Mop head comprising capacitive web elements, and method of making the same

A mop head comprising a plurality of web elements having involutions therein. The involutions may be formed by treatment conditions comprising successive tensioning/detensioning, compression, differential stressing or stretching, twisting, or combinations of these or other conditions or treatments imparting involutions to the web elements. In a preferred aspect, the web elements are formed of a non-woven material comprising a cellulose and synthetic fiber blend. Mop heads of the invention are usefully employed in dry mopping and/or wet mopping applications.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a mop head comprising a plurality of web 
elements, and to a method of making same. 
More specifically, the present invention relates to a mop head comprising 
fibrous web elements for the retention of solids and/or fluids, for 
dry-mopping and/or wet-mopping applications. The web elements of the mop 
head are structured to provide three-dimensional configurations including 
involutions providing enhanced holding ability (capacitance) for the 
retention and subsequent release of particulates and/or fluids. 
2. Description of the Related Art 
The raw materials employed in mop head yarn elements can be of many 
different types. There are primarily two different types of fibers in 
common use in such yarn elements, cellulose-based fibers and 
petroleum-based fibers. Cellulose-based fibers used in this industry are 
typically cotton or rayon fibers. The most common petroleum-based fibers 
employed in mop applications are polypropylene, polyester, and nylon 
fibers. Cellulose fibers are generally derived from natural resources 
without chemical restructuring of their properties, as is typical of most 
synthetics. 
Mop yarns may also comprise miscellaneous fibers of undetermined origin, in 
addition to cotton or rayon. These miscellaneous fibers may be a blend of 
fibers which are produced as a by-product of manufacturing processes in 
textile mills running virgin raw materials. As these mills produce end 
products such as denim, sheeting, towels, etc., the process machinery 
throw off fibers and trimmings waste which are assimilated through various 
collection devices to be baled and reused or sold. This waste fiber 
by-product has approximately the same fiber composition as the end product 
being manufactured. 
A prevalent raw material used for the manufacture of mop yarn is 100% 
cotton fiber. This fiber is generally used in three different types: (1) 
virgin cotton; (2) gin motes or gin mote blends; and (3) waste of 100 % 
cotton. 
Virgin cotton is cotton produced by the ginning process, with no 
reprocessing being involved. For mop yarn this virgin cotton generally is 
lower grade cotton such as good ordinary or below grade class, and may 
contain shorter, less mature fibers, or naturally stained fibers which may 
contain a greater amount of leaf, stick or stem than higher grades of 
cotton. 
Gin motes are one of the by-products generated by the cotton ginning 
process. These by-products comprise the fibers separated from the virgin 
cotton when it is cleaned in the cotton gin. The quality of the gin mote 
fibers is directly related to the quality of the virgin cotton being 
ginned. If the cotton being ginned is of higher classes of quality, then 
the gin motes will consist of better quality fibers. However, if the gin 
motes are not reprocessed prior to the manufacture of yarn therefrom, a 
yarn will be processed which has an extremely high trash content, e.g., 
leaf, stick and stem particles included in the fibers. As a result, most 
mop yarn manufacturers reprocess the raw gin motes into cleaned-up gin 
mote blends. 
Waste of 100% cotton is used very little in the manufacture of mop yarn 
because of its limited supply. 
Another cellulose-based raw fiber material which is widely employed in the 
manufacture of mop yarn is rayon. Rayon is a viscose fiber produced 
primarily from wood pulp or other sources of regenerated cellulose. This 
fiber is produced by dissolving purified cellulose using certain solvents 
and chemical baths for hardening. After hardening, it is cut to staple 
lengths. The diameter of the fiber can vary and it is denoted by its 
direct relation to weight. 
Most mop yarns are formed of cellulosic or other natural materials, or else 
of natural/synthetic blends. Synthetic (e.g., petroleum-based) fibers are 
not generally used alone in mop head applications for wet-mopping usage, 
for the reason that many synthetic fibers cannot absorb water, but rather 
must rely on their capillary reaction to liquids. This means that the yarn 
must be sufficiently porous to permit the moisture to diffuse between the 
fibers and be held between the fibers in a clinging manner. The positive 
aspects of synthetic fibers for mop head application include their 
strength, high wearability, and limited shrinkage characteristics. In many 
mopping applications, the mop head may suitably employ mop yarn of only 
synthetic fibers. An oil mop of such type is disclosed in U.S. Pat. No. 
3,748,682. 
