TUFTED ARTICLES AND METHOD OF MAKING SAME

Abstract: A tufted mat and a method for its manufacture are described. The mat is suitable for use as a floor mat and comprises a sheet-like substrate and a pile layer comprising tufted bundles of textured synthetic resinous filaments, each having a linear density of at least 800 denier, the filaments in each bundle formed into loops of random shapes and orientations and intermingled with loops in adjacent bundles of filaments in the pile layer.

Description: TUFTED ARTICLES AND METHOD OF MAKING SAME The present invention relates to tufted articles suitable for use as floor mats for placement at the entryways of buildings and to a method of making such articles. Background Of The Invention Because of their excellent wear resistance, pile fabrics made with synthetic fibers (e.g., nylon) are widely used as floor mats employed at the entryways of buildings or as artificial lawns, for example. Such articles are preferably constructed to maintain their shape against repeated loads from pedestrian foot traffic and the like. Floor mats, for example, typically include a fibrous or fabric surface to provide a desired wiping function to remove soil or sand from the shoe soles of pedestrians. Many available mats, however, are less than satisfactory because of their generally limited capacity to retain or store removed soil and water. Such mats may require frequent shaking and washing to rejuvenate the mat for subsequent use. Japanese Unexamined Utility Model Publication No. 2-122092 discloses an article having loop piles comprised of resinous synthetic filament bundles. The loop piles are formed on a substrate sheet to provide a pile layer comprising regularly arranged piles wherein the filaments within each of the piles are neither randomly oriented nor intermingled with filament loops in adjacent bundles. U.S. Patent Nos. 4,351,683 and 3,837,988 describe resilient, open porous three dimensional fibrous webs used as mats. The mats comprise a multiplicity of coarse uncrimped filaments having a diameter from 0.1 to 4 mm wherein the filaments are interengaged to form rigid porous nonwoven structures. These webs do not include a tufted loop pile layer with random void spaces therein. U.S. Patents 4,893,439 and 4,820,566 describe the use of large denier fibers to remove dirt. U.S. Patent 4,893,439 describes an abrasive article made of a nonwoven web comprised of helically crimped fibers ranging in linear densities from about 6 to 400 denier per filament ("dpf '). U.S. Patent 4,820,566 and related Japanese Unexamined Patent Publication No. 63-288262 describe a tufted carpet comprising a plurality of tufts of fine denier fibers (e.g., having linear densities from about 15 to 50 dpf) and a plurality of stiff coarse denier fibers (e.g., having linear densities from about 150 to 500 dpf). Pile yarns used in floor coverings are generally made of textured or crimped fibers having a liner density of 500 denier or less. Various known crimping methods have been employed to impart a desired texture or crimp to the fibers. These methods include stuffer box or air-jet crimping, for example, to form a pile structure comprising textured fibers in an unopened state. These known textured fibers, however, are generally of a linear density no greater than 800 denier, generally have less than optimum crimp rigidity and have not been completely satisfactory for forming a durable pile layer in a mat. It is desirable to provide an improved construction for a tufted mat or like article with a pile layer thereon comprising tufted textured fibers having linear densities of at least 800 dpf and having an improved void structure so that the mat is capable of wiping and absorbing dirt such as moist soil or sand and retaining the same within the mat. It is also desirable to provide the foregoing mat to be durable enough to withstand the repeated impacts by pedestrian traffic. Summary Of The Invention The present invention provides a tufted article suitable for use as a floor mat that is capable of withstanding significant pedestrian traffic and is useful for placement at the entryway of a building, for example, to wipe wet and/or dirty shoe soles. The mat of the invention will retain dirt and water therein to prevent the retracking of retained dirt. In one aspect, the invention provides an article suitable for use as a floor mat comprising a sheet-like substrate and a tufted pile layer extending from one side of the substrate, the pile layer comprising tufted bundles of textured synthetic resinous filaments, each filament having a linear density of at least 800 denier, the filaments in each tufted bundle arranged in loops of random shapes and orientations and intermingled with loops in adjacent tufted bundles