Highly transparent textured belt

Abstract

The present invention relates to an industrial fabric for producing textured products, the industrial fabric having a first layer, such as a woven base fabric, and a second layer, such as a film, extending over at least a portion of the top surface of the first layer. The second layer has macrovoids and microvoids. In certain embodiments, the macrovoids provide texture to textile products fabricated on the industrial fabric, and the microvoids limit or prevent penetration of the fibers of the product into the microvoids while increasing the permeability of the industrial fabric.

Description

[Technical field]

[0001] The present invention relates to industrial fabrics such as texturing belts used in the paper industry and in nonwoven processes, such as for textile products, to create three-dimensional structure in products made thereon. [Background technology]

[0002] During the papermaking process, a fibrous web is formed by deposition of a fibrous slurry, for example an aqueous dispersion of cellulose fibers, onto a moving forming fabric in the forming section of a papermaking machine. A large amount of water is expelled from the slurry through the forming fabric, leaving a cellulose fibrous web on the surface of the forming fabric.

[0003] From the forming section, the newly formed cellulose fibrous web advances to a press section that contains a series of press nips. The cellulose fibrous web passes through the press nips supported by a press fabric, or often between two such press fabrics. In the press nips, the cellulose fibrous web is subjected to compressive forces that squeeze water out of the cellulose fibrous web and bond the cellulose fibers in the web to one another so as to make the cellulose fibrous web into a paper sheet. The water is accepted by the press fabric or fabrics and ideally does not return to the paper sheet.

[0004] The paper sheet finally advances to a dryer section which includes at least a series of rotatable dryer drums or cylinders internally heated by steam. The newly formed paper sheet is wound in a serpentine path around each of the series of drums in turn by a dryer fabric which holds the paper sheet tight against the surface of the drum. The heated drums reduce the moisture content of the paper sheet to a desired level by evaporation.

[0005] It should be understood that the forming fabric, press fabric and dryer fabric all take the form of endless loops on the papermaking machine and function in a conveyor fashion. It should also be understood that papermaking is a continuous process that proceeds at a significant rate; that is, the fibrous slurry is continuously deposited on the forming fabric in the forming section, while the newly produced paper sheet is continuously wound onto rolls after it exits the dryer section.

[0006] Woven fabrics come in many different forms. For example, they may be woven endlessly or flat and then seamed into an endless form. Alternatively, they may be produced by a process commonly referred to as modified endless weaving, in which the machine direction (MD) yarns are used to provide seaming loops at the widthwise edges of the backing fabric. In this process, the MD yarns weave back and forth continuously between the widthwise edges of the fabric, weaving back and forth at each edge to form seaming loops. The backing fabric produced in this way is put into an endless form when installed on a papermaking machine, and is therefore called an on-machine seamable fabric. To make such a fabric into an endless form, the two widthwise edges are seamed together. To facilitate seaming, many current fabrics have seaming loops at the lateral edges of the fabric at its two ends. The seaming loops themselves are often formed by the MD yarns of the fabric. The seam is often formed by joining two ends of a press fabric together, interlocking seaming loops at the two ends of the fabric, and passing a so-called pin or pintle through a passage defined by the interlocking seaming loops to lock the two ends of the fabric together.

[0007] Texturing belts in the papermaking field are used to make three-dimensional nonwoven, tissue and towel structures. Typically, these belts are employed in the forming section of the papermaking process, where the increased caliper of the belt can directly impart caliper, bulk and three-dimensional patterning to the manufactured textured product, such as a roll. For this type of texturing belt, there is usually a base weave, for example for dimensional stability and load-bearing properties. Often these belts have a second layer top surface that is added to the base weave specifically to impart caliper, texture, pattern and bulk. This top surface can be of a thermoplastic or thermosetting material and may be applied directly in chemical form or first manufactured as a sheet and then bonded to the surface of the belt base fabric. The bond can be chemical or thermal or a combination thereof.

[0008] However, these belts suffer from several problems, including, for example, loss of permeability that occurs when a significant portion of the base weave of the belt is covered by a second material. Permeability is lost as the second material covers and blocks otherwise open areas of the base weave. A consequence of reduced permeability in the belt is reduced control of the sheet during forming when a vacuum is used to draw fibers into the textured side of the belt and to hold the fibers in place prior to removal.

[0009] One option to address the permeability loss and its associated problems is to slow down the belt speed to avoid turbulence and hold the sheet in place. However, slowing down the speed has the negative effect of increasing production time. Other negative effects of slowing down the belt speed include increasing the cost of the product and reducing the overall production capacity of the machine. A second option that has been implemented in the art is to increase the vacuum level. However, this has the negative effect of resulting in increased loss of fibers, for example, into the belt and through it. Summary of the Invention [Means for solving the problem]

[0010] The present invention relates to an industrial fabric for producing textured products. The industrial fabric includes a first layer and a second layer. The second layer extends over at least a portion of an upper surface of the first layer. The second layer includes a plurality of macrovoids and microvoids. The macrovoids impart texture to a product produced thereon. The microvoids limit fiber penetration of product fibers into the microvoids.

[0011] In certain embodiments, the microvoids make the industrial fabric more permeable.

[0012] In other embodiments, the fibers of the textured product stretch and / or bend into the macrovoids.

[0013] In some embodiments, the fibers of the textured product are selected from the group consisting of spunbond fibers, staple fibers, meltblown fibers, spunlaced fibers, wet laid fibers, thermally bonded fibers, natural fibers, synthetic fibers, and combinations thereof.

[0014] In yet other embodiments, the second layer is a nonwoven layer.

[0015] In certain other embodiments, the second layer comprises a material selected from the group consisting of engineered polymers, thermoplastics, thermoplastic polyurethanes, elastomers, cross-linked plastics, rubbers, polyamides, polyesters, copolyesters, EVA (ethylene-vinyl acetate), and combinations thereof.

[0016] In some embodiments, the first layer is a fabric substrate, hi other embodiments, the first layer is a fabric substrate selected from the group consisting of a woven fabric, a nonwoven fabric, a machine direction yarn arrangement / array, a cross machine direction yarn arrangement / array, a braid, a series of separate rings, a spiral link, an extruded mesh, and a knit construction.

