NON-SKID UNDERLAYMENT

Abstract

Described are flooring systems which include an underlayment material that has a non-skid surface. The non-skid performance may arise from frictional properties, as opposed to adhesive properties. Such a flooring system may include a top flooring layer, a subfloor, and an underlayment material disposed between the subfloor and the top flooring layer. Methods for a non-skid underlayment are disclosed herein, as well as methods of manufacture. The underlayment material may comprise at least one layer and a non-skid surface for engaging the subfloor, the surface comprising thermoplastic rubber.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application No. 62/031,703 filed Jul. 31, 2014, which is incorporated by reference herein as if fully set forth.

BACKGROUND

Flooring systems generally comprise an aesthetic (e.g., decorative) top flooring layer installed over a structural substrate (commonly referred to as a subfloor). An underlayment layer may be interposed between the top flooring layer and the substrate for purposes of sound reduction, cushioning, moisture barrier, and/or protection.

The top flooring layer must be installed on a flat, level, substrate for both structural and aesthetic reasons. For example, any bumps or irregularities in the substrate may be visible to the consumer, which is not aesthetically pleasing. Moreover, beyond undesirable light reflection and other cosmetic drawbacks, top flooring layers are generally fragile enough that such irregularities eventually lead to transfer through to the top layer, increased wear, cracking, or other damage. In cases of interlocking top flooring layer components (e.g., laminate flooring, engineered flooring), irregularities in the substrate may prevent proper mechanical interaction, thereby undermining the integrity of the top flooring layer and creating unsightly gaps or even trip hazards.

One type of irregularity in a flooring system can result from the underlayment slipping or bunching to create wrinkles during installation of the underlayment, or more often, during installation of the top flooring layer. For example, in some installations, components of the top flooring layer are slid into place. If the friction between the top flooring layer component and the underlayment is greater than the friction between the underlayment and the substrate, the underlayment may bunch. Therefore, better systems, methods, and non-skid compositions are needed.

SUMMARY

A flooring system as disclosed herein may include an underlayment material that has a non-skid surface. The non-skid performance may arise from frictional properties, as opposed to adhesive properties. Such a flooring system may include a top flooring layer, a subfloor, and an underlayment material disposed between the subfloor and the top flooring layer. Methods for a non-skid underlayment are disclosed herein, as well as methods of manufacture. The underlayment material may comprise at least one layer having a non-skid surface for engaging the subfloor, the surface comprising thermoplastic rubber.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts a top perspective sectional view of a flooring system having a non-skid underlayment material.

FIG. 2 depicts a cross-sectional view of a flooring system having a non-skid underlayment material.

FIG. 3 depicts a cross-sectional view of a non-skid underlayment material.

FIG. 4 depicts a bottom perspective sectional view of a non-skid underlayment material.

FIG. 5 depicts a cross-sectional view of a non-skid underlayment material.

FIG. 6 depicts a cross-sectional view of a non-skid underlayment material.

FIG. 7 is a diagram of a method for manufacturing a non-skid underlayment material.

DETAILED DESCRIPTION

FIG. 1 illustrates a flooring system 100. The flooring system 100 may be used in a commercial or residential setting. The flooring system 100 may include a top flooring layer 102, which may also be referred to as flooring. The top flooring layer 102 may be mainly for decorative purposes. Examples of top flooring layers 102 include carpet, tile, sheet vinyl, luxury vinyl tile (or planks), solid hardwood, engineered wood, and laminate flooring.

The flooring system 100 may include a subfloor 104. The term “subfloor” refers to the structural substrate above which a top flooring layer 102 is installed. Examples of subfloors 104 include concrete, plywood, oriented strand board (OSB), composite wood, and in some cases, existing vinyl or hardwood flooring. Often, the subfloor 104 may contain multiple irregularities in its surface. For example, the subfloor 104 may include a depression 106. The depression 106 may be a dimple, a gouge, or a low spot. The subfloor 104 may include projections from its surface such as a bump (e.g., a high spot) 108, or in cases where the subfloor is of plywood, oriented strand board (OSB), or composite wood, a projecting nail head 110. The subfloor may have a multiplicity of irregularities of differing heights and depths. For example, in concrete subfloors, both high spots and low spots are fairly typical.

