Patent ID: 12241201

DETAILED DESCRIPTION

The present disclosure more fully describes various embodiments with reference to the accompanying drawings. It should be understood that some, but not all embodiments are shown and described herein. Indeed, the embodiments may take many different forms, and accordingly this disclosure should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.

Various embodiments are directed to a dimensionally stable carpet tile that is resistant to both doming and curling, as well as to mold and mildew buildup. The carpet tile described in various embodiments herein also has the ability to be installed with minimal preparation. For example, the carpet or carpet tile described herein can be installed over remnants of previous installation materials, without fear of old adhesives or other chemicals migrating into the new carpet installation. This can have a substantially impact on installation time as well as on labor. Additionally, the carpet tile described herein provides cushioning and acoustic resistance, while having a high resistance to moisture.

The carpet tile is a multi-layer carpet tile comprising a facecloth (comprising a primary backing, face yarn, and optionally a pre-coat layer), bonded to a backing construction comprising an extruded polymer secondary backing layer and a cushion bonded to the extruded polymer secondary backing layer to define, at least in part, the bottom surface of the carpet tile. The cushion comprises a reinforcing scrim layer, usually a fibrous reinforcing scrim layer (e.g., woven or nonwoven) embedded within a polymer layer (which may be woven or nonwoven). The reinforcing scrim layer may also be an air-laid scrim. In certain embodiments, the cushion includes a polyester foam layer. In certain embodiments, the cushion comprises a weight ratio of 3 to 30 oz per square yard. In certain embodiments, the reinforcing scrim layer has a weight of 0.25 to 2.5 oz per square yard. Unless otherwise specified, the weights specified herein, such as the weight of the reinforcing scrim layer, indicate dry weights, although this does not preclude embodiments where the corresponding weights are wet weights.

The carpet tile product disclosed herein remains resistant to deformation (dimensional deformation, curling, or doming) due at least in part to the presence of the cushion on the bottom surface of the carpet tile. The product is resistant to mold and mildew buildup, due to its ability to wick moisture from the subfloor to the seams, where it may evaporate into the air.

Carpet Tile

Referring to the figures, in which like numerals refer to like elements through the several figures,FIG.1is a cross sectional view (not to scale) of a carpet tile100in accordance with various embodiments of the present invention. In the illustrated embodiment, the carpet tile100includes face yarn105, which may be either tufted or woven into a primary backing110to form a facecloth111. The face yarn105may be made from various materials, both natural and synthetic, such as nylon 6, nylon 6, 6, cotton, wool, nylon, acrylic, polyester, polyamides, polypropylene, and other polyolefins. The face weight of the face yarn105can be approximately 5 ounces per square yard to approximately 50 ounces per square yard.

The primary backing110may be formed from a substrate such as a woven substrate, a tape yarn substrate, and/or other substrate construction that imparts stability to the carpet tile100. The substrate may be made from a polyester, such as poly(ethylene terephthalate) [PET], poly(trimethylene terephthalate) [PTT], poly(butylene terephthalate) [PBT], poly(ethylene terephthalate-co-isophthalate), poly(ethylene naphthalene dicarboxylate) [PEN], and copolymers thereof, and/or combinations thereof, with PET being preferred. In certain embodiments, the primary backing110may comprise a low melt polyester material configured to bind the various fibers together upon application of heat to the primary backing. The substrate may also comprise sheathed fibers, which may comprise a polyester core surrounded by a polyamide and/or polyolefin sheath. Typically, the polyester core may be made from PET, PTT, PBT, PEN, poly(ethylene terephthalate-co-isophthalate) and copolymers thereof. The polyamide sheath may be made from polycaprolactam [nylon 6], poly(7-heptanamide) [nylon 7], polycapryllactam [nylon 8], poly(9-nonanamide) [nylon 9], poly(tetramethylene adipamide) [nylon 4,6], poly(hexamethylene adipamide) [nylon 6,6], poly(methylene-4,4′-dicyclohexylene dodecanediamide), poly(1,4-cyclohexylenedimethulene suberamide), poly(m-phenylene isophthalamide), and poly(p-phenylene terephthalamide), with polycaprolactam [nylon 6] being the preferred polyamide. In certain embodiments, the primary backing110may be formed using a woven substrate using any conventional natural or synthetic woven material, such as cotton, jute, rayon, paper, nylon, polypropylene and other polyolefins, polyamides, polyesters, and the.