[0017] In other embodiments, at least a portion of the macrovoids and / or microvoids in the second layer are of a shape selected from the group consisting of circular, elliptical, polygonal, and lobed.

[0018] In a particular embodiment, the polygonal shape is selected from the group consisting of a triangle, a rectangle, a square, and a trapezoid.

[0019] In some embodiments, the second layer extends the entire length and / or width of the first layer.

[0020] In another embodiment, the industrial fabric has a permeability of at least 300 CFM.

[0021] In yet another embodiment, the top surface of the first layer is the molding side top surface of the backing.

[0022] In certain embodiments, the second layer is laminated to the first layer.

[0023] In yet other embodiments, the second layer is a film.

[0024] In some embodiments, the first layer and second layer are laminated together using heat and pressure.

[0025] In yet other embodiments, the macro- and micro-voids are laser-formed and / or drilled voids.

[0026] In certain embodiments, the second layer is a film, and the film comprises a compound selected from the group consisting of engineered polymers, thermoplastics, thermoplastic polyurethanes, elastomers, crosslinked plastics, rubbers, polyamides, polyesters, copolyesters, EVA, and combinations thereof.

[0027] In other embodiments, the macrovoids are the topographical features of the second layer and are complementary to the desired texture in the textured product.

[0028] In some other embodiments, the macrovoids have diameters ranging from 6 mm to 12 mm. In still other embodiments, the microvoids have diameters ranging from 1 mm to 5 mm. In certain embodiments, the macrovoids have diameters ranging from 50 mm to 12 mm. 3 From 90mm 3 In another embodiment, the microvoids have a void volume in the range of 20 mm 3 From 50mm 3 The void volume ranges from 0.01 to 0.05.

[0029] In certain embodiments, the industrial fabric has a closed area of ​​about 5% to about 95%.

[0030] In another embodiment, the industrial fabric has an effective closed area of ​​about 5% to about 95%.

[0031] In some embodiments, the microvoids prevent substantial fiber penetration of the textured product into the microvoids.

[0032] In yet other particular embodiments, the textured product fibers are crosslinked into microvoids.

[0033] In certain embodiments, the first layer of the industrial fabric is selected from woven and nonwoven fabrics.

[0034] In other embodiments, the first layer of the industrial fabric comprises the machine side.

[0035] In some embodiments, the industrial fabric is a papermaking fabric. In certain embodiments, the industrial fabric is a texturing belt or a processing belt.

[0036] The invention further relates to a method for producing a textured product. The method includes texturing the product with an industrial fabric, the industrial fabric including a first layer, such as a base fabric, and a second layer, such as a film, extending over at least a portion of the top surface of the first layer. The second layer includes a plurality of macrovoids and microvoids. The macrovoids provide texture to the product fabricated thereon. The microvoids limit penetration of product fibers into the microvoids. [Brief description of the drawings]

[0037] [Figure 1] 1(A) and 1(B) are top views of a texturing film for use as a second layer over a first layer, such as a backing, according to the present invention. The second layer is a perforated film for use over a backing surface. The film has macrovoids and microvoids. FIG. 1(C) is a top view of a conventional texturing film for use as a second layer over a first layer, such as a backing. The second layer is a perforated film for use over a backing surface. The film has only macrovoids. FIG. 1(D) is a top view of another conventional texturing film for use as a second layer over a first layer, such as a backing. The film has only macrovoids. [Diagram 2] FIG. 2 is an enlarged view of the film of FIG. 1(B). [Diagram 3] Figure 3(A) is a top view of a woven base fabric for use as a first layer. Figure 3(B) is a close-up of the woven base fabric of Figure 3(A). Figure 3 is used herein to refer to both Figure 3(A) and Figure 3(B). [Figure 4] Figure 2 shows the film laminated onto the fabric of Figure 3. Figure 4 shows the fabric yarns in the MD direction with a width of 0.30 mm and the fabric yarns in the cross machine direction (CD) with a width of 0.33 mm. [Diagram 5]5 shows the film of FIG. 2 laminated onto the backing of FIG. 3 with a microvoid ring pattern. The first microvoid has a diameter of 1.26 mm, the second microvoid has a diameter of 1.45 mm, the third microvoid has a diameter of 1.23 mm, and the fourth microvoid has a diameter of 1.41 mm. FIG. 5 shows the cross-sectional diameter of the microvoid ring pattern as 4.73 mm. [Figure 6] 2 is a view of the film of FIG. 2 laminated onto the backing of FIG. 3, with a measurement between the first and second macrovoids in the cross-machine direction of 7.48 mm. In the machine direction, there is a distance of 6.99 mm between the first and second macrovoids. When measured from the inner center of the first macrovoid to the inner center of the second macrovoid, the measurement is 14.81 mm. [Figure 7] FIG. 2 shows the film of FIG. 2 laminated onto the backing of FIG. 3 with microvoids surrounding a single macrovoid in the laminate film of FIG. 2. The nominal diameter of the microvoid in FIG. 2 is 1.40 mm. The diameter of the macrovoid is 8.00 mm. [Figure 8] 4 is a cross-sectional view of a belt of the present invention in which the film of FIG. 2 is laminated onto the backing of FIG. 3. [Figure 9] FIG. 9 is an enlarged cross-sectional view of the belt of FIG. 8. [Figure 10] FIG. 9 is an enlarged cross-sectional view of the belt of FIG. 8. [Figure 11] FIG. 9 is an enlarged cross-sectional view of the belt of FIG. 8 with measurements of the woven base fabric having a thickness of 0.85 mm and the laminate film having a thickness of 2.93 mm. [Figure 12] FIG. 1 illustrates nonwoven product fibers interacting with a belt of the present invention. [Figure 13] FIG. 1 illustrates nonwoven product fibers interacting with a belt of the present invention. [Figure 14] 1 is a cross-sectional view of nonwoven product fibers interacting with a belt of the present invention; [Figure 15] 1 is a cross-sectional view of nonwoven product fibers interacting with a belt of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] The terms "comprising" and "comprises" in this disclosure may mean "including" and "includes" or may have the meaning commonly given to the terms "comprising" or "comprises" in U.S. Patent Law. When used in the Claims, the terms "consisting essentially of" or "consists essentially of" have the meaning ascribed to these terms in U.S. Patent Law. Other aspects of the invention are described or become apparent in the following disclosure (and within the scope of the invention).

