Pile fabric

Abstract

The invention relates to a pile fabric having a support structure and at least one tuft, the at least one tuft comprising a plurality of fibers. In order to provide an improved pile fabric for filtration, the invention provides for the fibres of the at least one tuft to have different cross-sectional shapes.

Description

[0001] DESCRIPTION

[0002] upholstery

[0003] The present invention relates to a pile fabric comprising a support structure and at least one pile tuft connected to the support structure, wherein the at least one pile tuft has a plurality of fibers.

[0004] Upholstery fabrics are well known.

[0005] DE 199 12 548 A1 relates to a pile fabric with a textile backing structure and a trimming of pile threads anchored in the backing structure. The pile threads consist entirely or partially of a multi-filament yarn containing fine filaments on the one hand and coarse filaments on the other, the linear density of which is 25 times greater than the linear density of the fine filaments.

[0006] DE 36 15 684 A1 describes a velour textile in the form of a woven fur. The yarns forming the pile consist of elongated, smooth filaments that mimic the guard hairs of fur, and of interspun and shrunken staple fibers that form the denser and shorter undercoat.

[0007] In the following, certain terms within the meaning of the present invention are explained in more detail.

[0008] A fiber is a small textile structure. It is a linear, elementary structure made of a material / fabric. The fiber has an external shape (longitudinal shape: smooth, plain, or curly; cross-sectional shape: round, square, etc.) and is solid or hollow. It can be continuous (filament) or of a limited length (staple fiber).

[0009] A composite fiber is a fiber made from a combination of different materials to achieve specific properties such as strength, lightness, or other desired characteristics. This type of fiber consists of at least two different types of fibers or materials that are either joined together or separately in a spliced ​​fiber (composite).

[0010] A nonwoven fabric is a structure made of fibers of limited length, continuous fibers or cut yarns that are combined and bonded together to form a fiber layer.

[0011] A knitted fabric is a textile fabric made from thread systems by forming stitches on a knitting machine.

[0012] A knitted fabric is a fabric made by knitting. While in knitting, the row of stitches with all the individual stitches is created at once, in knitting, the stitches are formed one after the other.

[0013] A thread is a collective term for linear textile structures. At least two yarns are connected by twisting (twisting).

[0014] A yarn is a linear textile structure made up of several fibers.

[0015] A cover yarn is a yarn that is created by wrapping or covering a core yarn with an additional fiber material.

[0016] A filament is a fiber with virtually unlimited length (at least 1,000 mm). Filaments are also called continuous fibers.

[0017] A monofilament is a single filament. Micro-monofilaments are filaments with an equivalent diameter of less than 0.03 mm (30 pm).

[0018] A multifilament is a bundle of monofilaments.

[0019] A staple fiber is a fiber with a limited length (less than 1,000 mm). A distinction is made between long staple fibers (< 600 mm), medium staple fibers (< 60 mm), and short staple fibers (< 40 mm). A ply is the number of single yarns and / or pre-twisted yarns contained in plied yarns or twisted yarns.

[0020] A fabric is a textile surface structure made up of at least two thread systems (warp or weft) which, when viewed on the fabric surface, cross each other in a pattern at an angle of exactly or approximately 90°.

[0021] A pile fabric is a multidimensional structure consisting of a fluidizable, filter-active fiber layer (pile fiber layer) and a backing fabric. Within the scope of the present invention, a pile fabric can also be designed entirely or partially as a looped fabric, i.e., have uncut loops.

[0022] A backing fabric or support structure is a textile fabric with large, flow-relevant and non-filter-active pores that serves as a support for the pile fiber layer. Pile tufts are connected to this support. Flow-relevant pores are defined as the openings in the support structure that remain permeable to the fluid even when scaling or fouling begins. Scaling refers to the deposition of minerals, such as calcium carbonate, on the surfaces of the pile filter. Scaling can lead to blockages and increased pressure drop, which can impair the effectiveness of the entire wastewater treatment system. Fouling refers to the accumulation of undesirable substances, such as organic materials, sludge, microorganisms, and other particles, on the surface and within the pores of pile filters.The flow-relevant pores include, for example, openings with a length > 100 pm and a width > 100 pm, abbreviated > 100 pm x 100 pm, in particular > 200 x 200 pm, preferably > 400 x 400 pm, particularly preferably > 800 x 800 pm; very particularly preferably > 1,000 x 1,000 pm, and most preferably > 1,200 x 1,200 pm.

