RU2780191C2 - Two-layer non-woven mat obtained by wet molding - Google Patents

Abstract

FIELD: building materials.

SUBSTANCE: carpet tile contains a layer of fleecy fabric, primary lining connected to the layer of fleecy fabric, secondary lining connected to primary lining, and a two-layer non-woven mat obtained by wet molding, wherein the two-layer non-woven mat obtained by wet molding contains the first layer containing a set of glass fibers and the first binder, and the second layer containing a set of synthetic fibers and the second binder.

EFFECT: obtaining a two-layer non-woven mat.

22 cl, 8 dwg

Description

FIELD AND PRIOR ART OF THE INVENTION

[0001] Carpet tiles offer significant advantages over carpets or solid carpeting. For example, the use of carpet tiles for flooring provides an easy installation method and allows the removal of individual tiles that wear or stain more than other tiles, while tiles that do not wear or stain. may remain in place. In addition to this, tiles can be rearranged or replaced to enhance decorative impacts. Conventional carpet tiles comprise a fleecy material set on one side to a layer of flexible thermoplastic (including elastomeric) material that is stiffened with a layer of suitable stiffening fibers such as fiberglass fibers. As a rule, the tile is reinforced on the reverse side with another layer of elastic elastomer or thermoplastic material, which can be applied adhesive for installing carpet tiles on the floor.

[0002] Conventional carpet tiles are made using a two-layer method. In some two-layer processes, the product must pass through the production line twice. In the first pass, the non-woven fiberglass mat is bonded to the rough fabric with an extruded thermoplastic secondary liner to form a rough fabric/extruded liner/fiberglass composite. At the end of this process, the rough fabric/extruded liner/fiberglass composite is then wound into an A-frame roll. In a second pass, the composite is again covered with the same or a different secondary extruded backing and an optional layer of felt (such as polyester spunbond) can be added as the finished underside of the carpet tile. In other two-layer processes, the product passes through the line only once. In the first pass, a plastisol coating/secondary liner is applied to the rough fabric before the fiberglass nonwoven mat is bonded to form the rough fabric/extruded liner/fiberglass composite. The rough fabric/extruded liner/fiberglass composite is then recoated with the plastisol coating/secondary liner (whereby the coating is applied to the uncoated upper side of the fiberglass) in a subsequent step. This second layer of plastisol is designed to result in a fully wetted fiberglass mat providing sufficient lamination strength to act as the finished underside of the carpet tile. These two-part methods are both inefficient and costly.

The essence of the invention

[0003] Embodiments of the present invention are directed to carpet tiles that can be produced using a single layer industrial process while providing improved dimensional stability. Such carpet tiles can not only reduce production costs and increase production efficiency by eliminating steps from the manufacturing process, but also eliminate the need for multiple secondary backing layers. The carpet tiles of the present invention achieve these results by incorporating a two-layer, wet-spun nonwoven mat in place of one of the secondary backing layers, as well as an optional layer of felt. The top layer of the nonwoven mat is formed from large glass fibers, while the second layer is formed from synthetic fibers and/or a combination of synthetic fibers and large glass fibers. The synthetic fiber layer provides a smoother, non-itchy surface that remains open and easy to manipulate for installers.

[0004] In one embodiment, carpet tiles are provided. The carpet tile may comprise a fleece fabric layer, a primary backing bonded to the fleece fabric layer, a secondary backing bonded to the primary backing, and a two-layer wet-spun nonwoven mat. The two-layer wet-spun nonwoven mat may comprise a first layer containing a plurality of glass fibers and a first binder and a second layer containing a plurality of synthetic fibers and a second binder.

[0005] In another embodiment, a method for installing carpet tiles is provided. The method may include making carpet tiles. The carpet tile may comprise a fleece fabric layer, a primary backing bonded to the fleece fabric layer, a secondary backing bonded to the primary backing, and a two-layer wet-spun nonwoven mat. The dual layer wet-spun nonwoven mat may comprise a first layer containing a plurality of glass fibers and a binder and a second layer containing a plurality of synthetic fibers and a binder. The method may also include applying an adhesive between the exposed surface of the second layer and the floor substrate and applying force to the top surface of the carpet tile to adhere the carpet tile to the floor substrate using the adhesive.

[0006] In another embodiment, a method for making carpet tiles is provided. The method may include making a fleece fabric layer having a primary liner and covering the primary liner with a secondary liner. The method may also include applying a two-layer wet-spun nonwoven mat to the exposed surface of the secondary backing to form a carpet sheet. The two-layer wet-spun nonwoven mat may comprise a first layer containing a plurality of glass fibers and a binder and a second layer containing a plurality of synthetic fibers and a binder. The first layer may be positioned facing the secondary lining. Further, the method may include cutting the sheet into a plurality of carpet tiles.

Brief description of the drawings

[0007] The various features, aspects, and advantages of the present invention will become more apparent upon reading the following detailed description with reference to the accompanying figures, in which like references represent like details in the figures, where:

[0008] FIG. 1A is an isometric view of carpet tiles according to embodiments.

[0009] Fig. 1B is a side view of the carpet tile in Fig. 1A.

[0010] FIG. 2 is a schematic view of a two-layer wet-spun nonwoven mat according to embodiments.

[0011] FIG. 3 is a schematic view of a manufacturing system that manufactures a two-layer wet-spun nonwoven mat according to embodiments.

[0012] FIG. 4 is a schematic view of a manufacturing system that manufactures a two-layer wet-spun nonwoven mat according to embodiments.

[0013] FIG. 5 is a method for forming carpet tiles using a two-layer wet-spun fiber mat according to embodiments.

[0014] FIG. 6 is a schematic view of a manufacturing system that manufactures carpet tiles according to embodiments.

[0015] FIG. 7 is a schematic view of a manufacturing system that manufactures carpet tiles according to embodiments.