The flooring system may include a non-skid underlayment material 120 interposed between the top flooring layer 102 and subfloor 104. The underlayment material 120 may have greater frictional properties with respect to the subfloor 104 than its frictional properties with respect to the top flooring layer 102, as will be described. The flooring system 100 may have additional layers (not depicted).

The top flooring layer 102, underlayment material 120, and subfloor 104, may be assembled by any practicable means. The underlayment material 120 may be laid on the subfloor 104 and the top flooring layer 102 laid upon the underlayment material without affixing them to each other (e.g., a floating installation method). The underlayment material 120 may be glued to the subfloor 104 with adhesive and the top flooring layer 102 glued to the underlayment material with adhesive (e.g., a double glue down installation). One layer of the top flooring layer 102, underlayment material 120, and subfloor 104 may be glued to its adjacent layer with adhesive without affixing the top flooring layer to the subfloor (e.g., a single glue down installation). Similarly, one layer of the top flooring layer 102, underlayment material 120, and subfloor 104 may nailed or tacked to another layer, or both. Examples of nailing and/or tacking installations include carpet installation and hardwood flooring installation over a wood-based subfloor. Advantages of the underlayment material 120 for a floating installation in particular will be described.

Turning to FIG. 2, a cross section of a flooring system 200 is depicted. The flooring system 200 may be used in a commercial or residential setting. The flooring system 200 may include a top flooring layer 202, which may be carpet, tile, sheet vinyl, luxury vinyl tile (or planks), solid hardwood, engineered wood, and laminate flooring.

The flooring system 200 may include a subfloor 204 similar to that described in FIG. 1.

The flooring system 200 may include a non-skid underlayment material 220 interposed between the top flooring layer 202 and subfloor 204. The underlayment material 220 may have greater frictional properties with respect to the subfloor 204 than its frictional properties with respect to the top flooring layer 202. The underlayment material 220 may be lightweight and easy to handle.

The flooring system 200 may include an optional vapor barrier layer 230. As described in detail herein with respect to FIG. 3, the underlayment material 220 itself may have moisture vapor transmission properties that are suitable for certain applications. In some applications, however, additional moisture vapor protection may be desirable. If desired, a vapor barrier layer 230 may be disposed between the top flooring layer 202 and the subfloor 204. The vapor barrier layer 230 may be a film, which may be a polypropylene film, or a polyethylene film, or a foil, disposed between the underlayment material 220 and the subfloor 204. The vapor barrier layer 230 may be adhered to the underlayment material 220 and/or to the subfloor 204. The flooring system 200 may be assembled by any practicable means, generally depending on the type of subfloor 204 and top flooring layer 202.

Turning to FIG. 3, a cross section of a non-skid underlayment material 320 which can be used in the flooring systems of FIG. 1 and/or FIG. 2 is depicted. The underlayment material 320 may have at least two layers of distinct composition and/or mechanical properties, and may be a bilaminate (as illustrated). The underlayment material 320 may have additional layers (not depicted). The underlayment material 320 may be a single layer (such as depicted in FIGS. 5 and 6).

The underlayment material 320 may comprise a first layer 322. In a flooring system, the layer 322 may be adjacent to a top flooring layer (not depicted).

The layer 322 may comprise a fiber (such as a non-woven), a film (such as a thermoplastic polyolefin film, a PVC film, an EVA film, a vinyl film, or other membrane), a foil (such as a metallic foil), or a foam (such as a memory foam, polyurethane foam, EVA foam, PVC foam, latex foam, or a polyolefin foam). The layer 322 may comprise polyethylene, may consist essentially of polyethylene, or may consist essentially of a polyethylene foam. The layer 322 may comprise a non-cross-linked foam. The layer 322 may comprise a memory foam. The layer 322 may comprise non-cross-linked polyethylene. The layer 322 may have a density less than about 25 kg/m3. The layer 322 may have a density less than about 20 kg/m3. The layer 322 may have a density selected to compress under loading. The layer 322 may have a 25% compressive strength of less than about 1 kg/cm2 as measured by JIS K6767. The layer 322 may have a 25% compressive strength of less than about 0.8 kg/cm2 as measured by JIS K6767. The layer 322 may contribute to the SLP and MVTR of the underlayment material 320.