The general characteristics desirable for mop yarns and fiber structures in 
mopping applications include: 
(1) high durability and abrasion resistance; 
(2) high absorption characteristics as demonstrated by soft, e.g., loosely 
twisted yarns; 
(3) ready driability; 
(4) high wet tensile strength; and 
(5) the ability to withstand repeated launderings and not shrink 
significantly, 
with characteristics (1) and (5) being important in both wet mopping as 
well as dry mopping applications, while characteristics (2), (3), and (4) 
are desirable for wet-mopping applications. 
U.S. Pat. No. 4,717,616 issued Jan. 5, 1988 to A. D. Harmon, et al 
discloses a mop head construction comprising a plurality of substantially 
parallel, abutting strands of textile material, such as roving, or cords 
of twisted strands and yarns. The main deficiency of this product lies in 
the fact that absorption is being accomplished through the use of 
capillary action exhibited by very finely divided fibrous structures 
possessing a low fluid pick-up and retention capacity on a unit volume 
basis, thereby physically limiting the amount of fluids, e.g., liquids, or 
mixtures of liquids and particulates, that can be absorbed per unit 
volume. Further, due to its large surface area per unit volume, the 
renewability and driability of this type of fabric is poor. The fluid that 
is taken up by such mop head is not readily released, so that the sorptive 
capacity which initially is present is not efficiently used after liquid 
is taken up, until the fibrous structure dries by evaporation of the 
retained fluid. 
U.S. Pat. No. 4,313,774 issued Feb. 2, 1982 to J. P. Arthur describes a mop 
head made of a non-woven fabric of a cellulose and synthetic fiber blend 
which is made by combining plural non-woven continuous fabric sheets in a 
composite superimposed stack, ultrasonically sealing the stack in a 
continuous transverse direction of the sheet in the center portion 
thereof, and then cutting the stack between the ends of the sheets and the 
central portion to form a plurality of strips. 
U.S. Pat. No. 4,114,224 issued Feb. 2, 1988 to E. Disko discloses a mop 
comprising plural absorptive elements comprising superposed flat layers of 
bonded non-woven fabric comprising a fibrous web and a binder. The fibrous 
web comprises at least about 50% by weight of hydrophilic fibers and the 
binder is present in about 25% to 100 % of the fibers, at about 50-400 
grams per square meter. The binder is printed onto the fabric in the 
pattern. The non-woven fabric layers are joined along a medial spine, from 
which the layers are slit to the extremities thereof to form parallel flat 
strips ranging in width from about 15-40 millimeters and in length from 
about 20-60 centimeters. 
U.S. Pat. No. 3,520,017 issued July 17, 1970 to T. V. Moss describes a mop 
swab including a multiplicity of absorbent mop cords which are secured 
together adjacent the ends of the swap by strands of thread or yarn which 
extend transversely to the swab in and among the mop cords. The mop cords 
may also be secured substantially centrally of the swab in a 
bunched-together relationship, by a canvass or fabric band. 
It would be a significant advance in the art of mop head structures to 
provide a mop head having a significantly enhanced capacity for 
particulates and/or liquids, encompassing both dry mopping and wet mopping 
utility, relative to mop head structures of the prior art. 
It is therefore an object of the present invention to provide such an 
improved mop head structure having utility for diverse dry mopping and/or 
wet mopping applications. 
SUMMARY OF THE INVENTION 
In one aspect, the present invention relates to a mop head comprising a 
plurality of web elements having involutions therein. These involutions 
may be formed by subjecting web elements to an involution-forming 
treatment such as (a) successive tensioning and detensioning conditions, 
(b) compression conditions, (c) differential stressing conditions, (d) 
twisting conditions, and (e) combinations of such conditions, e.g., 
twisting, stretching, and possibly pushing and pulling, whereby the web 
elements comprise such involutions therein. 
The web elements employed in the mop head of the present invention may be 
of any suitable material of construction, as for example polymeric 
materials of synthetic character, or natural or synthetic fibrous 
materials, as well as blends, combinations, and composites thereof. 
Preferably, the web element is a fibrous web element, although it may be 
suitable to employ ribbons of thermoplastic materials or any other 
suitable web compositions in the broad practice of the present invention. 
The mop head of the invention may be configured in the form of an array of 
loops of the fibrous web elements comprising the involutions, or the mop 
head may comprise an array of such groups and free ends retentively held 
in the array configuration by suitable structural means such as a clamp 
fitting or banding which in turn is coupleable to a mop handle to provide 
a complete mop device. 