Detailed description of the invention

[0016] The present description only provides illustrative embodiments and is not intended to limit the scope or configuration of the present invention. Rather, the present description of exemplary embodiments will provide those skilled in the art with a valid description for implementing one or more exemplary embodiments. It will be understood that various changes may be made with respect to the function and arrangement of the elements without departing from the spirit and scope of the present invention as set forth in the appended claims.

[0017] Embodiments of the present invention provide carpet tiles that, instead of two separate layers of thermoplastic backing as in conventional tiles, use a single application of thermoplastic backing between the primary backing and the reinforcing mat/scrim. In such typical applications, the mat/scrim must provide the necessary dimensional stability and create a suitable finished surface facing the floor. Embodiments of the present invention achieve the desired dimensional stability by providing a two-layer, wet-spun nonwoven mat in which one layer is comprised of bonded polymer/synthetic fibers and the other layer is bonded glass fibers. Not only does this mat provide dimensional stability, but the polymer/synthetic layer also acts as a finished floor-facing surface because the polymer/synthetic layer is not itchy or otherwise uncomfortable to handle and therefore provides a surface that is operable. during installation.

[0018] Dimensional stability is important for carpet tiles. Dimensional stability is understood in the art to be the ability of a carpet tile to lay flat and remain flat and square on a floor surface under conditions of normal use, as described in US Pat. No. 4,010,302, the entire contents of which are hereby incorporated by reference. The Aachen industry standard test DIN STD 54318 is used to determine dimensional stability. Fiberglass mats or scrims can be placed between layers of flexible thermoplastic backing to provide dimensional stability to the carpet tiles.

[0019] Turning now to the figures, here the carpet tile 100 of the present invention is shown in Fig. 1A. Although shown here as square, it will be understood that the carpet tile 100 may be cut or otherwise formed into any desired shape and may be sized to suit any desired application. In addition, the textile topsheet may be formed from any fabric or other textile material to suit the needs or aesthetics of a particular application. Carpet tile 100 may include a textile top layer over one or more layers of backing and a two-layer wet-spun nonwoven mat having a top layer of glass fibers and a bottom layer of synthetic fibers. For example, as shown in FIG. 1B, the carpet tile 100 may comprise a fabric layer 102, such as a pile fabric layer, or a layer of other fabric, serving as the exposed top surface of the carpet tile 100. The fabric layer 102 can be attached to the primary backing layer 104 . The primary lining layer may be made of polyester and/or polypropylene. Primary liner 104 may be attached to secondary liner 108 by a latex precoat 106 that is positioned between primary liner 104 and secondary liner 108 in some embodiments. The secondary liner 108 may be formed from a thermoplastic elastomer and/or a plastisol material such as polyolefins, polyvinyl chloride (PVC) and/or polyurethane.

[0020] The two layer fiberglass mat 110 may be bonded to a secondary liner 108. As best seen in FIG. layer 114, which is formed from a plurality of synthetic fibers and a binder. The second layer 114, formed from synthetic fibers, provides a soft, non-itchy, open bottom surface that can be handled by tile installers. This layer helps eliminate the need for tile installers to come into direct contact with the itchy layer of glass fibers. The glass fibers of the first layer 112 may have diameters ranging between 8 and 25 microns, between 8 and 16 microns, and more commonly between 11 and 16 microns, and in some embodiments, they may contain a mixture of large fibers having an average diameter ranging between 8 and 11 µm mixed with a second type of coarse fibers having a diameter between 12 and 25 µm. The coarse fibers may be between about ¼ inch and 2 inches (6-51 mm) in length. The first layer 112 may contain 60-95% glass fibers and 5-40% binder. The second layer 114 may contain 60-95% synthetic fibers and 5-40% binder. The synthetic fibers of the second layer 114 may be fusible or laminable fibers such as polyester, polypropylene, nylon, polyethylene, and the like. The binder may be an acrylic type binder such as Dow QRXP-1692 or BASF Acrodur 950L. In some embodiments, the second layer 114 may also contain a percentage of glass fibers mixed with synthetic fibers to further enhance the dimensional stability of the carpet tile 100. In some embodiments, the first layer 112 may have a thickness between about 0.1 mm and 1 .5 mm, while the second layer 114 may have a thickness between about 0.1 mm and 4 mm, so that the mat 110 has an overall thickness between about 0.2 mm and 5.5 mm.

[0021] The two-layer fiberglass mat 110 can be formed by a wet molding process such that there is no separate binder or adhesive used to bond the layers to each other. For example, the nonwoven mats discussed below comprise multiple layers of fibers made in a single step or process. In other words, the layers of the mats discussed below are not formed separately, and then combined at a later stage or process (ie, made separately and then bonded together). Rather, the layers are formed simultaneously, resulting in a mat that functions as one layer in terms of structure and integrity despite containing different fiber compositions and having different layer densities. Accordingly, the discussed mats can be manufactured at lower cost and in less time.

[0022] The first layer 112 may contain a mixture of glass fibers of various sizes. Glass fibers of different sizes form layers of different densities within the mat. For example, the top layer may contain both large fibers and microfibers. Coarse fibers or larger diameter fibers may have a size range between about 8 and about 25 microns, and smaller diameter fibers or microfibers can have a size range between about 0.5 and 6 microns. In a more specific embodiment, large fibers or fibers of larger diameter may have a size range between about 8 and about 16 microns, and more often between about 11 and 16 microns.

[0023] In one specific embodiment, the larger diameter fibers may be fibers with a diameter of about 13 microns, and the microfibers may be about 3 microns in diameter. The mat contains at least one binder that binds large diameter fibers and microfibers together to form a fibrous mat. The binder may be water repellent and/or contain a water repellant such as a stearylated melamine water repellant.