of filaments in the pile layer. The pile layer preferably has a thickness when measured outward from the surface of the substrate of at least 5 mm and preferably between 5 mm and 15 mm. The face weight of the tufted pile layer is preferably between 600 and 2000 g/m and more preferably between 900 and 1300 g/m , and the void ratio of the pile layer is preferably within the range between 50% and 80%, and more preferably between 60% and 80%, to provide a pile layer with a desired ability to retain soil and which is resilient and durable enough to withstand pedestrian traffic without significant deterioration. The synthetic resinous filaments preferably comprise thermoplastic materials such as nylon, polyolefin, polyester, polycarbonate, polystyrene or the like, and the individual filaments have a preferred linear density within the range from 1000 to 1800 denier. The sheet-like substrate may be a woven or nonwoven fabric comprising fibers made from natural or synthetic materials selected from jute, cotton, polyester, polypropylene, polyester and combinations thereof. A secondary backing may be affixed to the substrate and is preferably a cured coating formed from vinyl plastisol, polyurethane, rubber latex or like materials. As used herein, "pile layer" means the surface layer of the mats described herein comprising tufted bundles of coarse denier fibers. "Void ratio", expressed as a percentage, is a value relating to the volume of empty space within the pile layer of an article determined according to the procedure set forth below. "Denier" refers to the fineness of a fiber, sometimes also referred to as linear density, and is defined as the weight in grams of a 9,000 meter fiber. "Face weight" refers to the weight of the tufted pile layer per unit of area. In referring to fiber loops of "random" shapes and orientations, it will be understood that the shapes and orientations of the fiber loops are not ordered or of a fixed configuration. "Tufting" refers to a process which inserts portions of yarn into a woven or nonwoven backing material, as known to those in the art. "Bundle" refers to the portion of yarn inserted into a woven or nonwoven backing material in the tufting operation. A plurality of bundles extending from a surface of the woven or nonwoven backing material collectively form a pile layer. "Textured" or "crimped" in referring to the filaments of fibers herein refers to the waviness of the filament or fiber. "Fiber" and "filament" are used interchangeably and refer to a threadlike structure comprising the materials described herein. In another aspect, the invention provides a method for producing an article suitable for use as a mat, comprising: providing a textured yarn comprising a plurality of textured filaments, the filaments each having a linear density of at least 800 denier; and tufting the yarn to a substrate to form a plurality of bundles on one side of the substrate , the plurality of bundles forming a pile layer on the one side of the substrate, and each bundle of the pile layer comprising loops of the textured filaments wherein the loops are randomly shaped and oriented and are intermingled with loops in adjacent bundles of the pile layer. In this aspect of the invention, tufting is carried out to provide the pile layer with a thickness of at least 5 mm and preferably in the range between 5 mm and 15 mm with a void ratio in a range between 50% and 80% and a face weight between 600 and 2000 g/m , as mentioned above. The pile layer is formed using yarn made of two to twelve fibers, preferably four to ten fibers, having the aforementioned linear density. The yarn is tufted on a sheet-like substrate or cloth backing, such as a woven or nonwoven fabric, using a general purpose tufting machine. The tufting density and height of the loop pile above the backing are selected so that the above- described void ratio is satisfied. A pile layer having a desired void ratio is prepared by selecting a suitable gauge and stitch of the tufting machine while taking into consideration the size of filament, the number of crimps per filament and the number of filaments in the yarn, as known by those skilled in the art. The method preferably further comprises forming a secondary backing on another side of the substrate opposite the pile layer, the secondary backing preferably comprises a cured coating of a material selected from vinyl plastisol, polyurethane, rubber latex and similar materials. The invention provides articles useful as floor mats, for example, having excellent wiping ability and which have a significant void volume to retain dirt such as soil or sand therein. The articles of the invention are tough and resilient and are able to withstand significant use, including repeated pedestrian traffic