US 3148404 A
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Description (OCR text may contain errors)
Sept. 15, 1964 c. N- JENSEN 3,148,404
scouams PADS Filed Feb. 6, 1963 INVENTOR. CARL N. JENSEN ATTORNEY United States Patent 3,148,404 SCOURING PADS Cari N. Hansen, Byram, Conn, assignor to The (Iarborundum tConipany, Niagara Falls, N.Y., a corporation of Delaware Filed Feb. 6, 1%3, Ser. No. 257,959 16 Claims. (Cl. 695) This invention relates to scouring pads and the like and is particularly concerned with scouring pads and implements which are especially adapted for kitchen use in scouring and polishing cooking utensils but are also suitable for other cleaning purposes.
While many materials and devices have previously been used and proposed for use in the cleaning and polishing of kitchen utensils none has been entirely satisfactory. This is demonstrated by the fact that from time to time new materials, new devices, and modifications of old devices are being put on the market and bought in substantial quantities. It therefore appears that improved scouring pads are desirable and sought after.
Accordingly, it is an object of the present invention to provide a novel scouring pad of the character described which cleans utensils such as pots and pans efficiently and with a minimum of effort.
Another object of the invention is to provide a novel scouring pad of the character described which is more convenient to use than the pads previously sold for this purpose.
A further object of the invention is to provide a novel scouring pad of the character described which is highly effective in polishing the surfaces of utensils such as pots and pans.
Other objects and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings in which:
FIGURE 1 is a perspective view of a scouring pad in accordance with the present invention, and
FIGURE 2 is an enlarged elevation of the pad shown in FIGURE 1 with a portion in section, the better to illustrate the construction of said pad.
The foregoing objects are achieved according to the present invention by providing on at least one side of a flexible, resilient, porous body a Water resistant layer or coating which incorporates a metal powder as a scouring and polishing agent, and providing over said coating a second coating or layer of a cleaning agent.
In the drawings the scouring pad is comprehensively designated by the numeral 11 and the body or backing is indicated by the numeral 12. In FIGURE 2 it is seen that on the upper surface of the body 12 is a layer or coating 13 of adhesively bound scouring and polishing agent and that the outer face of the coating 13 carries a thin layer 14 of a cleaning agent.
As stated above the backing 12 is a flexible, resilient, porous body. Bodies desirable for the present purpose have interconnecting pores so that the body will absorb and hold a substantial quantity of water or other liquid used for cleaning. Although a number of flexible, resilient porous materials may be used in carrying out the invention an organic foam or foam-like material is preferred. Excellent results have been obtained with polyurethane foam of either the ester or the ether type. However, such flexible, resilient, foamed materials as foamed natural and synthetic rubber latices and polyvinyl foam are also suitable and in some instances such foam-like material as cellulose sponge may be employed.
In order to have the body or backing absorbent enough to hold a substantial quantity of water a majority of the pores or cells in the foam or foam-like material must be interconnecting. On the other hand a minor propor tion of well distributed closed pores are not objectionable and may, in fact, be advantageous in making the body firmer though not hard or non-resilient. It is also important that the organic foamed or foam-like material employed shall be resistant to deterioration by hot water such as is used in the washing of cooking utensils and be substantially unaffected by soap, detergents, fats, greases and other substances which commonly occur in dish water. Since for efficient scrubbing action a high degree of flexibility and resilient compressibility is required the foamed or foam-like material should possess these properties and there should be no substantial loss of the properties under the conditions of use. The thickness of the backing may vary from about Ai-inch to about 1-inch but pads having a body or backing about /z-inch thick have been generally found most satisfactory.
The scouring or polishing agent employed in making scouring pads or implements in accordance with the present invention is preferably a metal powder. It has been found that sponge iron powder (minimum Fe content about 97%) of approximately 40 +190 mesh size is very satisfactory but other metals or alloys of approximately the same hardness can also be used. For example, several copper base alloys containing aluminum and iron and nickel-copper alloys are suitable. The particle size distribution of the metal powder may likewise be varied, it being understood that with finer particles or a greater proportion of line particles there will be less tendency to scratch polished surfaces while larger particles or more relatively large particles will increase the scouring activity. At the same time very hard materials will tend to scratch more easily than ones of lesser hardness. It will be understood that commercially available metal powders may be employed and that such powders may include without prejudice small amounts of impurities such, for example, as metal oxides or the like.