The fibrous web elements may be formed of any suitable material, such as 
woven or non-woven or felted webs, in any suitable material of 
construction, including cellulosic and synthetic materials, polymeric 
treated fibers, and blends thereof. 
In another aspect, a mop head of the type broadly described hereinabove is 
impregnated with a dust-attracting substance, which may be lipophilic in 
character, and preferably is a wax or oil-based material. 
In a further aspect, the further invention relates to a method of making a 
mop head, comprising the steps of: 
providing web elements which are treatable to impart involutions thereto, 
e.g., which are formed of a material which under treatment conditions 
selected from the group consisting of (a) successive tensioning and 
detensioning conditions, (b) compression conditions, (c) differential 
stressing conditions, (d) twisting conditions, and (e) combinations of 
such conditions, form involutions therein; 
subjecting the web elements to treatment conditions which form the 
involutions therein; and 
assembling an array of the involution-bearing web elements to form the mop 
head. 
In respect of the method described immediately hereinabove, it will be 
appreciated that the assembly step of forming the web elements into an 
array may be carried out prior or subsequent to the step of subjecting the 
web elements to the involution-forming treatment conditions. 
Other aspects and features of the invention will be more fully apparent 
from the ensuing disclosure and appended claims. 
The present invention is based on the surprising and unexpected discovery 
that instead of relying on the use of finely divided or hollow fibers or 
randomly created, structurally unstabilized or otherwise haphazardly 
created structural regions, as do conventional mop materials, involutions 
may be formed in web elements and employed to substantially enhance the 
capacity of the web elements and mop head comprising same for pick-up, 
retention, and release of particulates and/or liquids. By such expedient, 
the mop head of the present invention is able to accommodate dry mopping 
as well as wet mopping applications. As used herein, the term 
"involutions" refers to deformations in the web element of the mop head 
constituting a deviation from the local planar character of the web. 
Accordingly, involutions in accordance with the invention include folds, 
wrinkles, creases, bends, curls, rolls, apertures, dimples, bosses and the 
like, which function to increase the holding or carrying capacity of the 
web elements for particles and/or liquids. 
The web elements of the present invention thus are to be distinguished from 
the planar fibrous web elements employed in the mop head structures shown 
and described in the aforementioned U.S. Pat. Nos. 4,313,774 and 
4,114,224. 
In contrast to the anticipated deficiencies of the involuted web elements 
of the present invention, which would be expected to present a 
significantly reduced surface area to the surface or article being mopped 
by reason of the involutions, i.e., so that there would be expected to be 
less contact area for mopping of particulates and/or liquid, it has been 
unexpectedly discovered that the involutions in fact present an enhanced 
capacity matrix for take-up and retention of the particulates and/or 
liquids, which in addition function to readily release the collected 
particulates and/or liquids without undue effort. Further, it has been 
found that in wet mopping applications, the involutions function to 
promote evaporative drying of the mop subsequent to use, relative to mop 
heads comprising planar web elements, so that the mop is more quickly 
rendered dry for enhanced subsequent usage, relative to a corresponding 
mop head comprising planar web elements and containing liquid. 
Involuted web elements of the mop head of the present invention are capable 
of taking up and retaining large amounts of particulates and/or liquids, 
utilizing relatively small amounts of structural material, as compared 
with conventional mop head structures comprising planar fibrous web 
elements. The latter mop heads are characterized by inherently low pick-up 
and retention capacity per unit of volume, which physically limits the 
amount of particulates and/or liquids which can be accommodated by the mop 
on a unit volume basis. 
In addition, mop head articles comprising web elements of the present 
invention have been found in wet mopping applications to achieve an 
unexpectedly high extent of release of previously picked-up and retained 
liquids. For example, a mop head comprising involuted web elements of 
cotton, rayon, or wood pulp/synthetic blends typically release 80% to 90% 
of previously picked-up and retained liquid, as compared to 40% to 50% 
release levels which are characteristic of prior art mop heads of cotton 
or rayon spun yarn elements. 
In a particular aspect of the invention, the web elements may be twisted 
into the form of elongate strands having involutions, or interstices, 
which provide a substantial capacity for particulates and/or liquid 
pick-up, retention and release, as compared to conventional mop head 
structures.