over the pile layer of the article, without substantial deterioration. In applications such as floor mats, for example, the thickness and density of the pile layer can be constructed to accommodate expected levels of pedestrian traffic and associated levels of soil or dirt expected therefrom. Those skilled in the art will further understand and appreciate the various features and advantages of the invention upon further consideration of the remainder of the disclosure, including the detailed description of the preferred embodiment and the appended claims. Brief Description Of The Drawings In describing the preferred embodiment of the invention, reference is made to the various figures wherein: Figure 1 is a top plan view of a mat according to the present invention; Figure 2 is an elevated view, in cross section, of the mat shown in Figure 1, taken along the 2-2 line thereof; and Figure 3 is an elevated view, in cross section, of the mat shown in Figure 2, taken along the 3-3 line thereof. Detailed Description Of The Preferred Embodiment The details of the preferred embodiment will now be described with reference to the various figures wherein the structural features of the embodiment are identified by reference numerals and wherein like reference numerals indicate like structures. The tufted mat of the present invention may be produced by conventional carpet making equipment and specifically by the use of known tufting technology. Tufting is a process which inserts tufts of yam into a woven or nonwoven backing material. Yam is a collection of textured fibers of an appropriate size, in continuous or discontinuous lengths. The yarn is tufted to a substrate by inserting portions of the yam through the backing material using vertically reciprocating needles, similar to the action of a conventional sewing machine. In the present invention, yams comprising a plurality of coarse denier fibers of at least 800 denier, are fed to a collection of spaced needles on a needle bar. The coarse fibers are inserted into a primary backing to create continuous areas comprising tufted bundles of the coarse denier fibers, typically in side by side rows. Referring to Figure I, a surface 10 of a pile layer comprises a random arrangement of tufted loops of coarse filaments 1 wherein the filaments 1 each have a fineness or linear density of at least 800 denier and preferably between 1000 and 1800 denier. The loops of filaments assume random shapes and orientations, so that the individual loops are intermingled with one another throughout the pile layer. The intermingled loops of filaments 1 collectively form a pile layer having an open structure capable of receiving and retaining dirt. As shown in Figure 2, the pile layer comprises loops 12 of synthetic filaments 1 extending from tufted bundles 14. The bundles 14 are the tufted portions of the aforementioned yam which protrude through a primary sheet-like substrate 16 as a result of the tufting operation. The bundles 14 are arrange along a surface of the substrate 16 with the textured filaments 1 deployed in loops 12 which extend outward from the center of each bundle 14. The bundles 14 are spaced apart in an orderly fashion on the surface of the primary substrate 16 with adjacentbundles 14 spaced sufficiently close to one another that loops 12 from adjacent bundles 14 are intermingled to form a pile layer 20 (Figure 3) with a substantially uniform face weight and thickness per unit area and which presents a substantially uniform surface of fibrous material suitable for use as a floor mat, for example. A secondary backing member 18 is preferably affixed to a side of the primary substrate 16 opposite the pile layer 20. The secondary backing member 18 comprises a cured resin layer and is typically included in the article to provide weight or body to the article. When the article is used as a floor mat, for example, the secondary backing member 18 is normally included in the construction to prevent the mat from slipping or otherwise being displaced when it is walked over by pedestrians during normal use. As shown in Figures 2 and 3, the filaments 1 of the tufted bundles 14 form loops 12 of random shapes and orientations. Each of the loops 12 extend up from the center of a bundle 12 along one side of the primary substrate 16. The loops 12 of each of the bundles 14 extend randomly from the center of the bundle 14, intermingling with the loops 12 in adjacent or surrounding bundles 14. In this manner, the intermingled loops 12 form a cooperative or interrelated structure, collectively forming the pile layer 20 with a thickness T (Figure 2) which, preferably, is within the range from 5 mm to 15 mm. Articles of the invention, when used as floor mats, will typically have a face weight of the