The face yarn105may be tufted through the primary backing110so that the ends of the face yarn105extend in an outwardly direction from the topside of the primary backing110to form an upper surface of the carpet tile100. Typically the face yarn is tufted into the primary backing110at a weight of approximately 2.6 ounces per square yard to approximately 5.9 ounces per square yard, and more preferably approximately 3 ounces per square yard. The tufting may be performed using conventional techniques that are well known in the art. Furthermore, the tufted face yarn105loops may be left as uncut to form an uncut pile carpet, cut to form a cut pile carpet, or partially cut to form a tip sheared carpet, as is well known in the art.

In certain embodiments, the facecloth111includes a pre-coat layer115that is applied to a first side of the facecloth, which is the same as the bottom surface of the primary backing110. The pre-coat layer115penetrates the tufted face yarn105and encapsulates individual ends of the yarn bundles to at least partially bind the tufted face yarn105to the primary backing110. This may prevent one end of an individual fiber from being pulled out of the carpet backing during the manufacturing process. The pre-coat layer115may also act as a tackifier to provide an acceptable binding surface for a subsequent polymer layer. In an exemplary embodiment, the pre-coat layer115comprises a hot melt adhesive (HMA) that contains a tackifying resin or agent alone or in combination with polyethylene. In various embodiments, the pre-coat layer115comprises an aqueous-latex based polymer configured to support the face yarn105within the primary backing110upon drying. In certain embodiments, the pre-coat layer115comprises butadiene acrylate based polymers, vinyl acetate ethylene, vinyl acetate-ethane copolymers, and/or latex based compounds, such as styrene butadiene copolymer latex (SBR latex). The pre-coat layer115may include one or more other compositions, such as inert filler materials (e.g., fly ash) as discussed in reference to the extruded polymer secondary backing layer120herein. The pre-coat layer115may also include one or more flame retardant materials such as, but not limited to, aluminum trihydrate (ATH) or magnesium hydroxide (MgOH) for applications where flame-retardancy is desired. One or more flame retardants may be necessary to comply with applicable regulations regarding the installation and/or usage of carpet tiles in certain applications, for example, when such carpet tiles are installed in transportation vehicles (e.g., buses, aircraft, and/or the like).

The pre-coat layer115may be applied to a bottom surface of the primary backing110in the range of approximately 2 ounces per square yard to approximately 20 ounces per square yard, and more preferably in the range of approximately 8 ounces per square yard to approximately 12 ounces per square yard.

Disposed on a bottom surface of the facecloth111is a backing construction comprising an extruded polymer secondary backing layer120and a cushion130. The backing construction is arranged such that the extruded polymer secondary backing layer120is positioned between the cushion130and the facecloth111. In such an embodiment, a first (top) side of the extruded polymer secondary backing layer120is bonded to the precoated facecloth111, and a second (bottom) side of the extruded polymer secondary backing layer120is bonded to the cushion130. The extruded polymer secondary backing layer120is embodied as a resin comprising one or more components collectively configured to give the resulting carpet tile100a flat overall appearance without substantial doming (a central portion of the carpet tile100rising relative to the edges such that a top surface of the carpet tile100is convex) or curling (the edges of the carpet tile100rising relative to the central portion such that a top surface of the carpet tile100is concave). The resin of the extruded polymer secondary backing layer120may comprise a polyolefin, a thermoplastic polymer, a mixture of two or more polyolefins, or a mixture of one or more polyolefins together with one or more other polymers. For example, the resin may comprise polyvinyl chloride, polyethylene, and/or polypropylene. As specific examples, a polyolefin polymer is embodied as 1-propene, ethylene copolymer or ethylene-propylene copolymer. In certain embodiments, the resin of the extruded polymer secondary backing layer120comprises the polymer mixture in an amount between about 10-40 wt % of the resin of the extruded polymer secondary backing layer120(and of the extruded polymer secondary backing layer120itself). In an embodiment, the carpet tile comprises a single extruded polymer secondary backing layer. In other embodiments, the carpet tile comprises multiple extruded polymer secondary backing layers.