The adhesive used to bond the scouring or polishing agent to the porous backing should be flexible enough to adhere to the backing during repeated flexing while at the same time it should hold the particles of scouring agent securely. A large number of such adhesives are known including polyvinyl chloride plastisols, acrylic emulsions, urethane resin adhesives, mixtures of latices with resin solutions or dispersions, and solutions of rubber-resin blends. The last-mentioned products are particularly useful in porducing scouring pads in accordance with the present invention. There are many of these rubberresin blend adhesives available on the market which are suitable but in general, those containing blends of synthetic rubbers with phenolic resins are preferred. Among the suppliers of such adhesives are industrial Latex Company, Perry-Austen Manufacturing Company, and Goodyear Tire and Rubber Company, the latter selling such adhesives under the trademark Pliobond.
Among the properties desired in the adhesive to be used are adequate strength to securely hold the scouring and polishing material, flexibility so that the flexibility of the pad as a whole is not diminished, and resistance to hot water and the other substances encountered in dish water so that the scouring agent Will not be released by deterioration of the adhesive. The rubber-resin blend adhesives possess these properties and additionally are quickly cured at moderate temperatures, thus facilitating manufacture of the scouring pads.
In the following, a preferred example of the production of novel scouring pads according to the invention will be described.
Example 1 A mixture of 50 pounds of approximately -40 +100 mesh size sponge iron powder and 50 pounds of a rubberresin blend adhesive, the adhesive containing approximately 24% solids including the vulcauizing agents, antioxidants and other modifying agents conventionally employed in such adhesives, is made and applied by reverse roller coating to a slab of polyurethane foam /z-inch thick. The coating machine is adjusted to give a coating weighing approximately 3 oZ./ft. on a dry basis. The slab is then run through an oven heated to approximately 206 F. to dry the coating, the time required being about 5 minutes. The coated slab is then coated with a detergent cleaning agent by passing it, coated side down, over a roller which dips into a tank or pan of the detergent and then over a bar to smooth out the detergent coating and remove excess detergent. The detergent coating is air-dried and the slab may thereafter be cut into pads of desired size, approximately 2 inches x 2 inches being the most generally used size.
Many surface-active materials of varying composition may be employed as cleaning agents in producing scouring pads according to the present invention. In general such materials should be solid at ordinary temperatures, and water soluble. Among the usable materials are common sodium-fatty acid soaps and surface-active agents or detergents of both the anionic and non-ionic types. While cationic surface-active agents can be used they are not preferred because of their incompatibility with anionic materials such as soap and other common detergents which might also be present in the water used for scouring. In many instances a non-ionic detergent is preferred since such products are compatible with other materials. There are on the market a large number of surface-active agents of both the non-ionic and anionic types any of which are suitable for use in carrying out the invention if they are water soluble and solid at ordinary temperatures.
The amount of cleaning agent employed may vary considerably but it will be understood that too thick :1 coating will interfere with the scrubbing action of the scouring and polishing agent. In general a coating of about it- V2 oz./ft. solid detergent or other cleaning agent will be satisfactory with a coating of about /3 oz./ft. being preferred. The cleaning agent, as pointed out above, should be solid at ordinary temperatures. For application to the surface of the slab of resilient flexible porous material a solution may be prepared. it will be understood that other ways of applying the solution of cleaning agent such for example, as spraying may be used if convenient. It will also be understood that there may be included with the cleaning agent, builders, fillers and/or other commonly employed additives.
The application of the layer of adhesively bound scouring and polishing agent to the porous backing or body can be by other methods than that described above, as
shown by the following example:
Example 2 A rubber-resin blend adhesive, containing approximately 24% solids, including the vulcanizing agents, antioxidants, and other agents conventionally employed in such adhesives, is roller coated on the face of a slab of polyurethane foam /2 -inch thick. The coating machine is adjusted to give a film weighing approximately 3 oZ./ft. Sponge iron powder having an approximate mesh size of -40 +100 is then fed by gravity over the adhesive coated surface and the excess powder, that which does not adhere to the adhesive, is removed by vibration. A deposit of approximately 3 oz./ft. of the iron powder is obtained. The adhesive holding the powder is cured by a 5 minute heat treatment at approximately 200 F. and a sizing adhesive coating is then applied over the scouring agent. The sizing adhesive is preferably a more dilute solution of the same adhesive employed before but a modified or different adhesive may be used if desired. About 1 /2 oz./ft. of sizing adhesive is normally a sufficient coating. After a further short, about 5 minute, heat treatment at approximately 200 F. the slab is coated with a surface-active cleaning material in the same way as in Example 1. After air drying the layer of cleaning material the slab may be cut into scouring pads of desired size.