[0023] A pile fiber layer is a layer consisting of a multitude of individual fibers. The individual fibers (pile) are bundled into tufts (tufts) and bonded to the support structure. Solids retention is determined solely by the pile fiber layer. The finer the fibers in the pile fiber layer, the higher the solids retention, meaning smaller particles can be separated.

[0024] The pile fabric can be defined by, among other things, the height of the erected pile fibers, the diameter of the individual filaments, the specific surface area of ​​the pile fibers, the basis weight of the pile fabric, and the size of the flow-relevant pores in the support structure. There is no defined pore size for the separation of particles / solids in pile fabrics or the pile fiber layer.

[0025] Pile cloth filtration is a mechanical process for the separation of organic and inorganic solids as well as surface-active substances from Newtonian and non-Newtonian fluids, especially from liquids and gases, preferably from water, and particularly preferably from wastewater. It broadly belongs to the processes of surface filtration, cake filtration, or precoat filtration (with fixed aids). In addition to the sieving effect, true filtration effects are achieved across the depth of the pile fiber layer. Pile cloth filtration represents an important subfield of cloth filtration and is used primarily for water and wastewater treatment. Pile cloth filtration uses three-dimensional filter media, so-called pile cloths.The pile fabric is mounted, for example, either on a disc (disc filter), consisting of individual segments, a drum (drum filter / pressure drum filter), a plate (plate filter) or a lattice carrier with a diamond-shaped cross-section (diamond filter).

[0026] The invention is based on the object of providing an improved padding material for filtration.

[0027] The object is achieved in a pile fabric according to the preamble of claim 1 in that the fibers of the at least one pile tuft have different cross-sectional shapes.

[0028] The fibers of the at least one pile tuft have different cross-sectional shapes. The cross-sectional shape of the fibers can be, for example, round, oval, polygonal, triangular, octobal, lobed, trilobal, rectangular, hollow, dumbbell-shaped, serrated, flat, ribbon-shaped, Y-shaped, or star-shaped.

[0029] Within the scope of the invention, it has surprisingly been shown that such pile fabrics exhibit better filter properties than conventional pile fabrics. The different fibers lead to different behavior of the fibers within the filter medium during production and during its use, which makes it possible to optimally design the filter medium for the respective application. The different fibers in the pile tufts form different cross-sections of the pile fiber layer.

[0030] This creates a filter-active pile fiber layer with a non-filter-active support structure, with the pile fiber layer being tailored to the respective fluid matrix and filtration process. The composition of the pile fiber layer with different fibers can advantageously influence the solids removal rate, the regenerability of the filter medium, the cloth resistance, the vacuum, and the amount of rinse water generated during filtration.

[0031] Advantageous embodiments of the invention include the following:

[0032] • The fibers of at least one pile tuft can, for example, consist of different materials.

[0033] • It is also possible that the fibers of the at least one pile tuft have different equivalent diameters.

[0034] • The fibers of at least one pile tuft can have different textures.

[0035] • Furthermore, it is also possible that the fibers of at least one pile tuft have different swirls.

[0036] • Finally, the fibers of the at least one pile tuft may differ in their chemical and / or biological degradability.

[0037] Any combination of these preferred embodiments is also possible.

[0038] Preferably, the fibers of some of the pile tufts of the pile fabric are different.

[0039] Particularly preferably, the fibers of all pile tufts of the pile fabric are different. It is possible for the pile fabric to have homogeneous pile tufts, each with a different fiber type. Another possibility is for the pile fabric to have two or more types of pile tufts, each with a different fiber type, and also differ from type to type.

[0040] This allows the pile fiber surface or the pile fiber layer in pile fabric filtration to be advantageously tailored to the respective fluid matrix, the respective filtration process, and the respective suction / cleaning technology or suction lip (e.g., a smooth, profiled, or bristle-covered surface of the contact area between the pile fiber surface and the suction lip) of the filtration unit. The filtration properties can be modified by adjusting the pile fiber layer, equivalent to the use of different grain sizes in multi-layer filters in water treatment. In particular, the depth effect of the pile fiber layer in terms of filtration technology and thus the solids absorption capacity and solids release capacity or regenerability during suction can be intensified.