The resin of the extruded polymer secondary backing layer120may additionally comprise one or more additives, such as an inert filler material, a colorant, an antioxidant, a tackifier, a viscosity modifier, a flame retardant, and/or the like.

The inert filler material may constitute the majority of the resin of the extruded polymer secondary backing layer120(by weight), and may function as a low cost material that adds weight to the extruded polymer secondary backing layer120to aid in forming an at least substantially flat carpet tile100. For example, the inert filler material may constitute between about 20-80 wt % of the resin and/or the extruded polymer secondary backing layer120.

The inert filler material may be made from carbonates such as calcium carbonate (CaCO3), cesium carbonate (CsCO3), strontium carbonate (SrCO3), and magnesium carbonate (MgCO3); sulfates such as barium sulfate (BaSO3); oxides such as iron oxide (Fe2O3or Fe3O4), aluminum oxide (Al2O3), tungsten oxide (WO3), titanium oxide (TiO2), silicon oxide (SiO2); silicates, such as clay; metal salts; fly ash and the like.

Additionally, the inert filler material may be made from post-consumer products, such as post-consumer glass, post-consumer carpets and/or other post-consumer recycled materials. In cases where the inert filler is made from post-consumer glass, the post-consumer glass is ground into a fine glass powder before it is added as filler. The glass cullet may be made from automotive and architectural glass, also known as plate glass, flint glass, E glass, borosilicate glass, brown glass (bottle glass), green glass (bottle glass), or coal fly ash, or a combination thereof. In the case where post-consumer carpet is used as the inert filler material, the post-consumer carpet maybe ground into a fine cullet and added to the hot melt adhesive. In addition to the post-consumer carpet, remnants and trimmings of carpet (e.g., comprising trim waste from cutting carpet tiles from rolls of carpet, sometimes referred to as window waste), fine waste fibers that are a result of the shearing process, and the like, that are produced as a by-product during the manufacturing process may also be used to form the inert filler material.

The filled or unfilled polymer may also contain a colorant, such as carbon black or another colorant(s) to provide color and increase the opaqueness of the extruded polymer secondary backing layer120. Typically, the colorant may be present in an amount less than or equal to approximately 1 wt % the filled or unfilled resin and extruded polymer secondary backing layer120. For example, the colorant may be present in an amount between about 0.1-0.5 wt % of the extruded polymer secondary backing layer120. As a specific example, the colorant may be present in an amount of approximately 0.1 wt % of the resin and the extruded polymer secondary backing layer120.

Moreover, to reduce the possibility of thermo-oxidation degradation, the polymer may also contain one or more antioxidants. Some suitable antioxidants include, but are not limited to amines, 2,2′-methylene bis-(4-methyl-6-tert-butylphenol), 2,4,6-tri-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 4,4′-thio-bis-(6-tert-butyl-m-cresol), butylated hydroxy anisole, butylated hydroxy toluene, bis(hydrogenated tallow alkyl),oxide; tris(2,4-ditert-butylphenyl)phosphite and 1,3,5 triazine-2,4,6(1H, 3H, 5H)-trione,1,3,5,tris-((3,5-(1-dimethylethyl))-4-hydroxyphenyl)methyl. Typically, the antioxidant may be present in the filled or unfilled extruded polymer secondary backing layer120in an amount less than or equal to approximately 2 wt % of the resin and/or the extruded polymer secondary backing layer120, such as between about 0.05-0.5 wt % of the resin and/or the extruded polymer secondary backing layer120.

