribution can encompass several layers and leads to a particularly strong bond between the individual layers. Practical tests have shown that the finer the elementary filaments are, the further they are transported into the adjacent layers.

[0092] The nonwoven fabric according to the invention comprises at least two layers A containing filaments of the first fiber component, and at least one layer B containing filaments of the second fiber component. This results in the alternating base layer sequence ABA. As explained above, by incorporating layer B into the interior of the layered composite, a composite nonwoven fabric with outstanding durability can be obtained. Furthermore, because the outer surfaces of the nonwoven fabric are formed by layers A, the nonwoven fabric exhibits very good performance characteristics.

[0093] The base layer sequence ABA of one embodiment can be extended by further alternating layers A and B. Another preferred embodiment of the invention thus comprises the layer sequences: A(BA)nBA, with n = 1 to 20, preferably from n = 5 to 15, and particularly from 8 to 12. Examples of layer sequences are therefore ABABABA, ABABABABA, etc. It is conceivable that one or more layers A comprise several underlayers A' and / or one or more layers B comprise several underlayers B'. The fiber titer in the respective underlayers can be the same or different. In a spinning machine with 15 spinning positions, the following arrangement of the underlayers A' and B' would be conceivable, for example: A'A'B'B'B'A'B'B'B'A'B'B'B'A'A', which results in A(BA)2BA for the subsequent viewer of the cross-section.

[0094] According to a preferred embodiment of the invention, the outer layers in the layer sequences are each formed by layers A. Furthermore, the layer sequences are advantageously characterized by an alternating arrangement of layers A and B. However, as explained above, it is also conceivable that the layer sequence includes further layers different from A and B.

[0095] It has also proven advantageous to arrange the layer sequence of layers A and B, as well as any other layers present in the nonwoven fabric, in such a way as to result in a symmetrical layer structure. This arrangement has the advantage of yielding a particularly uniform, laterally symmetrical property profile.

[0096] According to a preferred embodiment of the invention, all layers A and / or B each have fibers with the same fiber titer. This embodiment is advantageous because it allows for particularly easy production of the nonwoven fabric. However, according to an alternative preferred embodiment, different layers A (and / or B) and / or sublayers A' (and / or B') have fibers with different fiber titers. The advantage of this is that the properties of the nonwoven fabric can be adjusted very precisely and on a side-by-side basis.

[0097] The nonwoven fabric can also contain additional layers. These additional layers could be designed as reinforcing layers, for example in the form of a scrim, and / or they could comprise reinforcing filaments, nonwovens, woven fabrics, knitted fabrics, and / or laid fabrics. Preferred materials for forming these additional layers are plastics, such as polyester, and / or metals. It is generally conceivable that these additional layers could form the outer layers of the nonwoven fabric. However, it is advantageous that the additional layers are (optionally additionally) arranged within the nonwoven fabric between layers A and B.

[0098] The polymers used to manufacture the filaments of the nonwoven fabric may contain at least one additive selected from the group consisting of color pigments, antistatic agents, antimicrobials such as copper, silver, gold, or hydrophilizing or hydrophobizing additives in an amount of 150 ppm to 10 wt.%. The use of these additives in the polymers allows for adaptation to customer-specific requirements.

[0099] As explained above, the cleaning cloth according to the invention is characterized by excellent mechanical properties. According to a preferred embodiment of the invention, the cleaning cloth is characterized by high durability. For example, it has been found that exemplary nonwovens according to the invention show no holes even after 850 industrial washing cycles in accordance with DIN EN ISO 155797.

[0100] Advantageously, the nonwoven fabric is further characterized by an easily adjustable tear strength according to DIN EN ISO 155797.

[0101] Furthermore, the nonwoven fabric according to the invention is characterized by a readily adjustable moisture content. The nonwoven fabric according to the invention can be produced in a manner known to those skilled in the art. A particularly simple method has proven to be the production of at least one first fiber layer comprising filaments of the first fiber component and at least one second fiber layer comprising filaments of the second fiber component, and the bonding of these layers together.