[0041] For example, one or more thick fibers with a larger cross-section can stabilize and / or structure finer fibers with a smaller cross-section. One or more fiber types with a larger cross-section can serve as spacers in the pile fiber layer. The fiber types with a larger cross-section protrude from the support structure, while the fiber types with a smaller cross-section are adjacent to the support structure.

[0042] Several different fibers can be blended into a pile tuft to produce pile fabrics. Different fibers can also be used in staple fibers in yarn to produce pile fabrics.

[0043] At least two types of fiber are mixed together in the pile fiber layer. The fiber mixtures can be single fiber admixtures up to a ratio of 1:1 and / or 2 to n fiber types. The fibers can be present in the pile fiber layer as filament and / or monofilament and / or staple fiber and / or yarn and / or twisted yarn. The pile fiber layer can contain various types of mixed yarn. For example, a mixed yarn of

[0044] • Multifilament with the same or different filament diameter,

[0045] • Multifilament with monofilament,

[0046] • Multifilament and staple fiber,

[0047] • Monofilament and staple fiber,

[0048] • Staple fiber with the same or different filament diameters,

[0049] • Multifilaments with monofilament(s) admixture or

[0050] • Monofilament with the same or different filament diameter.

[0051] Preferably, there is an even distribution (homogeneous distribution) of the fiber mixture in each individual pile tuft and the entire pile fiber layer.

[0052] The fibers can be made of chemically or biologically stable or unstable materials. A preferred embodiment of the invention involves the use of biodegradable fibers, with some of the fibers preferably being biostable and some biodegradable. Biodegradable fiber materials lead to holes in the pile fiber layer over time. Thus, the targeted use of biodegradable fibers enables the targeted formation of openings in the pile fiber layer over time.

[0053] Biodegradable materials can also be advantageously used to promote the targeted colonization of biofilm on or in the pile fiber layer. The bioavailable material can serve as a nutrient source for applications where there is no continuous nutrient supply.

[0054] The direction of coating or the position of the pile fiber layer can advantageously influence the formation and structure of the filter-active layer. Depending on the direction of coating, for example, coarse and fine filtration can be achieved, or a higher or lower filter resistance can be achieved. The pore structure and pore size within the pile fiber layer can advantageously be specifically defined and matched to the fluid matrix. For example, the pore size can be minimized by matching the fibers of the pile fiber layer to the fluid matrix.

[0055] The position of the pile fiber layer, the direction of the pile fiber layer, the composition of the pile fiber layer from different fibers and the structure of the carrier structure can, for example, produce the following structures from different layers for filtration:

[0056] • A first fine, dense filter-active layer, a transition layer and an open-pore support structure close to the carrier structure,

[0057] • A first layer (pile fiber surface) made of coarse, fine, medium-fine and coarse fibers close to the support structure.

[0058] By adjusting the fiber layers through the fiber mixture, the storage volume for particles or solids in or on the pile fiber layer can be advantageously increased.

[0059] In contrast to multi-layer filters, the connection of the fiber mixtures with the carrier structure makes it impossible to separate the fiber types.

[0060] Thicker fibers and / or filaments can be incorporated into the pile fiber layer as spacers and structural elements.

[0061] The pile tufts can range in length from 5 to 200 mm. A pile tuft length of 21 mm corresponds to approximately 6 mm pile fiber height, depending on the connection to the support structure and the fiber type / material. A pile tuft length of approximately 38 mm corresponds to approximately 14 mm pile fiber height, depending on the connection to the support structure and the fiber type / material.

[0062] One embodiment of the invention is that the at least one

[0063] Pile tuft has at least one multifilament with a plurality of filaments, wherein the filaments of one multifilament and / or the filaments of a plurality of multifilaments and / or a plurality of multifilaments of a plurality of pile tufts are different.

[0064] A further embodiment of the invention is that the at least one pile tuft consists of one to 100 different fibers, preferably two to 50 different fibers, particularly preferably three to 10 different fibers.

[0065] A further embodiment of the invention is that the fibers in the pile tufts are in the form of staple fibers and / or yarns and / or twisted yarns.

