Abstract:
An autoclavable mop head comprising one or more folded tubular strand elements. The tubular strand elements incorporate an arrangement of elongate depressed channels and raised profile segments extending along their surface in the length direction.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application 60/797,427 filed May 4, 2006 the contents of which are hereby incorporated by reference in their entirety as if fully set forth herein 
     
     TECHNICAL FIELD 
       [0002]    The present invention relates generally to fluid retaining mop structures, and more particularly to a mop head incorporating one or more fluid retaining strand elements of contoured, tubular construction. At least a portion of the strand elements are folded over multiple times to define two opposing folded edge boundaries. The folded strand elements are operatively connected to a backing structure for attachment to a mop handle. A process for forming the mop head is also provided. 
       BACKGROUND OF THE INVENTION 
       [0003]    Mop heads incorporating tubular strand elements of so-called “edgeless” construction are known. One such construction, which is marketed by Contec Inc. of Spartanburg, S.C., is formed from a skein of surface contoured circular knit material of tubular construction which is formed on a winding apparatus using a pair of support bars which rotate relative to one another. The skein structure is formed from a single continuous tube of the knit material. Upon removal from the winding apparatus, the skein thus has an interior and two ends formed by the reverse folds in the knit tube where it has been passed around the winder bars. The skein structure is thereafter inserted into a relatively narrow width containment sleeve which is seamed to the interior of the skein structure at a substantially central location to contain the tubular elements in the wound structure. Seams are also applied at slightly inboard positions relative to the folded over ends of the skein structure so as to avoid undue spreading of the individual folded over elements. The mop head so formed is thereafter attached to a handle at the central containment sleeve. 
         [0004]    Cleanrooms are used in many industries and in many environments including surgical suites in hospitals and clinics, pharmaceutical and medical device manufacturing facilities, genetic engineering laboratories, and micro-electronic manufacturing facilities. The advent of cleanrooms has led to a search for improved means to clean the walls and other surfaces of the cleanroom environment without introducing further contamination in the form of lint and other particles from the cleaning device itself. Typical solutions to the problems associated with cleaning cleanrooms have included cloth wipes, tacky rollers, sponge and string mops. However, none of these systems presented a satisfactory cleaning system to meet all the needs of cleaning a cleanroom without creating additional problems, such as new forms of contamination either in the form of material particles or in the form of fabric dissolved in the cleaning or sanitizing solvents. Additionally, many of these cleaning devices are not autoclavable and therefore cannot be repeatedly sterilized in heat, pressure and steam. 
         [0005]    U.S. Pat. No. 5,678,278 (incorporated by reference in its entirety) teaches an autoclavable surface cleaning member incorporating a liquid absorbent solvent resistant interior material and an abrasion resistant exterior material wherein the abrasion resistant material does not abrade creating loose fibers or lint and protects the liquid absorbent material from creating fibers and particles during use. 
       SUMMARY OF INVENTION 
       [0006]    The instant invention offers advantages and alternatives over the prior art by providing an autoclavable mop head that is suitable for use in cleanrooms. For purposes of this discussion, a cleanroom is defined as a room that requires a particle controlled working environment and may require that all surfaces be disinfected or sterilized against micro-organisms such as fungi, bacteria, molds and viruses. 
         [0007]    According to one potentially preferred feature, a cleanroom compatible mop head is provided that does not degrade or abrade during use or does so minimally and accordingly, creates very little additional lint or particles that could further contaminate the cleanroom environment. 
         [0008]    According to another potentially preferred feature, a cleanroom compatible mop head is provided that is autoclavable so that the cleaning device itself can be repeatedly sterilized in heat, pressure and steam. 
