Patent Application
20120042462
The present invention is related to steam-cleaning and disinfecting. More specifically, the invention is related to steam cleaners which direct steam at a surface via a nozzle, and for an absorbent pad for use in combination therewith to absorb the condensed steam from the surface.
Steam-cleaning appliances are well known and commonly used to clean surfaces, such as floors. Such appliances typically sanitize and disinfect by dispensing steam at the floor. In many arrangements of such apparatuses, it is preferential to dispense the steam from the same portion of the apparatus, such as its underside, that contacts the floor to maximize penetration of the steam into the pores and fissures thereof. The dispensed steam naturally condenses into liquid water upon contact with the cooler floor, creating puddles. A disadvantage common to such prior art steamers is a failure to fully remove these puddles.
Wiping pads have been employed with such appliances to collect the condensed water, but in appliances where steam is dispensed from the underside, such wiping pads have had to compromise between the ability to avoid interfering with the dispensing of the steam to the floor, requiring porosity and or a lack of absorbency, and the ability to soak up the condensed water from the floor, requiring absorbency.
Super-absorbent polymers are well known, and commonly used in such items as disposable diapers and mopping pads. Such polymers typically include hydrophilic fibers and hydrogel-forming particles. Such hydrophilic fibers often include cotton, and such hydrogel-forming particles often include polyacrylate. A deterrent to using such
As used herein, the term “superabsorbent material” means any absorbent material having a gig capacity for water of at least about 15 gig, when measured under a confining pressure of 0.3 psi. Because a majority of the cleaning fluids useful with the present invention are aqueous based, it is preferred that the super absorbent materials have a relatively high gig capacity for water or water-based fluids.
Representative superabsorbent materials include water insoluble, water-swellable superabsorbent gelling polymers (referred to herein as “superabsorbent gelling polymers”) which are well known in the literature. These materials demonstrate very high absorbent capacities for water. The superabsorbent gelling polymers useful in the present invention can have a size, shape and/or morphology varying over a wide range. These polymers can be in the form of particles that do not have a large ratio of greatest dimension to smallest dimension (e.g., granules, flakes, pulverulents, interparticle aggregates, interparticle crosslinked aggregates, and the like) or they can be in the form of fibers, sheets, films, foams, laminates, and the like.
The use of superabsorbent gelling polymers in fibrous form provides the benefit of enhanced retention, relative to particles, during the cleaning process. While their capacity is generally lower for aqueous-based mixtures than it is for water, these materials still demonstrate significant absorbent capacity for such mixtures. The patent literature is replete with disclosures of water-swellable materials. See, for example, U.S. Pat. No. 3,699,103 (Harper et al.), issued Jun. 13, 1972; U.S. Pat. No. 3,770,731 (Harmon), issued Jun. 20, 1972; U.S. Pat. No. Reissue 32,649 (Brandt et al.), reissued Apr. 19, 1989; U.S. Pat. No. 4,834,735 (Alemany et al.), issued May 30, 1989.
Superabsorbent gelling polymers useful in the present invention include a variety of water-insoluble, but water-swellable polymers capable of absorbing large quantities of fluids. Such polymeric materials are also commonly referred to as “hydrocolloids”, and can include polysaccharides such as carboxymethyl starch, carboxymethyl cellulose, and hydroxypropyl cellulose; nonionic types such as polyvinyl alcohol, and polyvinyl ethers; cationic types such as polyvinyl pyridine, polyvinyl morpholinione, and N,Ndimethylaminoethyl or N,N-diethylaminopropyl acrylates and methacrylates, and the respective quaternary salts thereof. Typically, superabsorbent gelling polymers useful in the present invention have a multiplicity of anionic functional groups, such as sulfonic acid, and more typically carboxy, groups. Examples of polymers suitable for use herein include those which are prepared from polymerizable, unsaturated, acid-containing monomers. Thus, such monomers include the olefinically unsaturated acids and anhydrides that contain at least one carbon to carbon olefinic double bond. More specifically, these monomers can be selected from olefinically unsaturated carboxylic acids and acid anhydrides, olefinically unsaturated sulfonic acids, and mixtures thereof.
Some non-acid monomers can also be included, usually in minor amounts, in preparing the super absorbent gelling polymers useful herein. Such non-acid monomers can include, for example, the water-soluble or water-dispersible esters of the acid-containing monomers, as well as monomers that contain no carboxylic or sulfonic acid groups at all. Optional non-acid monomers can thus include monomers containing the following types of functional groups: carboxylic acid or sulfonic acid esters, hydroxyl groups, amide-groups, amino groups, nitrile groups, quaternary ammonium salt groups, aryl groups (e.g., phenyl groups, such as those derived from styrene monomer). These nonacid monomers are well-known materials and are described in greater detail, for example, in U.S. Pat. No. 4,076,663 (Masuda et al), issued Feb. 28, 1978, and in U.S. Pat. No. 4,062,817 (Westerman), issued Dec. 13, 1977, both of which are incorporated by reference.
Olefinically unsaturated carboxylic acid and carboxylic acid anhydride monomers include the acrylic acids typified by acrylic acid itself, methacrylic acid, ethacrylic acid, a-chloroacrylic acid, a-cyanoacrylic acid, ˜-methylacrylic acid (crotonic acid), a-phenylacrylic acid, ˜-acryloxypropionic acid, sorbic acid, a-chlorosorbic acid, angelic acid, cinnamic acid, p-chlorocinnamic acid, ˜-sterylacrylic acid, itaconic acid, citroconic acid, mesaconic acid, glutaconic acid, aconitic acid, maleic acid, furmaric acid, tricarboxyethylene and maleic acid anhydride.
Olefinically unsaturated sulfonic acid monomers include aliphatic or aromatic vinyl sulfonic acids such as vinylsulfonic acid, allyl sulfonic acid, vinyl toluene sulfonic acid and styrene sulfonic acid; acrylic and methacrylic sulfonic acid such as sulfoethyl acrylate, sulfoethyl methacrylate, sulfopropyl acrylate, sulfopropyl methacrylate, 2-hydroxy-3-methacryloxypropyl sulfonic acid and 2-acrylamide-2-methylpropane sulfonic acid.
Preferred superabsorbent gelling polymers for use in the present invention contain carboxy groups. These polymers include hydrolyzed starch-acrylonitrile graft copolymers, partially neutralized hydrolyzed starch-acrylonitrile graft copolymers, starch-acrylic acid graft copolymers, partially neutralized starch-acrylic acid graft copolymers, saponified vinyl acetate-acrylic ester copolymers, hydrolyzed acrylonitrile or acrylamide copolymers, slightly network crosslinked polymers of any of the foregoing copolymers, partially neutralized polyacrylic acid, and slightly network crosslinked polymers of partially neutralized polyacrylic acid. These polymers can be used either solely or in the form of a mixture of two or more different polymers. Examples of these polymer materials are disclosed in U.S. Pat. Nos. 3,661,875, 4,076,663, 4,093,776, 4,666,983, and 4,734,478.
Most preferred polymer materials for use in making the superabsorbent gelling polymers are slightly network cross-linked polymers of partially neutralized polyacrylic acids and starch derivatives thereof. Most preferably, the hydrogel-forming absorbent polymers comprise from about 50 to about 95%, preferably about 75%, neutralized, slightly network cross-linked, polyacrylic acid (i.e. poly(sodium acrylate/acrylic acid)). Network cross-linking renders the polymer substantially water-insoluble and, in part, determines the absorptive capacity and extractable polymer content characteristics of the superabsorbent gelling polymers. Processes for network cross-linking these polymers and typical network cross-linking agents are described in greater detail in U.S. Pat. No. 4,076,663.
While the superabsorbent gelling polymers is preferably of one type (i.e., homogeneous), mixtures of polymers can also be used in the implements of the present invention. For example, mixtures of starch-acrylic acid graft copolymers and slightly network cross-linked polymers of partially neutralized polyacrylic acid can be used in the present invention.
While any of the superabsorbent gelling polymers described in the prior art can be useful in the present invention, it has recently been recognized that where significant levels (e.g., more than about 50% by weight of the absorbent structure) of superabsorbent gelling polymers are to be included in an absorbent structure, and in particular where one or more regions of the absorbent layer will comprise more than about 50%, by weight of the region, the problem of gel blocking by the swollen particles can impede fluid flow and thereby adversely affect the ability of the gelling polymers to absorb to their full capacity in the desired period of time. U.S. Pat. No. 5,147,343 (Kellenberger et al.), issued Sep. 15, 1992 and U.S. Pat. No. 5,149,335 (Kellenberger et al.), issued Sep. 22, 1992, describe super absorbent gelling polymers in terms of their Absorbency Under Load (AUL), where gelling polymers absorb fluid (0.9% saline) under a confining pressure of 0.3 psi. (The disclosure of each of these patents is incorporated herein.) The methods for determining AUL are described in these patents. Polymers described therein can be particularly useful in embodiments of the present invention that contain regions of relatively high levels of superabsorbent gelling polymers. In particular, where high concentrations of superabsorbent gelling polymer are incorporated in the cleaning pad, those polymers will preferably have an AUL, measured according to the methods described in U.S. Pat. No. 5,147,343, of at least about 24 m1!g, more preferably at least about 27 ml/g after 1 hour; or an AUL, measured according to the methods described in U.S. Pat. No. 5,149,335, of at least about 15 ml/g, more preferably at least about 18 ml/g after 15 minutes.
U.S. Pat. No. 5,599,335 (Goldman et al.), issued Feb. 11, 1997, and U.S. Pat. No. 5,562,646 (Goldman et al.), issued Oct. 8, 1996 (both of which are incorporated by reference herein), also address the problem of gel blocking and describe super absorbent gelling polymers useful in overcoming this phenomena. These applications specifically describe superabsorbent gelling polymers which avoid gel blocking at even higher confining pressures, specifically 0.7 psi. In the embodiments of the present invention where the absorbent layer will contain regions comprising high levels (e.g., more than about 50% by weight of the region) of superabsorbent gelling polymer, it can be preferred that the superabsorbent gelling polymer be as described in the aforementioned patents to Goldman et al.
Other superabsorbent materials useful herein include hydrophilic polymeric foams, such as those described in commonly assigned U.S. Pat. No. 5,650,222 (DesMarais et al.), issued Jul. 22, 1997; U.S. Pat. No. 5,387,207 (Dyer et al.), issued Feb. 7, 1995; U.S. Pat. No. 5,563,179 (DesMarais et al.), issued Oct. 8, 1996; U.S. Pat. No. 5,550,167 (DesMarais), issued Aug. 27, 1996; and U.S. Pat. No. 5,260,345 (DesMarais et al.), issued Nov. 9, 1993; each of which is incorporated by reference herein. These references describe polymeric, hydrophilic absorbent foams that are obtained by polymerizing a high internal phase water-in-oil emulsion (commonly referred to as HIPEs).
These foams are readily tailored to provide varying physical properties (pore size, capillary suction, density, etc.) that affect fluid handling ability. As such, these materials are particularly useful, either alone or in combination with other such foams or with fibrous structures, in providing the overall capacity required by the present invention.
Where superabsorbent material is included in the absorbent layer, the absorbent layer will preferably comprise at least about 15%, by weight of the absorbent layer, more preferably at least about 20%, still more preferably at least about 25%, of the superabsorbent material.
The absorbent layer can also consist of, or comprise, fibrous material. Fibers useful in the present invention include those that are naturally occurring (modified or unmodified), as well as synthetically made fibers. Examples of suitable unmodified/modified naturally occurring fibers include cotton, Esparto grass, bagasse, kemp, flax, silk, wool, wood pulp, chemically modified wood pulp, jute, ethyl cellulose, and cellulose acetate. Suitable synthetic fibers can be made from polyvinyl chloride, polyvinyl fluoride, polytetrafluoroethylene, polyvinylidene chloride, polyacrylics such as ORLON®, polyvinyl acetate, Rayon®, polyethylvinyl acetate, non-soluble or soluble polyvinyl alcohol, polyolefins such as polyethylene (e.g., PULPEX®) and polypropylene, polyamides such as nylon, polyesters such as DACRON® or KODEL®, polyurethanes, polystyrenes, and the like. The absorbent layer can comprise solely naturally occurring fibers, solely synthetic fibers, or any compatible combination of naturally occurring and synthetic fibers.
The fibers useful herein can be hydrophilic, hydrophobic or can be a combination of both hydrophilic and hydrophobic fibers. As indicated above, the particular selection of hydrophilic or hydrophobic fibers will depend upon the other materials included in the absorbent (and to some degree the scrubbing) layer. That is, the nature of the fibers will be such that the cleaning pad exhibits the necessary fluid delay and overall fluid absorbency. Suitable hydrophilic fibers for use in the present invention include cellulosic fibers, modified cellulosic fibers, rayon, polyester fibers such as hydrophilic nylon (HYDROFIL®). Suitable hydrophilic fibers can also be obtained by hydrophilizing hydrophobic fibers, such as surfactant-treated or silica-treated thermoplastic fibers derived from, for example, polyolefins such as polyethylene or polypropylene, polyacrylics, polyamides, polystyrenes, polyurethanes and the like.
Suitable wood pulp fibers can be obtained from well-known chemical processes such as the Kraft and sulfite processes. It is especially preferred to derive these wood pulp fibers from southern soft woods due to their premium absorbency characteristics. These wood pulp fibers can also be obtained from mechanical processes, such as ground wood, refiner mechanical, thermo mechanical, chemo-mechanical, and chemo-thermo-mechanical pulp processes. Recycled or secondary wood pulp fibers, as well as bleached and unbleached wood pulp fibers, can be used.
Another type of hydrophilic fiber for use in the present invention is chemically stiffened cellulosic fibers. As used herein, the term “chemically stiffened cellulosic fibers” means cellulosic fibers that have been stiffened by chemical means to increase the stiffness of the fibers under both dry and aqueous conditions. Such means can include the addition of a chemical stiffening agent that, for example, coats and/or impregnates the fibers. Such means can also include the stiffening of the fibers by altering the chemical structure, e.g., by cross-linking polymer chains.
Where fibers are used as the absorbent layer (or a constituent component thereof), the fibers can optionally be combined with a thermoplastic material. Upon melting, at least a portion of this thermoplastic material migrates to the intersections of the fibers, typically due to interfiber capillary gradients. These intersections become bond sites for the thermoplastic material. When cooled, the thermoplastic materials at these intersections solidify to form the bond sites that hold the matrix or web of fibers together in each of the respective layers. This can be beneficial in providing additional overall integrity to the cleaning pad.
Amongst its various effects, bonding at the fiber intersections increases the overall compressive modulus and strength of the resulting thermally bonded member. In the case of the chemically stiffened cellulosic fibers, the melting and migration of the thermoplastic material also has the effect of increasing the average pore size of the resultant web, while maintaining the density and basis weight of the web as originally formed. This can improve the fluid acquisition properties of the thermally bonded web upon initial exposure to fluid, due to improved fluid permeability, and upon subsequent exposure, due to the combined ability of the stiffened fibers to retain their stiffness upon wetting and the ability of the thermoplastic material to remain bonded at the fiber intersections upon wetting and upon wet compression. In net, thermally bonded webs of stiffened fibers retain their original overall volume, but with the volumetric regions previously occupied by the thermoplastic material becoming open to thus increase the average interfiber capillary pore size.
There exists a need for improvement in the sanitizing of surfaces and objects, and such is an object of the present invention. There exists the need for improvement of steaming and steam-cleaning apparatuses, and such is an object of the present invention. There exists the need for elimination of the improvement of microbial regeneration conditions on surfaces and objects after steaming, and such as an object of the present invention. There exists the need for causing the sanitizing agent to penetrate deeply into the pores and fissures of surfaces and objects, and such as an object of the present invention. Further needs and objects exist, which are addressed by the present invention, as may become apparent by the included disclosure of an exemplary embodiment thereof.
The invention lies in a combination of a steaming appliance and an absorber, and/or in the absorber alone.
In one exemplary embodiment, the invention may be practiced in a combined steaming appliance and absorber, the steaming appliance having an underside having a nozzle for dispensing steam from the underside to a surface to be steamed. The absorber is disposed between the underside and the surface and comprises a pad having an opening there-through. The pad is disposed relative to the underside for absorbing the dispensed steam from the supporting surface as the element rests upon and is moved along the surface. The opening is shaped and disposed to avoid the nozzle, such that steam exiting the nozzle is dispensed directly to the surface without impacting the pad.
Preferably, the pad is made of or includes a super-absorbent material, such as hydrophilic fibers and hydrogel-forming particles. More preferably, the hydrophilic fibers are cotton fibers and the hydrogel-forming particles are made of sodium polyacrylate.
The exemplary absorber may further include an envelope for containing the pad, the envelope having a bottom sheet for resting on the surface and made of a porous fabric, and a top sheet having a fastening element for attaching the absorber to the underside to retain the relative disposition of the pad to the underside. The fastening element is preferable a series of Velcro-type loops, removably connectable to a mating series of Velcro-type hooks on the underside of the appliance. Alternative. The hooks and loops could be swapped between the absorber and the appliance, or any acceptable means of removable affixation could be used, such as an adhesive strip.
The invention may also be embodied in an absorber for a steaming appliance as described above, the absorber having a pad of super absorbent material with an opening through and disposed substantially centrally in the pad.
The exemplary absorber, as disclosed, could include an envelope for containing the pad, the envelope having top and bottom sheets sealed along three edges to create a hollow interior chamber. The bottom sheet would preferably be made of a porous fabric and the top sheet would preferably have the afore-mentioned fastening element for attachment to a steaming appliance.
The unsealed fourth edge of the envelope would preferably provide a second opening for removal and replacement of the pad. This second opening would preferably be closable and re-openable by means of a second fastening element, such as a zipper. Alternatively, the second fastening element could include any appropriate means for temporarily sealing the fourth edge, such as a Velcro-type hook and loop fastening strip, or an adhesive strip.
The invention may also be embodied in an absorber for a steaming appliance including a planar pad of hydrophilic fibers and hydrogel-forming particles, and having a pad opening there-through and disposed substantially centrally there-in. The absorber, as disclosed, may include an envelope comprising a porous non-woven fabric surrounding a hollow chamber, the fabric having an envelope opening for reception and removal of the pad into and from the chamber.
Further features and aspects of the invention are disclosed with more specificity in the Detailed Description, Drawings, and Appendices provided herein and showing exemplary embodiments of the invention.
Many aspects of the invention can be better understood with reference to the included drawings and appendices. The components in the drawings are not necessarily to scale, and all components may not be present in all views, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Reference is now made to
As best seen in
Top sheet 118 further includes an opening 134 and Velcro-type loop strips 136. The strips and hole are arranges so that the envelop may be affixed by the loops strips to the hook strips 108 of the appliance to affix the absorber to the underside 104, and to align opening 134 with the array of nozzles 106. Pad 114 includes elongate opening 138 there-through, which, when the absorber is affixed to the appliance, is also aligned with the nozzle array.
Referring now specifically to
Pad 114 preferably comprises a matrix of hydrophilic fibers, such as a web of cotton, and a high-absorbency material commonly known as “superabsorbent polymer” (SAP). The SAP material is preferably comprised of superabsorbent hydrogel-forming particles, such as sodium polyacrylate. As an alternative to cotton, the matrix may comprise some other natural fiber such as cellulose fluff, or less preferably, synthetic fibers, polymeric fibers, meltblown fibers or a combination of meltblown fibers and natural fibers. Superabsorbent material may be substantially homogeneously mixed with the hydrophilic fibers, or may be otherwise combined into the absorbent pad.
The pad may also alternatively comprise a laminate of fibrous webs and super absorbent material or other suitable means of maintaining a superabsorbent material in a localized area. The high-absorbency material in the absorbent pad may be selected from among other well-known natural, synthetic and modified natural polymers and materials. The high absorbency materials can be inorganic materials, such as silica gels, or organic compounds, such as cross-linked polymers. The term cross-linked refers to any means for effectively rendering normally water-soluble materials substantially water insoluble but swellable, whereby absorbent properties are available but the swelled material is substantially immobile after absorbing water-based liquids. Such means can include, for example, physical entanglement, crystalline domains, covalent bonds, ionic complexes and associations, hydrophilic associations such as hydrogen bonding, and hydrophobic associations or Van der Waals forces.
Pad 114 may alternatively comprise a standard barrier tissue layer covering and containing the SAP material and forming a tissue layer there-around. Such tissue layers are well known in the art both in terms of materials and functions. The tissue layers generally are permeable to fluids, but retain the absorbent material therein. A single tissue layer could be wrapped entirely about, and secured to, the pad. Other arrangements, containing layers of various materials disposed on surfaces and/or encompassing absorbent material are contemplated as being within the scope of the invention.
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 to trade names: “Favor” super-absorbent powder (Stockhausen, Greensboro, N.C.); “Sanwet” super-absorbent involutions 172 therein. For example, the web elements powder (Sanyo, Kyoto, Japan); “Aridall” super-absorbent polymer (Chemdal); “Aquasorb” sorbent (Aqualon, Wilmington, Del.) “SuperSorb” (Super Absorbent 15 Company, Lumberton, N.C.); and “DryTech” super absorbent (Dow Chemical Company, Midland, Mich.).
A cross section of absorber 102 is shown in
Referring next to
While the invention has been shown and described with reference to these specific exemplary embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention, and that the invention should therefore only be limited according to the following claims, including all equivalent interpretation to which they are entitled.
This application is a Continuation of and claims the benefit of pending U.S. application Ser. No. 11/885,994, filed Sep. 10, 2007, and Ser. No. 29/378,185, filed Jan. 11, 2010, the entire teachings of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11885994 | Sep 2007 | US |
| Child | 13013956 | US | |
| Parent | 29378185 | Nov 2010 | US |
| Child | 11885994 | US |