[0066] A further embodiment of the invention is that the fibers differ in their texturing and / or intermingling.

[0067] The fibers can be smooth to highly curved, swirled, or textured. The fibers can also be pleated. The fibers can also be non-intermingled to highly intermingled. Intermingling refers to the selective intermingling of fibers to gather multifilaments together.

[0068] An advantageous embodiment of the invention is that the fibers comprise hollow fibers. A particularly advantageous embodiment is that the hollow fibers have a filling, wherein the filling can preferably comprise an adsorbent, in particular activated carbon. Alternatively, the filling can also comprise an additive or a wax.

[0069] A further advantageous embodiment consists in providing the fibers with a coating and / or additive. The coating and / or additive can impart certain properties to the fibers, for example, by giving them a hydrophilic or hydrophobic surface or making them conductive. Another preferred embodiment of the invention consists in providing the fibers with a coating and / or additive that imparts antibacterial properties, for example, by means of a silver-, copper-, or zinc-containing coating.

[0070] A further embodiment of the invention is that the fibers have a fiber thickness between 0.001 and 700 dtex, preferably between 0.005 and 500 dtex, particularly preferably between 0.01 and 435 dtex.

[0071] For a fibre made of polyethylene terephthalate (PET), in the textile technical sense polyester (PES), with a density of 1.38 g / cm 3 A fiber thickness of 0.001 to 700 dtex corresponds to an equivalent diameter of 0.3 to 254 pm, a fiber thickness of 0.005 to 500 dtex to a diameter of 0.7 to 215 pm and a fiber thickness of 0.01 to 435 dtex to a diameter of 1.0 to 200 pm.

[0072] For example, a PES ultrafiber with a fiber thickness of 0.26 dtex has a diameter of 4.9 pm, a PES microfiber with a fiber thickness of 0.6 dtex has a diameter of 7.4 pm and a PES standard fiber with a fiber thickness of 4.6 dtex has a diameter of 20.6 pm.

[0073] For example, in a blend of PES ultrafiber with PES standard fiber, the ratio of fiber thicknesses is about 18.8, for example, in a blend of PES ultrafiber with PES microfiber, the ratio of fiber thicknesses is about 2.3, and for example, in a blend of PES microfiber with PES standard fiber, the ratio of fiber thicknesses is about 7.7.

[0074] According to the present invention, the titer of the coarse filaments is less than 25 times greater than the titer of the finer filaments when two different fibers form the pile tuft. Thus, a titer ratio of less than 1:25 exists.

[0075] If three or more fibers form the pile tuft, the titre ratio of the different fibers can generally be freely selected.

[0076] If three fibers form the pile tuft, the titer ratio is preferably from 1:1:1 to 1:500:1,000, preferably from 1:1:2 to 1:250:500, and particularly preferably from 1:2:2 to 1:100:250. If there are more than three different fibers in the pile tuft, the titer of the different fibers is preferably identical; particularly preferably, the titer of the next larger fiber is 2 times, particularly preferably 5 times, and most preferably 10 times larger than the titer of the smaller fiber.

[0077] A further embodiment of the invention is that the pile fiber layer has a basis weight between 100 and 10,000 g / m 2 , preferably between 200 and 5,000 g / m 2 , particularly preferably between 250 and 1,500 g / m 2 has.

[0078] The basis weight of the entire pile fabric is, for example, between 200 and 15,000 g / m 2 , preferably between 300 and 6,000 g / m 2, particularly preferably between 400 and 1,800 g / m 2 .

[0079] A further embodiment of the invention is that the pile fabric has an air permeability of 10 to 5,000 l / m 2 / s, preferably from 50 to 4,000 l / m 2 / s, particularly preferably from 100 to 2,000 l / m 2 / s and most preferably from 150 to 1,500 l / m 2 / s.

[0080] The air permeability (determined according to DIN EN ISO 9237) depends on the equivalent fiber diameter.

[0081] A further embodiment of the invention is that the support structure is a woven fabric, a knitted fabric, a nonwoven fabric or a mixture thereof.

