Patent Publication Number: US-2015082569-A1

Title: Cleaning article with differential overlap between sheet and tow fibers

Description:
FIELD OF THE INVENTION 
     The present invention relates to cleaning articles, and more particularly to cleaning articles comprising tow fibers and the like. 
     BACKGROUND OF THE INVENTION 
     Various cleaning articles have been created for dusting and light cleaning. For example, cloth rags and paper towels used dry or wetted with polishing and cleaning compositions have been used on relatively flat surfaces. But, rags and paper towels are problematic for reasons such as hygiene (the user&#39;s hand may touch chemicals, dirt or the surface during cleaning), reach (it may be difficult to insert the user&#39;s hand with the rag or paper towel into hard-to-reach places) and inconvenience (cleaning between closely-spaced articles typically requires moving the articles). 
     To overcome the problems associated with using rags and paper towels, various dust gathering devices having feathers, lamb&#39;s wool, and synthetic fiber brushes have been utilized for more than a century, as illustrated by U.S. Pat. No. 823,725 issued in 1906 to Hayden. Such dust gathering devices can be expensive to manufacture, and as such are designed to be cleaned and reused. One problem associated with a reusable dust gathering device is that such dust gathering devices may not hold or trap dust very well. Soiled, reusable devices are typically cleaned via shaking or through other mechanical agitation. This process is not entirely satisfactory as it requires an extra step during, interrupting and/or following the cleaning process. Furthermore, the attempted restoration of the device may not be successful, allowing redeposition of the previously collected dust. 
     To address the problems experienced with reusable dust gathering devices, disposable dust gathering devices have been developed which have limited re-usability. These disposable dust gathering devices may include brush portions made of synthetic fiber bundles, called tow fibers, attached to a sheet as shown in 2010/0319152. Or the tow fibers may be attached to a plate as shown in U.S. Pat. No. 4,145,787. The disposable cleaning article may be used for one job (several square meters of surface) and discarded, or may be restored and re-used for more jobs, then discarded. Traditional cleaning articles including feather dusters, cloths, string mops, strip mops and the like, are not disposable for purposes of this invention. 
     Such devices may be made, for example, according to U.S. Pat. Nos. 6,813,801; 6,968,591; 6,984,615; 7,228,587; 7,231,685; 7,234,193; 7,234,914; 7,237,296; 7,237,297; 7,243,391; 7302729; 7,302,730; and/or 7,334,287 (having a common related application). The patents in this linage have a common feature—strips laterally extending from both sides of a generally planar article. The strips serve the purpose of increasing surface area of intermediate tow fibers by promoting deformation of the tow fibers out of the plane of the article. This approach has the attendant problem that excessive material is used for the strips. If the strips have the same length, taken from the longitudinal axis, as the tow fibers, the strips can interfere with the tow fibers fully contacting the target surface. 
     Another problem with a cleaning article comprising strips is that such cleaning articles are typically packaged in a flat state. To get optimum performance, a user should pre-fluff the cleaning article prior to use. Even with instructions, many users simply do not understand how to correctly perform this step. Some users do not read the instructions and entirely skip this step. Furthermore, the strips can be partially joined together due to improper cutting during manufacture, making the fluffing insufficient or more difficult. The problem of strips in such cleaning articles is exacerbated in U.S. Pat. No. 5,953,784 which teaches strips extending not only from both sides of the cloth, but also from the front. 
     One attempt to overcome this problem is found in U.S. Pat. No. 7,566,671 which does not use laterally extending strips. However, this attempt has the drawback that the cleaning implement thereof only cleans on one side of the implement—not both sides as taught by the lineage of 6,813,801. 
     An attempt to overcome the single-sided cleaning disadvantage of the aforementioned U.S. Pat. No. 7,566,671 is found in U.S. Pat. No. 7,251,851 which teaches a spiral duster. However, this approach starts with a construction similar to that of the aforementioned U.S. Pat. No. 6,813,801 lineage and U.S. Pat. No. 823,725—leading the intended solution back to the same approach which started the problem 100 years ago. 
     Thus, there is a need for a cleaning article which does not require gather strips. Such cleaning article may further provide for advantageous use of the tow fibers to gather and retain dust and may also allow the user to minimize or eliminate the often overlooked or improperly performed fluffing step. 