[0024] Typically, the first layer 112 is a non-woven fibrous mat 110 formed using coarse fibers. The coarse fiber layer 112 provides dimensional stability to the finished carpet tile 100. The term "coarse fibers" in this application is understood to mean glass fibers having an average diameter between about 8 and 25 microns and an average length between about ¼ inch and 2 inches (6-51 mm). Coarse fibers can be made from E glass, C glass, T glass, soda borosilicate glass, A and S glasses, basalt, mineral wool, slag fiber, and mixtures thereof. In one particular embodiment, the first layer 112 may be formed entirely from coarse fibers having an average fiber diameter ranging between 8 and 25 microns, between 8 and 16 microns, and more commonly between 11 and 16 microns. In another embodiment, the first layer 112 may be formed from a combination of coarse fibers of various sizes that are generally uniformly dispersed or distributed throughout the first layer 112. For example, the first layer 112 may be formed from a first type of coarse fibers having an average diameter ranging between 8 and 11 µm, which are then mixed with a second type of coarse fibers having a diameter between 12 and 25 µm. In another embodiment, the first layer 112 may be formed from a combination of coarse glass fibers having a fiber diameter ranging between 8 and 25 microns and a synthetic fiber having a fiber diameter ranging between 0.3 and 8 denier. For example, the weight percentage of large fibers in the second layer 112 may vary between 70 and 99 percent, while the weight percentage of synthetic fibers may range between 1 and 30 percent. The inclusion of a synthetic fiber may be necessary to combat the difference in shrinkage characteristics between glass fibers and synthetic fibers.

[0025] In some embodiments, the second layer 114 may be formed from synthetic fibers alone, such as polyester, polypropylene, polyethylene terephthalate (PET), and/or other synthetic materials. In another embodiment, the second layer 114 may be formed from a combination of large glass fibers and synthetic fibers. When a combination of coarse fibers and synthetic fibers is used, the coarse fibers and synthetic fibers are generally uniformly dispersed or distributed throughout the second layer 114. In an embodiment that includes both coarse fibers and synthetic fibers, the weight percentage of coarse fibers and synthetic fibers may change. For example, the weight percentage of coarse fibers in the second layer 114 may vary between 1 and 80 percent, while the weight percentage of synthetic fibers may range between 20 and 99 percent. In another embodiment, the weight percentage of large fibers in the second layer 114 may vary between 1 and 20 percent, while the weight percentage of synthetic fibers may vary between 80 and 99 percent, which would result in a mat 110 that significantly smoother and less itchy. The inclusion of coarse fibers in the second layer 114 provides additional strength and integrity to the layer and helps to increase the dimensional stability of the finished carpet tile 100.

[0026] In embodiments where both the first layer 112 and the second layer 114 are made with a combination of large glass fibers and synthetic fibers, the ratio of glass fibers to synthetic fibers is clearly different in each of the two layers.

[0027] As noted above, in some embodiments, the second layer 114 may be formed entirely from synthetic fibers having an average fiber diameter between 0.3 and 8 denier. The second layer 114 may be formed from synthetic fibers of a single, relatively uniform size, or the second layer 114 may be formed from a combination of synthetic fibers of different sizes that are generally uniformly dispersed or distributed over the second layer 114. For example, the second layer 114 may be formed from the first type of synthetic fibers having an average diameter in the range between 0.3 and 1 denier, which are then mixed with a second type of synthetic fibers having an average diameter in the range between 1.5 and 8 denier. The weight percents of the first and second synthetic fiber types may vary in the second layer 114. For example, the weight percent of the first synthetic fiber type may vary between 5 and 50 percent, while the second synthetic fiber type may vary between 50 and 95 percent. . The percentages of the first and second types of synthetic fibers may vary depending on the desired texture or perceived tactile feel of the resulting layer 114. For example, if layer 114 is to be smooth, layer 114 will contain a higher percentage of smaller synthetic fibers.

[0028] The mat 110 includes a binder that binds together the respective fibers in the first layer 112 and the second layer 114 and that also binds together the first layer 112 and the second layer 114. In one embodiment, the mat 110 includes a single binder that functions as for tying together the fibers in the respective layers, and for tying together the respective layers. The binder is generally uniformly or relatively uniformly dispersed or distributed throughout the mat 110. In other words, the binder may be distributed uniformly in the first layer 112 and in the second layer 114, and may also be uniformly distributed over the first and second layers 112, 114. Since the binder is relatively uniform is distributed over mat 110 such that mat 110 does not contain a separate binder or binder layer (or other adhesive) at the interface between the first layer 112 and the second layer 114. In other words, there is no concentration of binder at the interface or interface between the first and second layers 112, 114 because the binder is uniformly distributed over mat 110. This even distribution of binder results from the formation of the first and second layers 112, 114 in the same step. In addition, the fibers of the first and second layers 112, 114 are more coherent, more interconnected and intermingled with each other at the interface or at the boundary of the layers due to the formation of layers at the same stage. This results in a smoother transition between the first and second layers 112, 114.

[0029] The binder is uniformly or evenly distributed over the top and bottom layers and there is no concentration of the binder at the interface. In addition, since the two layers are formed at the same time, there is a small gradient of glass and synthetic fibers at the interface, which enhances the physical bond or interweaving of the fibers of the upper and lower layers. Specifically, a portion of the synthetic fibers of the second layer 114 at or near the interface migrates into the first layer 112 and vice versa. The degree of fiber migration and the resulting physical bond or entanglement is unique to mats formed in accordance with the present invention, since such entanglement and migration is not achieved without simultaneous formation of layers. Fiber migration is a desirable feature because it makes the interface between the layers smooth, which can allow for partial penetration of the second liner 108 into the second layer 114. Fiber migration also forms a strong bond between the layers.

[0030] In some embodiments, mat 110 may have an integrated thickness between about 0.1 and 1.5 mm. In some embodiments, the thickness of the mat 110 may be less than 20 percent of the total thickness of the carpet tile 100. The first and second layers are of appropriate thickness. For example, the thickness of the first layer 112 may be between 0.05 mm and 0.5 mm, and the thickness of the second layer 114 may be between 0.05 mm and 1 mm. Each of these layers 112, 114 may also be defined as a percentage of the total thickness of the mat. For example, the first layer 112 may be between 10% and 70% of the total mat thickness, and the second layer 114 may be between 30% and 90% of the total mat thickness.