DETAILED DESCRIPTION OF THE INVENTION, AND PREFERRED EMBODIMENTS THEREOF 
With references to the drawings, FIG. 1 shows an elevation view of a 
tetrahedral cellular structure 32 defining an interior interstitial space 
34 bounded by legs 33, 35, 37, 39, 41 and 43. The legs are structural 
elements which may be filamentous or filar in character and may be formed 
of materials such as rayon, blends, acrylic, polypropylene, cotton, metal, 
etc. 
The resulting tetrahedral cellular structure when placed in proximity to a 
fluid such as water, organic solvent, etc., provides by virtue of its 
shape a region into which the fluid will flow by capillarity and surface 
tension effects. Thus, this structure is usefully employable in web 
elements comprising a mop head structure. The involutions provided by this 
structure are also advantageous in dry mopping applications, wherein the 
interior space of the cellular structure provides a locus for the take-up 
and retention of particulates, e.g., dust particles, sawdust, etc. It will 
be recognized that the shape of the cellular structure may be varied 
widely for wet mopping applications, depending on the viscosity, surface 
tension, and other physical characteristics of the fluid sought to be 
sorbed, as well as for dry mopping applications, depending on the size and 
character of the solid matter sought to be taken up and retained by the 
mop. 
FIG. 2 shows a perspective view of a longitudinally extending web element 
(filament) 38, featuring involutions defining capacitive areas 40 and 42. 
Materials employed in the construction of this web element can be porous 
or nonporous materials, including, but not limited to, knitted or woven 
fabrics, incorporating plastics, metals, ceramics, cotton, rubber, etc., 
as a structural materials, so that when treated as herein described, the 
filament will form a continuous laterally involuted structure. 
This laterally involuted web element 38 when placed in proximity to a fluid 
such as water, organic solvents, etc., provides by virtue of its shape a 
region into which the fluid will flow by capillarity and surface tension 
effects. When placed in proximity to a particulate, the web element 
provides the involutions as retention spaces for the particulates, which 
are able to pass into the capacitive areas defined by the involutions and 
to be retained, pending shaking, washing, or other removal step for 
disengagement of the particulates from the elongated web element. It will 
be recognized that the shape of the sorptive structure may be varied 
widely in wet mopping applications, depending on the viscosity, surface 
tension and other physical characteristics of the fluid sought to be 
sorbed, as well as in dry mopping applications, depending on the 
characteristics of the particulates sought to be taken up and retained by 
the mop comprising such elements. 
The filament shown in FIG. 2 can for example be manufactured by introducing 
a ribbon of a knit material such as jersey onto two pairs of pull rollers 
with the first set revolving at a given speed and the second set revolving 
at some multiple thereof e.g., three times as fast, thereby stretching the 
material to or near, but not above, its elastic limit, and creating an 
imbalance in the internal forces present in the material, thereby causing 
the edges of the material to roll laterally inwardly into an involute 
form. 
In an illustrative aspect, an involuted web element may be formed by the 
following steps: 
(a) providing a web of a flexible material; 
(b) unidirectionally stretching the flexible web to an extent in the 
vicinity of, but not exceeding, the elastic limit of the web material; and 
(c) terminating the unidirectional stretching to impart involutions to the 
web, thereby forming the involuted web element. 
An involuted web element may also be formed in the broad practice of the 
present invention by a process comprising: 
(a) providing a web of flexible material; and 
(b) imparting collaterally imbalanced stresses to the material of the web, 
causing deformation of the web to yield involutions therein, and resulting 
in an involuted web element as the product article. 
The filament web element shown in FIG. 2 can be manufactured in an 
alternative manner, by introducing a web of internally and collaterally 
prestressed material to a processing step which selectively relieves 
stress on only one side of the web, e.g., by passing the web into an 
appropriately designed infrared, ultrasonic, or radio-frequency heating 
apparatus, causing a net imbalance of stress forces to result, which in 
turn causes the edges of the web to roll into an involute form. 
The filament structure shown in FIG. 2 can be manufactured in still another 
way, by introducing a web of internally stress-free material into a 
process which will induce stress on only one side of the web, such as by 
passing the web into an appropriately designed glass bead peening or shot 
peening apparatus, resulting in a net imbalance of stress forces, which in 
turn causes the edges of the web to roll inwardly into an involute form. 