     SUMMARY OF THE INVENTION 
     The invention comprises a cleaning article. The cleaning article is optionally removably attachable to a handle. The cleaning article comprises at least one layer of tow fibers and at least one sheet joined together in face to face relationship. At least some of the tow fibers overhang the edge of the sheet. The amount of the overlap is different throughout at least a portion of the longitudinal length of the cleaning article. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic exploded perspective view of a cleaning article according to the prior art and having strips on two outer laminae. 
         FIG. 2  is a broken schematic top plan view of a cleaning article according to the present invention and having a sheet with a concave notch on one side of the longitudinal axis L and having convex shapes on the other side of the longitudinal axis L. 
         FIG. 3  is a broken schematic top plan view of a cleaning article according to the present invention and having a tow fiber layer which changes in density and monotonically changes in length on one side of the longitudinal axis and a random shape on the other side of the longitudinal axis L. 
         FIG. 4  is a broken top plan view of an alternative embodiment of a sheet usable with the present invention and having scallops on one side of the longitudinal axis L and having a convex/concave shape with rectilinear sides on the other side of the longitudinal axis L. 
         FIG. 5  is a broken top plan view of an alternative embodiment of a tow fiber layer usable with the present invention and having notches on one side of the longitudinal axis L and having a sinusoidal edge on the other side of the longitudinal axis L. 
         FIG. 6  is a broken top plan view of sheet material usable with the present invention and having four individual nested sheets usable with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , the cleaning article  10  may be generally elongate, having a longitudinal axis L, although other shapes are contemplated and feasible. The cleaning article  10  may be removably attachable to a handle  35  and/or may be used without a handle  35 . A suitable handle  35  is disclosed in commonly assigned US Publication 2011/00099764. 
     The z-direction of the cleaning article  10  is the direction perpendicular to the sheet  12  which is typically closest to the handle  35  (if present) of the cleaning article  10 , the XY plane is defined as the plane defined by the sheet  12  and is typically perpendicular to the z-direction. The cleaning article  10  may have a longitudinal axis L and a transverse axis T orthogonal thereto. The cleaning article  10 , and respective components thereof, may have two longitudinal edges  20  parallel to the longitudinal axis L and two transverse edges  22  parallel to the transverse axis T. 
     The length of the cleaning article  10 , etc. is taken in the longitudinal direction. The width of the cleaning article  10  corresponds to the transverse direction perpendicular to the length direction and disposed within the plane of the sheet  12 . The thickness is defined as the dimension in the z-direction. The length and width of the strips shown in the art are taken in the transverse and longitudinal directions, respectively. 
     The cleaning article  10  may be thought of as having two, three or more laminae joined in face-to-face relationship. The laminae may comprise a tow fiber lamina  14 , intermediate two laminae of generally planar sheets  12 . Alternatively, a single tow fiber layer  14  may be joined to a single generally planar sheet  12 . The tow fiber layer  14  is shown to comprise four layers, although one of skill will understand from one to several layers are feasible and contemplated for use with the present invention. Likewise, one, two, three or more sheets  12  are feasible and contemplated for use with the present invention. 
     An attachment system may provide for removable attachment of the cleaning article  10  to a suitable and optional handle  35 . The cleaning article  10  attachment system and optional complementary handle  35  attachment may comprise adhesive joining, cohesive joining, mechanical engagement, etc. One common attachment system comprises sleeves  30  into which the tines  36  of the handle  35  may be inserted. The sleeves  30  may be disposed on an outer lamina  12 . 
     The sheet  12  may have an outwardly facing preferential cleaning side and a second inwardly facing attachment side opposed thereto. The sheet  12  may comprise a nonwoven sheet  12 . Suitable nonwovens may be made according to commonly assigned U.S. Pat. Nos. 6,797,357; 6,936,330, D489,537 and/or D499,887. 
     Adjacent the sheet  12  may be a compressible and/or deformable second lamina of fibers  14 . The second lamina may comprise tow fibers  14 . The tow fiber lamina  14  may be joined to the sheet  12  in face-to-face relationship. The tow fiber lamina  14  may be suitable for directly contacting the target surface during cleaning. 
     The tow fibers  14  may be synthetic. As used herein “bundle fibers” and/or “tow” refer to fibers comprising synthetic polymers including polyester, polypropylene, polyethylene and cellulose materials including cellulose acetate and mixtures thereof manufactured wherein the individual fibers are relatively long strands manufactured in bundles. The bundle fibers may be defined as any fibers having distinct end points and at least about 1 cm in length. The cleaning article  10  of the present invention may further comprise an optional absorbent core (not shown). 