tufted pile layer 20 between 600 and 2000 g/m 2 and preferably between 900 and 1300 g/m 2 . Those skilled in the art will appreciate that the face weight of the pile layer 20 may be adjusted to provide a desired value by yam spacing (or machine gauge) as well as by tuft length to provide a desired pile height, yam or filament denier, and the like. A pile height higher than the aforementioned upper limit (e.g., greater than 15 mm) is generally not desired because it may present a tripping hazard. Conversely, a pile layer shorter than the aforementioned lower limit (e.g., less than 5 mm) is similarly undesired because it may have insufficient capacity or void space for the storage of dirt and moisture. Also, if the stitch spacing is too tight, the resulting pile layer 20 may comprise bundles 14 which are too closely spaced to one another, again resulting in an article (e.g., a mat) that may not have sufficient volume (e.g., void volume) for the storage of dirt and moisture. As mentioned, a suitable void volume for the articles of the invention is between 50 and 80% and preferably between 60 and 80%. Void volume, as used herein, is expressed as a percentage and is a measure of the capacity of an article (e.g., a mat) for holding dirt, sand, water and the like within the open space of the pile layer formed by the loops of the aforementioned tufted bundles. The determination of void volume is based on the capacity of the article for holding dry sand having a known apparent density (e.g., 1.4 g/cm 3 ), and the void volume is determined according to the formula: K (%) = [ (W - W 0 ) / (1.4 x S x T) ] x 100 where W 0 is the initial weight (grams) of the article (e.g., free of retained dirt or moisture); W is the weight (g) of the article after the pile layer has been filled with dirt, sand, water or the like; T is the thickness of the pile layer; and S is the area of the article (e.g., 100 cm ). The pile layer 20 in the articles of the invention is a durable and resilient structure comprised of randomly shaped spaces formed by the looped coarse filaments 1. The loops 12 provide the pile layer 20 with the capacity for the storage of dirt and moisture while also providing a resilient surface that can function as a mat and which is strong and resilient enough to withstand significant and repeated pedestrian traffic. Suitable filaments for use in the articles of the invention can comprise any of a variety of materials including any of a variety of cured or hardened thermoplastic synthetic resins, such as nylon, polyolefin (e.g., polypropylene), polyester (e.g., polyethylene terephthalate), polycarbonate or polystyrene. The filaments 1 used in the articles of the invention preferably are crimped, continuous, coarse filaments having a fineness or a linear density of at least 800 denier and preferably in a range between 1000 and 1800 denier. Such crimped filaments having the linear densities within the aforementioned ranges provide the rigid durable pile layer 20, as mentioned. One preferred material suitable for use in the articles of the invention is the 1300 denier nylon 6 fiber available under the trade designation "Tufgrass NMK" from Hagiwara Industry, Japan. The aforementioned fibers used in the articles of the invention may be of any cross sectional configuration. Preferably the cross sectional configuration of the fibers are circular, polygonal or oval rather than flat, so as to avoid the generation of anisotropy in rigidity. Filaments less than 800 dpf are undesirable because they will tend to flatten more readily when exposed to foot traffic traversing the article. Flattening of the pile layer is undesired because the ability of the layer 20 to wipe and retain soil diminishes as the layer is flattened. Filaments having linear densities greater than 2000 dpf are not recommended because of the difficulty in imparting crimp to fibers of such sizes, and crimping is desired because coarse crimped fibers provide the aforementioned open loops 12 having random configurations and orientations in the pile layer so that loops 12 in each bundle of the pile layer intermingle with the loops 12 in adjacent bundles. Continuous filaments are desired due to the requirements of the conventional equipment employed in the manufacture of the articles of the invention. Specifically, conventional tufting equipment generally requires coarse yams to be made of continuous filaments. The primary backing used in the articles of the invention is a fabric which may be woven or nonwoven and may be formed of natural fibers, synthetic fibers or combinations of natural and synthetic fibers. Preferred fibers include natural fibers comprising cotton or jute and synthetic fibers comprising polypropylene or polyester. The fibers of the primary backing may