Moreover, the extruded polymer secondary backing layer120may additionally include one or more tackifiers to aid in forming a strong mechanical bond with the pre-coat layer115(if present), the primary backing110, and/or the cushion130discussed in further detail below.

The resin of the polymer secondary backing layer120may additionally include one or more viscosity modifiers and/or compatibilizers, such as, for example, olefins of higher or lower molecular weight than the resin discussed herein or ethylene maleic anhydride copolymer, to ensure proper flow and bonding of the resin within filler and polymers when applying onto a facecloth111. The viscosity modifier may be present in an amount between about 0.1-3 wt % of the resin and the extruded polymer secondary backing layer120.

In certain embodiments, the resin of the extruded polymer secondary backing layer120may additionally comprise one or more flame retardants, such as, but not limited to, aluminum trihydrate (ATH), magnesium hydroxide (MgOH), various phosphorous based FR compounds such as Ammonium Polyphosphate, Ammonium Polypyrophosphate, silicone or siloxane flame retardants, or other flame retardants known in the trade, for applications where flame-retardancy is desired. One or more flame retardants may be necessary to comply with applicable regulations regarding the installation and/or usage of carpet tiles in certain applications, for example, when such carpet tiles are installed in transportation vehicles (e.g., buses, aircraft, and the like).

Referring again toFIG.1, the carpet tile100additionally comprises a cushion130pressed against the extruded polymer layer120to define, at least in part, the bottom surface of the carpet tile100. The cushion130imparts dimensional stability to the finished carpet tile100. Because the cushion130is positioned on the bottom surface of the carpet tile100, the cushion130provides additional support against curling and/or doming of the carpet tile.

The cushion130comprises a polymer layer132with an integrated reinforcing scrim layer134, as seen inFIG.2. In an alternative embodiment (not pictured), the cushion130does not comprise a reinforcing scrim layer, and consists solely of a polymer layer132. In such instances, the polymer layer may be stabilized to achieve properties similar to that of a polymer layer132with the reinforcing scrim layer134through thermal, chemical or mechanical process, or a combination thereof.

In an embodiment, the polymer layer132may comprise polyester. Such polyesters include, but are not limited to, PET, PTT, PBT, PEN, poly(ethylene terephthalate-co-isophthalate) and copolymers thereof. In a preferred embodiment, the polyester is PET. The polymer layer132may be woven or nonwoven. In a preferred embodiment, the polymer layer132is nonwoven.

In other embodiments, the polymer layer132may include any suitable material, such as PVC, polyurethane, polyethylene, and so on. The polymer layer132can include a foam type material or in some instances, can include non-foam type materials.

The reinforcing scrim layer134, if present, may comprise a fibrous material provided in either a woven or non-woven configuration. When provided on the bottom surface of the carpet tile100, the cushion130provides desirable protection against mold and mildew formation when the carpet tile100is on a wet subfloor. In an embodiment, the reinforcing scrim layer134is in the middle of the cushion130, such that approximately half of the polymer layer132is on one side of the reinforcing scrim layer134, and approximately half of the polymer layer132is on the other side of the reinforcing scrim layer134. In other embodiments, about 0.1-99.9% of the polymer layer132is on one side of the reinforcing scrim layer134, and about 99.9-0.1% of the polymer layer132is on the other side of the reinforcing scrim layer134. In an embodiment, so little of the polymer layer132is on the top side of the reinforcing scrim layer134that the reinforcing scrim layer134is in contact with the extruded polymer layer120. In an embodiment, a first side of the reinforcing scrim layer134is in contact with the extruded polymer layer120, and a second side of the reinforcing scrim layer134is in contact with the polymer layer132. In this embodiment, the polymer layer132may be in contact with the extruded polymer layer120due to the openness of the reinforcing scrim layer134.