     The sheet  12 , fibrous layer  14  and non-planar structure  16  may be joined together by thermal bonding, autogenous bonding, ultrasonic bonding, heat sealing, adhesive and/or other means known in the art. The sheet  12  may comprise two plies, joined together in face-to-face relationship. The sheet  12 , fibrous layer  14  and non-planar structure may be bonded in a pattern which provides a central spine  42  parallel the longitudinal axis L. 
     The joining of the tow fiber layer  14  and generally planar sheets  12  may be done with any combination of continuous bonds  38  and/or spot bonds  38 , as known in the art. The bonds  38  may be used to create sleeves for an attachment system as known in the art and discussed herein. 
     The bonding pattern joining the two plies may be provided in a pattern which provides a sleeve  30  complementary to and able to receive the tines  36  of the handle  35 , if used with the cleaning article  10  of the present invention. Particularly, the bonding may be provided in a pattern which is generally longitudinally oriented, so that the tines  36  may be inserted into the sleeve  30  created between adjacent bonds  38 . 
     The bond pattern may provide a continuously bonded or discretely bonded central spine  42 . Outboard of the central spine  42 , the bond pattern may comprise one or more continuous or discontinuous bond sites. The space between the central spine  42  bond and the outboard bonds  38  may create a sleeve  30  for receiving a tine  36  of the optional handle  35 . If desired, the sheet  12  may be shrunk/strained in the cross-direction. This process can provide rugosities or wrinkles in sheet  12 . The rugosities/wrinkles space apart the plies of sheet  12 , allowing for easier insertion of the tines  36  into the sleeve  30 , if so desired. 
     Referring to  FIG. 2 , the cleaning article  10  according to the present invention for removable attachment to a handle  35  has a longitudinal axis L defining a longitudinal length. Again, the cleaning article  10  comprises at least one layer of tow fibers  14 . The tow fibers extend transversely outward from proximal ends juxtaposed with said longitudinal axis L to distal ends laterally remote therefrom. The tow fiber layer  14  further has first and second opposed faces and defines a tow fiber width TFW. The tow fiber width TFW is the distance from the longitudinal axis L to the distal end of a particular tow fibers taken in a straight, planar and transverse direction. The tow fiber width TFW may be straight or variable throughout the longitudinal length. 
     The cleaning article  10  further comprises a generally planar sheet  12  disposed on a first face of the at least one layer of tow fibers  14 . The sheet  12  having a sheet  12  width SW taken in a straight, planar and transverse direction. The sheet  12  width SW is being predominantly less than the tow fiber width TFW. The difference between sheet  12  width SW and tow fiber width TFW varies along a predominant portion of the longitudinal length of the cleaning article  10 . This geometry is referred to herein as ‘differential overhang DO. 
     Of course such differential overhang DO is relevant throughout the longitudinal length where there is coincidence between the sheet  12  and layer of tow fibers  14  and is controlled by the longitudinally shorter of these components. By predominantly, it is meant that the sheet  12  width SW is less than the tow fiber width TFW, throughout at least 50%, 75% or 100% of the longitudinal length of said sheet  12 . However, a cleaning article  10  having a differential overhang DO throughout at least 10, 20, 30 or 40% of the longitudinal length is also contemplated. 
     Of course, if there are one or more sheets  12  interposed between plural layers of tow fibers  14 , or vice versa, each sheet  12 /tow fiber layer  14  will provide a different combination of sheet  12  width SW and tow fiber width TFW. Each such combination will provide a respective differential overhang DO therebetween. The differential overhang DO may be the same or different, as desired. Conversely, in one embodiment, the cleaning article  10  may be symmetric about the longitudinal axis L. If so the differential overhang DO of the tow fibers over the edge of the sheet  12  will be the same on both sides of the longitudinal centerline. 
     Referring to  FIG. 3 , if desired, each longitudinal edge of either and/or more sheets  12  may be notched to be concave, providing a sheet  12  referred to as concave. If the tow fiber layer  14  is of constant width, this arrangement provides a differential overhang DO which is relatively greater as the transverse axis T is approached and relatively lesser as either transverse edge is approached. This arrangement provides the advantage that the relatively greater differential overhang DO near the center of the cleaning article  10  may provide relatively greater fluffing of the tow fibers near the center of the cleaning article  10 . 
