US3350735A - Scouring pad - Google Patents

Description

Nov. 7, 1967 J. 5. PRATT 3,350,735

SCOURING PAD Filed 'July 19, 1965 3 Sheets-Sheet 1 Nov. 7, 1967 J. 5. PRATT 3,350,735

SCOURING PAD Filed July 19, 1965 5 Sheets-Sheet Nov 7, 1967 .Ls. PRATT 3,350,735

SCOURING PAD Filed July 19, 1965 r Sheets-Sheet 3 United States Patent 0 3,350,735 SCOURING PAD James S. Pratt, Brooklyn, N.Y., assignor to Purex Corporation, Ltd., Lakewood, Calif., a corporation of California Filed July 19, 1965, Ser. No. 472,939 6 Claims. (Cl. 15-10434) ABSTRACT OF THE DISCLOSURE A scouring pad in which a soft lofty mass of metal wool, the perimetrical portions of which are compressed into a relatively dense band encircling the main body of the mass, is secured to one face of a flexible backing sheet by a layer of adhesive covering said one face, the dense band being embedded in the layer of adhesive whereas, the metal wool at the bottom of the main body of the mass is in surface adhesive contact with the layer of adhesive.

The present invention relates to an embossed metal wool scouring pad of the type embodying a mass of metal Wool which is adhesively secured to a pliable backing sheet of foamed or expanded plastic material. The plastic backing sheet serves the purpose of providing an easily gripped surface by which the user may hold the pad and its structure is such that it has a tendency to expel water and thereby reduces the possibility of slippage of the pad in the users hand. The pad is soft, lofty and flexible and is easily manufactured on a mass production basis.

A particular embodiment of the pad comprises a backing sheet made from a relatively large-cell, open plastic foam which is covered on one side with a thin film of adhesive. The adhesive is preferably impervious to water penetration and provides the means by which a mass of metal wool may be secured to the backin member. The metal Wool is preferably arranged to extend longitudinally of the backing member and is firmly embedded in the adhesive film along the perimetrical boundaries of the mass while the other fiber strands at the bottom of the mass are in a surface adhesive contact only. Thus the main body of the mass remains lofty and resilient, retaining the natural cohesion of the metal wool fibers. The latter feature permits the mass of wool in use to be pressed into full surface contact with the particular object being cleaned. The mass of metal wool is preferably impregnated with a liberal quantity of a soap or detergent. In use, the user holds the pad by means of the backing sheet and experiences little difiiculty in maintaining a firm grip thereon due to the combination of the large size open cellular structure of the backing sheet and the waterproof nature of the adhesive film which serves as a barrier to the penetration of water from the metal wool to the backing side. Of further importance, the foamed plastic backing is soothing to touch and offers optimum protection to the users fingers and the pad is bulky, presenting ample padding between the users fingers and any rough particles on the surface being cleaned.

The scouring pad is capable of a number of refinements and variations in its structural embodiments and compositions of metal wool utilized, and thus the specific forms disclosed herein are intended to be illustrative only of 3,350,735 Patented Nov. 7, 1967 ICC the general principles and relaitons of the components. For a fuller understanding of the nature and objects of the scouring pad of the present invention and of the advantages afforded thereby, reference should be had to the following description taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a perspective view of a pad constructed in accordance with the principles of the present invention;

FIGURE 2 is a sectional view of the pad shown in FIGURE 1 as taken along a vertical cutting plane pass ing through the transverse axis of the pad, the thickness dimension being exaggerated for purposes of illustration and clarity;

FIGURE 3 is a fragmentary longitudinal sectional view of the adjacent ends of two of the pads shown in FIG- URE 1, prior to severing the pads from the continuous Web in which they are made;

FIGURE 4 is a fragmentary longitudinal sectional view of one end of the pad shown in FIGURE 1 after it has been severed from the continuous web along the axis A-A in FIGURE 3;

FIGURE 5 is a perspective view of the foamed plastic backing sheet and adhesive film covering one side thereof, with the plastic backing sheet being partly broken away to illustrate a pigment incorporated in the adhesive for the purpose of masking the mass of metal wool so that the latter is not visible through the backing sheet;

