Padded fabric

Abstract

The invention relates to a pile fabric with a backing fabric and at least one pile tuft, wherein the at least one pile tuft has a plurality of fibers. In order to provide an improved pile fabric for filtration, the invention proposes that the fibers within at least one pile tuft are different.

Description

[0001] The present invention relates to a pile fabric comprising a backing fabric and at least one pile tuft connected to the backing fabric, wherein the at least one pile tuft has a plurality of fibers.

[0002] In the following, certain terms within the meaning of the present invention are explained in more detail.

[0003] 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).

[0004] 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).

[0005] 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.

[0006] A knitted fabric is a textile fabric made from thread systems by forming stitches on a knitting machine.

[0007] 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.

[0008] A thread is a collective term for linear textile structures. At least two yarns are connected by twisting (twisting).

[0009] A yarn is a linear textile structure made up of several fibers.

[0010] A cover yarn is a yarn that is created by wrapping or covering a core yarn with an additional fiber material.

[0011] A filament is a fiber with virtually unlimited length (at least 1,000 mm). Filaments are also called continuous fibers.

[0012] A monofilament is a single filament. Micro-monofilaments are filaments with an equivalent diameter of less than 0.03 mm (30 µm).

[0013] A multifilament is a bundle of monofilaments.

[0014] 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).

[0015] A ply is the number of single yarns and / or pre-twisted yarns contained in plied yarns or twisted yarns.

[0016] 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°.

[0017] 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.

[0018] 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 backing fabric that remain permeable to the fluid even when fouling begins. Flow-relevant pores include openings with a length ≥ 100 µm and a width ≥ 100 µm, abbreviated ≥ 100 µm x 100 µm, in particular ≥ 200 x 200 µm, preferably ≥ 400 x 400 µm, particularly preferably ≥ 800 x 800 µm, very particularly preferably ≥ 1,000 x 1,000 µm, and most preferably ≥ 1,200 x 1,200 µm.

[0019] A pile fiber layer is a layer consisting of a multitude of individual fibers. The individual fibers (pile) are bundled into tufts (pile tufts) and bonded to the backing fabric. 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.

[0020] 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 backing fabric. By definition, there is no defined pore size for the separation of particles / solids in pile fabrics or the pile fiber layer.

[0021] 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).

[0022] Upholstery fabrics are well known.

[0023] DE 199 12 548 A1 relates to a pile fabric consisting of a textile support structure and a facing of pile threads anchored in the support structure. The pile threads consist at least partially of a multi-filament yarn containing, on the one hand, fine filaments and, on the other hand, coarse filaments whose linear density is more than 25 times higher than the linear density of the fine filaments.

[0024] The invention is based on the object of providing an improved padding material for filtration.

[0025] The problem is solved in a pile fabric according to the preamble of claim 1 in that the fibers are different within at least one pile tuft.

[0026] 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.

[0027] This creates a filter-active pile fiber layer with a non-filter-active backing fabric, 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.

[0028] In this context, “being different” preferably means the following: • The fibers of at least one pile tuft can, for example, consist of different materials. • It is also possible that the fibers of the at least one pile tuft have different equivalent diameters. • The fibers of at least one pile tuft can have different cross-sectional shapes. • The fibers of at least one pile tuft can have different textures. • Furthermore, it is also possible that the fibers of at least one pile tuft have different swirls. • Finally, the fibers of the at least one pile tuft may differ in their chemical and / or biological degradability.

[0029] Each of these possibilities represents a preferred embodiment of the invention. Any combination of these preferred embodiments is also possible.

[0030] Preferably, the fibers of some of the pile tufts are different. Particularly preferably, the fibers of all pile tufts are different.

[0031] It is possible for the pile fabric to have homogeneous pile tufts, each with a different fiber. Another possibility is that the pile fabric has two or more types of pile tufts, each with a different fiber and also differing from type to type.

[0032] 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, similar 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.

[0033] 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 backing fabric, while the fiber types with a smaller cross-section adhere to the backing fabric.

[0034] 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.

[0035] At least two fiber types are blended together in the pile fiber layer. These fiber blends 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.

[0036] The pile fiber layer can contain different types of blended yarn. For example, a blended yarn made of • Multifilament with the same or different filament diameter, • Multifilament with monofilament, • Multifilament and staple fiber, • Monofilament and staple fiber, • Staple fiber with the same or different filament diameters, • Multifilaments with monofilament(s) admixture or • Monofilament with the same or different filament diameter.

