Abstract:
The present invention is directed to a soap-bar cover comprising a water-permeable fabric, and particularly a soap-bar cover exhibiting a stretch and recovery performance while maintaining a substantially planar surface. Soap-bar covers fabricated in accordance with the present invention are particularly useful as a means for enhancing the cleansing properties of commercially available soap-bar products. The soap-bar cover is composed of a woven or nonwoven fabric exhibiting stretch and recovery properties. Use of a stretch and recovery fabric in the soap-bar cover allows for the cover to conform to the contours of the soap-bar and is thus able to adjust to a wide variety of soap-bar profiles including cubic and ovoid.

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates to a water-permeable fabric covering for bar-form personal hygiene soaps, and more particularly, to fabric soap-bar cover that exhibits the ability to conform to the shape of the soap-bar and yet maintain a essentially planar surface suitable for further application of performance and/or aesthetic enhancing agents.  
         BACKGROUND OF THE INVENTION  
         [0002]    The practice of employing washcloths and similar bathing articles during the conduction of personal hygiene cleansing is well known. The use of a washcloth allows for improved abrasiveness imparted by the surface of the washcloth combined with improved soap retention when soaps are either applied thereon or used separately.  
           [0003]    Washcloth materials have historically been composed of woven cotton fabrics, such as terrycloth. A deleterious effect realized in the daily use of a natural fiber woven washcloths is that due to the entrainment of exfoliated skin, dirt and oils into the washcloth, combined with the moist environment common to bathrooms, bacterial growth is encouraged. Bacterial growth is undesirable in a washcloth as propagation of the bacteria results in an accompanying malodor and reduced sanitary conduction contradictory to the purpose for which a washcloth is intended. A natural fiber woven washcloth must be laundered frequently in order to remove these contaminants and thereby return the washcloth to a useable state.  
           [0004]    To improve upon the performance of natural fiber washcloths, fabricators of such articles have focused upon the use of synthetic materials. Synthetic materials, and particularly plastic resins, offer many advantages in washcloth construction. Of particular importance is the use of plastic resins result in a washing matrix that is resilient to bacterial growth due to the lower surface energies inherent to the plastic versus a natural fiber. Further, plastics can be treated during the formation of the washing matrix with agents that impart a biocidal or biostatic performance. The combination of inherent and active bacterial growth reduction due to the use of plastic resins results in a washcloth that can be used for a longer period than a natural fiber woven washcloth.  
           [0005]    The combination of a washcloth with the detergent source has been of particular interest in the formation of washcloths or similar bathing aids with enhanced performance and appeal.  
           [0006]    U.S. Pat. Nos. 4,510,641 and 4,665,580, both to Morris, teach the application of a multilayered scouring pad about a central pocket in which to receive a detergent, the layers consisting of metallic nonwoven materials superimposed on supporting netting layers.  
           [0007]    U.S. Pat. No. 4,733,426 to George, addresses the fouling problem inherent to sponges by encasing a sponge within an elastic woven covering.  
           [0008]    U.S. Pat. No. 4,969,225 to Schubert, describes a scrub brush whereby the soap-bar becomes integrated into the lofty, fibrous structure and once integrated, becomes the internal backbone of the scrub brush.  
           [0009]    U.S. Pat. No. 6,042,288 to Rattinger, et al., employs a detergent in the form of a soap-bar encased within a sponge structure consisting of multiple layers of tubular netting. The overall construct is highly three-dimensional, the inventors having described the combination of soap-bar and sponge as being “ball like”.  
           [0010]    U.S. Pat. No. 6,085,380 to Gonda, et al., focus upon a derivation of washcloth whereby a pouf is formed from a spiral wound thermoplastic filament. The user treats the pouf with a separate liquid or gel detergent prior to application in bathing. U.S. Pat. No. 6,026,534, also to Gonda, et al., utilizes a pouf constructed of independent, finite length filaments extending from a central core and resulting a spherical construct. Again, a detergent is applied to the pouf prior to use.  