     Referring to  FIG. 4 , if desired, each longitudinal edge of one or more sheets  12  may be concave, providing a sheet  12  referred to as concave. If the tow fiber layer  14  is of constant width, this arrangement provides a differential overhang DO which is relatively greater as either transverse edge is approached and relatively lesser as the transverse axis T is approached. This arrangement provides the advantage that the relatively lesser differential overhang DO near the center of the cleaning article  10  may provide relatively greater fluffing of the tow fibers near the transverse edges  22  of the article. 
     If desired, the cleaning article  10  may have a notch which is arcuate and has a radius of curvature which increases as the transverse axis T is approached. This arrangement provides for a more rapid change in the amount of fluffing incurred. In a nonlimiting example, for the embodiment described herein having a length ranging from 140 to 200 mm and a transverse width ranging from 90 to 130 mm, the differential overhang DO may range from 4 to 60 mm, from 5 to 50 mm or from 10 to 30 mm at various positions along the longitudinal edges  20 . 
     In yet another embodiment, the cleaning article  10  may comprise a first sheet  12  having respective first sheet  12  longitudinal edges  20  with a first sheet  12  geometry. The cleaning article  10  may further comprise a second sheet  12  having respective second sheet  12  longitudinal edges  20  and a respective second sheet  12  geometry. The first sheet  12  geometry and second sheet  12  geometry may be different, so that the first sheet  12  longitudinal edges  20  and second sheet  12  longitudinal edges  20  are not identically disposed outward from the longitudinal axis L. This arrangement provides the benefit that the differential overhang DO associated with each sheet  12  provides for differential and potentially greater fluffing. 
     In yet another embodiment, the longitudinal edges  20  of the sheet  12  may be serrated. The serrations may be of identical, similar and/or different pitch and or depth. The serrations may be sawtooth, square, sinusoidal, etc. and/or any combination thereof. 
     Referring to  FIG. 3  in another embodiment, the sheet  12  longitudinal edges  20  of the one or more sheets  12  may be straight and parallel. Conversely, the tow fiber layer  14  longitudinal edges  20  may be curved, notched, concave, convex, etc. to differentially overhang the longitudinal edges  20  of said sheet  12 . This arrangement provides the benefit that regularly shaped sheets  12  may be utilized and the tow fiber layer  14  width varied to provide the differential overhang DO. 
     The tow fiber layer  14  may be concave as described above with respect to the sheet  12  or may be convex as likewise described above with respect to sheet  12 . Alternatively, the tow fiber layer  14  may monotonically increase or monotonically decrease in width, and in respective corresponding differential overhang DO, as either transverse edge is approached. This arrangement provides the benefit that fluffing may be controlled as a function of the longitudinal position. Conversely, the tow fibers may be randomly arranged to provide a cleaning article  10  wherein said the differential overhang DO occurs randomly throughout said longitudinal length. 
     If desired, in yet another embodiment, the cleaning article  10  according to the present invention may comprise tow fiber layers  14  having plural decitex values. Particularly, in a non-limiting example a single tow fiber layer  14  may comprise plural decitex values. Additionally or alternatively, each tow fiber layer  14  may comprise a single decitex value, but different tow fiber layers  14  may have mutually different decitex values. 
     The decitex values may range from about 1 to about 30, and ratio of decitex values may range from 1.5:1 to 5:1. If desired the layer of tow fibers having a higher decitex value may be placed relatively closer to the top layer of tow fibers, and the layer of tow fibers having a lower decitex value may be placed relatively closer to the target surface being cleaned. 
     In yet another embodiment, the cleaning article  10  may comprise a first tow fiber layer  14  having a respective first tow fiber layer  14  longitudinal length taken in the transverse direction. This cleaning article  10  may further comprise a second tow fiber layer  14  having a respective second tow fiber layer  14  longitudinal length. The first tow fiber layer  14  longitudinal length may be different than the second tow fiber layer  14  longitudinal length. 
     Referring to  FIG. 4 , an alternative sheet  12  according to the present invention may have a longitudinal edge  20  comprising plural scallops. The scallops may be of different depth and width, as shown or may be of identical geometry. Alternatively or additionally such a sheet  12  may comprise a concave or convex shape made of rectilinear sides  20 ,  22 . Any of these geometries will provide a differential overhang DO of the tow fiber layer  14  relative to the sheet(s)  12 . 