The layer 322 may be a non-woven fiber.

The layer 322 may have a thickness in a range from about 0.5 mm to about 6.0 mm. The thickness of the layer 322 may be in a range from about 1.5 mm to about 2.5 mm.

The underlayment material 320 may comprise a second layer 324 affixed to the layer 322. The layer 322 may be laminated to the layer 324 at the interface of their surfaces. Alternatively, the layer 322 may be connected to the layer 324 by any known means (e.g., mechanical).

The layer 324 may comprise a fiber (such as a non-woven), a film (such as a thermoplastic polyolefin film, a PVC film, an EVA film, a vinyl film, or other membrane), a foil (such as a metallic foil), or a foam (such as a memory foam, polyurethane foam, EVA foam, PVC foam, latex foam, or a polyolefin foam).

The layer 324 may comprise a cross-linked polypropylene copolymer (EPC) and a linear low density/polyethylene (LLDPE) blend foam with an EPC content of about 20% to 90% by weight. Preferably, the EPC content is between 50% and 90%. More preferably, the EPC content is between 70% and 90%. Other olefin materials that are suitable for use include, for example, homopolymers and copolymers of polyethylene, including high-density polyethylene (HDPE), low-density polyethylene (LDPE), very-low-density polyethylene (VLDPE), ultra-low-density polyethylene (ULDPE), and polymers or copolymers of polypropylenes, including cross-linked ethylene propylene copolymer.

The layer 324 may comprise a foam underlayment material such as, the FLOORMUFFLER™ underlayment available from Diversified Foam Products, Inc. (www.floormuffler.com).

The layer 324 may have a 25% compressive strength of at least about 0.85 kg/cm2, as measured by JIS K6767. Preferably, the layer 324 has a 25% compressive strength of at least about 1.0 kg/cm2. More preferably, the layer 324 has a 25% compressive strength of at least about 1.2 kg/cm2. Compressive strength is a property of the foam structure obtained primarily by the selection of resin, foam density, and the manufacturing processes used to convert resin into foam. It should be understood that higher polypropylene content may produce higher compressive strength and, accordingly, lower average reflected SPL. Density may also be a factor. For example, to increase compressive strength from approximately 3 kg/cm2 to approximately 6 kg/cm2, the foam density may be increased from about 100 kg/m3 to about 121 kg/m3.

The layer 324 may contribute reduced moisture vapor transmission rates (MVTR) to the underlayment material 320 without the need for the additional barrier layers. The layer 324 may have a MVTR of <3.0 lb/1000 ft²/24 hr. Flooring industry standards for MVTR of less than 3.0 lb/1000 ft²/24 hr are typically achieved by adding additional vapor barrier layers that add to both product cost and weight.

The layer 324 may contribute a desirable reflected sound pressure level (SPL) to the underlayment material 320. SPL varies with foam composition, extent of cross-linking, density, and thickness. The layer 324 may have a polypropylene content of greater than about 60% to greater than about 90%. The layer 324 may have a cross-link percentage or cross-link level that may range from about 40% to about 80%. Higher cross-link levels are possible; however, if cross-linking is too high, the foam will be difficult to roll onto a core, and will be difficult to lay flat. The type of resins selected, the amount of chemical cross-linking agent used, and the amount of exposure to a radiation source, such as an electron beam irradiation device, dictate the degree of cross-linking Also, in general, higher cross-link percentage provides slightly higher compressive strength. It is expected, therefore, that higher cross-link percentage should lead to slightly lower reflected SPL for the layer 324. It is also expected that higher cross-link percentage should also lead to lower MVTR.