[0082] Flow-relevant pores include, for example, openings in the pile material support structure with a length > 600 pm and a width > 600 pm, abbreviated > 600 pm x 600 pm, in particular > 700 x 700 pm, preferably > 800 x 800 pm, more preferably > 900 x 900 pm, more preferably > 1000 x 1000 pm, more preferably > 1100 x 1100 pm, more preferably > 1200 x 1200 pm, more preferably > 1300 x 1300 pm, more preferably > 1400 x 1400 pm, more preferably > 1500 x 1500 pm, more preferably > 1600 x 1600 pm, more preferably > 1700 x 1700 pm, more preferably > 1800 x 1800 pm, more preferably > 1900 x 1900 pm, more preferably > 2000 x 2000 pm, more preferably > 2100 x 2100 pm, more preferably > 2200 x 2200 pm, particularly preferably > 2300 x 2300 pm; very particularly preferably > 2400 x 2400 pm, and most preferably > 2500 x 2500 pm. The area of ​​the flow-relevant pores is, for example, > 0.36 mm 2 , preferably > 0.49 mm 2 , more preferably > 0.64 mm 2, more preferably > 0.81 mm 2 , more preferably > 1 .00 mm 2 , more preferably > 1.21 mm 2 , more preferably > 1.44 mm 2 , more preferably > 1.69 mm 2 , more preferably > 1.96 mm 2 , more preferably > 2.25 mm 2 , more preferably > 2.56 mm 2 , more preferably > 2.89 mm 2 , more preferably > 3.61 mm 2 , more preferably > 4 mm 2 , more preferably > 4.41 mm 2 , more preferably > 4.84 mm 2 , particularly preferably > 5.29 mm 2 ; most preferably > 5.76 mm 2 , and most preferably > 6.25 mm 2 In particular, depending on the type of pile material support structure, the flow-relevant pores do not have to be rectangular.

[0083] Depending on the pile material structure, flow-relevant pores and / or non-flow-relevant pores can be rectangular with rounded corners, circular, diamond-shaped, trapezoidal, star-shaped or a mixture thereof.

[0084] A further embodiment of the invention consists in that identical and different pile tufts are connected to the support structure to form a line pattern or a checkerboard pattern and / or a combination of a line pattern and a checkerboard pattern.

[0085] The checkerboard pattern can include rows of different pile tufts (tufts made of different fibers). The linear pattern can include lines of different pile tufts. The different pile tufts can also alternate in a line.

[0086] A further embodiment of the invention is that the pile tufts are connected to the support structure with a W-tuft, a double W-tuft or a V-tuft.

[0087] In principle, the fibers can be made from inorganic or organic natural materials

[0088] plastics, metals or alloys, in any combination. A preferred embodiment of the invention is that the fibers are made of polypropylene (PP), viscose, polyacrylonitrile (PAN), polyester (PES), polyvinyl chloride (PVC), polycarbonate (PC), polyethylene terephthalate (PET), polyimide (PI), polytetrafluoroethylene (PTFE), polyamide (PA), polyethylene (PE), polymethyl methacrylate (PMMA), polyoxymethylene (POM), polyvinylidene fluoride (PVDF), polybutylene terephthalate (PBT), polyether ketones (PEK), polyamideimide (PAI), polyetheretherketone (PEEK), polyphenylsulfones (PPSU), polyphenylene sulfide (PPS), polycarbonate (PC), styrene-acrylonitrile copolymer (SAN), acrylonitrile-butadiene-styrene copolymer (ABS), syndiotactic polystyrene (SPS), polyurethanes (PUR), linen, kenaf, flax, jute, cotton, bast, hemp, silk, carbon, glass, minerals, aramid, iron, Aluminium, copper, zinc, lead, silver, gold, platinum, nickel, titanium, cobalt, chromium, tin, manganese, tungsten, vanadium,austenitic stainless steel (e.g. A2), ferritic stainless steel, martensitic stainless steel, duplex stainless steel and / or high-alloy stainless steel (e.g. A4) or combinations thereof.

[0089] A further embodiment of the invention is that the fibers have a lipophilic and / or hydrophobic surface.

[0090] Finally, the use of a pile fabric according to the invention for pile fabric filtration is also according to the invention.

[0091] In the following, embodiments of the invention are explained in more detail with reference to drawings.