           [0011]    There is a prevalence of “net” type enclosures, whereby the soap-bar is placed simply in the confines of an oversized bag constructed of open mess fabrics. U.S. Pat. Nos. 3,167,805, 4,228,835, 4,480,939 and 5,462,378 typify patents teaching to this general construct A problem inherent to soap-bar covers designed heretofore is the combined effect of excessive material consumption, with a corresponding increase in construction difficulty and cost necessary to fabricate such covers, and the resulting highly bulky nature of these covers is such that packaging is also made more difficult and costly. Further, there is a desire by both the users and fabricators of such soap-bar covers to have an article with enhanced performance and aesthetics capabilities. There remains an unmet need for a soap-bar covering which reduces the consumption level of material components yet exhibits suitable design flexibility to address performance and aesthetics issues  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention is directed to a soap-bar cover comprising a water-permeable fabric, and particularly a soap-bar cover exhibiting a stretch and recovery performance while maintaining a substantially planar surface. Soap-bar covers fabricated in accordance with the present invention are particularly useful as a means for enhancing the cleansing properties of commercially available soap-bar products.  
           [0013]    The soap-bar cover is composed of a woven or nonwoven fabric exhibiting stretch and recovery properties. Use of a stretch and recovery fabric in the soap-bar cover allows for the cover to conform to the contours of the soap-bar and is thus able to adjust to a wide variety of soap-bar profiles including cubic and ovoid. Further, as an initial soap-bar is consumed during application in personal hygiene applications, a second soap-bar, of same or different profile, can be inserted and consumed in conjunction with the remnants of the initial soap-bar.  
           [0014]    Suitable woven fabrics include primary knits, warp or circular knits, weft insertion, or woven fabrics including stitch-through technologies, and may include such fibers and filaments that exhibit an inherent elasticity, such as typified by aliphatic-aromatic polyesters and other elastomers.  
           [0015]    A suitable nonwoven fabric may be selected from conventional means well known in the art, including the use of staple fiber, continuous filaments, and the combinations thereof. Such fibers and filaments may either exhibit an inherent elasticity, such as typified by aliphatic-aromatic polyesters and other elastomers, or be rendered elastic by application of specialized elastic binding chemistries. An exemplary nonwoven fabric embodying the principles of the present invention comprises a hydroentangled nonwoven web preferably comprising staple length textile fibers of about 0.8 to 15.0 denier having a basis weight of about 0.5 to 8.0 ounces per square yard, preferably 2.0 to 4.0 ounces per square yard. More preferably, the nonwoven web comprises fibers of about 1.0 to 3.0 denier, with the web having a basis weight of about 2.5 to 3.5 ounces per square yard. Use of polyester fibers is presently preferred, but it is within the purview of the present invention to form the present nonwoven fabric from blends which include at least a portion of synthetic fibers blended with natural fibers, and from substantially continuous filaments of either homogeneous or multi-component polymeric construction.  
           [0016]    In a current preferred embodiment, hydroentanglement is effected so as to impart a rectilinear pattern to the fibrous or precursor nonwoven web, which pattern is preferably oriented at an angle between about 30° and 60° relative to a machine-direction of the web. In a preferred method of formation, the fibrous web is subjected to preliminary hydroentanglement to lend integrity thereto prior to formation of the rectilinear pattern in the web by hydroentanglement on a patterned forming surface.  
           [0017]    In order to impart elastic characteristics to the nonwoven fabric to fabricate the soap-bar cover, a polymeric binder composition is substantially uniformly applied to the nonwoven fabric. Although the specific amount of binder can be varied while keeping with the principles disclosed herein, it is presently preferred that the binder composition comprises between about 17% and about 31%, by weight, of acrylic binder. Subsequent to application of the polymeric binder composition, the nonwoven web is dried to form the present nonwoven fabric. Significantly, the resultant nonwoven fabric exhibits elastic characteristics (i.e., stretch or extensibility, and recovery) in the cross-direction of the fabric. In accordance with the present invention, the fabric exhibits at least about 20% extensibility in the cross-direction, and at least about 50% recovery in the cross-direction, preferably at least about 50% extensibility in the cross-direction, with at least about 75% recovery. The fabric is thus engineered to exhibit a relatively high degree of cross-direction elasticity.  
           [0018]    An advantage in the use of a stretch and recovery fabric as described is that a substantially planar surface of the nonwoven fabric is present on the face of the soap-bar. This substantially planar face on the nonwoven fabric is receptive to application of performance and/or aesthetic enhancing agents. Performance enhancing agents include exemplary materials such as mild abrasives, exfoliants, or skin care additives, which can be applied directly and uniformly to the substantially planar surface by conventional means. Aesthetic enhancement of the substantially planar surface includes application of alternate fragrances and the printing, or transference, of ornamental designs to at least one face of the soap-bar cover. Such ornamental designs, including related soap-bar product trademarks, hotel logos, and instruction for use, can be applied directly and legibly to the soap-bar cover. Thermochromic inks may also be used in the ornamental design applique so as to change color when heated or chilled during application in personal hygiene routines.  