[0037] Preferably, there is an even distribution (homogeneous distribution) of the fiber mixture in each individual pile tuft and the entire pile fiber layer.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] Advantageously, the pore structure and pore size within the pile fiber layer can 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.

[0042] 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 backing fabric can, for example, produce the following structures from different layers for filtration: • A first fine, dense filter-active layer, a transition layer and an open-pore support structure close to the back tissue, • A first layer (pile fiber surface) made up of coarse, fine, medium-fine and coarse fibers close to the backing fabric.

[0043] 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.

[0044] In contrast to multi-layer filters, the connection of the fiber mixtures with the backing fabric makes it impossible to separate the fiber types.

[0045] Thicker fibers and / or filaments can be incorporated into the pile fiber layer as spacers and structural elements.

[0046] 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 bonding to the backing fabric and the fiber type / material. A pile tuft length of approximately 38 mm corresponds to approximately 14 mm pile fiber height, depending on the bonding to the backing fabric and the fiber type / material.

[0047] One embodiment of the invention is that the at least one pile tuft comprises 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.

[0048] 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.

[0049] 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.

[0050] A further embodiment of the invention is that the fibers differ in their cross-sectional shape.

[0051] The cross-sectional shape of the fibers can be, for example, round, oval, polygonal, triangular, octolobal, lobed, trilobal, rectangular, hollow, dumbbell-shaped, serrated, flat, ribbon-shaped, Y-shaped or star-shaped.

[0052] A further embodiment of the invention is that the fibers differ in their texturing and / or intermingling.

[0053] 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.

[0054] 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.

[0055] 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 applying a silver-, copper-, or zinc-containing coating.

[0056] 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.

[0057] For a fibre made of polyethylene terephthalate (PET), in the textile technical sense polyester (PES), with a density of 1.38 g / cm 3A fiber thickness of 0.001 to 700 dtex corresponds to an equivalent diameter of 0.3 to 254 µm, a fiber thickness of 0.005 to 500 dtex to a diameter of 0.7 to 215 µm and a fiber thickness of 0.01 to 435 dtex to a diameter of 1.0 to 200 µm.

[0058] For example, a PES ultrafiber with a fiber thickness of 0.26 dtex has a diameter of 4.9 µm, a PES microfiber with a fiber thickness of 0.6 dtex has a diameter of 7.4 µm and a PES standard fiber with a fiber thickness of 4.6 dtex has a diameter of 20.6 µm.

[0059] For example, in a blend of PES ultrafiber with PES standard fiber, the fiber strength ratio is approximately 18.8; for example, in a blend of PES ultrafiber with PES microfiber, the fiber strength ratio is approximately 2.3; and for example, in a blend of PES microfiber with PES standard fiber, the fiber strength ratio is approximately 7.7.

[0060] 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.

[0061] If three or more fibers form the pile tuft, the titre ratio of the different fibers can generally be freely selected.

[0062] 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 largest fiber is 2 times, particularly preferably 5 times, and most preferably 10 times greater than the titer of the smaller fiber.

[0063] 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.

[0064] 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 .

[0065] 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.

[0066] The air permeability (determined according to DIN EN ISO 9237) depends on the equivalent fiber diameter.

[0067] A further embodiment of the invention is that the backing fabric is a woven fabric, a knitted fabric, a nonwoven fabric or a mixture thereof.

[0068] The backing fabric can, for example, be a fabric with large, flow-effective pore openings of ≥ 100 x 100 µm, preferably of ≥ 200 x 200 µm, particularly preferably of ≥ 400 x 400 µm, even more preferably of ≥ 800 x 800 µm, very preferably of ≥ 1,000 x 1,000 µm and most preferably of ≥ 1,200 x 1,200 µm.

[0069] A further embodiment of the invention is that identical and different pile tufts are connected to the backing fabric to form a line pattern or a checkerboard pattern.

[0070] 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.

[0071] A further embodiment of the invention is that the pile tufts are connected to the backing fabric with a W-tuft, a double W-tuft or a V-tuft.

[0072] In principle, the fibers can consist of inorganic or organic natural materials, 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, Aluminum, 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.

[0073] A further embodiment of the invention is that the fibers have a lipophilic and / or hydrophobic surface.