The density of the layer 324 as determined by method ASTM D3575, may be about 20 to about 200 kg/m3. The layer 324 may have a range of density from about 40 to about 100 kg/m3. The layer 324 may have a range of density from about 50 to about 60 kg/m3. Higher density tends to increase the compressive strength of the foam and thereby reduce the reflected SPL. Increasing foam density, however, tends to add to product cost due to increased raw material consumption to manufacture. Density may be controlled by a number of factors, the types of resins used, the degree of cross-linking, process conditions, and the type and amount of foaming agent used. The thickness of the layer 324 may be in a range from about 0.5 mm to about 6.0 mm. The thickness of the layer 324 may be in a range from about 1.5 mm to about 2.5 mm. Thickness is dictated by the resin selection, type and amount of chemical foaming agent used, extruded sheet thickness, tension during the foaming operation, and the amount of heat applied during the conversion of sheet into foam. A 100 ft² roll of layer 324 may weigh less than about 5 lbs, while providing low reflected sound pressure levels in the 300 Hz to 1000 Hz range and MVTR performance that meets flooring industry standards.

The layer 324 has a surface 326. The surface 326 provides non-skid properties to the underlayment material 320. The surface 326 may provide non-skid properties to the underlayment material 320 without imparting adhesive properties. The surface 326 may comprise thermoplastic rubber. The surface 326 may comprise a melt-process-able rubber. The surface 326 may be a natural rubber, a thermoplastic urethane, a styrene-butadiene rubber, a styrene ethylene butylene styrene block copolymer, an ethylene propylene diene monomer rubber, a nitrile rubber, or a blend of any of these, with or without a thermoplastic rubber.

The surface 326 may comprise polypropylene or polyethylene.

The surface 326 may comprise a cling foam, such as an emulsion cling foam, a PVC foam plastisol, a highly plasticized PVC solid, an ethylene vinyl acetate, an acrylic, polyethylene, or polyurethane foam or solid, or any polymer that can be formed with frictional, but not tacky, properties (e.g., frictional properties, as opposed to adhesive properties).

The surface 326 may be formed as a coating.

The surface 326 may be formed by laminating a layer comprising the material that comprises the surface to the layer 324.

The surface 326 may describe the boundary (e.g., the physical exterior) of the layer 324. For example, the surface 326 may be formed by dispersing the material comprising the surface throughout the layer 324, such that the face of the layer 324 is a surface with non-skid properties.

The underlayment material 320 may comprise additional layers. For example, a vapor barrier polypropylene film or polyethylene film may be adhered to the underlayment material 320 before the underlayment is rolled (as described below). Thus, the underlayment material 320 may be delivered to the point of installation with the optional vapor barrier already adhered thereto, thus simplifying installation of the underlayment material and vapor barrier.

The underlayment material 320 may include non-skid elements affixed, adhered to, or resulting from, the layer 322, layer 324, or both.

The underlayment material 320 may include a foil layer to reflect heat.

The underlayment material 320 may include means to adhere adjoining sections of underlayment. The underlayment material 320 may include a tape strip (not depicted) to facilitate installation. The underlayment material 320 may comprise a first roll (not depicted) having a tape strip on a first planar surface of the underlayment, and a pull-out lip (not depicted) on the first planar surface, axial to the tape strip, such that when the first roll is unrolled and laid out next to a second roll that has also been unrolled and laid out, the tape strip of the first roll will engage the lip of the second roll, thereby connecting the first and second rolls. This may include creating a moisture resistant engagement between the tape strip and the lip (e.g., sealing what otherwise may be a vapor gap between two adjacent underlayment sections). The lip may extend axially from the roll in a range from about 0.5 in to about 8 in. The lip may be formed from a layer affixed to the underlayment 320 that extends axially fully across the roll, or may be a strip.

The underlayment material 320 may include at least one of an anti-microbial additive, a flame retardant additive, and an adhesion promoter.

The underlayment material 320 may be embossed or de-bossed for lamination, traction, or alignment purposes. The underlayment material 320 may receive printed materials, such as instructions, trademarks, or other communications.

The underlayment material 320 may have an Impact Insulation Class (IIC) value greater than about 40, greater than about 50, and/or greater than about 55, but less than about 80.