FIGURE 6 is a longitudinal sectional view of another embodiment of the pad wherein the backing sheet is comprised of wet strength paper and the adhesive film is also of a foamed character;

FIGURE 7 is a longitudinal sectional view of another embodiment of the pad wherein a mass of steel wool is secured to each side of a foamed plastic backing sheet;

FIGURE 8 is a longitudinal sectional view of still another form of the pad wherein a mass of steel wool is secured to each side of a polyethylene film;

FIGURE 9 is a schematic view illustrating one form of apparatus with which the pad of the present invention may be manufactured; and

FIGURES l0 and 11 illustrate on enlarged scale, stations in the apparatus of FIGURE 9 wherein, respectively, the metal wool is applied to the foamed plastic backing, and the metal wool thereafter impregnated with soap.

Throughout the description, like reference numerals are used to indicate like parts in the drawings.

One embodiment of the scouring pad 10 of the present invention is illustrated in FIGURES l to 5. As shown, the scouring pad comprises a backing sheet 11 which is preferably made from a synthetic plastic material, and in particular, a plastic foam such as may be produced from polyurethanes, vinyls, polyethylenes, and co-polymer mixtures thereof. The backing sheet 11 has a generally porous or cellular structure as shown, the pores or cells 12 therein generally numbering approximately 30 to the lineal inch. In other words, the backing sheet presents a plurality of open skeletal structures as compared to other types of foamed materials which have a closed cell structure and a globular-like surface appearance. The surface of the backing sheet of the present invention has a pronounced skeletal appearance. The use of this type of material having relatively large cells, facilitates the users grasping the backing sheet portion of the scouring pad and provides excellent results in preventing slippage from the hand when used. Furthermore, the character of the foamed plastic with large pore openings is such that it tends to expel water in the event the side of the backing sheet held by the user inadvertently becomes wet while being used. A porous structure of more than 30 pores per lineal inch has a tendency when wet to be slippery in the users hand. The use of a plastic foam for the backing sheet has the advantage that it gives a measure of rigidity to the scouring pad while being sufficiently flexible to be bent to various shapes when used. The texture of the plastic foam backing sheet is smooth and pleasing to touch and provides maximum shielding of the users fingers from the scouring element in use.

As seen in FIGURE 1, the backing sheet 11 may have a regular shape such as a rectangle or a square although other shapes including circular and octagonal may be used. The inner face 13 of the backing sheet 11 is covered by a water-resistant non-porous adhesive in the form of a thin film 14 as shown (FIG. 2). The adhesive is a water insoluble and water impervious type, and when used in conjunction with polyurethane and polyethylene foams, a polyethylene adhesive was found to give best results. Other adhesives generally capable of remaining solid at temperatures up to 250 F. may also be used. As for example, a hot melt-type micro-crystalline wax and poly ethylene adhesive was also found to give good results. Polypropylene and polyvinyl chloride dispersions (Plastisol) may also serve as adhesives.

Another important function of the adhesive film 14 in addition to its constituting a non-porous water barrier to prevent passage of water from one face to the other in the backing sheet, is that it enhances the lateral stiffness of the backing sheet but yet permits the backing sheet to retain sufiicient flexibility to be bent into shape configurations and crevices of the surface being cleaned with the scouring pad. Although an important feature of the pres ent invention is the waterproof nature of adhesive film 14, it is recognized that there may be some applications for which the scouring pad is used which would make it advantageous to permit water penetration from the metal wool side to the backing sheet. In this case, the adhesive film may be pierced as by needling to facilitate water passage therethrough.