           [0019]    It is a further aspect of the present invention that a soap-bar cover enhances the aesthetic appeal of a soap-bar by reducing the ability of foreign matter to entrain in the surface of the soap-bar.  
           [0020]    It is a further aspect of the present invention that a soap-bar cover enhances the ability of the user to retain the soap-bar product (the soap-bar within a soap-bar cover) when such soap-bar product becomes wet.  
           [0021]    It is a further aspect of the present invention that a soap-bar cover further includes a means for suspending the soap-bar product so that excess water can drain away during periods of non-use.  
           [0022]    Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]    [0023]FIG. 1 is a diagrammatic view of one form of an apparatus for forming the present nonwoven fabric according to one form of the method of the present invention; and  
         [0024]    [0024]FIG. 2 is a photograph of a top-plan view of an exemplary soap-bar cover assembly containing a soap-bar, the assembly inclusive of a nonwoven fabric embodying the principles of the present invention.  
         [0025]    [0025]FIG. 3 is a photograph of a side view of an exemplary soap-bar cover assembly containing a soap-bar, the assembly inclusive of a nonwoven fabric embodying the principles of the present invention.  
         [0026]    [0026]FIG. 4 is a photograph of a bottom top-plan view of an exemplary soap-bar cover assembly containing a soap-bar, the assembly inclusive of a nonwoven fabric embodying the principles of the present invention, into which a bar of soap is being inserted.  
         [0027]    [0027]FIG. 5 is a photograph of a top-plan view of an exemplary soap-bar cover assembly, the assembly inclusive of a nonwoven fabric embodying the principles of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0028]    While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.  
         [0029]    U.S. Pat. No.3,485,706, to Evans, hereby incorporated by reference, discloses a process for effecting hydroentanglement of nonwoven fabrics.  
         [0030]    U.S. Pat. No. 5,098,764, hereby incorporated by reference, discloses a nonwoven fabric having unique characteristics and properties, which permit use of the fabric in a wide variety of applications. A method and apparatus for manufacturing the fabric are also disclosed, including a hydroentanglement (sometimes referred to as spun-laced) process by which a precursor nonwoven web of fibers is subjected to hydroentanglement on a forming surface to impart a rectilinear pattern to the web. The present invention can be practiced in accordance with the teachings of this patent, and as appropriate, reference will be made to this patent in connection with the present disclosure.  
         [0031]    U.S. Pat. Nos. 5,670,234, 5,674,587, and 5,827,597, hereby incorporated by reference, disclose a topographical support member, which can be employed for imparting a pattern to a nonwoven fabric during hydroentanglement, with the resultant fabric again having desirable properties, which lend it for use in many different applications. Fabrics formed in accordance with the teachings of this fabric are sometimes referred to as “tricot”.  
         [0032]    The present invention contemplates use of the methods disclosed in the above-referenced patents for manufacture of soap-bar covers exhibiting elastic characteristics, that is, stretch and recovery, at least in the cross-direction of the fabric. Nonwoven fabrics typically exhibit a machine-direction and a cross-direction, that is, with reference to the direction, which extends along the length of the fabric, i.e., the direction in which it is manufactured (the machine-direction), and the direction of the fabric, which extends perpendicularly to the machine-direction, typically across the width of the fabric. Fabrication of a soap-bar cover begins with the manufacture or procurement of a suitable nonwoven fabric embodying the principles of the present invention. Manufacture of a suitable nonwoven fabric is initiated by providing a precursor nonwoven web which preferably comprises staple length textile fibers of about 0.8 to about 15.0 denier having a basis weight of about 0.5 to about 8.0 ounces per square yard. While it is contemplated that the present invention can be practiced with the use of synthetic fibers (of homogeneous and/or multi- component polymeric composition), natural fibers, and blends thereof, as well as melt-spun filaments (of homogeneous and/or multi-component polymeric composition) such as continuous spunbond filaments or melt-blown fragmentary filaments, use of 100% polyester staple fiber is presently preferred. Fiber or filament profile is not a limitation of the present invention. In current practice of the present invention, polyester staple length fibers having a denier of about 1.5 have been particularly preferred. These fibers are commercially available under the product designation 54W, from Dupont Akra.  