[0039] The term "yarn" or plural "yarns" in the following disclosure may refer to monofilament, multifilament, twisted, textured, covered, composite, and stretch-broken fibers of any material known to those skilled in the art. The yarns may be made of carbon, nylon, rayon, fiberglass, cotton, ceramic, aramid, polyester, metal, polyethylene glass, polyamide, polypropylene, and / or other materials that exhibit desired physical, thermal, chemical, or other properties. Further examples of suitable compounds include, for example, polycyclohexylene dimethylene terephthalate (PCT), cyclohexane dimethanol terephthalate (PCTA), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyether ketone ketone (PEKK), and polyethylene naphthalate (PEN). In general, any yarn of the first layer of the industrial fabric of the present invention may be made of any commercially available material that is compatible or can be made compatible to be bonded to the second (e.g., top) layer, which is a nonwoven fabric.

[0040] The terms "void" or the plural "voids" have their conventional and ordinary meaning. Thus, these terms may refer, for example, to a cavity or void within an otherwise solid or semi-solid material, or to a hole or gap through which a material, such as air or water, can pass. These terms may also be understood as descriptive terms, such as, but not limited to, holes or cavities.

[0041] "Macrovoids" in the following disclosure means voids in the sheet-contacting or molding side surface of a layer of material that are large enough to allow partial or complete fiber penetration into at least a portion of the void and are larger than "microvoids."

[0042] "Microvoids" in the following disclosure means voids in the sheet-contacting or molding side of a layer of material that limit fiber penetration into the void. "Microvoids" are smaller than "macrovoids." Microvoids typically prevent complete, significant, or substantial penetration or penetration of fibers into the void area of ​​the microvoid. In some embodiments, the microvoids may result in partial fiber penetration or penetration into the void area of ​​the microvoid.

[0043] "Lamination," "laminating," "laminate," or "laminated" are used interchangeably in the following disclosure and have their conventional and ordinary meanings. Thus, these terms may refer to the firm attachment of two or more layers, e.g., to one another, using, e.g., resins and / or heat. The materials bonded together can be the same or different materials. Lamination can be accomplished, for example, by layering a preformed layer on top of a second layer, or by applying a sticky material on top of the second layer and allowing the sticky layer to cure to a solid or semi-solid state.

[0044] A "Closed Area" or "CA" as used in the following disclosure is a portion or part of the second layer of the industrial fabric of the present invention, e.g., a film, that is free of any macrovoids or microvoids. For example, in a second layer that is a film, a "Closed Area" would be a solid area of ​​the film.

[0045] As used in the following disclosure, "effective closed area" or "ECA" is a portion or part of the second layer of the industrial fabric of the present invention, e.g., a film, that does not contain macrovoids. Thus, "effective closed area" refers to a portion or part that contains closed areas and microvoids. For example, in a second layer that is a film, the "effective closed area" would be the solid areas of the film plus the microvoids. The phrase "effective closed area" is used because microvoids can add bulk to a textile product and improve sheet formation, but do not necessarily form a consistent, defined pattern in the finished textile product.

[0046] As used in the following disclosure, the terms "machine direction" (MD) and "cross-machine direction" (CD) are used according to their well-understood meanings in the art, i.e., the MD of an industrial fabric, such as a belt, refers to the direction in which the industrial fabric moves, e.g., in a tissue / towel or nonwoven manufacturing process, while CD refers to the direction perpendicular to the MD of the industrial fabric.

[0047] As used in the following disclosure, the term "breathability" is used in accordance with its meaning as is well understood in the art. For example, the American Society for Testing and Materials ("ASTM") defines the term "breathability" as the rate of airflow that passes vertically through a known area under a given air pressure difference between two sides of the material. This is generally defined as the rate at which a water pressure drop across 0.5 inches of fabric is measured in ft 3 / min / ft 2It is expressed in units of air per minute (m2) or abbreviated as CFM ("cubic feet per minute").

[0048] The present invention solves the above-mentioned problems associated with permeability loss, particularly in textured belts having a layer of material covering at least a portion of the belt's base fabric. Specifically, the present invention provides an industrial fabric, such as a belt, having a second layer, such as a film, attached to a first layer, such as a woven fabric, where the second layer has voids of different sizes, i.e., "macro" and "micro" voids. The "macro" voids provide the desired texture, pattern and bulk to the textured product produced on the industrial fabric. The "micro" voids are typically small enough to prevent and avoid substantial fiber penetration into the microvoids while substantially maintaining a solid, closed area of ​​the second layer (e.g., film) over the first layer (e.g., woven base fabric). In other words, the macrovoids provide texture to the textile product produced on the industrial fabric, and the microvoids maximize the flow of fluids (e.g., air and / or water) through the industrial fabric while limiting fiber loss (waste) of the textured product during the manufacturing process. Fiber loss is understood to be fibers that are pulled completely through the laminate belt structure and do not become part of the final product, e.g., waste.

[0049] Typically, microvoids limit the amount of texturing in the textile fabricated thereon. For example, in some embodiments, the microvoids do not impart any pattern in the textile. In other embodiments, the microvoids can impart a background pattern to the textile, but do not substantially interfere with the pattern imparted by the macrovoids in the textile.

[0050] Thus, the combination of "macro" and "micro" voids allows and maintains permeability in industrial fabrics (e.g., belts) without sacrificing the caliper, texture, pattern and bulk of the textured textile product. The belts of the present invention do not have the adverse effect of increasing production time that occurs when belt speeds are reduced. The belts of the present invention allow texture to be imparted while retaining permeability that allows the production of products, e.g., webs, to be carried out at the same processing speeds that were possible prior to the use of the texturing belt. The belts of the present invention also better maintain sheet holddown and sheet quality, e.g., by increasing airflow or breathability. The belts of the present invention have the advantage that areas of the belt closed to no fiber penetration nevertheless allow the penetration of air (or water) through the microvoids.