         [0009]    According to one contemplated aspect, a cleanroom compatible mop head is provided formed from arrays of knit tubular material which incorporates an arrangement of elongate depressed channels and raised profile segments or ridges extending along its surface in the length direction. Each strand element is folded over itself multiple times to define two opposing folded edge boundaries and seamed to a carrier strip running in transverse relation to the fold direction. The carrier strips with folded strand elements attached are secured to a backing structure adapted for attachment to a mop handle. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The accompanying drawings which are incorporated in and which constitute a part of this specification illustrate potentially preferred embodiments and practices in accordance with the present invention and, together with the general description of the invention given above and the detailed description set forth below, serve to explain the principles of the invention wherein: 
           [0011]      FIG. 1  is a simplified illustration of a circular knitting machine as will be well known to those of skill in the art for use in forming the absorptive tube element of a mop head according to the present invention; 
           [0012]      FIG. 2  illustrates an exemplary mop head according to the present invention in attached relation to a handle structure; 
           [0013]      FIG. 3  is an elevation plan view of the mop head in  FIG. 2 ; 
           [0014]      FIG. 4  is a cross sectional side view of an individual strand of the mop head in  FIG. 3 ; 
           [0015]      FIG. 5  illustrates an exemplary cross section of an individual strand taken through line  5 - 5  in  FIG. 1 . 
       
    
    
       [0016]    While the invention has been illustrated and generally described above and will hereinafter be described in connection with certain potentially preferred embodiments and procedures, it is to be understood that in no event is the invention to be limited to such illustrated and described embodiments and procedures. On the contrary, it is intended that the present invention shall extend to all alternatives and modifications as may embrace the broad principles of this invention within the true spirit and scope thereof. 
       DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0017]    Reference will now be made to the various drawings wherein to the extent possible, like reference numerals are utilized to designate like components throughout the various views. In  FIG. 1 , there is illustrated a circular knitting machine  10  such as will be well known to those of skill in the art. By way of example only, and not limitation, one knitting machine  10  which has been identified as suitable for practice of the present invention is a model ST3AH/ZA high speed, single feed, circular knit machine having a cylinder size of 1.5 inches in diameter and 48 needle slots available, manufactured by Lamb Knitting Machine Corporation having a place of business in Chicopee, Mass., USA. 
         [0018]    According to one contemplated practice, in operation a pair of yarns  12 ,  12 A is delivered from spools  13 ,  13 A to the knitting machine  10  for formation of a tubular knit structure  14 . The yarn  12  is preferably a 150 denier single textured polyester having either an “S” or “Z” twist construction. The yarn  12 A is preferably a 150 denier two ply textured polyester wherein one ply has an “S” twist and the other ply has a “Z” twist. Thus, the two yarn system incorporates yarn orientations with a combination of opposing twists. This balance in twist permits the knit structure to avoid undue curling when subjected to laundering operations. Of course, the particular yarn system selected may be varied as desired by the user. 
         [0019]    The tubular knit structure  14  which is formed according to the potentially preferred practice of the invention includes an arrangement of elongate channel depressions  20  running along the length of the tubular knit structure  14  ( FIG. 5 ). The depressions  20  are disposed between raised profile surface protrusions  24  across the surface of the tubular knit structure  14  such that an undulating or corrugated surface profile is provided wherein the elongate channels and surface protrusions extend in alternating substantially parallel relation. 
         [0020]    According to a potentially preferred practice, the illustrated arrangement of channel depressions  20  and raised profile protrusions  24  is achieved by using a modified needle arrangement in the knitting equipment to create a space between courses formed during the knitting process. According to one exemplary practice, the circular knit machine as described above is modified to incorporate a needle arrangement with four needles in and two needles out in an arrangement which is repeated eight times around the circumference of the cylinder. This produces a profiled surface with eight cooperating channel depressions  20  and eight raised profile protrusions  24 . Of course this number may be greater or lower as desired but will preferably be at least four and will more preferably be about 6 or greater. According to one potentially preferred practice, the machinery is set up to produce a tubular knit structure with fourteen courses per inch (relaxed state) and a weight of about 6.1 grams per linear yard (relaxed state). The resulting construction is a modified jersey knit utilizing thirty-two active needles for knitting. 