[0102] In a further embodiment of the cleaning cloth according to the invention, the cleaning cloth has a water absorption capacity of 200 to 450%, preferably 250 to 400%, and more preferably 275 to 375%, as determined by the method disclosed in the description.

[0103] In a further embodiment of the cleaning cloth according to the invention, the cleaning cloth has a shrinkage of less than 10.0%, preferably less than 7.0%, and more preferably less than 4.0%, as determined by the method disclosed in the description.

[0104] In a further embodiment of the cleaning cloth according to the invention, the cleaning cloth has a pilling rate of 1 to 3.5, as determined by the method disclosed in the description.

[0105] Another object of the present invention comprises a method for producing the cleaning cloth according to the invention, comprising the following steps: (a) Providing a textile support material designed as a nonwoven fabric, wherein the textile support material comprises microfibers on at least one surface, (b) Impregnating the textile support material with an aqueous solution of polyvinyl alcohol to produce a polyvinyl alcohol-impregnated textile support material, and (c) Contacting the polyvinyl alcohol-impregnated textile support material with formaldehyde.

[0106] Step (a) comprises manufacturing processes known to those skilled in the art for providing textile carrier materials designed as nonwovens according to the invention. First, in step (a), a textile carrier material designed as a nonwoven is produced and optionally solidified in a manner known per se. If multi-component fibers, in particular multi-component continuous filaments, are used as the starting material, these can be split into microfibers by the mechanical stress during processing into a nonwoven.

[0107] However, it is also conceivable that a separate splitting step takes place, for example by applying water jets.

[0108] One embodiment of the nonwoven textile backing material described above can be produced as follows: First, the individual fiber layers are spun separately, laid down to form a nonwoven, and, if necessary, pre-strengthened, for example by needling. The fiber layers are then bonded together.

[0109] Particularly with regard to layers B, which, as explained above, are advantageously arranged inside the nonwoven fabric, pre-consolidation has proven to be useful, as this prevents fibers of the second fiber component from reaching the surface of the composite nonwoven fabric.

[0110] The individual layers can be joined using known joining methods such as sewing, gluing, laminating, calendering and / or needle fusing.

[0111] However, the individual layers are preferably joined by alternatingly arranging layers with fibers of the first fiber component and layers with fibers of the second fiber component on top of each other after their production, and then directly solidifying them, for example by mechanical strengthening and / or hydrofluid treatment, and simultaneously bonding them together.

[0112] Through hydrofluid treatment, the nonwoven fabric can be strengthened from the outside in, possibly split, and intimately interwoven with the coarser filaments inside. This process allows for particularly effective use of filaments with a low filament titer, as the fine filaments are transported very deep into the nonwoven fabric and, apparently due to their entanglement, lead to a particularly effective stabilization of the composite – a "tentacle effect".

[0113] The consolidation and splitting of the fiber layers is advantageously achieved by subjecting the optionally pre-consolidated nonwoven fabric at least once on each side to high-pressure fluid jets, preferably high-pressure water jets. The nonwoven fabric according to the invention can thereby acquire the appearance of a textile surface, and the degree of splitting of the composite filaments can be set to more than 80%. The treatment is preferably carried out using high-pressure fluid jets, particularly preferably with high-pressure water jets at a fluid jet pressure of 80 to 400 bar, more preferably 85 to 350 bar.

[0114] It is also conceivable that the fibers of the first and second fiber components originate from a uniform spinning and / or laying process, are produced simultaneously, and are laid down together. For this purpose, at least two spinning stations, each with uniform spinneret openings, can be provided, producing composite filaments with different numbers of elementary filaments or a mixture of composite filaments with mono-component filaments in a common spinning and drawing device. These filaments can then be laid down to form the nonwoven fabric according to the invention, as well as solidified by hydrofluid treatment and split into the elementary filaments.

[0115] This achieves the advantage that the production of spunbond nonwovens with different filament titers does not have to be carried out separately and no subsequent joining is necessary to obtain a multi-component spunbond nonwoven consisting of different filaments with different filament titers.