[0031] In some embodiments, the first layer 112 may be thicker than the second layer 114 because the first layer 112 may contain more large fibers. In addition, because the first layer 112 contains coarse fibers, the porosity of the first layer 112 may be greater than that of the second layer 114. The more porous first layer 112 allows the first layer 112 to absorb a portion of the secondary liner 108 when the mat 110 is used as a mat for a secondary backing 108, such as by lamination, during the manufacture of carpet tiles 100. Specifically, the secondary backing 108 may be relatively wetted or uncured and may absorb or penetrate the first layer 112 due to the porosity of the first layer 112. Penetration or absorption of the secondary backing 108 in the first layer 112 may bond secondary liner 108 to mat 110 during manufacture. The second layer 114 may be less porous than the first layer and may prevent the coarse fibers of the first layer 112 from being exposed to provide a smoother, non-itchy open bottom surface for carpet tiles 100.

[0032] Figure 3 is a schematic view of a manufacturing system 300 that manufactures a mat 110. In operation, manufacturing system 300 may manufacture a multilayer mat in a single step/process. That is, the layers of the mat are not formed separately, and then combined at a later stage or in the process (ie, not made separately and then bonded together). For this reason, mats 110 produced by production system 300 can be produced at a lower cost and in less time.

[0033] The production system 300 includes a plurality of fluid lines that deliver coarse fibers and synthetic fibers to a plant 302 that simultaneously forms the first and second layers 112, 114 of mat 110. Although a hydroforming plant 302 is illustrated, a long mesh or a delta former for making the first and second layers 112, 114 of the mat 110 in one step/in one process.

[0034] The manufacturing system 300 makes the first layer 112 using the first fluid line 304 that delivers the coarse fibers to the hydroformer. The first fluid line 304 includes at least one coarse fiber source 306 comprising one or more types of coarse fibers (eg, coarse fibers of various sizes, coarse fibers made from various materials, or a combination thereof). In fluid communication with the coarse fiber source 306 is a pump 308 (eg, a mass pump for viscous media) that pumps a first fluid 310 containing coarse fibers. For example, the first fluid 310 may contain water, viscosity modifiers, dispersants, antifoam agents, and the like mixed with coarse fibers. After passing through pump 308, first fluid 310 is diluted with dilution fluid 312 (eg, water, viscosity modifiers, dispersants, antifoams, or a combination thereof) which is stored in dilution tank 314. By diluting the coarse fibers, the manufacturing system 300 can enable a more even distribution of the coarse fibers in the first layer 112 using a hydroformer. Dilution fluid 312 is combined with first fluid 310 before first fluid 310 enters second pump 316. Pump 316 (eg, a non-viscous mass pump) can facilitate mixing of first fluid 310 and dilution fluid 312 prior to delivery to installation 302 for hydroforming. Upon exiting pump 316, first fluid 310 enters first inlet 318 of hydroformer 302. First inlet pipe 318 directs first fluid 310 to hydroformer 302, which forms first layer 112 of mat 110 by removing first fluid 310 and dilution fluid 312 from the fluid/coarse fiber mixture as the mixture is poured into hydroformer 302.

[0035] To form the second layer 114 of the mat 110, the manufacturing system 300 includes a second fluid line 320. The second fluid line 320 includes at least one synthetic fiber source 306 containing one or more types of synthetic fibers (eg, synthetic fibers of various sizes, synthetic fibers made from various materials, or a combination thereof). In fluid communication with the synthetic fiber source 306 is a pump 322 (eg, a bulk pump for viscous media) that pumps a second fluid 324 containing synthetic fibers. For example, the second fluid 324 may contain water, viscosity modifiers, dispersants, antifoam agents, and the like mixed with synthetic fibers. After passing through pump 322, second fluid 324 is diluted with dilution fluid 326 (eg, water, viscosity modifiers, dispersants, antifoams, or combinations thereof), which is stored in dilution tank 328. By diluting the second fluid 324, the manufacturing system 300 can enable the fibers to be evenly distributed in the second layer 114. The dilution fluid 326 combines with the second fluid 324 before the second fluid 324 enters the second pump 330. The pump 330 (for example, mass pump for non-viscous media) allows mixing of the second fluid 324 and dilution fluid 326 before delivery to the installation 302 for hydroforming. After exiting pump 330, second fluid 324 enters second inlet 332 of hydroformer 302. The second inlet pipe 332 directs the second fluid 324 to the hydroformer 302, which forms the second layer 114 of the mat 110 by removing the second fluid 324 and dilution fluid 326 from the fluid/fiber mixture when the mixture is poured into the hydroformer 302 over the first a mat layer 110 which is directly formed by the hydroformer 302. The second fluid 324 is directed or poured over the first mat layer 110 while the fluid is removed from the first fluid 310 so that the second layer 114 and the first layer 112 are formed simultaneously by the hydroformer 302.

[0036] In some embodiments, in fluid communication with the second fluid line 320 is a third fluid line 334. The third fluid line 334 includes at least one coarse fiber source 336 containing one or more types of coarse fibers (eg, coarse fibers of various sizes, coarse fibers made from various materials, or combinations thereof). In fluid communication with coarse fiber source 336 is a pump 338 (eg, mass pump) that pumps a third fluid 340 containing coarse fibers. The third fluid 340 may contain water, viscosity modifiers, dispersants, antifoam agents, and the like mixed with coarse fibers. After passing through pump 338, third fluid 340 may be pumped into second fluid line 320. Thus, the coarse fibers can be mixed with the synthetic fibers of the second layer 114. As illustrated, the third fluid line 334 is connected before the pump 330. By connecting before the pump 330, the production system 300 uses the turbulent flow through the pump 330 to facilitate mixing of the third fluid 340 with second fluid 324. However, in some embodiments, third fluid line 334 may be connected to second fluid line 320 after pump 330. For example, manufacturing system 300 may rely on pump 330 to mix third fluid 340 with second fluid. fluid 324. In other embodiments, third fluid line 340 may be connected either before or after pump 330. This arrangement may allow a third fluid to be smoothly introduced into the first and/or second fluid line at various positions.

