Patent Document

BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The subject invention relates to a holding frame and a mat assembly for absorbing liquid materials, such as oil, solvents and water based solutions and emulsions.  
           [0003]    2. Description of the Related Art  
           [0004]    Many industrial machines and automotive vehicles are known to splatter or drip fluids, such as oil solvents, water and the like. For example, many industrial machines employ oil to lubricate moving parts. Gaskets and seals between moving and stationary parts invariably wear and create the potential for leakage of the lubricant. Other industrial machines employ a lubricant at the interface of a tool and work piece. The lubricant can splatter while the work is being performed, and some of the splattered lubricant is likely to be deposited on the floor near the machine. Automotive vehicles also are likely to drip oil while the vehicle is idling and/or while lubricant is being added or changed. Thus, areas where a vehicle will park or idle and areas where a vehicle will be worked on often will have oil deposits on the floor. An accumulation of lubricant on a floor can be hazardous to workers or pedestrians. Additionally, the accumulated lubricant conceivably could be a fire hazard.  
           [0005]    Sorbents commonly are used on an area of a floor near an industrial machine that is apt to drip or spray a lubricant. Sorbents come in many different forms, including elongate tubes filled with particulates of sorbent material and mats of non-woven sorbent fiber. Mats are particularly desirable for many applications in that the mat can be walked upon by workers and/or other people who must traverse the oil-splattered floor. The prior art sorbent mats may be formed from non-woven fibers of polypropylene or polyester or blends of such synthetic fibers and recycled cotton fibers. The fibers may be placed in a mat configuration by any of several well known techniques, including needle punch, melt blown, air laid, carded and spun bond techniques. The mats of sorbent fibers also may be laminated with films and composites. Non-woven mats of sorbent material with a thickness of about ⅛″-⅜″ can provide an acceptably high degree of absorbency at a reasonable price. Furthermore, these thin non-woven fiber mats are easy to transport and store prior to use and are packaged easily for recycle after saturation. However, thin non-woven fiber mats can be moved in advertently with relative ease. Thus, forces generated by a person walking on a thin non-woven fiber mat, forces generated by a vehicle moving over the non-woven fiber mat or forces generated by air currents can cause the thin non-woven fiber mat to shift from its desired location. Similarly, these same forces can cause the prior art non-woven fiber mat to fold or crease, thereby creating a raised surface on which a worker may trip. Thus, the mat that is intended to avoid a slippery dangerous surface actually can contribute to its own hazardous condition.  
           [0006]    The prior art includes several thick, heavy, resilient fatigue mats that are used near work benches, retail counters and the like where workers are likely to stand for long periods of time. Fatigue mats are intended to improve foot and leg comfort, but typically do not absorb liquids. Fatigue mats typically are not very flexible, and hence are not likely to shift, fold or crease. However, the bulk of these prior art mats also make them more costly, and more difficult to ship, store and install. Attempts have been made to utilize the heavy thick characteristics of the fatigue mat to an advantage. For example, the prior art includes fatigue mats formed from several interengageable pieces, that are locked to one another in the manner of a jigsaw puzzle. The assembled pieces can be disassembled for discard or repositioning. The above-described cost and weight characteristics would make these types of prior art mats unacceptable for environments where frequent replacement is necessary, as is the case with sorbent mats that are intended to absorb liquid materials. Furthermore, the jigsaw puzzle type of mats are limited to certain sizes and shapes that are dictated by the sizes and shapes of the various components. Conceivably these prior art mats could be cut to match the specific sizes and shapes of an area. However, the thickness and rigidity that enable the respective jigsaw parts to be assembled also complicates cutting the parts. Furthermore, a cut edge of a thick mat can define a surface discontinuity over which a worker may trip.  
           [0007]    In view of the above, an object of the invention is to provide an inexpensive lightweight sorbent mat that can be installed securely and removed easily and quickly.  
           [0008]    It is another object of the subject invention to provide a lightweight inexpensive absorbent mat that can be adapted to any convenient size and shape.  
         SUMMARY OF THE INVENTION  
         [0009]    The subject invention is directed to a mat assembly that comprises a sorbent mat and a frame for overlying at least certain peripheral regions of the mat. The frame is sufficiently heavy to securely hold the sorbent mat in place. However, the frame can be separated from a spent sorbet mat and reapplied to a new sorbent mat. Thus, the sorbent mat is disposable and/or recyclable, while the frame is reusable.  
           [0010]    The mat may comprise a non-woven array of fibers and may have a backing layer on one side of the array of fibers. More particularly, the mat may comprise a non-woven array of randomly oriented polypropylene fibers, an array of polyester fibers, or a blend of either of these synthetic fibers with other fibers. For example, the mat may comprise a non-woven array of polyester and cotton fibers with a latex binder on one side. The non-woven array may be achieved by any of several known technologies, such as melt blown, spun bond, ultrasonic, airlaid or needle punch or a combination of these.  
           [0011]    The frame of the mat assembly preferably is formed from an elongate retention strip that is extruded or molded from a flexible synthetic material, such as an elastomer or rubber. The elongate retention strip has a bottom surface, a top surface and opposed longitudinal side edges. The bottom surface of the retention strip may be substantially planar, whereas the top surface of the retention strip may be tapered to narrower thicknesses at each of the opposed longitudinal side edges. Thus, the elongate retention strip of the frame may define a maximum thickness centrally between the side edges and may define reduced thicknesses in proximity to the side edges.  
           [0012]    The bottom surface of the retention strip from which the frame is formed has attachment means disposed at least at certain locations thereon. The attachment means may be attached during or after the extrusion or molding of the retention strip. The attachment means may comprise an array of hooked filaments that are releasably engageable with the fibers of the mat. For example, the attachment means may comprise one half of a Velcro assembly. The attachment means preferably comprises an elongate continuous ribbon or tape disposed along substantially the entire length of the bottom surface of the retention strip. However, a plurality of spaced apart attachment segments may be disposed at selected locations along the bottom surface of the retention strip. The attachment means may cover the entire bottom surface of the retention strip. However, it is sufficient and preferable to have the attachment means disposed centrally between the side edges of the retention strip. The attachment tape or attachment segments may be affixed to the bottom surface of the retention strip by adhesive. Alternatively, a non-adhesive affixation of the attachment means to the retention strip may be employed.  
           [0013]    The retention strip may be a coextruded structure with at least one section having a visual contrast. The contrasting section preferably is disposed at least on the upper surface of the retention strip and may be disposed centrally between the side edges of the retention strip. For example, a major portion of the retention strip may be extruded from a black elastomeric material, while a central portion of the retention strip may define longitudinally extending design, logos or printing. For example, a different color (e.g., yellow) may be provided as a warning signal.  
           [0014]    The mat assembly is employed by cutting the non-woven mat to a desired size and shape for the intended application. Mats of this type typically can be cut with a conventional scissor. The frame assembly has a size and shape corresponding to the size and shape of the periphery of the mat. More particularly, the frame assembly is formed from a plurality of retention strips. The retention strips may be pre-molded to specified dimensions. Alternatively, the retention strips can be cut with a utility knife, utility shears or heavy duty scissors for form the frame assembly. The bottom surfaces of the cut retention strips then merely are laid on the top surface of the mat. The Velcro or other attachment means on the bottom surface of the retention strips will releasably engage the non-woven fibers on upper peripheral regions of the mat. Thus, peripheral regions of the mat will be held in a substantially planar orientation on the substrate by the weight of the frame. Furthermore, the engagement between the bottom surface of the retention strip and the non-woven fiber array of the mat will prevent the frame from moving relative to the mat.  
           [0015]    The frame assembly can be formed by cutting the retention strip at an acute angle (e.g., 45°) at locations corresponding to the corners of the mat. Alternatively, the retention strip can be formed from a plurality of segments of specified length. The segments may be pre-molded or otherwise formed to have 45° corners. The retention strips preferably are symmetrical in cross-section, and hence a plurality of pre-formed retention strips with 45° ends can be butted to one another merely by reversing alternate strips to define a retention strip of any desired length. Thus, the frame effectively is mitered to overlie the corners of the mat. Alternatively, the frame assembly may comprise corner sections that extend through 90° at either an internal or an external corner. The remaining portions of the retention strips then can be cut at right angles to the longitudinal direction of the retention strip, and the strip may merely be butted against the corner pieces.  