[0051] The industrial fabric of the present invention is a fabric having both a sheet-contacting or forming side and a machine side. The forming side is the side that would be recognized in the art as the top side of an industrial fabric, such as a belt, that contacts a sheet or web of fibers during the manufacturing process, while the machine side is to be understood as the bottom side of an industrial fabric, such as a belt, that does not contact a sheet or web of fibers during the manufacturing process.

[0052] The industrial fabric of the present invention comprises at least a first layer and a second layer. The second layer comprises a sheet contact side or forming side, i.e., a surface that contacts a fiber-based product to be fabricated thereon. The first layer may also comprise a sheet contact side or forming side, i.e., a surface that contacts a fiber-based product to be fabricated thereon. In some embodiments, the first layer further comprises a machine side surface. In other embodiments, the industrial fabric comprises more than two layers, e.g., three or more layers. In certain embodiments, a padding layer may further be attached to the forming or machine side of the first layer. The padding layer may comprise, for example, a fine nonwoven fibrous material.

[0053] The present invention relates to industrial fabrics, such as belts, for making textured products, such as textured nonwoven products. In certain embodiments, the textured nonwoven products are made of natural or synthetic fibers or some combination thereof.

[0054] In a particular embodiment, the invention relates to an industrial fabric, such as a belt, having a backing with a forming side and a machine side. The backing further has a layer of material extending over at least a portion of the forming side. The backing constitutes a first layer of the belt, and the layer of material extending over at least a portion of the forming side of the backing constitutes a second layer of the belt, which may be a laminated layer. This second layer has both macrovoids and microvoids. The macrovoids are topographical features of the second layer that are complementary to the desired texture of, for example, a fiber-based product to be fabricated thereon. The microvoids may, for example, prevent the penetration of fibers into and through the first layer, which is the backing. The microvoids may be small enough to prevent the product fibers from passing through the second layer to the first layer for fiber types, such as nonwoven fibers, paper fibers, glass fibers, synthetic fibers, non-synthetic fibers, and / or metal fibers.

[0055] The present invention is advantageous at least because it is a solution to the loss of permeability in textured belts where the top surface layer (e.g., the top molding or sheet contacting surface of the belt) has only macrovoids. For example, the present invention, among other advantages, allows for the retention of permeability in the textured belt while providing texture to products produced on the belt and allowing web manufacturers to operate at the same process speeds as were possible prior to the use of textured belts in the prior art.

[0056] For example, in spunbond nonwoven manufacturing, air suction drives the fibers into the macrovoids of the fabric, thus affecting the fiber structure of the product. Those skilled in the art will understand that in spunbond nonwovens, fibers are continuously spun per manufacturing order or merge (switching from making one nonwoven product to making a different nonwoven product). For example, in the processing of spunbond nonwovens, spunbond fibers are quenched in cooling air in a quench chamber, and then (or simultaneously) exit the quench chamber and are stretched while resting in web form on a texturing belt (sometimes referred to by those skilled in the art as a spin belt). While dispersion of macrovoids can increase fiber density in the voids, typically fiber density is not affected by the vacuum air suction speed. In certain embodiments, the vacuum simply removes the incoming drawing air supply. That is, those skilled in the art will understand that the main function of the vacuum in this embodiment is to remove the incoming air. The amount of air exiting the vacuum after the stretch is typically designed to be equal (ideally), and the holes in the belt can control the local speed, thereby creating density differences in the sheet. Large diameter voids in the fabric can create very localized flows that deposit more fibers during vacuum suction. Where there are no voids, the fiber density is lowest. Smaller voids deposit less fibers, but the breathability in these areas can create smaller density gradients between the microvoids, thereby improving the overall tensile strength in the machine direction (MD) and cross machine direction (CD) of the produced sheet, for example. Thus, the overall permeability typically required to remove all of the stretch air and at the same time maintain the textile sheet on the surface of the fabric with acceptable tensile properties is in the permeability range of 400-700 CFM. Too low a permeability can cause flooding in the stretch area that disrupts the sheet, requiring faster suction speeds that make the textile structure more compact / less defined and weaker due to density gradients during production and subsequent post-processing. Higher initial permeability allows for lower suction values ​​resulting in increased loft in the final textile structure.

[0057] Thus, it is generally accepted that the permeability requirements for industrial fabrics, such as belts that handle textile products through production, are typically around 400-700 CFM.

[0058] In certain embodiments, the present invention relates to industrial fabrics, such as belts, for forming three-dimensional structures in paper, tissue, towels, and / or nonwoven processing. In some embodiments, a laser or other mechanism is used to form voids of different sizes and / or diameters in a second layer, such as a film, that extends partially or entirely over a first layer, which is a backing fabric. In certain embodiments, the voids formed are macrovoids and microvoids.

[0059] The macrovoids in a second layer (e.g., a film) on a first layer (e.g., a substrate) can provide a desired texture, pattern, and / or bulk to the textile product, while the microvoids are distributed in the second layer to avoid fiber penetration and to substantially maintain a solid closed area of ​​the second layer on the first layer while enhancing permeability. As an example, in spunbond nonwoven fabric production, the macrovoids are large enough in diameter so that when spunbond fibers are laid on the belt of the present invention, the fibers bend and stretch within the macrovoids, for example with the aid of air suction of a vacuum. In some embodiments, the fibers bend and stretch within the macrovoids so that they collectively take or have the shape of the macrovoids. The fibers are drawn into the macrovoids by the air suction. In contrast, when spunbond fibers are laid on a portion of the belt having microvoids, the void diameter is such that the fibers "bridge" the gap and are not drawn into the microvoids, for example by the vacuum. As a further example, another production of nonwoven fabrics may include the use of staple fibers. One skilled in the art will appreciate that these short fibers may also have long lengths which will cause them to bend or stretch with the aid of air suction, and may take on the shape of or fill the macrovoids, as well as the short fibers bridging the interstices of the microvoids.

[0060] The exact size, including diameter, of the macrovoids and microvoids can vary and can be related to the fiber diameter and fiber length used to form the fiber-based product on the industrial fabric. The diameter of the macrovoids and microvoids can also vary from the top of the void to the bottom of the void, for example having a cone shape. Typically, the macrovoids can provide texture, for example by allowing fiber penetration into the macrovoids, while the microvoids allow no fiber penetration or limited / minimal fiber penetration, enhancing the permeability of the industrial fabric despite such penetration and providing little or no texture to the textile product fabricated thereon.