[0092] It shows

[0093] Fig.1 a to 1 c a side view of different fiber arrangements,

[0094] Fig. 2a to 2g a side view of differently structured fibers,

[0095] Fig. 3 a bar diagram of the air permeability as a function of the structuring of the fibers, Fig. 4 a dot diagram of the maximum fluidization as a function of the vacuum in the suction bar and the slot speed in the suction bar for different structuring of the fibers,

[0096] Fig. 5a to 5c several cross-sections of different cross-sectional shapes of the fibers,

[0097] Fig. 6 a bar chart of air permeability as a function of the equivalent diameter of the fibers,

[0098] Fig. 7a to 7c a side view of different weavings of the pile tufts,

[0099] Fig. 8a to 8f a cross-section of different pile tufts in the pile fibre layer,

[0100] Fig. 9a to 9c a plan view of several different

[0101] Support structures,

[0102] Fig. 10a to

[0103] 10d a schematic plan view of the distribution of different

[0104] Pile knobs in the support structure,

[0105] Fig. 11 is a schematic representation of an inventive

[0106] upholstery,

[0107] Fig. 12 a dot diagram of the slot speed in the suction beam as a function of the vacuum in the suction beam for different pile materials,

[0108] Fig. 13a and

[0109] Fig. 13b Measured values ​​of parallel operation of single fiber pile fabric (EF) and mixed fiber pile fabric (MF).

[0110] Fig. 1a shows a schematic representation of a staple fiber. Fig. 1b shows a monofilament. Fig. 1c shows a multifilament composed of several monofilaments.

[0111] Figures 2a to 2d show fibers with varying degrees of bending. The fibers shown in Fig. 2a are smooth and not bent. The fibers shown in Fig. 2b are slightly bent. Fig. 2c shows strongly bent fibers. The fibers in Fig. 2d are strongly bent. Fig. 2e shows pleated fibers. The fibers in Fig. 2f are intermingled. Fig. 2g shows the intermingling point. The air permeability of the pile fabric can be varied by structuring the fibers.

[0112] Fig. 3 shows a diagram of air permeability (determined according to DIN EN ISO 9237) as a function of the fiber structure of the pile fabric. The pile fabrics have an identical back structure (> 800 pm x 800 pm), basis weight (860 g / m 2 ) and fiber thickness (7.4 pm; 0.6 dtex), but with different fiber texturing.

[0113] Fig. 4 shows two diagrams of maximum fluidization as a function of the vacuum in the suction beam (left diagram) and the slot speed in the suction beam vsiot (right diagram) for different fiber structures of the pile fabric. The pile fabrics have an identical back structure (> 800 pm x 800 pm), basis weight (860 g / m 2 ) and fiber strength (7.4 pm; 0.6 dtex), but different fiber texturing during filter cleaning, vsiot (slot speed in the suction bar, determined according to Grabbe, U. (1998) Investigations into advanced wastewater treatment using textile filter media - cloth filtration and microsieving. Institute for Urban Water Management and Waste Technology. Hanover, Leibniz University Hanover, Dissertation) and vacuum in the suction bar are operating parameters of the pile fabric filtration.

[0114] Figures 5a to 5c show different cross-sectional shapes of the fibers. Figure 5a shows cross-sectional shapes with rounded corners, for example, a circle, an oval, a star shape with rounded corners, double and triple dumbbells, a square with rounded corners, or a triangle with rounded corners.

[0115] Fig. 5b shows polygonal cross-sectional shapes, such as a square, a parallelogram, a triangle or a star.

[0116] Fig. 5c shows fibers with one or more cavities.

[0117] Fig. 6 shows two bar charts of air permeability (measured according to DIN EN ISO 9237) as a function of the equivalent fiber diameter of pile fabrics. The pile fabrics contain single fibers (left diagram) or mixed fibers (right diagram) in the pile fiber layer and have an identical back structure (> 800 pm x 800 pm), but different equivalent fiber diameters.

[0118] Figs. 7a to 7c show various weaves of the pile tufts for connecting them to the support structure. Fig. 7a shows a W-tuft, and Fig. 7b a V-tuft. Fig. 7c shows the formation of a pile fiber layer with a left-to-right weaving direction. This weaving creates a filter-active layer of pile tufts.