         [0021]    It is contemplated that the tubular knit structure  14  as described will be used in the construction of a cleaning surface for the mop head  30  across one side of a base or backing structure  38 . The backing structure  38  is preferably configured for operative attachment to a mop handle  40 . By way of example only and not limitation, the backing structure  38  may be in the form of a pouch or envelope of fabric or other suitable material so as to allow it to be form fitted over a relatively rigid support member  41 . Alternatively, the backing structure  38  may be one half of a hook and loop fabric system suitable for attachment to a complementary fabric held at the support member  41 . It is contemplated that the backing structure  38  may be of different sizes or shapes to allow application to various hardware 
         [0022]    As best illustrated through simultaneous reference to  FIGS. 2-4 , the mop head  30  is preferably formed from attachment of a plurality of skeins of the tubular knit material  14 . The skein structures may be formed by winding an extended length of the tubular knit material  14  multiple times around a pair of closely spaced bars and then removing the formed structure from those closely spaced bars. As illustrated, the resultant skein structure has an arrangement of laterally disposed folds  32  arranged along either side of an interior portion where the tubular knit material passes over itself. As will be appreciated, the folds  32  are formed at the location where the tubular knit material is wrapped around the opposing bars and reverses direction during the winding operation. Of course, it is also contemplated that a similar structure may be formed by hand coiling or other techniques as may be desired. Moreover, while it may be desirable to use a single long piece of tubular knit material  14  folded upon itself multiple times to form each skein of the mop head, it is also contemplated that two or more shorter lengths may be used if desired. Thus, it is to be understood that by the term “skein” is meant any structure in which one or more lengths of elongate material are folded upon themselves such that the folds define the edge boundary with discrete strand elements extending towards an interior and away from the edge boundary. 
         [0023]    According to the illustrated and potentially preferred practice, each skein structure forming the mop head  30  is attached to an elongate carrier strip  34  such as a fabric, film or the like via a seam  36  running along the length of the skein structure in transverse relation to the strands of tubular knit material  14  at positions inboard of the folds  32  so as to maintain a desired adjacent relation of the strand elements. Moreover, the ends of the tubular knit material where the winding begins and concludes are also held in hidden relation beneath the carrier strip  34 . By way of example and not limitation, the carrier strip  34  is preferably a relatively stable knit or woven fabric structure such as woven polyester or the like. Seam  36  may be a traditional sewn seam although other constructions such as welded seams and the like may also be used. 
         [0024]    As illustrated, the carrier strips  34  with attached skeins are preferably seamed into place across an outwardly projecting portion of the backing structure  38  in parallel relation. In one contemplated arrangement, the mop head has four strips of fabric with attached skeins seamed lengthwise along the mop head fabric  38  as illustrated in  FIG. 3 . However, any greater or lesser number of skeins may be utilized as desired. The mop head  30  may thereafter be cleanroom laundered and dried prior to attachment to the handle  40 . 
         [0025]    As previously indicated, the adjustment of the circular knitting machine  10  to produce the tubular knit material  14  with interspersed elongate channel depressions  20  and raised profile protrusions  24  yields substantially improved moisture retention capacity even when lower weights of material are utilized. This moisture retention capacity is referred to as “sorbent capacity” and may be made up of moisture retention resulting from absorption and/or adsorption at the strands of tubular knit material. In this regard, it is contemplated that the benefits of the present invention will be applicable to both hydrophilic as well as hydrophobic materials of construction although polyester which is hydrophobic may be particularly preferred. 
         [0026]    While the present invention has been illustrated and described in relation to certain exemplary and potentially preferred embodiments and practices, it is to be understood that such embodiments and practices are illustrative only and that the present invention in no event is to be limited thereto. Rather, it is contemplated that modifications and variations will no doubt occur to those of skill in the art upon reading the above description and/or through practice of the invention. It is therefore contemplated and intended that the present invention shall extend to all such modifications and variations which may incorporate the broad concepts of the present invention within the full spirit and scope thereof.