[0061] The depth of macrovoids and microvoids can vary and relate to the depth of a second layer (e.g., a film) above a first layer (e.g., a substrate) in an industrial fabric. Macrovoids and microvoids typically penetrate through the entire layer of a second layer, e.g., a film, exposing the first layer, e.g., a woven fabric, underneath the film, e.g., as seen when viewed from the top surface of the industrial fabric.

[0062] The pattern of macrovoids and microvoids can be any desired pattern. The pattern can include any combination of shapes. Shapes include, but are not limited to, circles, lines, dots, waves, slits, drawings, logos, trademarks, or any random or regular pattern desired. In certain embodiments, the macrovoids and / or microvoids can have a grid pattern or arrangement. In other embodiments, the macrovoids and / or microvoids can have no pattern and can be completely randomly located or arranged in the second layer of the industrial fabric.

[0063] Macrovoids may vary in diameter, area and / or void volume and do not have to have the same value throughout a single industrial fabric, such as a belt. Similarly, microvoids may vary in diameter, area and / or void volume and do not have to have the same value throughout a single industrial fabric, such as a belt. For example, in a single belt, one macrovoid may have a diameter of 8 mm while another macrovoid may have a diameter of 9 mm. Similarly, in this same belt, one microvoid may have a diameter of 2 mm while another microvoid may have a diameter of 3 mm. Additionally, variations in individual microvoid diameter measurements may be the result of, for example, manufacturing techniques.

[0064] In certain embodiments, the microvoided structure does not interfere with or alter the textural characteristics imparted to the product by the macrovoids. In yet other embodiments, the microvoided structure is large enough to allow fluid (e.g., air and / or water) to flow from the second layer to the first layer in industrial fabrics. In still other embodiments, the microvoided structure is small enough to prevent fibers from passing from the second layer to the first layer, depending on the type of fiber, e.g., nonwoven, paper, or glass. In certain embodiments, the microvoided structure imparts bulk to the textile product fabricated thereon.

[0065] The first layer in the industrial fabric may be a woven or nonwoven fabric. In the embodiment in which the first layer is a woven fabric, the woven fabric may be woven in various weave patterns, such as complex or simple, single layer or multilayer, for example, plain weave or satin weave. The woven fabric may be woven with monofilament yarn, monofilament twisted yarn, multifilament yarn or multifilament twisted yarn, and may be single layer, multilayer or laminate. The yarn for the woven fabric may be extruded from any one of several synthetic polymer resins, such as polyamide and polyester resins, used for this purpose by practitioners in the mechanical clothing technology field.

[0066] In other embodiments, the first layer in the industrial fabric is a permeable nonwoven. In certain embodiments, the nonwoven is selected from an extruded mesh, a knit structure, a MD and / or CD yarn arrangement, a braid, a series of separate rings, or other nonwoven products such as foil, film or spunbond, worsted, airlaid, meltblown or wetlaid.

[0067] In certain embodiments of the invention, a first layer of industrial fabric, such as a woven base, has a second layer, which may be a sheet or molded side layer of material, attached to it in some embodiments using adhesives, threads, screws, resins or other physical, chemical or thermal bonding techniques or combinations thereof.

[0068] In certain embodiments, the second layer of the industrial fabric is a polymer layer attached to the first layer. For example, the second layer can be attached or bonded, for example, as a polymer layer, to the molded side of the first layer (for example, the molded side of the base fabric) by chemical or mechanical means. The second layer can also be attached to the molded side of the first layer as a laminated film-like sheet or laminated film layer. Examples of materials that can be used for the second layer of material attached to the molded side of the first layer include thermoplastic materials. These thermoplastic materials can be laminated to the entire first layer (for example, the base fabric) or to selected portions or areas of the first layer. For example, if desired, a laminated film layer can be attached to only half of the molded side of the first layer, which is the base fabric. In some embodiments, the second layer is laminated to the first layer using heat and / or pressure.

[0069] In other embodiments, the second layer of industrial fabric is first formed as a film-like sheet or layer before being laminated to the first layer of industrial fabric.

[0070] In certain embodiments, the second layer of the industrial fabric is a film and is attached to the first layer, such as a backing, using adhesives, threads, screws, resins, or other physical, chemical, or thermal bonding techniques, or a combination thereof. In certain embodiments, the film can partially or completely penetrate into the backing. In certain embodiments, the film forms a substantially flat surface on the forming (front) side of the industrial belt in areas of the film that are free of any macrovoids or microvoids.

[0071] Any suitable material can be used to form the second layer of the industrial fabric, such as a film, on the first layer, such as a backing. Examples of suitable materials the second layer can comprise include, for example, PET (polyethylene terephthalate), EVA (ethylene-vinyl acetate), PE (polyethylene), polypropylene (PP), or PU (polyurethane), polyamides, polyesters, copolyesters, thermoplastics, thermoplastic polyurethanes, elastomers, cross-linked plastics, rubbers, and other engineered polymers.

[0072] In certain embodiments, the macrovoids and microvoids in the second layer of the industrial fabric form a circular shape. However, the macrovoids and microvoids can be any shape and / or size or mixture. For example, the macrovoids and / or microvoids can be circular, square, needle-like, rectangular, oval, MD or CD oriented icon, slit, non-polygonal, triangular, elliptical, polygonal, trapezoidal, and / or leaf-like. Furthermore, the shape of the macrovoids and / or microvoids can be different through the second layer from the top surface region of the second layer to the bottom surface region of the second layer. For example, the voids can have a circular shape in the top surface region of the second layer, but change or partially change shape through the second layer to be oval in the bottom surface region of the second layer.

[0073] Also, the macrovoids and microvoids can be of various sizes and / or shapes in the second layer of the industrial fabric, for example, the laminate film layer. That is, some macrovoids and / or microvoids in the laminate film layer may have a circular shape, other voids in the layer may have a triangular shape, and still other voids may have a leaf-like shape. Also, the macrovoids and / or microvoids may all have the same shape, for example, a circular shape, but may have different sizes, for example, one or more circular macrovoids may have a diameter of 4 mm, one or more circular macrovoids may have a diameter of 8 mm, and one or more circular macrovoids may have a diameter of 12 mm. In other embodiments, if 11 mm fibers are used to fabricate the product thereon, the second layer may have, for example, 12 mm macrovoids and 9 mm microvoids.