The reinforcing scrim layer134may contain fibrous materials, which themselves may constitute any number of natural or synthetic materials. The fibrous material may additionally and/or alternatively comprise one or more polymer based fibers, such as polyester fibers, polyamide fibers, polyurethane fibers, combinations thereof, and/or the like. For example, the polymer fibers may comprise polypropylene fibers, polyethylene fibers, sheathed polymer fibers (e.g., having a polyethylene core and a nylon or polypropylene sheath), and/or the like. As yet another example, the fibrous material may comprise a composite of polymer-based fibers and other fibers (e.g., glass fibers). Such a composite may comprise layers of non-woven and/or woven layers (e.g., a first layer comprising a polymer-based fiber material and a second layer comprising a glass fiber material).

Method of Manufacture

FIG.3is a schematic diagram of a portion of an example carpet tile manufacturing line that may be utilized to construct a carpet tile100as discussed herein, andFIG.3is a flow chart of an example method for constructing the carpet tile100according to certain embodiments. As discussed herein, the carpet tiles100may be manufactured as a portion of a continuous web and later cut into desired tile shapes and sizes. However, it should be understood that carpet tiles100may be manufactured according to any of a variety of manufacturing processes, such as a batch process in which each multi-layer carpet tile100is constructed as a separate component.

As shown inFIG.3, the process begins by providing a facecloth111having a plurality of face yarns105extending through a primary backing110(as indicated at Block401ofFIG.4). The facecloth111can optionally have a pre-coat layer disposed on a backside of the primary backing110. As discussed herein, the topside of the facecloth111ultimately forms the top surface of the completed carpet tile100. As mentioned, the tufted primary backing110is provided as a continuous web, which may be threaded along a web travel path defined by a plurality of rollers (e.g., powered rollers and/or idler rollers). In certain embodiments, the facecloth111may have a width between 72-80 inches, although it should be understood that the facecloth111may have any width with suitable production equipment, such as up to 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, and 200 inches.

As shown inFIG.3, the facecloth111is advanced along the web travel path in an inverted orientation with the backside of the facecloth111facing upward, as indicated at Block402ofFIG.4. The facecloth111is advanced past one or more extruder heads220configured to extrude a continuous sheet of a resin having an at least substantially uniform thickness onto the backside of the facecloth111to form the extruded polymer secondary backing layer120, as indicated at Block403. In certain embodiments, the extruder head220may comprise a single, elongated extrusion die tip opening extending across the entire width of the facecloth111such that the resin is extruded as a continuous sheet from the extruder head220. Alternatively, the resin may be extruded from a plurality of extruder heads220positioned across the width of the web travel path. The plurality of extruder heads may be spaced such that the resin flows together to form an at least substantially continuous extruded polymer secondary backing layer120having an at least substantially uniform thickness across the width of the facecloth111.

The one or more extruder heads220may be supplied by one or more extruders (e.g., single screw extruders and/or dual-screw extruders) configured to combine the various components of the resin prior to extrusion to form the extruded polymer secondary backing layer120. Once combined, the extruders and one or more extruder heads220provide the at least substantially continuous sheet of resin onto the bottom surface of the facecloth111at a temperature between about 275-500 degrees Fahrenheit and at a weight of between about 8-35 ounces per square yard. In embodiments in which the facecloth111comprises a hot melt pre-coat layer115, the resin may be applied to the facecloth111while the pre-coat layer115is sufficiently hot (as may be the case with a hot melt adhesive) so as to retain a tacky characteristic (e.g., while the pre-coat layer material remains above its softening point) to improve the mechanical bond strength between the facecloth111and the extruded polymer secondary backing layer120. However, it should be understood that the resin need not be applied to the facecloth111while a pre-coat layer115remains hot in embodiments that do not utilize a hot melt adhesive pre-coat layer115(e.g., embodiments without a pre-coat layer115and embodiments using an aqueous latex-based pre-coat layer115).