A similar effect may be accomplished in the formation of the structures 
shown in FIG. 2, 3, and 5, by employing composite web structures 
comprising laminated materials in which one side of the web is hydrophobic 
and the opposite side of the web is hydrophilic. If the hydrophilic side 
swells or bows laterally due to absorption of a liquid or due to weak 
magnetic interactions with a selected solvent or solute, the web will 
assume an involute form, and by tailoring the properties of the components 
of the composite web structure it is possible to selectively determine the 
degree of involutions and/or convolutions which will be responsive to 
various agents or reagents, liquids, fluids, heat, etc., and/or various 
processes and combinations thereof, and to create motile structures 
capable of involuting and de-involuting and also by proximity capable of 
rolling up and trapping a predetermined liquid or particulate material, 
and not involving and trapping another selected liquid or solid of 
different composition. 
It should be recognized that the structural embodiments disclosed herein 
are applicable on a molecular as well as macroscopic scale, making it 
possible to design molecular structures which may be motile under certain 
conditions, and may be used to trap some predetermined molecule or 
molecules by involuting in proximity to it, thereby enclosing it. A filar 
structure of the type shown in FIG. 2, 3, and 5 can thus be used as 
specific molecular trap by approximately tailoring the shape and size of 
the interstitial space therein. 
A mop head web element comprising a three-dimensional fabric may be 
constructed as a knitted fabric or may be built up from sheets of 
nonporous materials that have been embossed and perforated or molded into 
a series of component shapes that form the involutions, e.g., sorptive 
structures or solids trapping spaces, when the sheets or webs are stacked 
on one another. The structural material employed in this web element could 
be cellulose, plastic, wire of various metals, or even ceramic or other 
non-traditional mop head materials. 
FIG. 5 is an elevational view of a longitudinally twisted ribbon-like 
filament 66 defining a capacitive structure with involutions 68 formed as 
a result of the coils of ribbon being brought into proximity with each 
other by virtue of its twisted structure. The resulting structure when 
placed in proximity to a fluid such as water, organic solvent, etc., 
provides by virtue of its shape a region into which the fluid will flow by 
capillarity and surface tension effects. In dry mopping applications, 
wherein the ribbon-like filament 66 is employed in a mop head comprising a 
plurality of such elements, the involutions 68 provide regions into which 
dust or other particulate material may be taken up and retained by the mop 
head. 
FIG. 6 is a perspective view of a three-dimensional capacitive structure 
formed by the filar elements 52 defining a plurality of interstitial 
spaces 54 of cube-like configuration as involutions for take-up and 
retention of fluids and/or particulates. The filar elements may, for 
example, be of metal wire, or filaments of a thermoplastic material, or 
any other natural and/or synthetic material. 
FIG. 7 shows a perspective view of an involuted interposed reactive 
element, comprising interleaved elongate web elements 72 forming 
interstitial capacitive regions 74 as the involutions therebetween. The 
resulting structure when placed in proximity to a fluid such as an 
electrolyte, or some chemically reactive fluid, etc., provides by virtue 
of its shape an involution region 74 into which the fluid will flow by 
capillarity and surface tension effects. The individual leaves may be 
required for the construction of a battery, for example. In mopping 
applications, the involutions 74 provide capacitive spaces accommodating 
the take-up, retention, and release of particulates and/or fluid, for wet 
mopping as well as dry mopping applications. 
FIG. 8 is a perspective view of a mop 100 comprising a mop head 102 which 
is joined by means of a gathering band 103 and retention yoke 104 and 
associated handle fitting 106 to handle 108 of the mop. 
The mop head 102 as shown comprises a plurality of web elements 110 having 
involutions 116 therein. The web elements may for example comprise 
elongate twisted ribbons of fabric or other material which is treatable to 
form involutions therein, such as for example by (1) successive tensioning 
and detensioning conditions, (2) compression conditions, (3) differential 
stressing conditions, (4) twisting conditions, and (5) combinations of 
such conditions. Alternatively, the web elements may be formed of a 
material, e.g., an apertured non-woven fabric, which is intrinsically 
constructed with involutions. 