[0074] The present invention encompasses an industrial fabric for the manufacture of textured textile products, comprising at least a first layer and a second layer, the second layer being a top surface of the industrial fabric and comprising at least two different sized voids, the microvoids (i) having smaller open areas than the macrovoids, (ii) not altering the textural characteristics imparted to the product by the macrovoids, (iii) being large enough to allow fluid (e.g., air and / or water) to flow from the second layer to the first layer, and / or (iv) being small enough to prevent the penetration of product fibers through the second layer to the first layer, for fiber types such as nonwoven fibers, paper fibers, glass fibers, synthetic fibers, non-synthetic fibers and / or metal fibers.

[0075] In some embodiments, the nonwoven second layer of the industrial fabric is impermeable to air and / or water, except for macrovoids and microvoids. In some embodiments, the nonwoven second layer penetrates or blends into at least a portion of the first layer, which may be the substrate of the industrial fabric. In other embodiments, the nonwoven second layer does not penetrate or blend into any portion of the first layer.

[0076] In certain embodiments, the shape of the macrovoids and / or microvoids is variable and depends on final product design considerations (e.g., the desired pattern of a paper towel product produced on the industrial fabric of the present invention) and / or the fiber diameter and / or fiber length used in various molding processes for the manufacture of fiber-based products. As an example, the size and / or distribution of the macrovoids can be selected based on the specific design preferences of the textile product, such as the specific texture of a toilet paper or wipes, while the microvoids are distributed to enhance airflow through the belt when the product is formed on the belt of the present invention. Those skilled in the art will appreciate that the microvoids relate to the overall macrovoid structure such that the properties of the microvoids, such as size and / or distribution, can be determined to produce comparable airflow in a closed area of ​​the industrial fabric of the present invention. As a further example, in the belt of the present invention, the macrovoids will be large enough to allow fibers to penetrate, while at the same time, the microvoids in the belt will be large enough to prevent fiber penetration. In one example, a fiber-based nonwoven product may be made of fibers having a length of 4 mm. The macrovoids may be 8 mm in diameter while the microvoids may be 3 mm in diameter, thus allowing fiber penetration into the macrovoids while preventing fiber penetration into the microvoids. The placement of the microvoids and macrovoids in the second layer of the belt may be random or patterned or some combination thereof.

[0077] The macro- and microvoids in the second layer of the industrial fabric of the present invention can be formed or created by any suitable means, such as the use of lasers, drilling, or other chemical or mechanical means, such as mechanical drilling, embossing, molding, or any other suitable means that can create holes in the material that comprises the second layer. The use of lasers, drilling, or other chemical or mechanical means to create macro- and microvoids can be done at different stages of the production of the industrial fabric. For example, a second layer that is a film may be produced, and then a laser may be used to create holes in the film. After the film is perforated, the film may then be laminated to the first layer, such as a woven base fabric. Or, a film may be produced and then laminated to the base fabric. After lamination, the film may be perforated using a laser or other means.

[0078] The perforations in the second layer of the industrial fabric of the present invention may allow for air permeability, for example. For example, vacuum suction may be used during the formation of the textured product production area where the fibrous wet pulp forms a web on the belt of the present invention. In these embodiments, the perforations in the second layer may allow air from the vacuum to pass through at least some of the microvoids, thus increasing the overall belt permeability and web or sheet hold down.

[0079] For a better understanding of the present invention and its advantages and objectives obtained by its use, reference is made to the accompanying descriptive material in which non-limiting embodiments of the invention are illustrated in the accompanying drawings and in which corresponding components are identified by the same reference numerals. Those skilled in the art will appreciate that the design and permeability of industrial fabrics is important, as provisions must be made to allow for air removal while providing support, control and texture to the fiber-based products fabricated thereon.

[0080] As described in more detail below, FIGS. 1A-1D show an example and comparison of one embodiment of the present invention (FIGS. 1A and 1B) and a prior art example (FIGS. 1C and 1D).

[0081] FIG. 1A shows a top view of a film (101) for use as a second layer in an industrial fabric (e.g., a belt) for making textured products according to the present invention. In this figure, a thermoplastic film (101) is formed by extrusion. After the film (101) is fabricated, a laser is used to perforate macrovoids (102) and microvoids (103, 104) in the film (101). The laser perforates both circular macrovoids (102) and circular microvoids (103, 104) in the film (101). The laser perforates the film (101) in a specialized pattern. For example, 8 mm diameter macrovoids (102) are formed with rings of 1 mm diameter microvoids (103) surrounding each macrovoid. A square pattern of four 2 mm diameter microvoids (104) is located between four adjacent rings of 1 mm diameter microvoids (103).

[0082] The apertured film (example second layer) (101) is laminated to a woven base fabric (example first layer). The film of FIG. 1A (i.e., film only) has a CFM of 1170. The base fabric to which the film (101) of FIG. 1A is laminated (i.e., base only) has a CFM of 916. The apertured film of FIG. 1A has an ECA (closed areas of the film plus microvoids) of about 60.7% and a CA (solid areas of the film only) of about 38.6%. The finished belt, i.e., film and woven base fabric, has a CFM of 643. The air permeability CFM values ​​were measured using a TexTest Model FX3360 PortAir Portable Air

[0083] Determined by Permeability and Thickness Tester.

[0084] FIG. 1B shows a top view of a film (105) for use as a second layer in an industrial fabric (e.g., a belt) for making textured products according to the present invention. In this embodiment, a laser perforates the film (an exemplary second layer) with both circular macrovoids (106) and circular microvoids (107, 108). The laser perforates the film (105) in a specialized pattern. For example, 8 mm diameter macrovoids (106) are formed with rings of 1 mm microvoids (107) completely surrounding each macrovoid. Between four adjacent rings of 1 mm microvoids, a ring pattern of eight 1 mm microvoids (108) is perforated with one single 1 mm microvoid (116) in the center of the ring pattern of eight 1 mm microvoids (108). This perforated film has about 60.7% ECA and about 42.9% CA. The perforated film of Figure IB (i.e., film only) has a CFM of 948. The backing to which the film is laminated (example first layer) (i.e., backing only) has a CFM of 916. The finished belt, i.e., film and backing, has a CFM of 538.