be made from any of a variety known processes, and the backing may be needletacked to another material, such as a nonwoven mat, to provide a locking effect for the tufts and to prevent the backing material from unraveling, all in a known manner. A suitable backing material for use in the articles of the invention includes the nonwoven polyester material commercially available from Hagiwara Industry, Japan, under the designation "TUFPET CLOTH 22x13". The tufted articles of the present invention preferably also include a secondary backing which provides weight or body to the article so that when the articles are provided as mats, for example, the secondary backing prevents the article from being displaced when it is walked over. The secondary backing may be made from conventional materials, including cured materials selected from vinyl plastisol, polyurethane, rubber latex and similar materials. The secondary backing may be foamed, patterned or ribbed and may be filled with materials conventionally used in backings for mats and/or for carpeting materials. One commercial material suitable material for use in the formation of the secondary backing is poly(vinylchloride) plastisol available under the trade designation "Raditex VL-1070" from Higashi Chemical Co., Japan. As mentioned, the filaments used in the articles of the invention are textured (e.g., crimped). To achieve the desired degree of crimping of the filaments, any known texturizing method may be used. Such methods include twist-heating, twist-heat-detwisting, air-jet texturizing, knit-deknit, edge-crimping, gear-crimping and the like. The crimping method selected should be one that produces crimps in the filaments sufficient to allow the filament loops, after tufting to the primary substrate, to easily open or deploy, thereby forming the above described structure of randomly oriented filament loops collectively forming a pile layer. Suitable texturing of the filaments may be accomplished by using a combination of twist-heating and knit-deknit. In this process, a plurality of continuous filaments is collected, typically two to twelve filaments. The filaments are arranged in a parallel manner and the collection of filaments is twisted about the longitudinal axis of the collected fibers. The continuous filaments are typically twisted more than ten turns per meter of filament, preferably more than twenty turns per meter, and more preferably about 40 turns per meter. Twisting may be in the "Z" direction (e.g., counterclockwise) or in the : "S" direction (e.g., clockwise). In this manner, the filaments are formed into a coarse yam, and preferably all of the yam used in the formation of the pile layer have been formed by twisting the filaments in the same direction (e.g., either in the S or Z directions). The twisted filaments are then supplied to a conventional knitting machine where it is knitted into a fabric, and the knitted fabric is heated to set the texture of the filaments. A knitted fabric comprising nylon 6 fibers, for example, is typically heated at a temperature of about 130°C for a period of about 40 minutes. For other materials, the temperature at which the heat set operation is performed will typically be between about 100°C and the softening point of at least one of the filament components in the bundle. The determination of the appropriate heat set temperature is well within the skill of those in the art. Thereafter, the fabric is allowed to cool to room temperature, typically for 8 to 10 hours. The cooled fabric is then unraveled or "deknitted" to provide a textured yam suitable for use in the articles of the invention. The textured yam is supplied to a tufting machine and tufted through a primary substrate to form the pile layer, described above. The linear densities of the fibers (e.g., at least 800 denier) used in forming the pile layer in the articles of the present invention provide a coarse yam which, when tufted through the primary substrate, provides bundles that open naturally (e.g., without an additional opening operation). Once opened, the filament loops assume random shapes and orientations wherein the loops in one bundle are intermingled with the loops from adjacent tufted bundles. As mentioned, the twist imparted to the filaments is preferably uniformly one-directional to provide a loop pile structure with the aforementioned random shapes and orientations. Commercially available textured yams may be used in the manufacture of the articles of the invention. Textured yams made from the aforementioned 1300 denier nylon 6 fibers ("Tufgrass NMK"), for example, are commercially available from Hagiwara Industry. The articles of the invention may be used in any of a variety of applications where a resilient pile layer with an ability