The thickness of the underlayment material 320 may be in a range from about 1 mm to about 15 mm. The thickness of the underlayment material 320 may be in a range from about 3 mm to about 10 mm. Relatively thick layers of around 6.0 millimeters or more may interfere with wall molding or door clearances. The thickness of the underlayment material 320 may be in a range from about 4 mm to about 6 mm.

Turning to FIG. 4, a bottom perspective sectional view of a non-skid underlayment material 420 which can be used in the flooring systems of FIG. 1 and/or FIG. 2 is depicted. The underlayment material 420 may have at least two layers of distinct composition and/or mechanical properties, and may be a bilaminate (as illustrated). The underlayment material 420 may have additional layers (not depicted). The underlayment material 420 may be a single layer (such as depicted in FIGS. 5 and 6).

The underlayment material 420 may comprise a first layer 422 and a second layer 424. In a flooring system, the layer 422 may be adjacent to a top flooring layer (not depicted).

As discussed above, the layer 422 and the layer 424 may comprise a fiber (such as a non-woven), a film (such as a thermoplastic polyolefin film, a PVC film, an EVA film, a vinyl film, or other membrane), a foil (such as a metallic foil), or a foam (such as a memory foam, polyurethane foam, EVA foam, PVC foam, latex foam, or a polyolefin foam), provided that the layers have distinct compositional differences and/or differences in mechanical properties.

A surface 426 is disposed upon at least a portion of the layer 424. The surface 426 may be applied to the surface of the underlayment 420 which contacts the subfloor. The surface 426 provides non-skid properties to the underlayment material 420. The surface 426 may provide non-skid properties to the underlayment material 420 without imparting adhesive properties. The surface 426 may comprise thermoplastic rubber. The surface 426 may comprise a melt-process-able rubber. The surface 426 may comprise a natural rubber, a thermoplastic urethane, a styrene-butadiene rubber, a styrene ethylene butylene styrene block copolymer, an ethylene propylene diene monomer rubber, a nitrile rubber, or a blend of any of these, with or without a thermoplastic rubber.

The surface 426 may comprise polypropylene or polyethylene.

The surface 426 may comprise a cling foam, such as an emulsion cling foam, a PVC foam plastisol, a highly plasticized PVC solid, an ethylene vinyl acetate, an acrylic, polyethylene, or polyurethane foam or solid, or any polymer that can be formed with frictional, but not tacky, properties (e.g., frictional properties, as opposed to adhesive properties).

The surface 426 may be formed as a coating.

The surface 426 may be formed by laminating a layer comprising the material that comprises the surface to the layer 424.

The surface 426 may describe the boundary (e.g., the physical exterior) of the layer 424. For example, the surface 426 may be formed by dispersing the material comprising the surface throughout the layer 424, such that the face of the layer 424 is a surface with non-skid properties.

Recessed features 428 may be disposed in the layer 424, such as may be created by de-bossing. The recessed features 428 may balance against the non-skid effects of the surface 426, by reducing surface area of layer 424 that contacts the subfloor (not depicted). The features 428 may be absent in some embodiments. Additional embossed features or textures (not depicted) may be present.

Turning to FIG. 5, a sectional view of a non-skid underlayment material 520 which comprises a single layer 524 is depicted. The underlayment material 520 can be used in the flooring systems of FIG. 1 and/or FIG. 2. The underlayment material 520 may have additional layers (not depicted).

The layer 524 may comprise a fiber (such as a non-woven), a film (such as a thermoplastic polyolefin film, a PVC film, an EVA film, a vinyl film, or other membrane), a foil (such as a metallic foil), or a foam (such as a memory foam, polyurethane foam, EVA foam, PVC foam, latex foam, or a polyolefin foam). The layer 524 may comprise a cross-linked polypropylene copolymer (EPC) and a linear low density/polyethylene (LLDPE) blend foam with an EPC content of about 20% to 90% by weight. Preferably, the EPC content is between 50% and 90%. More preferably, the EPC content is between 70% and 90%. Other olefin materials that are suitable for use include, for example, homopolymers and copolymers of polyethylene, including high-density polyethylene (HDPE), low-density polyethylene (LDPE), very-low-density polyethylene (VLDPE), ultra-low-density polyethylene (ULDPE), and polymers or copolymers of polypropylenes, including cross-linked ethylene propylene copolymer.