           [0016]    The mat will remain planar and stationary due to the cooperation with the retention strips, and particularly the attachment portions on the bottom surface of the strip. The tapered configuration of the strips will substantially prevent accidental tripping by workers or other pedestrians near the mat assembly. Additionally, the preferred coextruded multi-color strips enhance visible detection of the mat assembly, and further reduce the likelihood of accidentally tripping over edge portions of the mat assembly. Oil or other liquids that may be deposited on the mat assembly will be absorbed by the non-woven fiber array of the mat. The bottom layer or backing sheet of the mat will prevent any such oil or liquids from permeating through the mat and onto the substrate. When the mat approaches saturation, the strips need merely be peeled away from peripheral regions of the mat. The mat then may be discarded or recycled in the conventional manner for such sorbent mats. A new section of mat then can be cut from a roll and placed on the section of the substrate that had previously been protected by the removed saturated mat. The previously employed retention strips of the frame assembly then can be repositioned around the periphery of the new mat.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is a perspective view of a mat assembly in accordance with the subject invention.  
         [0018]    [0018]FIG. 2 is a cross-sectional view taken along line  2 - 2  in FIG. 1.  
         [0019]    [0019]FIG. 3 is a top plan view of a retention strip of the mat assembly.  
         [0020]    [0020]FIG. 4 is a bottom plan view of the retention strip shown in FIG. 3.  
         [0021]    [0021]FIG. 5 is an end elevational view of the retention strip.  
         [0022]    [0022]FIG. 6 is a side elevational view of the attachment tape.  
         [0023]    [0023]FIG. 7 is a top plan view of a modular corner for use with the retention strips of FIGS.  3 - 5 .  
         [0024]    [0024]FIG. 8 is a bottom plan view of the modular corner shown in FIG. 7.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]    A mat assembly in accordance with the subject invention is identified generally by the numeral  10  in FIGS. 1 and 2. The mat assembly  10  comprises a mat  12  and a frame  14 . The mat  12  has a top surface  16  and an opposed bottom surface  18  which are spaced sufficiently apart to define a thickness for the mat  12  of about 0.25-0.375″. Portions of the mat  12  adjacent the top surface  16  comprise at least one non-woven array of fibers that exhibit appropriate absorbency for the intended use. Additionally, the top surface  16  of the mat  12  is formed to define an array of fuzzy loops facing upward. The fuzzy loops may be made by needle punch, air laid, resin, bonded, carded or buffed technologies. For example, portions of the mat  12  adjacent the top surface  16  may comprise randomly oriented polypropylene microfibers having diameters of 2-10 microns. An alternate mat could be formed from non-woven staple fibers of polypropylene 96%-98% and EMA 2%-4%, and these respective fibers could have diameters in the range of 25-35 microns. Still another alternate mat  12  could be formed from recycled cotton and polyester fibers oriented in a non-woven array and with a latex binder on one side.  
         [0026]    Portions of the mat  12  adjacent the bottom surface  18  preferably define a barrier that is chemical resistant and skid resistant. The barrier adjacent the bottom surface  18  of the mat  12  prevents liquid from striking through the mat  12  and hence avoids contamination of the floor and/or ground. Furthermore, the barrier adjacent the bottom surface  18  enhances the sorbent efficiency of the non-woven fabric adjacent the top surface  16  by forcing migration of liquid into the sorbent portions of the mat  12 . The barrier at the bottom surface  18  may be a low density polyethylene barrier film with a thickness of about 3 mils that is secured to the lower surface of the non-woven sorbent fabric. Alternatively, a chemical resistant non-skid backing can be co-extruded for attachment to the lower surface of the needle punch non-woven layer. Alternatively, a barrier may be defined by heat fusing one surface of a non-woven needle punch staple fiber mat. Still further, the bottom surface  18  may be a melt blown polypropylene non-woven lint-resistant cover stock. In all of these options, the barrier adjacent the lower surface  18  prevents strike through of liquid that may be deposited on the mat  12  and further resists skidding of the mat  12  on the supporting surface.  