[0119] Figures 8a to 8g show various pile tufts of a pile fiber layer in cross-section. On the left side, a single pile tuft is shown. On the right side, the formation of a filter-active layer by removing the pile fibers shown on the left is shown. As can be seen in Figures 8a to 8f, different filter layers can be formed in the pile fiber layer by distributing fibers with different equivalent diameters in the pile tuft. Figure 8g shows a pile tuft with fibers of different cross-sectional shapes.

[0120] Several different support structures are schematically illustrated in Figs. 9a to 9c. The support structure can be a woven fabric (Fig. 9a), a knitted fabric (Fig. 9b), or a nonwoven fabric (Fig. 9c).

[0121] Figs. 10b and 10d show different distributions of identical pile tufts in the support structure. The identical pile tufts have different fibers. The distribution can correspond to a checkerboard pattern (Fig. 10b) or multiple rows (Fig. 10d).

[0122] Figs. 10a and 10c show various distributions of different pile tufts in the support structure. The different pile tufts differ in their fibers. The distribution can correspond to a checkerboard pattern (Fig. 10a) or several rows (Fig. 10c). The different pile tufts alternate in rows.

[0123] Fig. 11 shows a pile fabric according to the invention. The pile fabric has a support structure. Pile tufts are connected to the support structure. The pile tufts have different fibers. The fibers can differ, for example, in their equivalent diameter, their cross-sectional shape or their material. The spatial distribution of the different fibers in the pile tuft is shown schematically in the enlarged view with several example distributions. In the spatial distribution of the fibers in the pile tuft, different gray levels correspond to different fibers. For example, the spatial distribution in the middle row on the right-hand side represents the case in which the left side of the pile tuft consists of one fiber type and the right side of the pile tuft consists of a different fiber type.

[0124] Fig. 12 shows a scatter plot of the slot speed vsiot in the extraction beam as a function of the vacuum in the extraction beam for different pile fabrics. The plot shows measured values ​​for different pile fiber layers made of single fibers (EF) and only one single fiber type, and for different pile fiber layers made of mixed fibers (MF) with two different fiber types. The fiber types differ in their equivalent fiber diameter. The pile fiber layers made of single fibers (EF) have an equivalent diameter of 20.6 pm and 7.4 pm, respectively. The pile fiber layer made of mixed fibers (MF) with an equivalent diameter of 8.2 pm consists of 50% of a first fiber type with an equivalent diameter of 10.5 pm (1.2 dtex) and 50% of a second fiber type with an equivalent diameter of 4.9 pm (0.26 dtex).The pile fiber layer made of mixed fibers (MF) with an equivalent diameter of 6.8 pm consists of 25% of a first fiber type with an equivalent diameter of 10.5 pm (1.2 dtex) and 75% of a second fiber type with an equivalent diameter of 4.9 pm (0.26 dtex).

[0125] Figures 13a and 13b compare measured values ​​from the parallel operation of single-fiber pile fabric (EF) according to the prior art and mixed-fiber pile fabric (MF) according to the present invention during pile fabric filtration for the filtration of biologically treated wastewater using a drum filter with upstream precipitation and flocculation with the addition of iron(II) chloride (2.1 mg Fe(III) / L). The following parameters are compared: filter speed (v) [m / h], water level (tank and riser shaft) [cm], recovery [%], resistance (cloth resistance) [cm / m / h], vacuum [mbar], and turbidity - inlet / outlet [NTU]. The water level in the tank is used to control the system, so that when it reaches approximately 30 cm, the filter is cleaned. This involves moving the pile fabric along the suction bar to fluidize the pile fiber layer and thus remove the absorbed solids from the pile fiber layer.

[0126] After filter cleaning, the permeability of the padding material is temporarily higher, leading to a higher water level in the riser shaft. The interval between filter cleanings directly influences the solids load capacity of the padding material (at a comparable discharge value). The longer the interval, the higher the solids load capacity of the padding material and the lower the rinse water generation and energy consumption of the padding material filtration.

[0127] The vacuum indicates the negative pressure at which the filter cleaning pump performs filter cleaning on the suction side. The higher the vacuum, the greater the hydraulic loss in the filter cleaning system. The recovery indicates the percentage drop in the water level in the tank from its starting point after cleaning. The greater the drop in the water level after cleaning, the greater the regeneration potential of the padding material through filter cleaning.