The layer 524 may comprise a foam underlayment material such as, the FLOORMUFFLER^TM underlayment available from Diversified Foam Products, Inc. (www.floormuffler.com).

A surface 526 is applied to at least a portion of the layer 524. The surface 526 provides non-skid properties to the underlayment material 520. The surface 526 may provide non-skid properties to the underlayment material 520 without imparting adhesive properties. The surface 526 may comprise thermoplastic rubber. The surface 526 may comprise a melt-process-able rubber. The surface 526 may comprise a natural rubber, a thermoplastic urethane, a styrene-butadiene rubber, a styrene ethylene butylene styrene block copolymer, an ethylene propylene diene monomer rubber, a nitrile rubber, or a blend of any of these, with or without a thermoplastic rubber.

The surface 526 may comprise polypropylene or polyethylene.

The surface 526 may comprise a cling foam, such as an emulsion cling foam, a PVC foam plastisol, a highly plasticized PVC solid, an ethylene vinyl acetate, an acrylic, polyethylene, or polyurethane foam or solid, or any polymer that can be formed with frictional, but not tacky, properties (e.g., frictional properties, as opposed to adhesive properties).

The surface 526 may be formed as a coating.

The surface 526 may be formed by laminating a layer comprising the material that comprises the surface to the layer 524.

The surface 526 may describe the boundary (e.g., the physical exterior) of the layer 524. For example, the surface 526 may be formed by dispersing the material comprising the surface throughout the layer 524, such that the face of the layer 524 is a surface with non-skid properties.

Turning to FIG. 6, a non-skid underlayment material 620 which comprises a single layer 624 is depicted. The underlayment material 620 can be used in the flooring systems of FIG. 1 and/or FIG. 2. The underlayment material 620 may have additional layers (not depicted).

The layer 624 may comprise a fiber (such as a non-woven), a film (such as a thermoplastic polyolefin film, a PVC film, an EVA film, a vinyl film, or other membrane), a foil (such as a metallic foil), or a foam (such as a memory foam, polyurethane foam, EVA foam, PVC foam, latex foam, or a polyolefin foam). The layer 624 may comprise a cross-linked polypropylene copolymer (EPC) and a linear low density/polyethylene (LLDPE) blend foam with an EPC content of about 20% to 90% by weight. Preferably, the EPC content is between 50% and 90%. More preferably, the EPC content is between 70% and 90%. Other olefin materials that are suitable for use include, for example, homopolymers and copolymers of polyethylene, including high-density polyethylene (HDPE), low-density polyethylene (LDPE), very-low-density polyethylene (VLDPE), ultra-low-density polyethylene (ULDPE), and polymers or copolymers of polypropylenes, including cross-linked ethylene propylene copolymer.

The layer 624 may comprise a foam underlayment material such as, the FLOORMUFFLER™ underlayment available from Diversified Foam Products, Inc. (www.floormuffler.com).

The layer 624 has a pair of surfaces 626. The surface 626 provides non-skid properties to the underlayment material 620 on both surfaces (such as the surface contacting the subfloor and the surface contacting the top flooring layer). The surface 626 may provide non-skid properties to the underlayment material 620 without imparting adhesive properties. The surface 626 may comprise thermoplastic rubber. The surface 626 may comprise a melt-process-able rubber. The surface 626 may be a natural rubber, a thermoplastic urethane, a styrene-butadiene rubber, a styrene ethylene butylene styrene block copolymer, an ethylene propylene diene monomer rubber, a nitrile rubber, or a blend of any of these, with or without a thermoplastic rubber.

The surface 626 may comprise polypropylene or polyethylene.