[0074] Finally, the use of a pile fabric according to the invention for pile fabric filtration is also according to the invention.

[0075] In the following, embodiments of the invention are explained in more detail with reference to drawings.

[0076] It shows Fig. 1a to 1c a side view of different fiber arrangements, Fig. 2a to 2g a side view of differently structured fibers, Fig. 3 a bar chart of air permeability depending on the structure of the fibers, Fig. 4 a dot diagram of the maximum fluidization as a function of the vacuum in the suction beam and the slot speed in the suction beam for different fiber structures, Fig. 5a to 5c several cross-sections of different cross-sectional shapes of the fibers, Fig. 6 a bar chart of air permeability as a function of the equivalent diameter of the fibers, Fig. 7a to 7c a side view of different weavings of the pile tufts, Fig. 8a to 8f show a cross-section of different pile tufts in the pile fibre layer, Fig. 9a to 9c a top view of several different back fabrics, Fig. 10a to 10d a schematic plan view of the distribution of different pile tufts in the back fabric, Fig. 11 a schematic representation of a pile fabric according to the invention, 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, Fig. 13a and Fig. 13b Measured values ​​of parallel operation of single-fiber pile fabric (EF) and mixed-fiber pile fabric (MF).

[0077] In Fig. Figure 1 a shows a schematic representation of a staple fiber. Fig. 1b shows a monofilament. Fig. Figure 1c shows a multifilament composed of several monofilaments.

[0078] The Fig. 2a to 2d show fibers with varying degrees of bending. Fig. The fibers shown in Figure 2a are smooth and not bent. The Fig. The fibers shown in Figure 2b are slightly bent. Fig. 2c shows strongly bent fibers. The fibers in the Fig. 2d are strongly curved. Fig. 2e shows pleated fibers. The fibers in the Fig. 2f are inter-term pay. Fig. Figure 2g shows the intermingling point. Structuring the fibers can alter the air permeability of the pile fabric.

[0079] Fig. Figure 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 µm x 800 µm), basis weight (860 g / m 2 ) and fiber thickness (7.4 µm; 0.6 dtex), but different fiber texturing.

[0080] Fig. 4 shows two diagrams of the maximum fluidization as a function of the vacuum in the suction beam (left diagram) and the slot speed in the suction beam V Slot(right diagram) for different fiber structures of the pile fabric. The pile fabrics have an identical back structure (> 800 µm x 800 µm), basis weight (860 g / m 2 ) and fiber thickness (7.4 µm; 0.6 dtex), but different fiber texturing during filter cleaning. V Slot (Slot velocity in the suction bar, determined according to Grabbe, U. (1998) Investigations into advanced wastewater treatment using textile filter media - cloth filtration and micro-sieving. 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.

[0081] In the Fig. 5a to 5c show different cross-sectional shapes of the fibers. Fig. Figure 5a shows cross-sectional shapes with rounded corners, such as 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.

[0082] In Fig. Figure 5b shows polygonal cross-sectional shapes, such as a square, a parallelogram, a triangle or a star.

[0083] In Fig. 5c shows fibers with one or more cavities.

[0084] Fig. Figure 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 µm x 800 µm), but different equivalent fiber diameters.

[0085] In Fig. 7a to 7c show different weaves of the pile tufts for connection to the backing fabric. Fig. 7a shows a W-pimple and Fig. 7b a V-pimple. Fig. Figure 7c shows the formation of a pile fiber layer when stroking from left to right. This stroking creates a filter-active layer of pile tufts.

[0086] The Fig. 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 side is shown. As shown in the Fig. 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. Fig. Figure 8g shows a pile tuft with fibers of different cross-sectional shapes.

[0087] In Fig. Figures 9a to 9c show schematic representations of several different back tissues. The back tissue can be a tissue ( Fig. 9a), a knitted fabric ( Fig. 9b) or a nonwoven fabric ( Fig. 9c).

[0088] In Fig. 10b and Fig. Figure 10d shows different distributions of identical pile tufts in the backing fabric. The identical pile tufts have different fibers. The distribution can be compared to a checkerboard pattern ( Fig. 10b) or several rows ( Fig. 10d).

[0089] In Fig. 10a and Fig. Figure 10c shows various distributions of different pile tufts in the backing fabric. The different pile tufts differ in their fibers. The distribution can be compared to a checkerboard pattern ( Fig. 10a) or several rows ( Fig. 10c). The different pile tufts alternate in rows.