[0037] The flow of first, second, and third fluids 310, 324, 340 through manufacturing system 300 may be controlled by controller 342. Controller 342 may include one or more processors 344 that execute instructions stored on one or more memory devices 346, to control the operation of various valves, as well as pumps. For example, the third 334 fluid line may include first and second valves 348, 350. As illustrated, the first valve 348 controls the flow of the third fluid 340 in the first fluid line 304, while the second valve 350 controls the flow of the third fluid. 340 in the second fluid line 320. By controlling the first and second valves 348, 350, controller 342 can control the amount of third fluid 340 combined with second fluid 324. This in turn controls the amount of coarse fibers in second layer 114 produced by hydroformer 302. Thus, the production system 300 can vary the coarse fiber content of the second layer 114 from 0 to 100 percent, and more commonly up to the percentages described in the mat embodiments herein.

[0038] The production system 300 may also control fluid flow through the first and second fluid lines 304, 320 using additional valves 352 and 354, as well as controlling pumps 308, 318, 322, 330, and 338. By controlling the flow of the first and second fluid 310, 324, the controller 342 may increase or decrease the thickness of the respective first and second layers 112, 114. In other words, the manufacturing system 300 may increase or decrease the thickness of the first and/or second layers 112, 114 of the mat 110 depending on specific needs. carpet tile 100. For example, manufacturing system 300 may increase the flow of first fluid 310 through fluid line 304 to increase the thickness of first layer 112 and decrease the flow of second fluid 324 to decrease the thickness of second layer 114. Similarly, manufacturing system 300 may reduce the flow of first fluid 310 through fluid line 304 to reduce thickness of the first layer 112 and increase the flow of the second fluid 324 to increase the thickness of the second layer 114.

[0039] When the first and second fluids 310, 324 enter the hydroformer 302, they come into contact with the conveyor belt 356, which extracts essentially the main part of the fluid in the first and second fluids 310, 324, leaving behind the combined first and second layers 112, 114. The manufacturing system 300 may then apply one or more binders 358. In some embodiments, binder 358 may contain resinous binders such as urea formaldehyde, modified urea formaldehyde, acrylic resins, modified acrylic resins, polyurethanes, polyvinyl chlorides, melamine resins, polyacrylic acid homopolymers or copolymers; cross-linking acrylic copolymers; cross-linked vinyl chloride is an acrylate copolymer, among other types of binders. Flame retardants such as aluminum trihydrate, organic phosphonates, antimony oxide, and the like can also be included in the binder.

[0040] These binders 358 may be stored in one or more binder sources 360. The binder(s) 358 may be applied in the first and second layers 112, 114 by moving the first and second layers 112, 114 under a spray or curtain of binder. Any excess binder can then flow through the first and second layers. Thus, manufacturing system 300 can bond fibers in their respective layers as well as bond layers 112, 114 together without having to perform multiple bonding steps/processes. In other words, the manufacturing system 300 can both bond fibers in respective layers and bond layers of fibers together in one step. The simultaneous application of the binder(s) 358 to the first and second layers 112, 114 results in a relatively uniform distribution of the binder over and between the first and second layers 112, 114 without forming or defining a layer of binder between the first and second layers 112, 114. In other words , a separate or individual layer of binder is not formed or defined at the interface or interface between the first and second layers 112, 114, as is the case in conventional systems where the layers are individually formed and combined in a subsequent process. The relatively uniform distribution of binder(s) 358 can increase mat strength and/or reduce problems such as layer delamination. In addition, the mat described herein has a less defined boundary between the first and second layers 112, 114 because these layers are formed simultaneously. Rather, the mat has a relatively smooth transition from the first layer 112 to the second layer 114 due to the simultaneous formation of the layers, which can increase strength and/or reduce problems such as layer delamination.

[0041] For convenience, when describing various embodiments herein, large fibers will be referred to as glass fibers. It should be understood that various other types of fibers can be used in any of the embodiments described herein, and that the embodiments are not limited to glass fibers unless otherwise indicated in the claims. It should also be understood that the use of a material other than glass fibers is contemplated in any of the embodiments. Fibers of a material other than glass fibers can be used in combination with glass fibers or instead of glass fibers. Accordingly, unless the claims expressly state otherwise, the concepts and embodiments described herein may include only glass fibers, only fibers of material other than glass fibers, or any combination of glass fibers and material other than glass fibers. . Exemplary fibers from a material other than glass fibers include inorganic fibers, mineral fibers, basalt fibers, polymeric fibers, synthetic fibers, organic fibers, natural fibers, and the like. Likewise, it is to be understood that the microglass fibers and/or large glass fibers described herein may be partially or completely replaced by polymeric, synthetic, or natural microfibers. Thus, the general term “fibers” and/or “coarse fibers” may be used in the claims, such usage being understood to cover a variety of fibers, including glass fibers and fibers of material other than glass fibers. The term "coarse fibers" will be understood in connection with the dimensions to be defined in this document.

[0042] Turning now to FIG. 4, a method 400 for forming a fibrous mat is illustrated here. In one particular embodiment, the fibrous mat may be a fiberglass mat 110 for carpet tiles, such as the carpet tile 100 described herein. At block 402, the first fluid mixture is poured or applied to the porous tape or surface. This first fluid mixture contains a first group of fibers that are uniformly mixed or dispersed in the first fluid. In one specific embodiment, the first group of fibers comprises (or consists of) large glass fibers having an average fiber diameter between 8 µm and 25 µm. When the first fluid mixture is applied to or poured onto the porous tape or surface, the first fluid is drained or removed from the first fluid mixture so that a layer of the first group of fibers is formed on the porous tape or surface. In some embodiments, a vacuum may be applied to the porous belt or surface to facilitate removal of the first fluid from the first fluid mixture.