These web elements may be formed of any suitable material of construction, 
as for example cellulosic materials, polymeric materials, synthetic 
resins, and any other natural or synthetic materials, and blends, 
combinations, and composites thereof. The web may suitably be fibrous in 
character, and comprise a woven or non-woven fabric of suitable 
composition. Preferred fiber materials include cotton, olefin, and 
polymeric fibers, polyesters, polypropylene, rayon, acrylics, 
rayon/polyester blends, cellulosic material such as wood pulp, wood 
pulp/polyester blends, etc. A highly suitable material for such web 
elements is a cellulose and synthetic resin fiber blend, including 
materials which are commercially available under the trademark 
SONTARA.RTM. from E. I. DuPont De Nemours and Company (Wilmington, Del.), 
including polyester, polyester/rayon blends, wood pulp/polyester blends, 
and aramid materials. Of these materials, which are spunlaced fabrics, a 
material comprising a 55%/45% by weight wood pulp/polyester blend, 
available as SONTARA.RTM. 8801 and 8818 are particularly preferred, since 
this material has a high sorptive capacity in wet mopping applications, as 
well as good dry mopping properties for dust mopping and the like. In 
general, the non-woven materials which may be usefully employed in web 
elements according to the present invention include any suitable 
configuration or structural type of non-woven materials, including 
melt-blown, spunlaced, spun-woven, spun-bonded, hydroentangled, etc. 
materials. 
Other non-woven materials which may be usefully employed in web elements in 
mop head articles of the present invention include the non-woven materials 
available under the following trade names: "Omega", "Webril", "Alpha", 
"Curity", "Kendall", and "Webcol" (Veratec [International Paper/Kendall]); 
"Assure", "Hydrospun", and "Dextex" (Dexter); "Likerag", "Reddrags", and 
"Busboy" (IFC); "Key Bak", "Solventwipe", "Chix-Plus", and "Duralace" 
(Chicopee); "Ultra Wipe" and "Sure Wipe" (Fort Howard); "Handiwipes" 
(Colgate/Polmolive); "Kimtex" (Kimberly-Clark); "Scott Cloth" (Scott 
Paper); "Nexus and Softspun" (Precision Fabrics Group, Inc.); and "Vilmed" 
(Freudenberg). 
As shown in FIG. 8, the mop head 102 features the fibrous web elements 110 
in the form of loops 112 as well as free ends 114. It will be recognized 
that the mop head may be configured solely as an array of loops, or 
alternatively as solely an array of free ends. In any event, the web 
elements of the mop head feature involutions 116 therein, which may take 
the form of creases, folds, wrinkles, bends, and the like, whereby a 
structure with pockets, crevices, interstices, etc., is provided. The 
resulting mop head may be fabricated in any suitable manner, as for 
example by tensioning and then detensioning the web elements, to form the 
involutions, or by compressing the web elements to form involutions 
therein, or by a combination of such procedures, or by any other procedure 
or treatment conditions which impart involutions to the web elements. 
In a preferred embodiment, the fibrous web elements of the mop head shown 
in FIG. 8 may be originally produced as edge cuttings or waste trimmings 
from the manufacture of garments such as surgical gowns, wash cloths, 
wipes, or the like. Such cuttings or trimmings, which are of continuous 
elongate form, may be tensioned and then relaxed to impart the involutions 
to the fabric, followed by cutting into suitable lengths or otherwise 
folding the elongated cuttings or trimmings into loops or other suitable 
configuration, to form the mop head structure. 
FIG. 9A is a perspective view of a fibrous web element 120 which may be 
employed as an element of a mop head, in combination with plural elements 
of the same type. The fibrous web element 120 as shown is elongated in 
form and is helically twisted, as at twist 122, to form a generally 
helically wound web element having a plurality of involutions 130 along 
its lengths, so that the respective web elements form strands or "ropes" 
of the fibrous materials. This element may be folded at a medial portion 
(not shown), and then suitably clamped or otherwise secured in a mop head 
together with a plurality of other web elements of similar type, to form 
loops, or alternatively a plurality of strands as shown may simply be 
gathered at one end and clamped or otherwise secured in a mop head array. 
As a variant embodiment, the helically twisted fibrous web element shown in 
FIG. 9A may be bound by a circumscribing filament 131, with the respective 
free ends thereof 132 and 133 being suitably tied or otherwise secured, so 
that the helically twisted web element is retained in a "tightly bundled" 
twisted configuration. Alternatively, the helically twisted web element 
may be retained in position by spot bonding, such as by dispersing an 
adhesive in droplet or other discontinuous form throughout the web element 
prior to helically twisting same, so that the resulting structure is 
bonded throughout its volume at discrete separate points, whereby the web 
element retains its structural integrity in the helically twisted form. It 
will be appreciated that a variety of binders, adhesives, and bondants may 
be employed for such purpose, depending on the character and composition 
of the web element and the intended use applications of the mop head in 
which such web element is to be employed. It may also be desirable in some 
instances to pattern print an adhesive or other bondant material onto the 
web element after it is helically twisted. For this purpose, 
heat-activated adhesives may desirably be employed, which are "set" at 
elevated temperature subsequent to application to the twisted web element. 