[0085] FIG. 1C shows a top view of a microvoid-free film (109) for use in manufacturing textured products. A laser has perforated the film (109) with circular macrovoids (110). The laser has perforated the film in a specialized pattern. For example, macrovoids with a diameter of 8 mm are formed. The film in FIG. 1C has a CA of about 60.7%. The finished belt, i.e., film and backing, has a CFM of 343.

[0086] FIG. ID shows a top view of a microvoid-free film (111) for use in manufacturing textured products. A laser has perforated the film (111) with circular macrovoids (112). The laser has perforated the film in a specialized pattern. For example, macrovoids with a diameter of 5 mm are formed. The film in FIG. ID has a CA of about 60.7%. The finished belt, i.e., film and backing, has a CFM of 313.

[0087] Figures 1A and 1B show film designs for use in textured belts made according to the present invention as comparative examples to Figures 1C and 1D. That is, belts made using films according to Figures 1A and 1B were compared to conventionally made belts made using films represented by Figures 1C and 1D, respectively. The comparative CFM values ​​show that the effect of adding microvoids in addition to macrovoids in the film according to the present invention improved the permeability by about 300 CFM (Figure 1A) and about 200 CFM (Figure 1B) compared to the conventional belt represented by the values ​​for the film and finished belt in Figure 1C. Figure 1D further shows a comparative example in which the CFM values ​​show that the effect of adding microvoids in addition to macrovoids in the film according to the present invention improved the permeability by about 300 CFM (Figure 1A) and about 200 CFM (Figure 1B) compared to the conventional belt represented by the values ​​for the film and finished belt in Figure 1D.

[0088] FIG. 2 shows an enlarged view of the film of FIG. 1B.

[0089] A woven base fabric (113) (Albany International Corp. Prolux N005 fabric) is shown in Figures 3A and 3B. Figure 3B shows an enlarged portion of the base fabric (113) of Figure 3A. The base fabric has a target CFM of 875. The target CFM can be based on a desired target CFM taking into account factors such as the particular design, yarn diameter, weave pattern, and / or heat treatment conditions. The target CFM can also be based on previous manufacturing and measurement knowledge.

[0090] 4-12 show different measurements of the apertured film of FIG. 2 (an exemplary second layer) when laminated to the backing of FIG. 3 (an exemplary first layer).

[0091] More specifically, Figure 4 is a top view showing the yarns of the backing fabric running in the MD and CD directions and having a nominal diameter of 0.30 mm. For example, the yarns of the backing fabric running in the MD direction (114) are shown to have a diameter of 0.30 mm. Figure 4 shows the yarns of the backing fabric running in the CD direction (115) having a diameter of 0.33 mm. The backing fabric (Figure 3) is visible in this top view through the macrovoids in the laminate film of Figure 2.

[0092] Figure 5 is a top view showing measurements of eight microvoids (108) forming a ring in the laminate film of Figure 2. There is a single microvoid (116) inside the ring. This microvoid pattern (of a ring of microvoids with the microvoid inside the ring) is located between four macrovoids. The first microvoid has a diameter of 1.26 mm. The second microvoid has a diameter of 1.45 mm. The third microvoid has a diameter of 1.23 mm. The fourth microvoid has a diameter of 1.41 mm. The diameter of this microvoid ring pattern is 4.73 mm. The backing fabric of Figure 3 is visible through the macrovoids in this view.

[0093] Figure 6 is a top view showing the measured spacing between the macrovoids in the laminate film of Figure 2. Here, in the cross machine direction, the distance between the first macrovoid (117) and the second macrovoid (118) is 7.48 mm. In the machine direction, the distance between the first macrovoid (119) and the second macrovoid (120) is 6.99 mm. When measured from the inner center of the first macrovoid (121) to the inner center of the second macrovoid (122), the measurement is 14.81 mm. The backing (113) of Figure 3 is visible through the macrovoids in this view.

[0094] FIG. 7 is a top view showing measurements of the microvoids surrounding a single macrovoid in the laminate film of FIG. 2. This figure also shows the diameter of the macrovoid (106) surrounded by the microvoids. Note that the backing (113) of FIG. 3 can be seen through the macrovoids in this view. Here, the first microvoid (123) is 1.43 mm in diameter. The second microvoid (124) is 1.44 mm in diameter. The third microvoid (125) is 1.34 mm in diameter. The fourth microvoid (126) is 1.36 mm in diameter. The fifth microvoid (127) is 1.32 mm in diameter. The sixth microvoid (128) is 1.51 mm in diameter. In this embodiment, the target or nominal microvoid diameter is 1.40 mm. The diameter of the macrovoid (106) inside the ring of eight surrounding microvoids is 8.00 mm.

[0095] Figure 8 shows a cross-sectional view of the film (105) of Figure 2 having macrovoids (106) and microvoids (108) laminated onto the woven base fabric (113) of Figure 3. Figures 9 and 10 show enlarged portions of the fabric of Figure 8. Figure 10 is an enlarged portion of the closed area (CA) of the fabric of Figure 8.

[0096] Figure 11 shows a cross-section of the closed area (CA) (129) of the fabric of Figure 8. Figure 11 shows the base fabric (113) as having a thickness of 0.85 mm. Figure 11 shows the laminate film (105) as having a thickness of 2.93 mm. There are no macro- or micro-voids in the second layer (film) in the belt portion shown in Figure 11.

[0097] 12 and 13 show a top view of nonwoven product fibers (130) interacting with a belt having the film (105) of FIG. 2 laminated to the backing (113) of FIG.

[0098] 14 and 15 show cross-sectional views of nonwoven product fibers (130) interacting with a belt having a film (105) of FIG. 2 laminated to a backing (113) of FIG. 3. Here, the fibers of the nonwoven product fabricated on the belt are seen to be drawn into and infiltrating the macrovoids (106) of the laminate film layer, but bridging the microvoids (108) of the laminate film. Here, the fibers bridge the microvoids by extending across the voids from one side of the microvoid to the other side of the microvoid. In some cases, the fibers completely bridge the voids without penetrating any of the fibers into the microvoid space. In other cases, some, but not substantial, of the fibers may infiltrate the microvoid space, while the remainder extends from one side of the microvoid to the other side of the microvoid.