         [0033]    As noted above, various combinations of fiber orientation and binder add-on can be successfully employed in achieving a nonwoven fabric exhibiting the characteristics of the present invention. Thus, the binder add-on or “finish level” of the finished nonwoven fabric can be varied in accordance with the teachings herein. It is desirable to have sufficient add-on to achieve the necessary fabric elasticity and durability.  
         [0034]    Stretch or extensibility and recovery characteristics of the present nonwoven fabric, in the cross-direction, have been selected to facilitate use in soap-bar applications while maintaining the necessary durability and elasticity of the fabric. It is presently preferred that the nonwoven fabric of the present invention exhibit extensibility in the cross-direction of at least about 50%, and more preferably at least about 60%. It is preferred that the nonwoven fabric of the present invention exhibit initial recovery of at least about 75%, with initial recovery of at least about 85% being particularly preferred. The following test methodology is employed for testing of fabrics, with this methodology being a modification of ASTM 3107-75, re-approved 1980, hereby incorporated by reference.  
         [0035]    The scope of the present methodology is for measuring stretch or extensibility under a constant weight for a set length of time, and for measuring recovery of stretch in the same fabric. Samples are prepared by cutting 2 inch by 20 inch (MD×CD) from the center, left side, and right side of a fabric sample. Cuts are taken no closer than 6 inches from the edge of the sample. A ruler with measurements in 0.10 inch increments is employed. The test employs one of five standardized weights (2.0, 2.5, 3.0, 3.5, or 4.0 pounds) depending upon the basis weight of the fabric, as set forth below. Starting 4 inches from the top each sample, a 10 inch section is bench marked. A clip is attached to the top of the sample and the sample is supported on a rack. Depending upon fabric basis weights, the following test weights are employed:  
         [0036]    BASIS WEIGHT (Per Yard 2 )/TEST WEIGHT  
         [0037]    1.0-3.9 ounces/(2.0 pounds)  
         [0038]    4.0-4.9 ounces/(2.5 pounds)  
         [0039]    5.0-5.9 ounces/(3.0 pounds)  
         [0040]    6.0-6.9 ounces/(3.5 pounds)  
         [0041]    7.0-7.9 ounces/(4.0 pounds)  
         [0042]    The weight assembly for the correct weight range is attached with a spring clip to the bottom of the sample. The sample is suspended, under the influence of weight, for 15 seconds. The calibrated ruler is used to measure the new, stretched length of the original sample, i.e., the distance between the ends of the original 10-inch marked section of the sample. This reading is recorded as B. The weight is removed, and the sample removed from the clips and rack. The sample is laid flat on a table or like surface. After 5 minutes to condition the sample, the relaxed length of the original sample, i.e., the distance between the ends of the 10 inch marked section is measured, thus providing record reading C.  
         [0043]    Calculations are made in accordance with the following:  
         [0044]    Percent stretch=(B−10)×10  
         [0045]    Percent recovery=100 minus [(C-10)×100]  
         [0046]    Average readings are taken from side, center, and side of the tested fabric.  
       EXAMPLE  
       [0047]    A stretch and recovery 100% PET nonwoven fabric was obtained in the form of a commercially available material specified as M-037X, from Polymer Group, Inc., of Benson, N.C. The M-037X comprised a preformed nonwoven web subjected to hydraulic energy to impart a predescribed image or pattern as shown in FIG. 1 and in accordance with above-referenced U.S. Pat. No. 5,098,764. The process includes an image transfer device 24 which receives the preformed nonwoven web P and which typically imparts a final pattern to the web. The web is subjected to hydroentanglement from three nozzle assemblies, designated 26, at a line speed of approximately 35 yards per minute, and an entangling pressure of 150 bar. Each of the nozzle assemblies is preferably configured in accordance with the above-described nozzle assemblies.  
         [0048]    Subsequent to patterned hydroentanglement, the web received a substantially uniform application of a polymeric binder composition at an application station 30. The web is then directed over a series of drying rollers  32 , operated at 310° F., with manufacture of the nonwoven fabric of the present invention thus completed.  
         [0049]    A binder composition, comprising an elastomeric emulsion, having the following formulation has been employed in the bath of the application station.  