The hot melt pre-coat layer115could also be applied via other methods such as via roll coaters, via a spray system, or via a slot coater.

After extruding the resin of the extruded polymer secondary backing layer120onto the facecloth111, the cushion130is laid onto the exposed bottom surface of the extruded polymer secondary backing layer120as indicated at Block404ofFIG.4. The extruded polymer secondary backing layer120remains above the resin softening point when the cushion130is laid onto the exposed surface of the extruded polymer secondary backing layer120, and the entire multi-layer web (including the facecloth111, the extruded polymer secondary backing layer120, and the cushion130) is passed through a nip250comprising two rollers positioned on opposite sides of the web travel path to compress the multi-layer web and to provide strong bonds between adjacent layers of the carpet tile100. During compression, the extruded polymer secondary backing layer120is bonded to the facecloth111, and the cushion130is bonded to the extruded polymer secondary backing layer120(as indicated at Block405). The cushion130defines at least a portion of the bottom surface of the resulting carpet tile100.

After the moving multi-layer web passes through the nip250, the web passes through one or more chilling rollers260to cool and harden the extruded polymer secondary backing layer120(shown at Block406). For example, the one or more chilling rollers260may be collectively configured to chill the extruded polymer secondary backing layer120to approximately room temperature (between about 75-80 degrees Fahrenheit).

In a non-pictured embodiment, the nip rollers may also serve as the chilling rollers.

The cooled multi-layer construction may then be passed to a tile cutting mechanism configured to cut the multi-layer web into a plurality of individual carpet tiles or to a take-up roller270for storage. For example the web may be passed into a die cutter to cut the material web into market-size carpet tiles100(e.g., 4″×8″, 12″×36″, 18″×18″, 24″×24″, or 36″×36″). The carpet tiles100can include square, rectangular, hexagonal or any other suitable shapes. Alternatively, the material web may be taken onto a large diameter (e.g., 8-foot diameter) drum where it can be taken to an off-line die cutting station for further processing into carpet tiles100.

EXAMPLE 1

An example carpet tile is manufactured according to the methodology discussed herein. The example carpet tile comprises a facecloth111comprising a primary backing layer110having a weight of at least approximately 4 ounces per square yard, and having face yarns105tufted therethough at a weight of at least approximately 14 ounces per square yard. The tufted primary backing is coated with a pre-coat layer115having a dry weight of at least approximately 12 ounces per square yard.

The facecloth111is passed under an extruder head220as a part of a continuous web, where the resin of the extruded polymer secondary backing layer120is extruded onto a backside of the facecloth111(such that the resin is extruded onto the exposed surface of the pre-coat layer115) to form the extruded polymer secondary backing layer120. In this example, the extruded polymer secondary backing layer120comprises a polyolefin resin mixture heated to a temperature of 325-475 degrees Fahrenheit (163-246 degrees Celsius) for extrusion.

The resin is extruded in a continuous sheet onto the facecloth111to create an at least substantially uniform extruded polymer secondary backing layer120having an at least substantially uniform thickness.

Before the extruded polymer secondary backing layer120cools to a temperature below the softening point of the resin, a cushion130comprising a reinforcing scrim layer embedded within polyester is laid onto the exposed surface of the extruded secondary backing layer120, and the entire multi-layer web is passed through a nip250and through one or more chilling rollers260to press the cushion130against the extruded polymer secondary backing layer120and to cool and harden the extruded polymer secondary backing layer120. The cooled web is then cut into individual carpet tiles100for evaluation.

The carpet tile100provided according to this example construction exhibits superior ability to resist or prevent mold or mildew growth when placed on a wet subfloor, with desirable durability and a relatively low weight. The carpet tile100also additionally can be installed with no or minimum preparation to the subfloor, for example, without substantially removing all the remnants of a previous installation without the risk of adhesives or other chemicals from prior installations migrating into the carpet tile100.

Conclusion

Many modifications and other embodiments will come to mind to one skilled in the art to which this disclosure pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosure is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.