[0116] According to one embodiment of the invention, at least three, preferably at least five, rows of spinning heads, each with uniform spinneret openings, are provided. These rows produce composite filaments with varying numbers of elementary filaments or a mixture of composite filaments with mono-component filaments in a common spinning and drawing device. Alternatively, at least one row with correspondingly different spinneret openings can be arranged in a spinneret package (curtain spinning), or a plurality of individual spinneret packages can be arranged in a so-called traversing tray.

[0117] These can then be laid down to form a nonwoven fabric, consolidated by hydrofluid treatment, and split into elementary filaments. A mechanical or thermal pre-consolidation process can precede the hydrofluid consolidation. According to this embodiment, nonwovens can be obtained that consist of layers with different filament titers and thus combine textile-physical properties that are otherwise only achievable by bonding separately produced layers.

[0118] Advantageously, the inventive method is further developed in such a way that the sequence of the spinning positions with respect to the depositing belt is selected so that the layer structures described above can be obtained in an arrangement ABA or A(BA)nBA of the composite layers.

[0119] According to a preferred embodiment of the invention, the sequence of the spinning positions with respect to the lay-up belt is selected such that an alternating titer of the filaments is generated over the thickness of the composite nonwoven fabric.

[0120] As explained above, to facilitate separation into the elementary filaments, the composite filaments can have a central opening, particularly in the form of a tubular, elongated cavity, which can be centered with respect to the central axis of the composite filaments. This arrangement reduces or eliminates the close contact between the elementary filaments, which is formed by the internal angles of the gaps or circular sections, before separation of the elementary filaments, as well as the contact in this area between different elementary filaments made from the same polymer.

[0121] To further strengthen the nonwoven structure, the composite filaments can exhibit latent or spontaneous crimping, resulting from an asymmetrical arrangement of the elementary filaments with respect to their longitudinal center axis. This crimping can be activated or enhanced by an asymmetrical geometric design of the cross-section of the composite filaments. This allows the nonwoven to be produced with a high thickness, a low modulus, and / or multiaxial elasticity.

[0122] In one variant, the composite filaments can exhibit latent or spontaneous crimping, which is due to a differentiation of the physical properties of the polymers forming the elementary filaments during the spinning, cooling and / or stretching processes affecting the composite filaments, leading to twisting caused by internal asymmetric loads with respect to the longitudinal center axis of the composite filaments, whereby the crimping may be activated or intensified by an asymmetric geometric design of the cross-section of the composite filaments.

[0123] The composite filaments may exhibit a latent crimp, which is activated by thermal, mechanical or chemical treatment prior to the formation of the composite nonwoven fabric.

[0124] The crimp can be intensified by an additional treatment prior to consolidation of the nonwoven fabric, for example, thermally or chemically. Consolidation of the nonwoven fabric according to the invention preferably takes place by treatment with high-pressure fluid jets. In this way, the elementary filaments can be tightly entangled during or after the division of the composite filaments using a mechanical means acting predominantly perpendicular to the plane of the fabric (needling, liquid pressure jets).

[0125] The filaments, particularly the composite filaments, can be deposited, for example, by mechanical and / or pneumatic deflection, whereby at least two of these deflection methods can be combined, as well as by spinning them onto an endless conveyor belt and mechanically by needling or by the action of liquid pressure jets, which may be impregnated with solid (micro)particles. The steps of entanglement and separation of the composite filaments into elementary filaments can be carried out in one and the same process step and with one and the same device, whereby the more or less complete separation of the elementary filaments can be followed by an additional process more focused on separation.

[0126] The strength and mechanical resistance of the nonwoven fabric can be significantly increased if the elementary filaments are bonded to one another by thermal fusion, which affects one or more of them, preferably by hot calendering with heated, smooth or engraved rollers, by drawing through a hot air tunnel oven, by drawing onto a drum through which hot air flows and / or by applying a binder contained in a dispersion or in a solution, or in powder form.

[0127] In one variant, the nonwoven fabric can also be consolidated, for example, by hot calendering before any separation of the uniform composite filaments into elementary filaments, with the separation taking place after the nonwoven fabric consolidation.