to retain soil and / or moisture is desired. The articles of the invention are particularly well suited for use as floor mats for placement at the entry way of buildings or the like, and such mats may be used in both indoor as well as outdoor applications. The articles of the invention may also be used as splash preventive members (e.g., splash guards or mud guards) for automobiles by attaching the article to the automobile in a conventional manner (e.g., to the inner side of an automobile wheel-arch). TEST METHODS The articles made and described in the Examples were evaluated according to the procedures set forth below. Soil/Sand Wiping Test This test procedures provides a determination of the amount of material that can be retained within the pile layer of a mat. Each mat tested was weighed before the test and all of the mats were of the same surface area, measuring 0.9 meters in width and 3.6 meters in length. In this determination, one adult wearing rubber soled shoes first stepped with both feet in a pan filled with dry sand. The dry sand had an average particle size of less than 640 microns and an apparent density of 1.4 g/cm . After stepping in the pan, the adult walked on the surface of the mat to be tested, placing six steps (three per each foot) on each mat using a normal walking step and without wiping.. After repeating this sequence 500 times, the weight (in grams) of sand left on the mat was measured. This test was repeated three times per mat. The same adult performed the testing of all mats herein. The average weight of retained sand for the three tests was recorded and the results were compared to evaluate the relative wiping abilities of each test mat. Thickness Reduction Percentage Bv Dynamic Load This test measure the reduction in the thickness of the pile layer for the mats tested, in accordance with Japanese Industrial Standard test method JIS L- 1021-1979 entitled "Testing Methods For Textile Floorcoverings", utilizing the rotary method described therein. Conditions included a load of 1 kg/arm (impact rotor) and the measurement of thickness reduction was made after 10,000 revolutions of the test mat on a rotary dynamic load tester. Three samples per test mat were evaluated according to the test method. The thickness reduction, expressed as a percentage, for each sample was determined according to the following formula: Thickness Reduction (%) = [(t 0 - 1,)/ 1 0 ] x 100 where t o is the thickness (mm) of the test specimen prior to impact loading; and tj is the thickness of the test specimen (mm) after impact loading for 10,000 revolutions of the test specimen. Measurement Of Void Ratio (%) This test measured the empty space within the pile layer of the test mats, providing a measure of the capacity of the mats for the storage of soil. Test specimens of 100 cm 2 (S) (10 cm x 10 cm) were weighed and the thicknesses of the pile layers (T) were measured for each specimen. The values for the initial weights (W 0 ) and the thicknesses were recorded. The pile layer of each test specimen was filled with dry sand having an apparent density of 1.4 g/cm so that the outer surface of the pile layer was concealed by the sand. The final weights (W) of the specimens were measured and recorded. The void ratio (K%) was determined for each test specimen according to the following formula: K (%) = [ (W - W 0 ) / (1.4 x S x T) ] x 100 The advantages and features of the present invention are further described below with reference to the following non-limiting Examples. EXAMPLES EXAMPLE 1 A textured yam was obtained from Hagiwara Industry, Japan, comprising six nylon filaments (commercially available from Asahi Chemical Industry, Japan, under the trade designation "Leona Special:") of circular cross-section, each filament having a linear density of 1300 dpf. The yam was prepared by twisting the six filaments in the Z-direction (right hand twist) at 40 turns/meter using a ring type general twist machine. Thereafter, the twisted filaments were fed to a knitting machine configured with 1 needle/cm to form a knitted fabric. The fabric was heated at a temperature of 130°C for 40 minutes and then cooled at room temperature for 8-10 hours and deknitted to provide a textured yam. The yam was fed to a tufting machine (5/32 gauge) to form tufted bundles 14 mm long at a stitch of 3.2 mm on a woven substrate of polyester fibers (commercially available from Hagiwara Industry under the designation "Tufpet Cloth 22x13"). The resulting pile layer had a thickness (T) of 9 mm and a face weight of 1226 g/m . A plastisol of poly vinyl chloride ("Raditex VL-1070" from Higashi Chemical Co.) was coated on the side of the woven substrate opposite the pile layer and cooled to form a secondary backing 2 mm thick. The pile layer of the mat had a random void structure formed by the filament loops from of the tufted bundles. The filament loops had random shapes and orientations, and loops from each of the bundles were intermingled with similar loops of adjacent bundles in the pile layer. The properties of the mat are reported in Table 1. Comparative testing of this mat established that the mat of Example 1 had a durable structure able to withstand repeated pedestrian traffic, had an excellent ability to wipe sand from shoe soles and was able to retain the sand in the structure of the pile layer. EXAMPLE 2 A mat was prepared as in Example 1 except that: the nylon filaments had a linear density of 1000 dpf; the bundle was twisted in the S-direction (left hand twist) at 60 turns/m; and the tufting operation was conducted under conditions to provide loops 14 mm long at a stitch of 3.2 mm. Thus, the mat of this Example had a pile layer 9 mm thick, a face weight of 926 g/m 2 and a secondary backing 2 mm thick. The pile layer of the mat had a random void structure formed by the filament loops from of the tufted bundles. The filament loops had random shapes and orientations, and loops from each of the bundles were intermingled with similar loops of adjacent bundles in the pile layer. The properties of the mat are reported in Table 1. Comparative testing of this mat established that the mat of Example 2 had a durable structure able to withstand repeated pedestrian traffic, had an excellent ability to wipe sand from shoe soles and was able to retain the sand in the structure of the pile layer. EXAMPLE 3 A mat was prepared as in Example 1 except: the nylon filaments had a linear density of 1800 denier; the textured filament bundle was fed to a tufting machine (5/32 gauge) to form loop piles 7 mm long on a woven backing of polyester fibers; and the tufting operation was conducted at a stitch of 3.2 mm so •y that a pile layer 6 mm thick and a face weight of 1244 g/m was obtained. The secondary backing was 2 mm thick. The pile layer of the mat had a random void structure formed by the filament loops from of the tufted bundles. The filament loops had random shapes and orientations, and loops from each of the bundles were intermingled with similar loops of adjacent bundles in the pile layer. The properties of he mat are reported in Table 1. Comparative testing of this mat established that the mat of Example 3 had a durable structure able to withstand repeated pedestrian traffic, had an excellent ability to wipe sand from shoe soles and was able to retain the sand in the structure of the pile layer. COMPARATIVE EXAMPLES 1 - 3 Three known tufted pile mats, all including a polymeric secondary backing, were evaluated with respect to compression of the pile layer, void ratio and weight of wiped soil according to the test methods previously described.. The test results are given in Table 1. COMPARATIVE EXAMPLE 1 was a commercial mat sold under the trade designation "Power Cell" by Teramoto Company of Japan. The mat had a cut pile layer 6 mm thick. The pile filament was a stuffer-box crimped nylon filament with a circular cross section and a linear density of 75 dpf. The mat also had a polyvinyl chloride backing that was 3 mm thick. COMPARATIVE EXAMPLE 2 was a commercial mat sold under the trade designation "Loop Runner" by Teramoto Company of Japan. This artificial lawn mat had a 1 mm thick foamed polyvinyl chloride backing layer. The loop pile was crimped polypropylene filaments, flat in cross section and having a linear density of 200 dpf. (crimping method is unknown) COMPARATIVE EXAMPLE 3 was a commercial mat available from the Minnesota Mining and Manufacturing Company, St. Paul, Minnesota under the trade designation "ENHANCE" #500. The mat was a carpet mat comprising tufts of flat polypropylene filaments having a linear density of 30 dpf and tufts of stuffer-box crimped polypropylene filaments each having a linear density of 300 dpf. As seen from the Table 1 , all the mats of Comparative Examples exhibit greater reduction in thickness of the pile layer as compared with those of Examples 1 - 3. Additionally, the void ratios for the mats of the Comparative Examples were about half those for the inventive mats of Examples 1 - 3. The inventive mats of Example 1-3 were also able to hold a higher volume of soil than the mats of the Comparatives. The pile layer in all of the inventive mats comprised loops of textured synthetic resinous filaments of random shapes and orientations, each having a linear density of at least 800 denier. The mats of the invention have a high resistance to compressive load and a desired ability to wipe and retain soil therein, making the mats very well suited for use as floor mats. Table 1 Example Comparative Example 1 2 3 1 2 3 Filament