[0043] According to block 404, the second fluid mixture is poured or applied to the porous tape or surface over the layer of the first group of fibers. The second fluid mixture contains a second group of fibers, which is homogeneously mixed or dispersed in the second fluid. In one specific embodiment, the second group of fibers comprises (or consists of) synthetic fibers having an average fiber diameter ranging between about 0.3 and 8 denier. In other specific embodiments, the second group of fibers comprises (or consists of) a combination of large glass fibers having an average fiber diameter ranging between 8 µm and 25 µm and synthetic fibers having an average fiber diameter ranging between 0.3 and 8 denier. The amount of each fiber type may be similar to the embodiments described herein.

[0044] When the second fluid mixture is applied or poured onto the porous tape or surface, the second fluid is drained or removed from the second fluid mixture so that a layer of the second fiber group is formed on the porous tape or surface and over the layer of the first fiber group. The second fluid mixture is poured or applied to the porous tape or surface when the first fluid is removed from the first fluid mixture. As such, the layer of the first group of fibers is generally not formed or fully defined until the second fluid mixture is poured or applied to the porous tape or surface. Thus, the first fiber group layer and the second fiber group layer are formed on the porous web or surface at the same time. The second fluid mixture can be poured directly vertically over the first layer of fluid, and thus both layers can be poured simultaneously one on top of the other. In other words, since the layer of the first fiber group is not formed or is not fully defined until the second fluid mixture is poured or applied to the porous tape or surface, the layer of the first group of fibers is formed or defined at substantially the same time as on the porous tape or surface. a layer of the second group of fibers is formed or defined. Since the first fiber group layer and the second fiber group layer are formed at the same time, the degree of intermixing or interlacing of the fibers at the interface between the two layers is much greater than in conventional fiber mats where one or both layers are formed or defined completely before the application of the other layer. In some embodiments, the second fluid mixture may be poured or applied to the porous tape or surface within 30 inches (75 cm) of where the first fluid mixture is poured or applied to the porous tape or surface. In such cases, the fibrous mat forming section (eg, porous tape) may be exceptionally long so that the first layer is still dehydrated when the second fluid mixture is applied to the tape. In other cases, the second layer may be cast within 12 inches (30 cm) or within 6 inches (15 cm) of the position where the first layer is cast or applied to the porous tape. In such cases, the first layer may be partially dehydrated but still in the process of being formed on the porous web. In some embodiments, the second layer 114 (eg, a denser layer) may be cast onto the porous tape first, and then the first layer 112 (eg, a less dense layer) may be cast over the second layer 114. In such cases, a denser layer may be formed at the bottom, while a less dense layer forms at the same time at the top.

[0045] At block 406, a binder is simultaneously applied to the first fiber group layer and to the second fiber group layer to bond the two layers together and to bond the different fibers in each layer together. In most embodiments, no adhesive is applied to either layer until block 406, or in other words, the layers typically do not contain adhesive until block 406. Simultaneous application of adhesive to both layers, which typically do not contain adhesive until block 406, results in more uniform or homogeneous distribution of the binder over the fibrous mat. In addition, simultaneous application of the binder to both layers results in a fibrous mat containing no concentrated binder layer at the interface between the two layers. Conventional fibrous mats typically contain some (increased) concentration of binder at the interface between the layers, since the fibrous layers are formed separately and then glued or bonded together with additional binder or other adhesive. The additional binder binds the two layers together and tends to be concentrated at the interface between the layers. In contrast, the method described herein can form a multi-layer fibrous mat design in which the binder is relatively uniformly or uniformly dispersed throughout the mat rather than being concentrated in one or more areas. In addition, a single binder can be used both for tying or gluing together the layers, and for tying or gluing together the fibers of the different layers. Conventional mats typically require the use of a plurality of binders to bind together the fibers of the individual layers and to subsequently bond those layers together.

[0046] In one specific embodiment, the fibrous mat that is formed according to the method 400 of FIG. 4 may be a carpet tile mat, such as carpet tile 100. In such embodiments, the mat may be applied to the secondary lining during formation of carpet tiles. The layer of the first group of fibers may be able to absorb a carpet tile material, such as a secondary liner, when the mat is adjacent to the secondary liner during formation of the carpet tile. In some embodiments, the layer of the second group of fibers may partially absorb the material of the secondary lining, but may block the material from passing through the mat to the outer surface of the second layer or absorbing the material. Thus, the mat may adhere to or bond with the secondary liner by absorbing the secondary liner material within the mat, but the material may not be visible on the outer surface.

[0047] It should be noted that while method 400 in FIG. 4 is described as forming two layers simultaneously, method 400 can be used to form three or more layers simultaneously as described. For example, block 404 may be repeated using a third slurry, a fourth slurry, and the like to form additional layers on the layer of the second fiber group. The binder may then optionally be simultaneously applied to each of the layers according to block 406. Thus, the method 400 of FIG. 4 is not limited to two-layer structures.

[0048] FIG. 5 depicts a single pass manufacturing system 500 for making carpet tiles, such as carpet tiles 100 of the present invention. The system 200 includes a coarse fabric source 502 that supplies a fabric layer 102, such as a fleece material (or other material suitable for carpet use) containing a primary backing 104. This fabric layer 102 can pass through the roller system 504 by passing through the extruder 506. The extruder 506 may extrude or otherwise supply the thermoplastic material or plastisol material that serves as the secondary liner 108 for the fabric layer 102. In some embodiments, prior to passing through the extruder 506, the fabric layer 102 is coated with a latex precoat 106, which can assist in strengthening the bond between the carpet yarn and the primary backing 104. A nonwoven mat source 508 is provided after the extruder 506 and supplies a two-layer, wet-spun nonwoven mat. 110 next to the extruded secondary liner 108.