         [0027]    In certain embodiments, the mat  12  may include an intermediate layer. For example, the mat  12  may have an upper layer of needle punch non-woven polypropylene and an intermediate layer of melt blown non-woven polypropylene that is hydrophobic or hydrophilic in accordance with requirements of a particular application. An LDPE barrier film then may be secured to the lower surface of the melt blown intermediate layer.  
         [0028]    The mat assembly  10  illustrated in FIG. 1 is of substantially L-shaped plan view configuration. This configuration is illustrated for discussion purposes only. A more typical configuration would be a rectangular mat assembly. However, many other configurations are possible in accordance with the subject invention. The configuration shown in FIG. 10 or any other configuration can be achieved with simple tools, such as scissors, utility snips and/or utility knives. In particular, the mat  12  can be cut easily with conventional scissors to a shape appropriate for the shape of the area on the substrate that is to be protected.  
         [0029]    As shown in FIG. 2, the mat  12  includes an edge  20 . As explained above, an edge region of a thin flexible mat easily can be folded into a non-planar shape, and can lead to accidental tripping by workers or pedestrians in the area of the mat  12 . The frame  14  of the mat assembly  10  substantially prevents the mat  12  from folding, wrinkling or otherwise moving. The frame  14  comprises a plurality of retention strips  24 . Each retention strip  24  is an elongate member coextruded from an elastomeric material, and preferably a flexible PVC, to include opposed longitudinal side edges  26  and  28 , a top surface  30  and a bottom surface  32 . The retention strip  24  includes a base portion  34  that extends unitarily between the sides  26  and  28 . The retention strip  24  further includes a contrast stripe  36  integrally extruded with the base  34  at a location on the top surface  30  centrally between the side edges  26  and  28 . The contrast stripe  34  is a different color than the base  34 . For example, the base  34  may be extruded from the black elastomeric material, while the contrast stripe  36  may be extruded from a bright yellow material. The coextrusion process is carried out to substantially prevent separation of the contrast stripe  36  from the base  34 .  
         [0030]    The retention strip  24  is extruded such that the bottom surface  32  is substantially planar and such that the top surface  30  is convexly arcuate between the side edges  26  and  28 , as shown most clearly in FIG. 5. More particularly, the strip  24  may define a maximum thickness of about ⅜″ at locations centrally between the side edges  26  and  28  and a minimum thickness of less than ⅛″ at locations substantially adjacent the side edges  26  and  28 .  
         [0031]    An attachment tape  40  is securely affixed to the bottom surface  32  of the retention strip  24 . The attachment tape  40  comprises a substrate  42  and an array of resiliently deflectable hooked filaments  44  extending from the substrate  42 . Attachment tapes  40  of this general type are sold under the trademark “VELCRO”. The substrate  42  of the attachment tape  40  is securely adhered to the bottom surface  32  of the retention strip  24  at a location centrally between the side edges  26  and  28  of the retention strip  24 . More particularly, the substrate  42  preferably is secured to the bottom surface  32  of the retention strip by a solvent or heat activated adhesive which is resistant to degradation of the adhesive due to plasticisers in the retention strip  24 . The retention strip  24  preferably defines a width “W” of about 3.50″ and the attachment tape  40  preferably defines a width of about 1.5″. Thus, regions of the bottom surface  32  between the attachment tape  40  and the respective side edges  26  and  28  define widths of about 1.0″.  