[0128] The hydraulic resistance of the pile fabric (cloth resistance) is determined by the water level ratio after filter cleaning in the tank and riser shaft, minus machine losses, relative to the filter speed. The higher the cloth resistance, the higher the hydraulic loss through the filter machine.

[0129] The turbidity in the inlet of the pile filtration (in combination with the filter speed) allows conclusions to be drawn about the solid surface load of the pile and, in combination with the turbidity in the effluent, is used to evaluate the pile with regard to its ability to separate substances from the inlet.

Claims

AMENDED CLAIMS received by the International Bureau on 15 September 2025 (15.09.2025) 1. Use of a pile fabric comprising a support structure and at least one pile tuft connected to the support structure, wherein the at least one pile tuft has a plurality of fibers, characterized in that the fibers of the at least one pile tuft have different cross-sectional shapes for fluid filtration.

2. Use according to one of the preceding claims, characterized in that the fibers of the at least one pile tuft consist of different materials.

3. Use according to one of the preceding claims, characterized in that the fibers of the at least one pile tuft have different equivalent diameters.

4. Use according to one of the preceding claims, characterized in that the fibers of the at least one pile tuft have different textures.

5. Use according to one of the preceding claims, characterized in that the fibers in the pile tufts are in the form of staple fibers and / or yarns and / or twisted yarns.

6. Use according to one of the preceding claims, characterized in that the fibers of the at least one pile tuft have different swirls.

7. Use according to one of the preceding claims, characterized in that the fibers of the at least one pile tuft differ in their chemical and / or biological degradability.

8. Use according to one of the preceding claims, characterized in that the fibers have a fiber thickness between 0.001 and 700 dtex, preferably between 0.005 and 500 dtex, particularly preferably between 0.01 and 435 dtex.

9. Use according to one of the preceding claims, characterized in that the pile fiber layer has a basis weight between 100 and 10,000 g / m2 , preferably between 200 and 5,000 g / m 2 , particularly preferably between 250 and 1,500 g / m 2 has.

10. Use according to one of the preceding claims, characterized in that the pile fabric has an air permeability of 10 to 5,000 l / m 2 / s, preferably from 50 to 4,000 l / m 2 / s, particularly preferably from 100 to 2,000 l / m 2 / s and most preferably from 150 to 1,500 l / m 2 / s.

11. Use according to one of the preceding claims, characterized in that the support structure is a woven fabric, a knitted fabric, a nonwoven fabric or a mixture thereof.

12. Use according to one of the preceding claims, characterized in that identical and different pile tufts are used to form a line pattern or a checkerboard pattern and / or a Combination of a line pattern and a checkerboard pattern with the supporting structure.

13. Use according to one of the preceding claims, characterized in that the pile tufts are connected to the support structure with a W-tuft, a double W-tuft or a V-tuft.

14. Use according to one of the preceding claims, characterized in that the fibers consist of inorganic or organic natural materials, plastics, metals or alloys, preferably of polypropylene (PP), viscose, polyacrylonitrile (PAN), polyester (PES), polyvinyl chloride (PVC), polycarbonate (PC), polyethylene terephthalate (PET), polyimide (PI), polytetrafluoroethylene (PTFE), polyamide (PA), polyethylene (PE), polymethyl methacrylate (PMMA), polyoxymethylene (POM), polyvinylidene fluoride (PVDF), polybutylene terephthalate (PBT), polyether ketones (PEK), polyamideimide (PAI), polyetheretherketone (PEEK), polyphenylsulfones (PPSU), polyphenylene sulfide (PPS), polycarbonate (PC), styrene-acrylonitrile copolymer (SAN), acrylonitrile-butadiene-styrene copolymer (ABS), syndiotactic polystyrene (SPS), polyurethanes (PUR), linen, Kenaf, flax, jute, cotton, raffia, hemp, silk, carbon, glass, aramid, iron, aluminum, copper, zinc, lead, silver, gold, platinum, nickel, titanium, cobalt, chromium,Tin, manganese, tungsten, vanadium, austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, duplex stainless steel and / or high-alloy stainless steel or combinations thereof.

15. Use according to one of the preceding claims, characterized in that the fibers have a lipophilic and / or hydrophobic surface. 16.

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