[0090] In Fig. 11 shows a pile fabric according to the invention. The pile fabric has a backing fabric. Pile tufts are connected to the backing fabric. 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 schematically shown in the enlargement 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 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.

[0091] The Fig. 12 shows a dot diagram of the slot velocity in the suction beam V Slotas a function of the vacuum in the extraction bar for different pile fabrics. The figures show measured values ​​for different pile fiber layers made of single fibers (EF) and only a 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 µm and 7.4 µm respectively. The pile fiber layer made of mixed fibers (MF) with an equivalent diameter of 8.2 µm consists of 50% of a first fiber type with an equivalent diameter of 10.5 µm (1.2 dtex) and 50% of a second fiber type with an equivalent diameter of 4.9 µm (0.26 dtex).The pile fibre layer made of mixed fibres (MF) with an equivalent diameter of 6.8 µm consists of 25% of a first fibre type with an equivalent diameter of 10.5 µm (1.2 dtex) and 75% of a second fibre type with an equivalent diameter of 4.9 µm (0.26 dtex).

[0092] The Fig. 13a and Fig.Figure 13b shows 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(III) chloride (2.1 mg Fe(III) / L). The following parameters are compared: filter velocity (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.

[0093] 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 consumption and energy requirements for padding material filtration.

[0094] 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 by which the water level in the tank drops from its starting point after cleaning. The greater the decrease in the water level after cleaning, the greater the regeneration potential of the padding material through filter cleaning.

[0095] 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.

[0096] 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. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 199 12 548 A1

[0023] Cited non-patent literature

[0000] Grabbe, U. (1998) Investigations into advanced wastewater treatment using textile filter media - cloth filtration and microsieving. Institute for Urban Water Management and Waste Technology. Hannover, Leibniz University Hannover, Dissertation

[0080] DIN EN ISO 9237

[0084]

Claims

[1] Pile fabric comprising a backing fabric and at least one pile tuft connected to the backing fabric, wherein the at least one pile tuft comprises a plurality of fibres, characterized by that the fibers are different within at least one pile tuft. [2] Pile fabric according to one of the preceding claims, characterized by that the fibers of at least one pile tuft consist of different materials. [3] Pile fabric according to one of the preceding claims, characterized by that the fibers of at least one pile tuft have different cross-sectional shapes. [4] Pile fabric according to one of the preceding claims, characterized by that the fibers of at least one pile tuft have different equivalent diameters. [5] Pile fabric according to one of the preceding claims, characterized by that the fibers of at least one pile tuft have different textures. [6] Pile fabric according to one of the preceding claims, characterized by that the fibres in the pile tufts are in the form of staple fibres and / or yarns and / or twisted yarns. [7] Pile fabric according to one of the preceding claims, characterized by that the fibers of at least one pile tuft have different swirls. [8] Pile fabric according to one of the preceding claims, characterized by that the fibers of at least one pile tuft differ in their chemical and / or biological degradability. [9] Pile fabric according to one of the preceding claims, characterized by 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. [10] Pile fabric according to one of the preceding claims, characterized by that the pile fiber layer has a basis weight between 100 and 10,000 g / m 2 , preferably between 200 and 5,000 g / m2 , particularly preferably between 250 and 1,500 g / m 2 has. [11] Pile fabric according to one of the preceding claims, characterized by 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. [12] Pile fabric according to one of the preceding claims, characterized by that the backing fabric is a woven fabric, a knitted fabric, a nonwoven fabric or a mixture thereof. [13] Pile fabric according to one of the preceding claims, characterized by that identical and different pile tufts are connected to the backing fabric to form a line pattern or a checkerboard pattern. [14] Pile fabric according to one of the preceding claims, characterized bythat the pile tufts are connected to the backing fabric with a W-tuft, a double W-tuft or a V-tuft. [15] Pile fabric according to one of the preceding claims, characterized bythat the fibers consist of inorganic or organic natural materials, plastics, metals or alloys, preferably 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, 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. [16] Pile fabric according to one of the preceding claims, characterized by that the fibers have a lipophilic and / or hydrophobic surface. [17] Use of a pile fabric according to one of the preceding claims for fluid filtration, preferably liquid filtration, particularly preferably pile fabric filtration.

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