The surface 626 may comprise a cling foam, such as an emulsion cling foam, a PVC foam plastisol, a highly plasticized PVC solid, an ethylene vinyl acetate, an acrylic, polyethylene, or polyurethane foam or solid, or any polymer that can be formed with frictional, but not tacky, properties (e.g., frictional properties, as opposed to adhesive properties).

The surface 626 may be formed as a coating.

The surface 626 may be formed by laminating a layer comprising the material that comprises the surface to the layer 624.

The surface 626 may describe the boundary (e.g., the physical exterior) of the layer 624. For example, the surface 626 may be formed by dispersing the material comprising the surface throughout the layer 624, such that the face of the layer 624 is a surface with non-skid properties.

FIG. 7 provides a flowchart of an example method 700 for manufacturing a polyolefin foam underlayment material. At 702, one or more polyolefin resins may be mixed with a foaming agent, one or more cross-linking agents, and/or one or more additives, into a homogenous mixture. Examples of polyolefin resins include polyethylene and/or polypropylene. Examples of cross-linking agents include peroxides (e.g., di cumyl peroxide, etc.) for polyethylenes, and di vinyl benzene for polypropylenes. Examples of additives include flame retardants, adhesion promoters, colorants, and anti-microbial agents. A homogenous mixture may be achieved by spinning the mixture in a mechanical mixer designed for compounding plastic resins. Examples of such mixers are well-known. To ensure complete and proper mixing, agitation rate, temperature, and processing duration may be selectively controlled during this step by well-known industrial process control means.

At 704, the mixture may charged, for example, into a conventional plastics extruder, into which the ingredients are conveyed in a barrel by a screw, to produce a solid, thin, plastic web. The ingredients may be initially compressed and mixed as the materials move along the screw.

Heater elements, along with the shearing action of materials against each other and the screw and barrel, cause the resins to melt into a viscous liquid state. Additives and/or colorants may be added to the product at this stage of the process as well. The screw pushes the melted extrudate through a die opening to produce the thin, solid web. The web may typically be between about 0.2 and about 3.0 millimeters in thickness, although not limited, as thicker or thinner webs can be produced as desired. As it is extruded, the web may cool from a molten state to a solid state. The web may then be trimmed, and wound into a roll.

At 706, the polymer resins may be cross-linked, for example by irradiation by electron beam. Other methods, such as chemical cross-linking, for example, may be employed. The degree of cross-linking may be controlled to result in a typical cross-link density of about 15% to about 80%. A higher percentage level of cross-linking is possible if desired. A desired degree of cross-linking may be achieved by the type of resins selected, the amount of chemical cross-linking agent used, and/or the exposure to a radiation source such as an electron beam irradiation device.

At 708, the continuous polymer web may be converted into a relatively low-density foam. For example, the foam may be heated by radiant heaters, molten salt, hot air, or other heating devices. The heat causes a reaction of the chemical foaming agent that causes the foaming agent to releases gases, thus forming a cellular structure in the web. The combination of resins selected, cross-linking, and the process used may be selected to create a fine-celled structure, with typical cells ranging from about 0.1 to about 1.0 millimeter. It should be understood that larger and smaller cell sizes are possible.

A desired thickness may be achieved by the resin selection, type and amount of chemical foaming agent used, extruded sheet thickness, tension during the foaming operation, amount of heat applied during the conversion of sheet into foam. For example, an extruded sheet having a thickness of about 1 millimeter may produce a relatively high density polyolefin foam having a thickness of about 1.5 millimeter if little foaming agent is used. A relatively low density foam having a thickness of about 2.5 millimeter may be produced if a greater quantity of foaming agent is used. A desired density may be achieved by the selection of resins used, the degree of cross-linking, process conditions, and the type and amount of foaming agent used.

The continuous polymer web may be converted into a relatively low-density foam. For example, the foam may be heated by radiant heaters, molten salt, hot air, or other heating devices. The heat causes a reaction of the chemical foaming agent that causes the foaming agent to releases gases, thus forming a cellular structure in the web.