[0128] Furthermore, the nonwoven structure can also be strengthened by chemical treatment (as described, for example, in the applicant's French patent no. 2 546 536) or by thermal treatment, which leads to controlled shrinkage of at least some of the elementary filaments after their possible separation. This results in shrinkage of the material in the lateral and / or longitudinal direction.

[0129] Furthermore, after consolidation, the nonwoven fabric can be subjected to chemical bonding or finishing, such as anti-pilling treatment, hydrophilization or hydrophobization, antistatic treatment, treatment to improve fire resistance and / or to change tactile properties or gloss, mechanical treatment such as roughening, sanforizing, sanding or tumble drying, and / or treatment to change appearance such as dyeing or printing.

[0130] Practical tests have shown that a nonwoven fabric with a particularly homogeneous structure can be obtained if the nonwoven is pre-strengthened by applying temperature and / or pressure, preferably by calendering at a temperature of 160 to 220 °C, preferably 180-200 °C and / or a line pressure of 20 to 80 N / mm.

[0131] Advantageously, the nonwoven fabric according to the invention is further subjected to spot calendering to increase its abrasion resistance. For this purpose, the split and consolidated composite nonwoven fabric is passed through heated rollers, at least one of which has raised areas that cause the filaments to fuse together at specific points. According to a preferred embodiment of the invention, the composite filaments are dyed by spin dyeing.

[0132] Due to its good water absorption capacity (absorption capacity) combined with its excellent washability, the cleaning cloth according to the invention is ideally suited for cleaning a wide variety of surfaces. Particularly good results are achieved when cleaning smooth surfaces.

[0133] As explained above, the cleaning cloth may have a coating containing polyvinyl formal in addition to the impregnation containing polyvinyl formal.

[0134] In the multilayer embodiments described above, the polyvinyl formalin-containing coating can be arranged on the first and / or third layer.

[0135] In the embodiment in which the nonwoven fabric comprises at least a first layer and a second layer, wherein the mean titer of the fibers forming the second layer differs from the mean titer of the fibers forming the first layer, preferably wherein the mean titer of the fibers forming the second layer is greater than the mean titer of the fibers forming the first layer, both the impregnation and the coating can be arranged on the first layer.

[0136] In the embodiment in which the nonwoven fabric comprises at least a first layer, a second layer and a third layer, wherein the second layer is arranged between the first layer and the third layer and the mean titer of the fibers forming the second layer differs from the mean titer of the fibers forming the first and third layers, wherein the mean titer of the fibers forming the second layer is greater than the mean titer of the fibers forming the first and third layers, both the impregnation and the coating can be arranged on the first and / or third layer.

[0137] A suitable manufacturing process is disclosed, for example, in WO 2015 / 124335.

[0138] In a general embodiment, the method comprises a step (a1) in which the textile carrier material, formed as a nonwoven fabric, is bonded. Bonding is a process step in nonwoven fabric production. In this step, the still loose cohesion of the fiber web is further processed in one or more steps into a stronger composite, the nonwoven fabric. Suitable methods are thermal (calendering; air-thru), chemical (using binders), and mechanical methods (needling; water jet bonding). In one embodiment, mechanical methods, in particular water jet bonding, are used. In water jet bonding, staple fibers or filaments are reoriented in all three dimensions and interlocked with each other using high-pressure water jets. The diameter of the holes from which the water jets emerge is typically 0.1 mm, and the distance between two holes in the nozzle strip is 0.6 mm.This process utilizes arrangements with single or double rows of nozzle holes. Beneath the unbound nonwoven fabric lies a screen through which the process water passes. This screen simultaneously increases the efficiency of the agitation / bonding process by partially reflecting the water jets. The process water is filtered and recycled, and the residual water content in the nonwoven fabric is extracted and dried. The textile properties of the nonwoven fabric, such as softness, are comparable to those of conventionally manufactured textiles (woven fabrics).

[0139] In a preferred embodiment of step (a1), the nonwoven fabric is obtained by treating a fiber pile containing composite fibers with high-pressure fluid jets to split the composite fibers at least partially into elementary fibers and to produce a solidified textile support material containing microfibers. In a preferred embodiment, the nonwoven fabric is obtained by treating a fiber pile containing composite filaments with high-pressure fluid jets to split the composite filaments at least partially into elementary filaments and to produce a solidified textile support material containing microfibers (here: microfilaments).