[0049] Mat 110 may be manufactured separately using manufacturing system 300 and/or method 400 as described above, and may include a top layer 112 of coarse glass fibers and a bottom layer 114 of synthetic fibers, and in some embodiments, a combination of synthetic fibers. and large glass fibers. The top layer 112 may be adjacent to the secondary liner 108. In some embodiments, the secondary liner 108 is thermoplastic in nature. The fabric layer 102, primary liner 104, secondary liner 108, and nonwoven mat 110 (and latex precoat 106 when included) may then pass through a second roll system, such as a pressure chill roll system 510, which may compress the respective layers together and cause bonding the layers together and crimping them by lowering the temperature of the chill rolls of the pressure chill roll system 510. In some embodiments, the secondary liner layer 108 is a plastisol in nature. The fabric layer 102, primary liner 104, plastisol secondary liner 108, and nonwoven mat 110 (and latex precoat 106 when included) can then be passed through a heating oven system to cure the plastisol and bond the various layers to each other. After cooling/curing, the various layers form a carpet roll and/or sheet 512 that can be delivered to a cutter 514 that cuts carpet 512 into individual carpet tiles 100. In some embodiments, before or after cutting the tiles, a layer of adhesive, such as a layer pressure-sensitive adhesive may be applied to the exposed underside of the carpet tile 100, sometimes along with a non-tacky release liner.

[0050] FIG. 6 depicts a one-pass method 600 for making carpet tiles, such as carpet tiles 100, in accordance with the present invention. Method 600 begins at block 602 by coating the rough fabric with a thermoplastic/plastisol secondary liner. In some embodiments, the coarse fabric may be provided in the form of a pile fabric layer having a primary lining. For example, the primary liner may be polyester, woven polypropylene, and/or nonwoven. The thermoplastic/plastisol secondary liner may be applied to the base liner by extruding the thermoplastic/plastisol material onto the base liner of the base fabric at block 604. At block 606, a two-ply wet-formed nonwoven mat may be applied to the exposed surface of the secondary backing to form a carpet sheet. For example, the mat may be laminated with a secondary lining material. In some embodiments, the first layer may be laminated to a secondary liner using a latex precoat. The two-layer wet-spun nonwoven mat may be similar to the wet-spun nonwoven mat 110 described above. For example, the mat may include a first layer containing a plurality of glass fibers and a binder and a second layer containing a plurality of synthetic fibers and a binder. The binders are generally the same and applied at the same time in the wet molded manufacturing process as described in FIGS. 3 and 4. The first layer of the wet molded nonwoven mat may be positioned facing the secondary liner, and in many embodiments , it can be located directly next to the secondary lining. However, it will be appreciated that in some embodiments, one or more additional layers, such as scrims and the like, may be interposed between the first layer of the wet-spun nonwoven mat and the secondary liner. Method 600 may also include cutting the carpet sheet into a plurality of carpet tiles, at block 608. Prior to cutting, the carpet sheet may pass through one or more rolls, such as a pressure chill roll system to compress adhesives to bond the various layers of carpet sheet to each other.

[0051] In some embodiments, method 600 may include applying an adhesive to the exposed bottom surface of the second layer. The adhesive may be applied before or after cutting the carpet sheet into individual carpet tiles. In some embodiments, the adhesive may be a pressure-sensitive adhesive that enables installation of the carpet tile by applying force to the top surface of the carpet tile after it is in its desired position on the floor substrate. In some embodiments, a release liner may be applied to the exposed surface of the adhesive to prevent the adhesive from sticking to another surface prior to installation of the carpet tiles. During installation, the removable patch can be removed to expose the adhesive.

[0052] FIG. 7 depicts a method for manufacturing a carpet tile, such as carpet tile 100, according to the present invention. Method 700 begins at block 702 to provide a carpet tile, such as carpet tile 100 described herein. For example, a carpet tile may comprise a fleece fabric layer, a primary backing bonded to the fleece fabric layer, a secondary backing bonded to the primary backing, and a two-layer wet-spun nonwoven mat. The two-layer wet-spun nonwoven mat may comprise a first layer containing a plurality of glass fibers and a first binder and a second layer containing a plurality of synthetic fibers and a second binder. The method 700 may include applying an adhesive between the exposed surface of the second layer and the floor substrate, at block 704. For example, the adhesive may be applied to the floor substrate just prior to placing the carpet tile adjacent to the floor substrate. In other embodiments, the adhesive is applied to the second layer before the carpet tiles are placed next to the floor substrate. In some embodiments, this may be done during the installation process, while in other embodiments, the adhesive may be applied to the carpet tiles during the manufacturing process. For example, a pressure sensitive adhesive may be applied to the second layer with a release liner covering the exposed surface of the adhesive. During installation, the release liner may be removed from the carpet tile to expose the pressure sensitive adhesive prior to positioning the carpet tile. At block 706, a force is applied to the top surface of the carpet tile to adhere the carpet tile to the floor substrate using an adhesive.

[0053] While several embodiments and arrangements of various components are described herein, it should be understood that various components and/or combinations of components described in various embodiments may be modified, rearranged, changed, adjusted, and the like. For example, the placement of components in any of the described embodiments may be adjusted or rearranged, and/or the various components described may be used in any embodiments in which they are not currently described or used. It should be considered that, as such, the various embodiments are not limited to the particular placement and/or structures of the components described herein.

[0054] In addition, it should be understood that any operable combination of features and elements described herein is also considered as described. In addition, whenever a feature is not discussed in connection with one of the embodiments of the present invention, the person skilled in the art thereby notes that some embodiments of the present invention may explicitly and specifically exclude such features, thereby providing support for negative limitations of the claims.

[0055] With several embodiments described, one skilled in the art will appreciate that various modifications, alternative designs, and equivalents can be used without departing from the spirit of the present invention. In addition, a number of well-known processes and elements are not described in order to avoid unnecessary complication of the present invention. Accordingly, the above description should not be construed as limiting the scope of the present invention.