A desired thickness may be achieved by the resin selection, type and amount of chemical foaming agent used, extruded sheet thickness, tension during the foaming operation, amount of heat applied during the conversion of sheet into foam. For example, an extruded sheet having a thickness of about 1 millimeter may produce a relatively high density polyolefin foam having a thickness of about 1.5 millimeter if little foaming agent is used. A relatively low density foam having a thickness of about 2.5 millimeter may be produced if a greater quantity of foaming agent is used. A desired density may be achieved by the selection of resins used, process conditions, and the type and amount of foaming agent used. The layer may be laminated to another layer (see FIG. 3).

At 710, at least one layer is provided (e.g., at least partially provided with) with a surface as described herein to provide non-skid properties to the underlayment material.

At 712, the finished foam web may be rolled onto a core, such as a cardboard or paper tube, for example.

At 714, the finished foam web may undergo further processing, for example, the foam web may be coated with an adhesive layer or release layer, laminated with films (including, for example, lips and tape strips as described above), foils, fabrics, nonwovens, or other foams, or molded for any of a variety of uses.

In another method, the underlayment material may be a lamination of a foam to a coated film (e.g., polyethylene, polypropylene, or others coated with the thermoplastic rubber) to provide a non-skid surface. For example, the film may be coated, and then the film could be laminated to the foam.

Claims

1. A flooring system, comprising:

a top flooring layer;

a subfloor; and

an underlayment material disposed between the subfloor and the top flooring layer, wherein the underlayment material comprises: at least one layer; and a non-skid surface disposed on the layer for engaging the subfloor, the surface comprising thermoplastic rubber.

2. The flooring system of claim 1, wherein the layer of the underlayment material is a cross-linked polyolefin foam.

3. The flooring system of claim 2, wherein the cross-linked polyolefin foam is produced from a resin composition comprising a blend of polyethylene and polypropylene.

4. The flooring system of claim 1, wherein the layer of the underlayment material is a non-cross-linked foam.

5. The flooring system of claim 4, wherein the non-cross-linked foam is a polyolefin foam.

6. The flooring system of claim 4, wherein the non-cross-linked foam consists essentially of polyethylene.

7. The flooring system of claim 1, further comprising a non-woven layer laminated to the layer of the underlayment material.

8. The flooring system of claim 1, wherein the surface is on both surfaces of the underlayment material.

9. A flooring system, comprising:

a top flooring layer;

a subfloor; and

an underlayment material disposed between the subfloor and the top flooring layer, wherein the underlayment material comprises: at least one polyolefin layer; a non-woven layer; and a non-skid surface disposed on the polyolefin layer for engaging the subfloor, the surface comprising thermoplastic rubber.

10. The flooring system of claim 9, wherein the at least one polyolefin layer is a cross-linked polyolefin foam.

11. The flooring system of claim 10, wherein the cross-linked polyolefin foam comprises a blend of polyethylene and polypropylene.

12. The flooring system of claim 9, wherein the at least one polyolefin layer is a non-cross-linked polyolefin foam that consists essentially of polyethylene.

13. The flooring system of claim 9, wherein the underlayment material includes at least one of an anti-microbial additive, a flame retardant additive, and an adhesion promoter.

14. The flooring system of claim 9, wherein at least one polyolefin layer is partially debossed.

15. A method, comprising:

placing an underlayment material between a subfloor and a top flooring layer, wherein the underlayment material comprises a non-skid surface for engaging the subfloor, the surface comprising thermoplastic rubber.

16. The method of claim 15, wherein the thermoplastic rubber provides a frictional resistance to movement for the underlayment material relative to at least one of the subfloor and the top flooring layer.

17. The method of claim 15, wherein the thermoplastic rubber does not provide an adhesive resistance to movement for the underlayment material relative to at least one of the subfloor and the top flooring layer.

18. An underlayment material for placing between a subfloor and a top flooring layer, wherein the underlayment material comprises:

a non-skid surface for engaging the subfloor, the surface comprising thermoplastic rubber.

19. The underlayment material of claim 18, wherein the underlayment material comprises a film that has been treated with the surface laminated to a foam layer.

20. The underlayment material of claim 19, wherein the film is a polyethylene film or a polypropylene film.