[0140] In step (b), PVA in the form of an aqueous solution is applied to the textile substrate using common application methods, such as the foulard method, a doctor blade application, spray application, a slapping machine, a slot nozzle, or a wide-slot nozzle. Impregnating the textile substrate with an aqueous PVA solution has proven particularly suitable. Depending on the desired coating or impregnation thickness, excess PVA can be squeezed off, scraped off, vacuumed off, or removed in other ways.

[0141] Step (c) comprises contacting the polyvinyl alcohol-impregnated textile substrate with formaldehyde. The treated substrate is preferably immersed in an aqueous salt solution and / or suspension, for example, a sodium sulfate solution, and subsequently in an acidic formaldehyde solution. In the aqueous salt solution, the water is removed from the PVA solution, causing the PVA to coagulate. In the acidic formaldehyde solution, the PVA is crosslinked to form polyvinyl formalin.

[0142] According to an advantageous embodiment, the aqueous PVA solution and / or suspension contains further additives, such as color pigments or other additives or particles, like the aforementioned scouring agent. The PVA solution preferably contains a solid PVA content of between 1 and 10 wt%, more preferably between 3 and 7 wt%.

[0143] It can be advantageous for cleaning performance if the impregnation does not completely cover the textile backing material, but rather if parts of the backing material, e.g., loops projecting from the center plane, extend beyond the impregnation. To achieve this, the amount of polyvinyl formal applied during the manufacturing process can be adjusted so that only a portion of the cleaning cloth's surface is impregnated. This can be achieved by a) appropriately dosing the amount of PVA solution used for impregnation (e.g., by saturating, squeezing, and / or applying the PVA solution across the entire width using rollers, spray nozzles, etc.), or b) by applying the PVA solution in a distributed, partial manner across the surface ("islands"), or c) by subsequently sanding off the polyvinyl formal foam layer on both outer surfaces of the cleaning cloth, thereby exposing the embedded backing material.

[0144] The inventive method enables the simple and highly productive manufacture of a textile structure which has a polyvinyl formalin-containing coating or impregnation on one or both sides. The polyvinyl formalin-containing impregnation can penetrate the textile substrate, thereby anchoring it firmly within the textile substrate.

[0145] In a preferred embodiment of the present invention, the textile substrate is coated simultaneously on both sides on a single machine. This allows the polyvinyl formalin-containing impregnation to be applied to the textile substrate in one operation, resulting in particularly high efficiency in the production of the textile structure. Examples Measurement methods basis weight

[0146] The basis weight of the cleaning cloth is determined according to DIN EN ISO 9073-1: 2023. The samples are washed with water before measurement and dried until a constant weight is achieved. This yields the dry weight. An average value is calculated from 5 samples of the same test material. thickness

[0147] The thickness of the cleaning cloth is determined according to DIN EN ISO 9073-2: 1996 (measuring area: 25 cm²; pressure: 0.5 kPa). An average value is calculated from 5 samples of the same test material. The thickness of the cleaning cloth is measured in a conditioned state with a water content of 200 wt.% based on the dry weight of the cleaning cloth. That is, if, for example, the dry weight of the cleaning cloth is 10 g, the dry cleaning cloth is moistened with 20 g of water, so that the sample for the thickness measurement has a weight of 30 g. Packing density

[0148] The packing density is calculated from the quotient of basis weight and thickness. Shrinkage

[0149] Shrinkage is determined after washing at 60°C.

[0150] Sample preparation: Label the sample with machine direction (MD m1) and transverse direction (CD m1). Mark a defined section in the machine direction and in the transverse direction, including the start and end points (i.e., 10 cm for each value). Record the values ​​for MD m1 and CD m1. Test procedure:

[0151] The cleaning cloth is washed 5 times at 60°C (e.g., Miele PW 811; colored wash 60°C). The shrinkage is calculated on the dry sample. To bring the test material to a dry state, the washed test material can be dried at 40°C in a hot air drying oven (drying in hot air drying ovens at 40°C normally has no effect on the shrinkage of the fabric).