In other instances, it may not be necessary to bond or helically wrap the 
helically twisted element, if it will maintain its twisted shape 
throughout its service life. 
It will be appreciated that the web element shown in FIG. 9A may be 
constructed of the same type of materials of construction as the 
ribbon-like filament of FIG. 5 hereof, and that the pitch and number of 
twists or turns per unit length may be widely varied in each, depending on 
the specific material of construction and the intended end use 
application. 
FIG. 9B is a perspective view of an alternative involuted web element 134, 
comprising a foam or other flexible material core 135, surrounding which 
is a helically twisted fabric or other covering 136, having involutions 
137 therein. 
FIG. 9C is a perspective view of another web element structure 138 which 
may be employed in the broad practice of the present invention. This web 
element structure comprises interbraided (and individually twisted) web 
elements 139 and 140, each of which may be of a type as shown in FIG. 9A. 
It will be appreciated that in addition to involutions 142 which are 
provided on the surfaces of these respective web elements, their 
interbraided structure also produces a series of interstitial regions 143, 
144, and 145, which are capacitive in character and thus provide 
additional involutions for pick-up, retention, and selective release of 
solid particulates and/or or fluids. 
The web elements employed in the broad practice of the present invention 
may have any suitable dimensional characteristics, however web elements 
having a diameter or lateral dimension of from about 1/16 to about 3.0 
inches, more preferably from about 1/8 to about 1.6 inches, and most 
preferably from about 3/8 to about 1 inch, may generally be employed to 
good advantage. 
FIG. 10 shows an alternative embodiment of a mop 150 comprising a mop head 
152 which is formed of a plurality of fibrous web elements 154 formed from 
respective superposed sheets, e.g., 156 and 158, with the array of 
superposed sheets being folded at a medial region 160 and secured at such 
medial region by a gathering band 159 and yoke 162 or other retention 
means. The yoke 162 in turn is joined to a handle fitting 164 into which a 
handle 166 is secured, to complete the mop structure. 
The superposed sheets 156, 158 in the mop head 152 are longitudinally slit 
to form web element edges 170 and are treated or otherwise configured to 
provide involutions 172 therein. For example, the web elements may be 
subjected to longitudinal tensioning followed by relaxation of the 
tensioning force to impart involutions 172 to the web elements. The 
longitudinal stretching and relaxation may be carried out at any suitable 
point of the manufacturing process, as for example prior to superposition 
of the constituent sheets, or after the sheets are superposed and before 
the sheets are longitudinally slit to form the discrete web elements, or 
after slitting of the web elements, or in any other manner serving to 
impart the desired involutions to the web elements as employed in the 
final mop head product. 
The web elements in the FIG. 10 mop preferably are fibrous in character and 
may comprise a composition such as 100 % rayon, cotton, or polyester 
blends, 100 % polyester, 70%/30% by weight rayon/polyester blends, or 
55%/45% wood pulp/polyester blends. Such materials are illustratively 
described, it being recognized that the web elements can be formed of any 
suitable material which has involutions therein or else is capable of 
having involutions imparted thereto, and is of appropriate character for 
the mopping application intended for the mop head article. 
FIG. 11 is a plan view representation of an apertured non-woven fabric 200, 
such as may be usefully employed to form web elements of a mop head 
article according to one embodiment of the present invention. As shown, 
the non-woven fabric comprises generally horizontally aligned strand 
members 202 and generally vertically aligned strand members 204, 
corporately defining a criss-crossed lattice having apertures 206 therein. 
These apertures define interstitial capacitive regions constituting 
involutions of the fabric, which may be employed to effective advantage in 
web elements of a mop head structure, e.g., such as is shown and described 
with reference to FIGS. 8 and 10 hereof, to accommodate the pick-up, 
retention, and selective release of particulates and/or fluids when such 
fabric is employed in web elements of a mop head structure. 
Apertured non-woven materials are generally of two main types, 
hydroentangled (spunlaced), and resin-bonded (water hold). These materials 
are well-known and readily commercially available, from manufacturers such 
as E. I. DuPont De Nemours & Company, Inc.; Chicopee; Veratec 
(International Paper/Kendall); and Fort Howard. Such apertured non-woven 
materials may be utilized in the form of unshaped strips, as the web 
elements of a mop head according to the present invention. Alternatively, 
such strips may be twisted, stretched, creased, folded, or otherwise 
configured or treated to introduce additional involutions thereto. By way 
of example, such non-woven fabrics could be employed to form web elements 
of the type shown and described with reference to FIGS. 9A, 9B, and 9C 
hereof. 