nylon nylon nylon nylon PP' PP PP (denier) (1300) (1000) (1800) (75) (200) (300) (30) Pile shape loop loop loop cut loop loop loop Thickness of pile 9 9 6 6 5 8 8 layer (mm) Thick, red. % of 2.3 3.0 0.7 5.8 14.5 7 P layer Void ratio (%) 71.7 74.3 89.5 34.8 47.5 41.9 Weight of wiped 271.6 269.7 261.8 232.5 240.3 258 soil (g) 1. Polypropylene. The articles of the invention provide a tough, resilient random pile structure with significant void space for the retention of soil or moisture while the tough pile layer is desirably resistant to compressive loads. Although the preferred embodiment of the invention has been described in some detail herein, various changes and modifications to the described embodiment will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

Claims: £LΔIMS What is claimed is: 1. An article suitable for use as a floor mat comprising a sheet-like substrate and a tufted pile layer extending from one side of the substrate, the pile layer comprising tufted bundles of textured synthetic resinous filaments, each filament having a linear density of at least 800 denier, the filaments in each tufted bundle arranged in loops of random shapes and orientations and intermingled with loops in adjacent tufted bundles of filaments in the pile layer. 2. A mat as defined by claim 1 , wherein the pile layer has a thickness in a range between 5 mm and 15 mm and a void ratio in a range between 50% and 80%. 3. A mat as defined by claim 1, wherein the synthetic resinous filaments comprise a thermoplastic material. 4. A mat as defined in claim 3 wherein the thermoplastic material is selected from the group consisting of nylon; polyolefin, polyester, polycarbonate and polystyrene. 5. A mat as defined in claim 4 wherein the polyolefin is polypropylene. 6. A mat as defined in claim 4 wherein the polyester is polyethylene terephthalate. 7. A mat as defined in claim 1 wherein the filaments have a linear density within the range from 1000 to 1800 denier. 8. A mat as defined in claim 1 wherein the substrate is selected from woven and nonwoven fabrics. 9. A mat as defined in claim 8 wherein the woven and nonwoven fabrics comprise fibers selected from natural and synthetic materials consisting of jute, cotton, polyester, polypropylene, polyester and combinations thereof 10. The mat as defined in claim 1 further comprising a secondary backing affixed to the substrate, the secondary backing comprising materials selected from the group consisting of vinyl plastisol, polyurethane and rubber latex. 11. A method for producing a mat, comprising: providing a textured yam comprising a plurality of textured filaments, the filaments each having a linear density of at least 800 denier; and tufting the yam to a substrate to form a plurality of bundles on one side of the substrate , the plurality of bundles forming a pile layer on the one side of the substrate, and each bundle of the pile layer comprising loops of the textured filaments wherein the loops are randomly shaped and oriented and are intermingled with loops in adjacent bundles of the pile layer. 12. The method defined in claim 11, wherein tufting is carried out to provide the pile layer with a thickness in the range between 5 mm and 15 mm and a void ratio in a range between 50% and 80%. 13. The method defined in claim 11 , wherein the synthetic resinous filaments comprise a thermoplastic material. 14. The method defined in claim 13 wherein the thermoplastic material is selected from the group consisting of nylon; polyolefin, polyester, polycarbonate and polystyrene. 15. The method defined in claim 14 wherein the polyolefin is polypropylene. 16. The method defined in claim 14 wherein the polyester is polyethylene terephthalate. 17. The method defined in claim 11 wherein the filaments have a linear density within the range from 1000 to 1800 denier. 18. The method defined in claim 11 wherein the substrate is selected from woven and nonwoven fabrics. 19. The method defined in claim 18 wherein the woven and nonwoven fabrics comprise fibers made from natural and synthetic materials selected from the group consisting of jute, cotton, polyester, polypropylene, polyester and combinations thereof 20. The method defined in claim 11 further comprising applying a material to another side of the substrate to provide a secondary backing useful to prevent slipping of the article along a surface, the material selected from the group consisting of vinyl plastisol, polyurethane and rubber latex.

Inventors: NAGAHARA KOJI, SAKAI HIDEYASU, NAGAHARA, KOJI, SAKAI, HIDEYASU
Applicants: MINNESOTA MINING & MFG, NAGAHARA KOJI, SAKAI HIDEYASU, MINNESOTA MINING AND MANUFACTURING COMPANY, NAGAHARA, KOJI, SAKAI, HIDEYASU
Application year: 1996
Main classification: D05C17
IPC codes: A47G27, A47L23, D05C17