[0099] Modifications to the above would be obvious to one of ordinary skill in the art, but would not cause the invention to be modified beyond the scope of the invention, and the following claims should be construed to include such situations.

Claims

1. 1. An industrial fabric for producing textured products, comprising: a first layer; and a second layer extending over at least a portion of the top surface of the first layer; the second layer includes a plurality of macrovoids and microvoids, the macrovoids providing texture to the product fabricated thereon and the microvoids limiting penetration of product fibers into the macrovoids; the industrial fabric has a permeability of at least 300 CFM and is determined at least in part by the nominal diameter of the macrovoids and the nominal diameter of the microvoids; the nominal diameter of the macrovoids is in the range of 6 mm to 12 mm; The nominal diameter of the microvoids is in the range of 1 mm to 5 mm. Industrial fabric.

2. 10. The industrial fabric of claim 1, wherein the microvoids increase the permeability of the industrial fabric.

3. An industrial fabric as described in claim 1, wherein the fibers of the textured product extend and / or flex within the macrovoids.

4. An industrial fabric as described in claim 1, wherein the second layer is a nonwoven fabric layer.

5. An industrial fabric as described in claim 1, wherein the second layer comprises a material selected from the group consisting of engineered polymers, thermoplastics, thermoplastic polyurethanes, elastomers, cross-linked plastics, rubber, polyamides, polyesters, copolyesters, EVA (ethylene-vinyl acetate), and combinations thereof.

6. An industrial fabric as described in claim 1, wherein the first layer is a base fabric selected from the group consisting of woven fabric, nonwoven fabric, machine direction yarn arrangement, cross machine direction yarn arrangement, braid, a series of independent rings, spiral link, extruded mesh, and knit structure.

7. An industrial fabric as described in claim 1, wherein at least some of the macrovoids and / or microvoids in the second layer have a shape selected from the group consisting of circular, elliptical, polygonal, and leaf-shaped.

8. An industrial fabric as described in claim 1, wherein the second layer extends over the entire length and / or width of the first layer.

9. An industrial fabric as described in claim 1, wherein the permeability of the industrial fabric is 400 to 700 CFM.

10. An industrial fabric as described in claim 1, wherein the second layer is laminated to the first layer.

11. An industrial fabric as described in claim 1, wherein the second layer is a film.

12. An industrial fabric as described in claim 1, wherein the macrovoids and microvoids are laser-formed voids and / or drilled voids.

13. An industrial fabric as described in claim 11, wherein the film comprises a compound selected from the group consisting of engineered polymers, thermoplastics, thermoplastic polyurethanes, elastomers, cross-linked plastics, rubber, polyamides, polyesters, copolyesters, EVA, and combinations thereof.

14. An industrial fabric as described in claim 1, wherein the macrovoids are topographical features of the second layer and are complementary to a desired texture in the textured product.

15. The industrial fabric of claim 1, wherein the macrovoids are 50 mm ３ From 90mm ３ Industrial fabrics with void volumes in the range of 16. The industrial fabric of claim 1, wherein the microvoids are 20 mm ３ From 50 mm ３ Industrial fabrics with void volumes in the range of

17. An industrial fabric as described in claim 1, comprising from about 5% to about 95% closed area.

18. An industrial fabric as described in claim 1, comprising an effective closed area of ​​about 5% to about 95%.

19. An industrial fabric as described in claim 1, wherein the textured product fibers bridge the microvoids.

20. 1. A method of making a textured product, comprising: texturing the product with an industrial fabric, the industrial fabric comprising: a first layer; and a second layer extending over at least a portion of the top surface of the first layer; the second layer includes a plurality of macrovoids and microvoids, the macrovoids providing texture to the product fabricated thereon and the microvoids limiting penetration of product fibers into the macrovoids; the industrial fabric has a permeability of at least 300 CFM and is determined at least in part by the nominal diameter of the macrovoids and the nominal diameter of the microvoids; the nominal diameter of the macrovoids is in the range of 6 mm to 12 mm; The method wherein the microvoids have a nominal diameter in the range of 1 mm to 5 mm.

21. A method as described in claim 20, wherein the fibers of the textured product extend and / or bend within the macrovoids.

22. The method of claim 20, wherein the fibers of the textured product are selected from the group consisting of spunbond fibers, staple fibers, meltblown fibers, spunlace fibers, wetlaid fibers, thermally bonded fibers, natural fibers, synthetic fibers, and combinations thereof.

23. The method described in claim 20, wherein the second layer is a nonwoven fabric layer.

24. The method of claim 20, wherein the microvoids increase the permeability of the industrial fabric.

25. The method of claim 20, wherein the second layer is a film.

26. A method as described in claim 20, wherein the macrovoids are topographical features of the second layer and are complementary to the desired texture in the textured product.

27. The method of claim 20, comprising an effective closed area of ​​about 5% to about 95%.

28. An industrial fabric as described in claim 1, wherein the first layer is selected from the group consisting of woven fabrics and nonwoven fabrics.

29. An industrial fabric as described in claim 1, wherein the industrial fabric is a papermaking fabric.

30. An industrial fabric as described in claim 1, wherein the second layer has a nominal thickness of approximately 3 mm.

31. The industrial fabric of claim 1, 1. An industrial fabric, wherein the permeability of the industrial fabric is determined, at least in part, by the total area of ​​the microvoids and the total area of ​​the macrovoids, and the total area of ​​the microvoids is at least 45% of the total area of ​​the macrovoids.

32. An industrial fabric as described in claim 31, wherein the total area of ​​the macrovoids is approximately 39%.

33. An industrial fabric as described in claim 32, wherein the total area of ​​the microvoids is at least 17%.

34. An industrial fabric as described in claim 1, wherein the permeability is at least 538 CFM and the total area of ​​the macrovoids is approximately 39%.

35. An industrial fabric as described in claim 1, wherein the first layer has a permeability greater than 900 CFM, the second layer has a permeability greater than 900 CFM, and the permeability of the industrial fabric is at least 500 CFM.

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