[0152] The marked points must be measured again with a ruler.

[0153] Note the length and width in mm (MD m² and CD m²). The shrinkage is then calculated using the following formulas: Scrumpf % = MD m 1 − MD m 2 × CD m 1 − CD m 2 / MD m 1 × CD m 1 × 100 Water absorption capacity

[0154] The water absorption capacity of a cleaning cloth is determined as follows. Prepare the test solution from tap water and a cleaner (e.g., Tanet SR 13) (e.g., 25 g of Tanet SR 13 are needed for 10 liters of tap water – adjust the test solution to the sample size). Weigh the dry test material and record the weight. Then determine its length and width. Place the test material in a container with the test solution (e.g., 0.25% Tanet SR 13) and let it stand for 10 minutes. Note: There must be sufficient free liquid in the container. Set a timer (2 minutes) and remove the test material. The test material should drip vertically downwards into a dish. Do not swirl it. After 2 minutes, weigh the test material on a scale and record the weight. Calculation:

[0155] Average weight in wet state [g] after 2 minutes; Water absorption capacity [g / cloth] = Average weight (wet state) [g] - Weight of the cloth (dry state) [g] Pilling rate

[0156] The pilling rate is determined according to ASTM D3512:2022. Examples 1 and 2

[0157] Two cleaning wipes according to the invention were produced as shown in the table below. The carrier material was a spunbond nonwoven fabric.

[0158] In the reference example, the backing material of the cleaning cloth consisted of a needle-punched nonwoven fabric made of polyvinyl alcohol fibers (titer >1.3 dtex). The reference example contains no microfibers. A needle-punched nonwoven fabric is a nonwoven fabric produced by needle-punching fiber webs. This fiber web consists of 100% PVA fibers. The manufacturing process begins with fiber preparation, in which the fibers are aligned in a carding machine. Subsequently, several layers of the carded web are laid on top of each other, a process known as cross-laying. These layers are then mechanically bonded in a needle-punching mill by barbed metal needles that pierce the web and interlock the fibers. After needle-punching, the needle-punched nonwoven fabric is treated with water-soluble polyvinyl alcohol, which is chemically cross-linked with formaldehyde to form water-insoluble polyvinyl formal. parameter Reference example Example 1 (easy version) Example 2 (difficult version) Water jet pressure n / a high (400 bar) Low (100 bar) Split grade n / a high (90%) lower (60%) Composition of carrier material 100% polyvinyl formal fibers 70% r-PET / 30% PA6 70% r-PET / 30% PA6 impregnation 100% PVA / Polyvinyl formic 100% PVA / Polyvinyl formic 100% PVA / Polyvinyl formic basis weight 90g / m²< 130g / m²< 180g / m²< basis weight impregnation 110g / m²< 38g / m²< 140g / m²< Distribution of coating to base material 55% (Coating) 22.5% (Coating) 43.75% (Coating) 45% (base) 77.5% (base) 56.25% (base) Water absorption (dry) 550% (155g / cloth) 300% (100g / cloth) 340% (158g / cloth) Water release (glass surface) 0.7g / m²< 0.6g / m²< 0.6g / m²< Washability (chemical thermal disinfection wash Ozonit Perform process 60°C) 50-200 cycles 400-500 cycles 300-400 cycles Shrinkage (60°C 5x) 14% 2,0% 2,5% Thickness ISO9073 / 2 1.5mm 0.7mm 1.4mm Cleaning performance against grease and dirt (few cycles are good) 63 cycles 42 cycles 25 cycles Packing density nb 185 kg / m³ 100 kg / m³

Claims

1. Cleaning cloth comprising a textile carrier material designed as a nonwoven fabric and an impregnation containing polyvinyl formal, wherein the textile carrier material comprises microfibers on at least one surface, preferably on both surfaces, and wherein the cleaning cloth comprises, based on the total weight of the cleaning cloth, 45 to 90 wt.% textile carrier material and 10 to 55 wt.% polyvinyl formal.