In order to enhance fluid take-up and retention capacity in wet mopping 
applications, the mop head of the present invention may comprise web 
elements having associated therewith any of a variety of 
sorption-enhancing materials or additives. For example, in a single-use 
mop application, the web elements may be impregnated or otherwise have 
associated therewith a super-absorbent material. Such super-absorbents, or 
hydrogels, may be of any suitable type, and are readily commercially 
available from a variety of sources, including the products available 
under the following trade names: "Favor" super-absorbent powder 
(Stockhausen, Greensboro, N.C.); "Sanwet" super-absorbent powder (Sanyo, 
Kyoto, Japan); "Aridall" super-absorbent polymer (Chemdal); "Aquasorb" 
sorbent (Aqualon, Wilmington, Del.) "SuperSorb" (Super Absorbent Company, 
Lumberton, N.C.); and "DryTech" super-absorbent (Dow Chemical Company, 
Midland, Mich). 
In order to enhance the particulate take-up and retention capacity in dry 
mopping applications, the mop head of the present invention may be treated 
with a suitable particulate-retention enhancing substance, such as a 
lipophilic or oil-based material. Examples include paraffinic oils, 
mineral oils, waxes, etc. In general, any substance or composition which 
is effective to enhance the particulate take-up and/or retention capacity 
of the mop head, and which is otherwise compatible with the mop head 
materials of construction and materials to be encountered in the mopping 
application, may be suitably employed. Hydrophilic as well as hydrophobic 
materials of such type may be employed, to the extent that same are 
effective to enhance the dry mopping capability of the mop head. Examples 
of dry mopping enhancement agents which may be potentially usefully 
employed on mop heads according to the present invention include 
formaldehyde resins, linseed oil, emulsified wax formulations, static 
cling treatment substances, anti-bacterial coatings of various types, and 
chemicals and formulations providing such a dry mopping enhancement 
function when impregnated or otherwise applied to the web elements of the 
mop head. 
A potentially usefully employed treatment for enhancing the particulate 
take-up, retention, and release capacity of the web elements of the mop 
head is a mop treatment composition commercially available as DUS-TROI 
BACTERIOSTATIC mop treatment, available from GOLDEN STAR INC. (North 
Kansas City, Mo.). Other mop treatment agents which may be usefully 
employed for such purpose in the broad practice of the invention include 
those available under the following trade names: "Sanco Treat" (Sanitary 
Products Corp.); "Aqua Mist" (I. Schneid, Inc.); "Aqua Sheen" (James 
Varley & Sons, Inc.); "Aqua-Treat" (Perma, Inc.); "Clean-Sheen" (Magee 
Industrial Division); "Cen-Dust" (Cental Chemical Company); "D-Dust" (Oil 
Specialties & Refinery Co., Inc.); "Duf" (Hysan Corp.); "Dy-Dust" (The 
Davis-Young Company); "Dust-Loc" (Tu-Way Products Co.); "Dust-n-Shine" 
(Wilen Manufacturing); "Floor Sheen" (James Varley & Sons, Inc.); 
"Guardian" (ABCO, Inc.); and "Noil" (Betco Corp.). 
With respect to bacterial properties of web elements which may be employed 
in accordance with the present invention, it is to be appreciated that the 
materials of construction of the web elements may be selected so as to 
provide an intrinsic bacterial barrier. For example, wood pulp in the form 
of tissue can be coentangled with polyester to form a wood pulp rich 
composite fabric that is very effective as a bacterial barrier. 
It will be further appreciated that mop heads according to the present 
invention may be treated with or comprise any other suitable materials, 
additives, treatment agents, and the like, which do not preclude the 
efficacy of the mop head for its intended purpose. Examples of such 
additional materials include flame retardants, surfactants, antioxidants, 
binders, reinforcing agents, pigments, etc. 
While the invention has been shown and described with a respect to 
illustrative embodiments, aspects and features, it will be recognized that 
numerous variations, modifications, and other embodiments are possible 
within the broad scope of the present invention, and all such 
modifications, variations, and other embodiments therefore are to be 
regarded as being within the spirit and scope of the invention.