     Alternatively or additionally, the transverse edges  22  of the sheet(s)  12  may be of variable distance from the transverse axis T. If used with a tow fiber layer  14  of constant distance from the transverse axis T this arrangement provides differential overhang DO of the tow fiber layer  14  relative to the sheet(s)  12  at the proximal transverse edge  22 , and particularly the distal transverse edge  22  of the cleaning article  10 . 
     Referring to  FIG. 5 , an alternative tow fiber layer  14  according to the present invention may have a longitudinal edge  20  comprising plural notches. The notches may be of different depth and width, as shown or may be of identical geometry. Alternatively or additionally such a tow fiber layer  14  may comprise a sinusoidal longitudinal edge  20 . Any of these geometries will provide a differential overhang DO of the tow fiber layer  14  relative to the sheet(s)  12 . 
     Alternatively or additionally, the transverse edges  22  of the tow fiber layer  14  may be of variable distance from the transverse axis T. If used with a sheet  12  of constant distance from the transverse axis T this arrangement provides differential overhang DO of the tow fiber layer  14  relative to the sheet(s)  12  at the proximal transverse edge, and particularly the distal transverse edge of the cleaning article  10 . 
     If desired, the various cleaning articles  10  described herein may be packaged and sold in a Some of the cleaning articles  10  may have the aforementioned concave sheet  12  and other cleaning articles  10  may have a convex sheet  12 . This arrangement provides the benefit that the user has a choice of different cleaning articles  10  for different tasks. 
     Referring to  FIG. 6 , a further unpredicted benefit occurs in manufacture. Convex and concave sheets  12  may be nested and cut from a single larger piece of material. As individual sheets  12  are cut from the larger material, waste is minimized due to the nesting. 
     One of skill will recognize that hybrids and combinations of the embodiments described above are contemplated and feasible. For example, any of the sheets  12  described herein may be used with any of the tow fiber layers  14  described herein. A single cleaning article  10  may comprise plural sheets  12  having like or different geometries and/or plural tow fiber layers  14  having like or different geometries. Such sheets  12  and tow fiber layers  14  may be disposed next to each other, interspersed or placed in any desired configuration of layers. 
     Further, any of the embodiments described herein may optionally include any one of, any combination of, or all of: a sheet  12  and/or tow fiber layer  14  having differential overhang DO as described herein, a sheet  12  with apertures, an elastically contracted sheet  12  and/or a cleaning article  10  having an elastically contracted upstanding panel, as shown in commonly assigned U.S. Pat. Nos. 8,893,345, 8,576,746 and 2013/0232706, respectively, all filed Mar. 9, 2012. 
     Any of the sheet  12  and/or layer of tow fibers  14  may be completely or partially coated with adhesive, wax, Newtonian or non-Newtonian oils or a combination thereof, in order to improve cleaning and increase retention of absorbed debris. If desired, the cleaning article  10  may optionally be used with a cleaning solution or other solution usable for other purposes such as treating the surface for appearance or disinfectant, etc. The cleaning solution may be pre-applied to the cleaning article  10 , creating a pre-moistened cleaning article  10  or may be contained within a separate reservoir for dosing onto the cleaning article  10  and/or target surface. The cleaning solution may comprise a majority water, and at least about 0.5, 2, 5 or 10% solids, or at least about 30% or 50% aqueous solvents, non-aqueous solutions or mixtures thereof (all by weight). 
     Optionally the cleaning article  10  may further comprise a non-planar structure, as disclosed in commonly assigned U.S. Pat. No. 8763197, filed Dec. 4, 2009. The non-planar structure may extend out of the XY plane, in the z-direction. 
     Referring back to  FIG. 1 , the cleaning article  10  may optionally further comprise gather strips  17 , as known from the prior art. As used herein, gather strips  17  refer to cantilevered elements extending transversely outwardly from the longitudinal centerline of the article  10 , and having a length (taken in the transverse direction) greater than the corresponding width (as taken in the longitudinal direction). The gather strips  17  lie within the XY plane as intended by manufacture, although may be deformed out of the XY plane due to fluffing before use, and/or deformations which occur in use due to movement against the target surface. The gather strips  17  may be incorporated into one of the sheets  12  described above or may be deployed on a separate sheet  12 . 
     The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.” 
     Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern. 
     While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.