[0056] When a range of values is given, it is understood that every intermediate value, up to one tenth of the unit lower limit, unless the context clearly dictates otherwise, between the upper and lower limits of this range, is also specifically described. Every smaller range between any formulated value or intermediate value in the formulated range and any other formulated or intermediate value in this formulated range is covered. The upper and lower limits of these smaller ranges may be independently included in or excluded from the range, and each range where either or both limits are included in the smaller range is also covered by the present invention, subject to any specific limit exclusion as set forth. range. Where a stated range includes one or both of these limits, ranges excluding either or both of these included limits are also included.

[0057] As used herein and in the appended claims, references to the singular include references to the plural unless the context clearly dictates otherwise. Thus, for example, reference to "method" includes a plurality of such methods, and reference to "device" includes reference to one or more devices and their equivalents known to those skilled in the art, and so on.

[0058] Also, the words "comprise", "comprising", "include", "including" and "includes", when used in the description and in the following claims, are intended to indicate the presence of the stated features, integers, components or steps, but they do not preclude the presence or addition of one or more other features, integers, components, steps, actions, or groups.

Claims (64)

1. Carpet tiles, containing: a layer (102) of fleecy fabric; a primary liner (104) associated with the fleece layer; a secondary lining (108) associated with the primary lining; and a two-ply wet-spun non-woven mat (110) bonded to a secondary liner, the two-ply wet-spun non-woven mat comprising: a first layer (112) containing a plurality of glass fibers and a binder; and the second layer (114) containing a plurality of synthetic fibers and a binder. 2. Carpet tiles according to claim 1, further comprising: a latex precoat applied between the primary liner and the secondary liner, the secondary liner being thermoplastic. 3. Carpet tiles according to claim 1, in which: the first layer is adjacent to the secondary liner, the secondary liner being thermoplastic. 4. Carpet tiles according to claim 1, in which: the plurality of glass fibers comprises glass fibers having an average fiber diameter of 8-25 µm. 5. Carpet tiles according to claim 1, in which: many synthetic fibers contain one or more materials of polyester, polyolefin or nylon. 6. Carpet tiles according to claim 1, in which: the secondary lining contains a thermoplastic material or plastisol. 7. Carpet tiles according to claim 1, in which: the second layer further comprises a plurality of glass fibers having a length of 1/4 inch - 2 inches (6-51 mm) and an average fiber diameter of 8-25 microns. 8. Carpet tiles according to claim 1, in which: the second layer contains only a plurality of synthetic fibers and a binder. 9. Method for installing carpet tiles, including: manufacture of carpet tiles containing: a layer of fleecy fabric; a primary lining associated with a layer of fleecy fabric; a secondary lining associated with the primary lining; and a two-ply wet-spun nonwoven mat bonded to a secondary liner, the two-ply wet-spun nonwoven mat comprising: a first layer containing a plurality of glass fibers and a binder, said first layer facing the secondary liner; and a second layer containing a plurality of synthetic fibers and a binder; providing an adhesive between the exposed surface of the second layer and the floor substrate; and applying force to the top surface of the carpet tile to adhere the carpet tile to the floor substrate using the adhesive. 10. The method of installing carpet tiles according to claim 9, in which: the adhesive is applied to the floor substrate prior to laying the carpet tiles on the floor substrate. 11. The method of installing carpet tiles according to claim 9, in which: the adhesive is applied to the second layer prior to laying the carpet tiles on the floor substrate. 12. The method of installing carpet tiles according to claim 9, in which: providing an adhesive between the exposed surface of the second layer and the floor substrate includes applying a pressure-sensitive adhesive to the second layer and applying a release liner to the pressure-sensitive adhesive; and the method further includes removing the release liner prior to applying force to the top surface of the carpet tile. 13. The method of installing carpet tiles according to claim 9, in which: the plurality of glass fibers comprises glass fibers having an average fiber diameter of 8-25 µm. 14. The method of installing carpet tiles according to claim 9, in which: many synthetic fibers contain one or more materials of polyester, polyolefin or nylon. 15. The method of installing carpet tiles according to claim 9, in which: the binder of the two-ply wet-spun nonwoven mat is distributed uniformly over the two-ply wet-spun nonwoven mat. 16. The method of installing carpet tiles according to claim 9, in which: the second layer further comprises a plurality of glass fibers having a length of 1/4 inch - 2 inches (6-51 mm) and an average fiber diameter of 8-25 microns. 17. Method for manufacturing carpet tiles, including: obtaining a layer of fleecy fabric containing the primary lining; covering the primary lining with a secondary lining; applying a two-ply wet-spun nonwoven mat to the exposed surface of the secondary backing to form a carpet sheet, the two-ply wet-spun nonwoven mat comprising: a first layer containing a plurality of glass fibers and a binder, said first layer facing the secondary liner; and a second layer containing a plurality of synthetic fibers and a binder; and cutting a carpet sheet into a plurality of carpet tiles. 18. The method of manufacturing carpet tiles according to claim 17, in which: application of the two-layer wet-spun nonwoven mat comprises laminating the first layer with a secondary liner using a latex precoat. 19. The method of manufacturing carpet tiles according to claim 17, in which: coating the primary liner with the secondary liner comprises extruding a thermoplastic material or a plastisol material onto the primary liner. 20. The method of manufacturing carpet tiles according to claim 17, further comprising: applying a pressure-sensitive adhesive to the second layer; and application of a removable overlay on a pressure-sensitive adhesive. 21. The method of manufacturing carpet tiles according to claim 17, further comprising: exposing the carpet sheet to the chill roll system before cutting the carpet sheet. 22. The method of manufacturing carpet tiles according to claim 17, in which: the binder of the two-ply wet-spun nonwoven mat is homogeneously distributed over the two-ply wet-spun nonwoven mat.

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