It will be understood that the amount of scouring and polishing agent employed can be varied over a rather wide range. While in Example 1 the scouring agent comprises about by weight of the dried adhesivescouring agent layer it will be evident that the amounts used can be less depending on the scouring activity desired or, with some adhesives, even more scouring agent may be used. In general for useful purposes finely divided sponge iron when used as a scouring agent may constitute from about 60% to about by weight of the coating. Equivalent amounts on a volume basis of other metal powders would be used. The thickness of the scouring layer may also vary as desired consistent with preserving the flexibility thereof and the desired thickness may, if it is preferred, be obtained by the successive application of a plurality of coatings. The thickness of the several coatings in such case and also their compositions, i.e. the kind and relative amounts of adhesive and securing agent, may vary as long as the adhesives are compatible so that a strong flexible product is obtained. While, in general, only one face of the pad carries a layer of securing agent it will be evident that if desired such a layer can be placed on both faces, the layers being identical or varying as desired within the scope of the invention as defined herein.
The scouring pads obtained in accordance with the present invention are efiicient and easily used. It is only necessary to dampen them and apply firm but not extreme pressure as the pad is moved over the surface to be cleaned. In experiments on different metal surfaces representative of those used in cooking utensils it has been found that the pads of the type described herein have excellent cleaning action in removing characteristic deposits of burned and cooked food. Good metal polishing action with very little or no scratching was obtained. It appears that the metal powder scouring agent has a burnishing effect in some cases with the result that the polishing action is outstanding.
Particle size of the metal powders can be determined with US. Standard sieves and approximately 40 means, as is commonly understood, that approximately all of the powder particles pass a No. 40 sieve and are held on a No. 100 sieve.
1. A scouring pad comprising a body of a flexible, resilient, porous material having on at least one face thereof an adhesively bound layer of a scouring and polishing agent, and, on the exterior of said pad only, a layer of a water-soluble cleaning agent covering each said layer of scouring and polishing agent.
2. A scouring pad as defined in claim 1 in which said scouring and polishing agent is finely divided metal powder.
3. A scouring pad as defined in claim 2 in which said polishing agent is finely divided iron powder.
4. A scouring pad as defined in claim 3 in which said body is polyurethane foam.
5. A scouring pad as defined in claim 3 in which said adhesive is a cured rubber-resin blend.
6. A scouring pad as defined in claim 3 in which the iron powder is sponge iron powder the particles of which are approximately all of such size as to pass a No. 40 sieve and be held on a No. 100 sieve.
7. A scouring pad as defined in claim 1 in which said adhesive is flexible and resistant to Water.
8. A scouring pad as defined in claim 7 in which said adhesive is a cured rubber-resin blend.
9. A scouring pad as defined in claim 8 in which said body is polyurethane foam.
10. A scouring pad as defined in claim 1 in which said body is an organic foamed material.
11. A scouring pad as defined in claim in which said body is polyurethane foam.
127 A scouring pad as defined in claim 10 in which said body is a foamed latex.
13. A scouring pad as defined in claim 10 in which said body is polyvinyl foam.
14. A scouring pad comprising a body of flexible, resilient polyurethane foam having on at least one face thereof a layer of finely divided metal powder, said metal powder being secured to said body by a flexible, water resistant adhesive comprising a rubber-resin blend, said body being free from abrasive and adhesive except in said surface layer, and a water-soluble, surface-active cleaning agent provided solely as a layer over said layer of metal powder.
15. A scouring pad as defined in claim 13 in which said metal powder is iron.
16. A scouring pad as defined in claim 15 in which the iron powder is sponge iron powder the particles of which are approximately all of such size as to pass a No. sieve and be held on a N0. sieve.
References Cited in the file of this patent UNITED STATES PATENTS 574,449 Pritschau Jan. 5, 1897 2,395,068 Rimer Feb. 19, 1946 2,650,158 Eastman Aug. 25, 1953 CERTIFICATE OF CORRECTION Patent No, 3 l l8 4O4 September 15 1964 Carl N. Jensen It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.
Column 2 line 44, for "porducingY read producing column 3, line 7, for "206 Fr," read 200 F0 column 6 line 3, for the claim reference numeral "13" read l4 --Q Signed and sealed this 6th day of April 1965,
ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents if- UNITED STATES PATENT OFFICE