         [0032]    The resiliently deflectable hooks  44  of the attachment tape  40  are releasably engageable with the fibers adjacent the upper surface  16  of the mat  12 . Thus, as shown in FIGS. 1 and 2, the bottom surface  32  of the retention strip  24  can be placed on portions of the top surface  16  of the mat  12  adjacent a side edge  20 . A minor downward force exerted on the retention strip  24  will cause the resiliently deflectable hooked filaments  44  of the retention strip  40  to releasably engage the fibers of the non-woven mat  12 . Thus, the retention strip  24  will be retained on portions of the upper surface  16  of the mat  12  adjacent the side edge  20 . Furthermore, the retention strip  24  will provide sufficient weight to prevent the mat assembly  14  from folding into a non-planar orientation. With this configuration, the mat will not assume a wrinkled or folded configuration that could cause workers or pedestrians near the mat assembly  10  to trip. Furthermore, the mat assembly  10  can be used at exterior locations without significant risk of the mat  12  blowing away from the portion of the substrate to which the mat assembly  10  had been applied initially.  
         [0033]    The retention strip  24  may be cut to any selected length by scissors, snips or a utility knife to appropriate dimensions based on the dimensions of the mat  12 . However, to avoid complicated mitering, the frame  14  includes a plurality of corners  50  that are premitered into a right angle configuration. The corners  50  include the attachment tapes  52  on the lower surface, as shown most clearly in FIG. 7. Furthermore, the corners  50  define a cross-sectional shape substantially identical to the cross-sectional shape of the strip  24  as shown in FIG. 5.  
         [0034]    The mat assembly  10  is employed by initially cutting the mat  12  to a selected size and shape depending upon the size and shape of the floor or other substrate to be protected. In this regard, the mat  12  may be purchased and stored in a roll form. Thus, a sufficient part of the mat  12  can be unrolled and cut to an appropriate size and shape. The cutting can be carried out with conventional scissors, snips or a utility knife. The mat  12  then is placed on the floor or other substrate to be protected, such that the bottom surface  18  of the mat  12  is supported on the floor or other substrate. As noted above, the bottom surface  18  preferably is a film or backing layer that is substantially impervious to the fluid that is apt to be deposited on the mat assembly  10 . As a result of this orientation, the non-woven fiber array adjacent the upper surface  16  faces upwardly. The corners  50  then may be placed at the convex or exterior corners and the concave or interior corners of the properly cut mat  12 . The installer then positions elongate linear sections of the retention strips  24  between the corners  50 . The retention strips  24  may be cut by scissors, snips or a utility knife to the appropriate linear dimension for fitting between adjacent corners  50 .  
         [0035]    The mat  12  of the mat assembly  10  provides sorbency for absorbing oil or other liquid that may be dripped or splattered. Thus, the mat  12  absorbs oil or other liquid that would otherwise accumulate on the floor. The strips  24  and the corners  50  function to hold the mat  12  in a substantially planar orientation. More particularly, corner and edge regions  20  of the mat  12  are prevented by the strips  24  and corners  50  from curling or folding upwardly in a manner that could create a safety hazard to workers or other pedestrians. Additionally, the contrast stripe  36  provides good visual indication of the presence of the mat assembly  10 , thereby further preventing a worker or pedestrian from accidentally tripping over the mat assembly  10 . Still further, the tapered narrow sides of the strip  24  minimize the potential for tripping as a person steps onto or off of the mat assembly  10 .  
         [0036]    After sufficient use, the mat  12  may approach saturation by oil or other liquid being spilled on the mat  12 . At this time, the strips  24  may be separated from the mat  12 . This merely requires an upward pulling of the strips  24  relative to the mat  12 . Such pulling force will deform the filament hooks  44  of the attachment tape  40  and further may cause some disengagement of the non-woven fibers of the mat  12 . The mat  12  then may be folded or rolled for discard or recycling as appropriate. The strips  24  and the corners  50 , however, are retained for further use. Thus, a new mat  12  can be cut as appropriate for disposition on the area of the floor from which the soiled mat  12  had been removed. The previously cut strips  24  and corners  50  then can be placed adjacent the edge regions  20  of the new mat  12  so that the restraining strips  40  releasably engage the upper surface  16  of the new mat  12 .  
         [0037]    While the invention has been described with respect to a preferred embodiment, it is apparent that various changes can be made without departing from the scope of the invention as defined by the appended claims.

Technology Category: 7