                                                                         Tween 20 (Wetting Agent)   0.2%               Antifoam Y-30 (Silicone Defoamer)   0.025%           10% Aqua Ammonia   0.3%           San Cure 861 (Polyurethane)   0.7%           Hystretch V-29 (Acrylic Binder)   X%   (variable)                Water   Balance of Bath                      
 
         [0050]    The particular material utilized an image transfer device in form of “20×20” pattern prior to binder application. The “20×20” refers to a rectilinear forming pattern having 20 lines per inch by 20 lines per inch configured in accordance with FIGS. 12 and 13 of U.S. Pat. No. 5,098,764 except mid pyramid drain holes are omitted. Drain holes are present at each corner of the pyramid (four holes surround the pyramid). The “20×20” pattern is oriented 45 degrees relative to the machine direction, with a pyramidal height of 0.025 inches and drain holes having a diameter of 0.02 inches.  
         [0051]    The durability of the M-037X greige fabric was confirmed by subjecting the fabric to a wash durability test. The wash durability test comprises subjecting sheets of fabric to a wash cycle including the use of a laundry type detergent, followed by drying the fabric through the use of a residential through-air dryer. A total of 25 test cycles were run, with stretch and recovery testing being performed at the 0, 5, 10, 15, 20, and 25 cycle points. The data is provided in TABLE 1.  
         [0052]    Prior to using the greige fabric to construct an exemplary soap-bar cover assembly; the fabric was pre-treated with a softening agent followed by jet dyeing and mechanical compaction to a level of 7%. Any suitable conventional textile dyeing can be employed, including, but not limited to, jet, beam, continuous range, pad, and garment. In addition, rotary screen-printing, heat transfer printing, digital printing, and flexographic printing can be applied solely or in conjunction with a dyeing procedure. It is also within the purview of the present invention that a mechanical treatment or treatments may be employed, either prior to or subsequent to printing and dyeing, to include such processes as sanforizing, micrexing, sanding, sueding, napping, or application of either the Bianchalanni or Scutcher process.  
         [0053]    The nonwoven fabric was then used to fabricate a soap-bar cover in accordance with the present invention. A needle size of 70 was utilized in conjunction with a Tex 21 perma-spun sewing thread at a range of between 9 to 11 stitches per inch. As will be appreciated, alternative techniques can be employed for forming the present cover from the above-described nonwoven fabric, including ultrasonic bonding, adhesive bonding and needlepunching.  
         [0054]    [0054]FIGS. 2 through 5 illustrate an exemplary soap-bar cover assembly formed in accordance with the present invention. The soap-bar cover assembly includes a mutual combination of a front and back nonwoven fabric pieces in the general rectilinear rectangular upper pad shape of a soap-bar, with an opening present in the assembly for receiving and retaining the soap-bar between front and back nonwoven fabric pieces and a peripheral nonwoven fabric extending about and secured to the upper pad at the periphery thereof. It is contemplated that the front and/or back nonwoven fabric piece may comprise independently a plurality of coplanar nonwoven fabric subsections, each subsection oriented such that the recoverable extensibility is best utilized for conforming to the variety of shapes soap-bars available. It is further contemplated that the front and/or back nonwoven fabric piece may comprise independently a plurality of non-extensible coplanar nonwoven fabric subsections, each subsection adjoining an extensible nonwoven fabric section oriented such that the recoverable extensibility is best utilized for conforming to the variety of shapes soap-bars available. Suitable non-extensible coplanar nonwoven fabric subsections include those nonwoven fabrics having multi-planar or nubbed profiles.  
         [0055]    Means for securing the opening in the soap-bar cover assembly include, but are not limited to, mechanical closures such as snaps, buttons, and hook-and-loop fasteners, as well as, interleaving or coordinating folds of the nonwoven fabric.  
         [0056]    To further enhance the ability of a soap-bar to drain excess water during periods of non-use, and thus reduce deleterious physical deteriorate of the soap-bar, various means may be employed. Such mean include, but are not limited to, eyelettes, hooks, straps and ropes which are formed in the soap-bar cover and utilize external apparati which engage said eyelettes, hooks, straps, and ropes. Further, as the soap-bar cover fabric is fibrous, a loop from a “hook-and-loop” fastener can be utilized to directly engage any region of the soap-bar cover.  
         [0057]    From the foregoing, it will be observed that numerous modifications and variations can be effected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiment illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims.