CLEANING PADS WITH ABRASIVE LOADED FILAMENTS AND ANTI-MICROBIAL AGENT

Abstract

A nonwoven, fibrous, article including a plurality of entangled fibers is provided; each of the fibers may have an anti-microbial agent alone or in combination with a plurality of abrasive particles. A nonwoven, fibrous, abrasive article including a plurality of entangled fibers is also provided; each of the fibers having a plurality of abrasive particles alone or in combination with an anti-microbial agent. A binder material bonds the fibers to each other at points of crossing and contact between the fibers.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application No. 60/973,544 filed Sep. 19, 2007 and U.S. provisional application No. 61/078,572 filed Jul. 7, 2008, which are incorporated by reference as if fully set forth.

FIELD OF INVENTION

The disclosure herein relates to nowoven fibrous pads including abrasive or anti-microbial agent. The disclosure herein also relates to nowoven fibrous pads including abrasive and anti-microbial agent.

BACKGROUND

Nonwoven fibrous abrasive pads are known for a variety of uses, such as floor machine pads, cleaning pads, etc. A surface may accumulate built-up dirt, debris, or mineral deposits. To clean the surface, it may be necessary to use an article that has scouring capabilities. The scouring capabilities may come from the substrate that is being used as the cleaning article, or the souring capabilities may come from abrasive materials added to the substrate.

Abrasive particles can be added by pouring an abrasive solution, such as SOFT SCRUB,™ available from the Dial Corporation of Scottsdale, Ariz., onto a nonwoven pad substrate. However, this requires both a substrate and a separate scouring solution, which can be inconvenient and messy. Further, the scouring solution is often chemically harsh, and therefore may not be as safe for the user to handle and store.

Some cleaning articles include an abrasive. In conventional nonwoven fibrous abrasive articles, the abrasive is typically a component of the binder (such as a latex emulsion or a solution polymer) utilized to join the fibers. U.S. Pat. No. 7,232,364, describes incorporating an abrasive particle in a water soluble binder. In aqueous environments, the abrasive is released during cleaning in order to come in contact with the cleaning surface. However, cleaning articles designed for re-use would quickly lose aqueous released abrasive. In selecting a more durable abrasive particle binder, its ability to adhere firmly both to the fibers and the abrasive particles employed must be considered, as well as its ability to retain such adherent qualities under the conditions of use. Even with more durable binders, however, abrasive particle bonding is weakened during use. Abrasive particles are, thus, eventually released, thereby reducing the effectiveness of the nonwoven fibrous abrasive article.

In addition to abrasive loss, microbial growths may develop on nonwoven fibrous pads. U.S. Pat. No. 6,841,244 describes anti-microbial agents in absorbent nonwoven materials such as mattress pads, rather than abrasive scouring pads. In the context of cleaning materials, such growth on nonwoven fibrous pads can develop into unpleasant odors, staining, embrittlement and premature product failure. Also, microbial growth and the byproducts thereof can cause allergic reaction.

Accordingly, there remains a need for an improved nonwoven fibrous abrasive article that will better retain its abrasive properties. There also remains a need for an improved nonwoven fibrous article that will be more resistant to microbial growth.

SUMMARY

In a first aspect, the invention relates a nonwoven article that includes a plurality of entangled fibers and a plurality of abrasive particles. The plurality of entangled fibers includes a plurality of crossing points and contact between the entangled fibers. The fibers are bonded to one another at at least a portion of the contact points. The plurality of abrasive particles are embedded in the entangled fibers.

In a second aspect, the invention relates to a method of manufacturing a nonwoven article. The method includes forming a combination including a polymer resin. The method also includes adding a plurality of abrasive particles to the combination. The combination is extruded through an extruder barrel, a spinneret and spinneret head to form a plurality of fibers. The fibers are entangled and bonded to each other at points of crossing and contact between the fibers. The method also includes curing the nonwoven article.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of the preferred embodiment of the present invention will be better understood when read in conjunction with the appended drawing. For the purpose of illustrating the invention, there are shown in the drawing embodiments which are presently preferred. It is understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawing:

FIG. 1 is magnified view of an embodiment of a nonwoven, fibrous, abrasive article in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Certain terminology is used in the following description for convenience only and is not limiting. The words “right,” “left,” “top,” and “bottom” designate directions in the drawings to which reference is made. The words “a,” and “one,” as used in the claims and in the corresponding portions of the specification, are defined as including one or more of the referenced item unless specifically stated otherwise. This terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import.

Referring generally to FIG. 1, an embodiment is illustrated as a article 10. The article 10 includes a plurality of entangled fibers 12, which form a nonwoven web. The fibers 12 intersect each other at points of crossing 20 and the fibers 12 are bound to each other at points 20 of crossing and contact between the fibers 12. In a preferred embodiment, a binder material 18 bonds the fibers 12 at the points 20 of crossing. In an embodiment, the fibers 12 have abrasive particles 14 embedded in the fibers 12. As used herein embedded means that the abrasive particles 14 are located in the material of fibers 12 and can be entirely within the circumference a fiber 12, within a fiber 12 but protruding from the fiber 12 edge, or a combination thereof. In a preferred embodiment, the abrasive particles 14 are embedded entirely within the circumference of fibers 12. In still another preferred embodiment, each of the fibers 12 has a plurality of abrasive particles embedded therein.

In an embodiment, the fibers 12, binder material 16, or abrasive particle 14 include at least one anti-microbial agent. In some preferred embodiments, the anti-microbial agent is carried in a plasticizer, which is mobile and capable of migrating throughout the end product.

The article 10 can be formed to a variety of thicknesses and formed or cut into a variety of shapes. It is generally used in cleaning applications, both industrial and household, as a scouring pad. For example, in one embodiment the article 10 may be part of an industrial automatic floor cleaner/polisher. In another embodiment, the article 10 may be utilized as scouring pad to remove hardened food particles from dishes, pots, pans, etc.

In use, because the abrasive particles 14 are a part of the actual fibers 12 of the nonwoven fibrous abrasive article 10, they are less likely to be released from the overall structure of the article 10, as compared to conventional nonwoven fibrous abrasive articles. Because the abrasive particles 14 are not released through friction and wear of binder material 18, the effective life of the nonwoven article 10 is extended.

In preferred embodiments, the manufacture of a nonwoven article includes forming combination that includes polymer resin and abrasive particles. The combination is then moved through an extruder barrel toward a spinneret to extrude the material through the spinneret head and form a plurality of fibers. The combination can be melted and then moved through the extruder barrel via a rotating screw. The result is a fiber with abrasive particles within the fiber. Abrasive particles may also protrude from the fiber outer surface. The fibers are cut to a desired length and then entangled by spinning the fibers and directly dispersing them into a web through the use of deflectors or air streams. In a preferred embodiment, the web is sprayed with a binder material to form globules of resin at points of crossing and contact between the fibers. The web is then cured to bind the fibers and form the nonwoven, fibrous, abrasive article. The process can be carried out using a webber, such as a “Rando Webber” (commercially available from Rando Machine Company, New York).

Abrasives will damage web forming machines, screws, extruder barrels, spinnerets, or spinneret heads. In a preferred embodiment, the abrasive is not added to the initial combination. Instead, abrasive is added through openings in the extruder barrel to form the final combination just before encountering the spinneret head. Due to the abrasive mixture, a spinneret head may have a short life, whether the abrasive is added to the initial combination or through openings in the extruder barrel. To extend its useful life, the spinneret head is preferably made of a higher strength material, in an embodiment the spinneret head is made of a ceramic. Alternatively, the spinneret head may be flexible in order move in response to the passage of abrasive particles and thereby increase its useful life.

In other preferred embodiments, an anti-microbial agent is included in combination. The combination is then extruded, as described above. However, if abrasive materials are not present, the extruder need not be made of higher strength or flexible materials. In alternative embodiments, the process is similar to that carried out above, but the anti-microbial agent is in combination with the binder material, rather than being included in combination with the polymer resin.

Methods of forming nonwoven articles and apparatuses therefore are described in U.S. Pat. Nos. 2,890,497; 3,797,074; 3,740,797; 3,768,118; 3,768,119; 3,772,739; 3,972,092; 4,018,646; 4,097,965; 6,846,450; and 7,232,364, which are incorporated herein as if fully set forth.

In some embodiments, nonwoven webs suitable for use as hand scouring implements can be utilized. Such webs may be made of, but are not limited to, an air-laid, carded, stitch-bonded, spunbonded, wet laid, or melt blown construction. In an embodiment, a nonwoven web is the open, lofty, three-dimensional air-laid nonwoven substrate described in U.S. Pat. No. 2,958,593, which is incorporated by reference as if fully set forth. This nonwoven web is formed by randomly disposed staple fibers. One successful commercial product comprising such a nonwoven web is that sold under the trade designation SCOTCH-BRITE™ available from 3M Company, St. Paul, Minn.

Other approaches to the manufacture of nonwoven articles include use of continuous filaments. Exemplary scouring articles made of continuous filaments are those described in U.S. Pat. Nos. 4,991,362 and 5,025,596, which are incorporated by reference as if fully set forth. These patents describe low-density abrasive articles formed with continuous, unidirectional crimped filament tow with the filaments bonded together at opposing ends of the pad.

Fibers 12 include natural or synthetic materials, and mixtures thereof. Synthetic materials are preferred, including those made of polyester (e.g., polyethylene terephthalate), polyethylene, nylon (e.g., hexamethylene adipamide, polycaprolactam), polyetheretherketone (PEEK), polypropylene, acrylic (formed from a polymer of acrylonitrile), rayon, cellulose acetate, polyvinylidene chloride-vinyl chloride copolymers, vinyl chloride-acrylonitrile copolymers, and so forth. The material can be a homogenous fiber or a composite fiber, such as bicomponent fiber. Other suitable polymers and blends thereof are also contemplated.

The binder material 18 may include phenolaldehyde resins, butylated urea aldehyde resins, epoxide resins, or polyester resins. In preferred embodiments, reinforcement is by the application of a binder 18 in the form of prebond resin to bond the fibers 12 at their mutual contact points 20 to form a three-dimensionally integrated structure. The prebond resin may be made of a thermosetting water-based phenolic resin. Polyurethane resins may also be employed. Other useful prebond resins may include those comprising polyureas, styrene-butadiene rubbers, nitrile rubbers, and polyisoprene. Additional crosslinkers, fillers, and catalysts may also be added to the prebond resin. Those skilled in the art will appreciate that the selection and amount of resin actually applied can depend on any of a variety of factors including, for example, the fiber 12 weight in the nonwoven web, the fiber 12 density, the fiber 12 type, as well as the contemplated end use for the finished article 10. Prebond resin is, however, not required and the invention is not to be constructed as being limited to nonwoven webs comprising any particular prebond resin.

Application of the prebond resin, when used, can be accomplished by any suitable means including roll coating, spray coating, dry powder coating, suspended powder coating, powder dropping, liquid dip coating, fluidized bed powder coating, electrostatic powder coating, critical gas dilution liquid resin coating, or other commonly used coating processes available to those skilled in the art.

Other known means of forming a three-dimensionally integrated structure from a nonwoven article 10 are within the scope of the present invention. As an alternative to a prebond resin applied to the fibers 12 to form the nonwoven article 10, the fibers 12 may be melt-bonded together at a portion of points 20 where they contact one another to form a three-dimensionally integrated structure, as described in U.S. Pat. No. 5,685,935, which is incorporated by reference as if fully set forth.

Fibers 12 for use in a nonwoven article 10 are preferably between about 20 and about 110 millimeters and more preferably between about 40 and about 65 millimeters in length. Preferably the fibers 12 have a fineness or linear density ranging from about 1.5 to about 500 denier, and more preferably from about 15 to about 110 denier. It is contemplated that fibers of mixed denier can be used in the manufacture of a nonwoven article in order to obtain a desired surface finish. The use of larger fibers is also contemplated, and those skilled in the art will understand that the invention is not limited by the nature of the fibers employed or by their respective lengths, linear densities and the like.

As previously described, a nonwoven article of the present embodiments is readily formed on a “Rando Webber” machine. Alternatively, a nonwoven article may be formed by other conventional processes. Where a spunbonded-type nonwoven article is employed, the filaments may be of substantially larger diameter, for example, up to 2 millimeters or more in diameter.

In preferred embodiments, the nonwoven web has a weight per unit area at least about 20 g/m², preferably between 20 and 1000 g/m², more preferably between 300 and 600 g/m². The foregoing fiber weights typically will provide a web, before needling or impregnation, having a thickness from about 1 to about 200 millimeters, typically between 6 to 75 millimeters, and preferably between 10 and 50 millimeters.

In embodiments including abrasives, known abrasives as well as combinations and agglomerates of such materials are contemplated. Abrasives having a Mohs' hardness of 1-8 or even greater may be provided. In some embodiments, a softer abrasive particles (e.g., those having a Mohs hardness in the range between 1 and 7) can be used. Suitable softer abrasives include, without limitation, inorganic materials such as flint, silica, pumice, and calcium carbonate as well as organic polymeric materials such as polyester, polyvinylchloride, methacrylate, methylmethacrylate, polycarbonate, and polystyrene as well as combinations of any of the foregoing.

Harder abrasives (e.g., having a Mohs hardness greater than about 8) can also be included within the abrasive cleaning article of the invention to provide a finished article having a more aggressive abrasive surface. Suitable hard abrasive materials include, without limitation, aluminum oxide including ceramic aluminum oxide, heat-treated aluminum oxide and white-fused aluminum oxide; as well as silicon carbide, alumina zirconia, diamond, ceria, cubic boron nitride, garnet, and combinations of the foregoing.

The average particle sizes of the foregoing abrasives is not limited but can range from about 1 to about 2000 microns. In an embodiment, the particle sizes for the abrasive particles 14 typically will be less than the average diameter of the fibers 12. However, the skilled artisan understands that the particle size and density can be adapted to the type of article and the application for which the article is intended. For example, both an industrial floor cleaner and a kitchen hand scrubber may include 200 denier nonwoven articles but the abrasive content can be modified. An industrial floor cleaner may require more aggressive abrasive, which may be achieved by including a large number of abrasive particles, hard abrasive particles, large sized abrasive particles, or a combination thereof. In contrast, a kitchen hand scrubber designed for fine dishes may require less aggressive abrasive in order to minimize introduction of scratches on the dish surface. Less aggressive abrasive can be achieved by including fewer, softer, or smaller particles.

In preferred embodiments, an anti-microbial agent is included in the nonwoven article and can be an anti-fungal agent, an anti-bacterial agent, an anti-protazoan agent, or an anti-parasitic agent. The anti-microbial activity of the anit-microbial agent can be to kill or prevent the growth of the microorganism. In one embodiment the anti-microbial agent is selected from antiseptics, microbicides, bactericides, and fungicides. In another embodiment, the anti-microbial agent is selected from substances that inhibit the growth of microbial, bacterial, fungal, or parasitic organsims. In further preferred embodiments, the anti-microbial agent can be 10, 16-oxybisphenoxy arsine (OBPA), n-(trichloro-methylthio)phthalimide, 2-n-octyl-4-isothiazolin-3-one, N-trichloro-methylthio-4-cyclohexene-1,2-dicarboximide (Captan), N-(trichloromethylthio)phthalimide (Folpet), amine-neutralized phosphate, or zinc 2-pyidinethiaol-1-oxide. In still further embodiments, the anti-microbial agent is an agent that is effective to prevent, reverse, or stop the accumulation of organisms in a film on a nonwoven fibrous article or within the nonwoven fibrous article. The present invention is not, however, limited to the materials above, and may include any suitable material or combination of materials capable of performing the above described function.

Some anti-microbial agents like OBPA can be present at concentrations of 0.04% in the final product. But the range of concentrations in the final product can vary depending on the agent and the desired level of anit-microbial activity.

In a preferred embodiment, the anti-microbial agent is formulated with a carrier into concentrations of 2-5% active ingredient. As a starting material, the carrier can be in a powder, liquid, or solid-pellet form. In a preferred embodiment, the carrier is a plasticizer, commonly epoxidized soybean oil, diisodecyl phthalate (DIDP), a resin, a PVC/PVA copolymer, or polystyrene. Te loading level of the anti-microbial agent, in a preferred embodiment, is 0.6-3%.

Plasticizers can also be selected from phthalates, including bis(2-ethylhexyl)phthalate (DEHP), disononyl phthalate (DINP), bis(n-butyl)phthalate (DnBP, DBP), butyl benzyl phthalate (BBzP), di-n-octyl phthalate (DOP or DnOP), diisooctyl phthalate (DIOP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), and di-n-hexyl phthalate. Phtalates can be useful in instances where good resistance to water and oils is required. Plasticizers can also be selected from esters of polycarboxylic acids with linear or branched aliphatic alcohols of moderate chain length, and dicarboxylic/tricarboxylic ester-based plasticizers. Trimellitates, including trimethyl trimellitate (TMTM), tri-(2-ethylhexyl)trimellitate (TEHTM-MG), tri-(n-octyl,n-decyl)trimellitate (ATM), tri-(heptyl,nonyl)trimellitate (LTM), and n-octyl trimellitate (OTM) can serve as a plasticizers. Trimellitates can be useful in instances where resistance to high temperature is required. Plasticizers can be selected from Adipate-based substances, including bis(2-ethylhexyl)adipate (DEHA),dimethyl adipate (DMAD), monomethyl adipate (MMAD), and dioctyl adipate (DOA). Adipates can also be used to provide mobility and are useful for low-temperature or resistance to ultraviolet light. Other plasiticizers that can be utilized in the present embodiments include sebacate-based plasticizers (e.g., dibutyl sebacate (DBS)), maleates (e.g., dibutyl maleate (DBM) or diisobutyl maleate (DIBM)),benzoates, epoxidized vegetable oils, sulfonamides, N-ethyl toluene sulfonamide (o/p ETSA) (ortho and para isomers), N-(2-hydroxypropyl) benzene sulfonamide (HP BSA), N-(n-butyl) benzene sulfonamide (BBSA-NBBS), organophosphates (e.g., tricresyl phosphate (TCP), tributyl phosphate (TBP), glycols/polyethers (e.g., triethylene glycol dihexanoate (3G6, 3GH) or tetraethylene glycol diheptanoate (4G7)), polymeric plasticizers, nitrobenzene, carbon disulfide and β-naphthyl salicylate. Plasticizers, such as DEHP and DOA, were found to be carcinogens and endocrine disruptors. Safer plasticizers with better biodegradability and less biochemical effects may be also be used. Some safer plasticizers that may be utilized in the present embodiments include acetylated monoglycerides, alkyl citrates, triethyl citrate (TEC), acetyl triethyl citrate (ATEC), tributyl citrate (TBC), acetyl tributyl citrate (ATBC), trioctyl citrate (TOC), acetyl trioctyl citrate (ATOC), trihexyl citrate (THC), acetyl trihexyl citrate (ATHC), butyryl trihexyl citrate (BTHC, trihexyl o-butyryl citrate),trimethyl citrate (TMC), alkyl sulphonic acid phenyl ester (ASE), and vinyl chloride copolymers.

The antimicrobial agents, plastics, and related methods described in Modern Plastics Encyclopedia, Mid-November Issue, Volume 70, Number 12, which is incorporated by reference as if fully set forth, may be used in the present embodiments.

All references cited herein are incorporated by reference as if fully set forth.

Having described in detail several embodiments of the present invention, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the invention, could be made without altering the inventive concepts and principles embodied therein. It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein. The present embodiments and optional configurations are therefore to be considered in all respects as exemplary and/or illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes thereto which come within the meaning and range of equivalency of said claims are therefore to be embraced therein.

Claims

1. A nonwoven article comprising:

a plurality of entangled fibers and a plurality of abrasive particles;

the plurality of entangled fibers including a plurality of crossing points and contact between the entangled fibers, the fibers bonded to one another at at least a portion of the crossing points and contact,

the plurality of abrasive particles embedded in the entangled fibers.

2. The nonwoven article of claim 1, wherein the entangled fibers comprise polymer resin formed from a material selected from at least one of the substances selected from the group consisting of polyester, polyethylene terephthalate, polyethylene, nylon, hexamethylene adipamide, polycaprolactam, polyetheretherketone, polypropylene, acrylic, rayon, cellulose acetate, polyvinylidene chloride-vinyl chloride copolymers, and vinyl chloride-acrylonitrile copolymers.

3. The nonwoven article of claim 2, wherein the material is polyethylene.

4. The nonwoven article of claim 1, wherein the plurality of abrasive particles are entirely within the circumference of the entangled fibers.

5. The nonwoven article of claim 1, wherein the plurality of abrasive particles are embedded in each of the entangled fibers.

6. The nonwoven article of claim 1, further comprising a binder material that forms at least a portion of the bonds between the entangled fibers.

7. The nonwoven article of claim 6, the binder further comprising an anti-microbial agent.

8. The nonwoven article of claim 1, wherein at least a portion of the bonds between the entangled fibers are melt bonds.

9. The nonwoven article of claim 1, wherein the abrasive particles are selected from at least one of the materials selected from the group consisting of lint, silica, pumice, calcium carbonate, organic polymeric materials, polyester, polyvinylchloride, methacrylate, methylmethacrylate, polycarbonate, polystyrene, aluminum oxide, ceramic aluminum oxide, heat-treated aluminum oxide, white-fused aluminum oxide, silicon carbide, alumina zirconia, diamond, ceria, cubic boron nitride, and garnet.

10. The nonwoven article of claim 1, further comprising an anti-microbial agent as part of the entangled fibers.

11. The nonwoven article of claim 10, wherein the anti-microbial agent includes at least one substance selected from the group consisting of 10, 16-oxybisphenoxy arsine (OBPA), n-(trichloro-methylthio)phthalimide, 2-n-octyl-4-isothiazolin-3-one, N-trichloro-methylthio-4-cyclohexene-1,2-dicarboximide, N-(trichloromethylthio)phthalimide, amine-neutralized phosphate, and zinc 2-pyidinethiaol-1-oxide.

12. The nonwoven article of claim 1, further comprising a plasticizer.

13. A method of manufacturing a nonwoven article, the method comprising:

forming a combination including a polymer resin;

adding a plurality of abrasive particles to the combination;

extruding the combination through an extruder barrel, a spinneret and spinneret head to form a plurality of fibers;

entangling the fibers;

bonding the fibers to each other at points of crossing and contact between the fibers; and

curing the nonwoven article.

14. The method of claim 13, further comprising moving the combination through the extruder barrel prior to the step of adding the plurality of abrasive particles; wherein the extruder barrel includes openings prior to the spinneret head and the step of adding a plurality of abrasive particles is accomplished by adding the plurality of abrasive particles through the openings.

15. The method of claim 14, wherein the spinneret head is resistant to the plurality of abrasive particles.

16. The method of claim 15, wherein the spinneret head is harder than the abrasive particles.

17. The method of claim 16, wherein the spinneret head is ceramic.

18. The method of claim 15, wherein the spinneret head is flexible.

19. The method of claim 13, wherein the combination further comprises an anti-microbial agent.

20. The method of claim 13, wherein the combination further comprises a plasticizer.