2. Cleaning cloth according to claim 1, wherein the cleaning cloth has a packing density of 30 to 1000 kg / m² 3 preferably 75 to 500 kg / m² 3 , and preferably 100 to 200 kg / m² 3 exhibits, as determined by the method disclosed in the description.

3. Cleaning cloth according to claim 1 or 2, wherein the microfibers are composite fibers that are at least partially split into elementary fibers.

4. Cleaning cloth according to one of claims 1 to 3, wherein the microfibers are formed as microfilaments.

5. Cleaning cloth according to claim 4, wherein the microfilaments are composite filaments that are at least partially split into elementary filaments.

6. Cleaning cloth according to any one of claims 1 to 5, wherein the textile carrier material comprises more than 60 wt.%, preferably more than 70 wt.%, and more preferably more than 80 wt.% microfibers.

7. Cleaning cloth according to one of claims 1 to 6, wherein the textile backing material has a basis weight of 50 to 400 g / m² 2 preferably 80 to 280 g / m² 2 , and preferably 100 to 200 g / m² 2 exhibits.

8. Cleaning cloth according to any one of claims 3 to 7, wherein the composite fibers or composite filaments comprise at least two thermoplastic polymers selected from the group consisting of polyacrylonitrile, polyamide, polycarbonate, polyester, polyetheretherketone, polyolefin, polystyrene, polyurethane and polyvinyl chloride.

9. Cleaning cloth according to any one of claims 3 to 8, wherein the composite fibers or composite filaments comprise (i) polyester and polyamide, preferably polyethylene terephthalate in combination with polyamide 6 or polyamide 66, or (ii) polyolefin and polyamide, preferably polypropylene in combination with polyamide 6 or polyamide 66.

10. Cleaning cloth according to any one of claims 3 to 9, wherein the composite fibers or composite filaments comprise 60 to 80 wt.% polyester and 20 to 40 wt.% polyamide, based on the total weight of the composite fibers.

11. Cleaning cloth according to any one of claims 1 to 10, wherein the nonwoven fabric is a spunbond nonwoven.

12. Cleaning cloth according to any one of claims 1 to 11, wherein the nonwoven fabric comprises at least a first layer and a second layer, wherein the mean titer of the fibers forming the second layer differs from the mean titer of the fibers forming the first layer, preferably wherein the mean titer of the fibers forming the second layer is greater than the mean titer of the fibers forming the first layer.

13. Cleaning cloth according to any one of claims 1 to 12, wherein the nonwoven fabric comprises at least a first layer, a second layer and a third layer, wherein the second layer is arranged between the first layer and the third layer and the mean titer of the fibers forming the second layer differs from the mean titer of the fibers forming the first layer and the third layer.

14. Cleaning cloth according to one of claims 1 to 13, wherein the impregnation has a basis weight of 10 to 300 g / m². 2 preferably 20 to 200 g / m² 2 , and more preferably 25 to 175 g / m² 2 exhibits.

15. Cleaning cloth according to any one of claims 1 to 14, wherein the cleaning cloth comprises 50 to 85 wt.%, and more preferably 55 to 80 wt.% of textile carrier material and 15 to 50 wt.%, and more preferably 20 to 45 wt.% of polyvinyl formal, based on the total weight of the cleaning cloth.

16. Method for producing a cleaning cloth according to any one of claims 1 to 15, comprising the steps of: (a) providing a textile carrier material designed as a nonwoven fabric, wherein the textile carrier material comprises microfibers on at least one surface, preferably on both surfaces; (b) impregnating the textile carrier material with an aqueous solution of polyvinyl alcohol to produce a polyvinyl alcohol-impregnated textile carrier material; and (c) bringing the polyvinyl alcohol-impregnated textile carrier material into contact with formaldehyde.

17. Method according to claim 16 wherein the nonwoven fabric is obtained by treating a fiber pile containing composite fibers by means of high-pressure fluid jets in order to split the composite fibers at least partially into elementary fibers and to produce a solidified textile carrier material containing microfibers, wherein the treatment is preferably carried out by means of high-pressure fluid jets with a fluid jet pressure of 80 to 400 bar.

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