Referring again to FIGURES 1 and 2, the scouring element which is secured to the adhesive film comprises a generally loose mass 21, of an abrasive wool, preferably a metal wool such as steel wool, although the present invention contemplates that other metal wools such as copper may also be used, and that other non-metallic mineral wools and even synthetic wools such as polypropylene and Mylar may be used. The metal wool mass 21 is generally co-extensive with the adhesive film and is comprised of a plurality of metal fiber strands 22 which are intertwined as shown and which are generally linearly oriented to extend in the same direction, i.e., longitudinally of the backing sheet. The metal wool fibers are preferably uniformly packed or evenly densified as shown and may vary as to grade according to the intended use being of any gage between coarse and fine strands. As seen in FIGURE 1, the metal wool mass is compressed into dense bands 23 adjacent the longitudinal edges of the pad, the bands being embedded in the adhesive film. Similarly, the metal wool mass is compressed into dense bands 26 near the transverse ends thereof, the bands 26 also being embedded in the adhesive film but being inset a distance from the transverse extremities of the pad. Thus there remains at each transverse end of the metal wool mass, lofty bundles of steel wool 27 presenting a plurality of tufted fibers which, along with the adhesive film and foamed backing sheet, provide a relatively soft edge structure which helps to protect the users hands (see FIG. 4). At the longitudinal edges of the pad, the bands 23 terminate at a point slightly inset of the edges of the foamed backing sheet 12 so that a similar soft foam edge structure is provided at the longitudinal sides of the pad (see FIG. 2). On the other hand, the fiber strands at the bottom of the mass and within the area enclosed by the bands 23, 26 are in surface adhesive contact only with film 14 as at 24.. The remaining metal wool or the main body of the mass remains lofty and resilient standing up from the backing sheet as at 25. The bands 23 can be formed in a number of known ways including the use of an embossing roller which compresses the metal wool into the dense bands 23, 26 and forces the latter into the adhesive layer. The remainder of the metal wool thus retain-s its soft, springy open nature and stands up in bold relief from the backing sheet as previously described, and offers the advantage that the metal wool mass 21 can be brought into full and uniform contact with the surface being cleaned. This represents an important advance over prior art scouring pads which generally utilize a corrugated metal wool mass which is rigid or stiff in texture and as such prevents adequate contact with the surface being cleaned. Furthermore, the bands 23, 26 serve to prevent unraveling of the ends of the metal wool strands 22.

The mass of steel wool 21 is filled with a liberal quantity of a solid soap 30 which is dispersed throughout the mass. Soap as used herein is intended to denote a detergent, cleansing or purging agent which at normal room temperature is solidified in flake form within the metal wool mass but which when admixed with water is loosened from the wool to serve its intended function. The fact that the metal wool mass is generally loose as distinguished from being corrugated as in prior art scouring pads permits the impregnation of the metal wool with larger quantities of soap than heretofore possible.

As seen in FIGURE 5 and to give the pad a more pleasing appearance, a pigment 40 may be mixed in with the adhesive film 14 to thereby color it and serve the function of masking the metal wool so that it cannot be seen through the backing sheet 11.

FIGURE 6 illustrates a somewhat different embodiment 50 of the scouring pad wherein the backing sheet 51 instead of being made from a plastic foam, is made from a paper material 52, as for example, creped or crinkled sheet. Ordinary wood pulp paper to which has been added chemical impregnates to give the paper high wet strength can also be used. The scouring pad 50 otherwise is the same as previously described except that the adhesive film 53 is of a foamed material such as polyethylene of substantial thickness to give better rigidity to the pad. The mass of metal wool 54 is secured to adhesive film 53 in the same manner shown in FIGURE 1.

The present invention contemplates that the scouring pad may be made with a steel wool scouring element bonded to both sides of a foamed plastic backing sheet. Referring to the pad shown in FIGURE 7, it comprises a backing sheet 81 of foamed plastic material similar to that used in the pad 10 and covered on its opposite faces or sides with thin films 82, 83 of waterresistant nonporous adhesive. Secured to the adhesive films 82, 83 are the steel wool scouring elements 84, 85 respectively, each being of the character of the metal wool mass 21 previously described and impregnated with a quantity of solid soap 86. The metal wool in each mass is banded and embedded in the respective adhesive films around the extremities of the masses as at 87 with the banding at the transverse ends of the pad being inset a distance so as to form lofty, soft metal wool bundles 88 at the transverse ends of the pad. The bands at the longitudinal sides of the pad are the same as those shown in FIGURES 1 and 2.

The pad 90 illustrated in FIGURE 8 utilizes a backing sheet 91 made of a polyethylene film of an appreciable thickness and to which is secured metal wool scouring elements 92, 93. The scouring elements are soaped as previously described and are embedded in the polyethylene film with the same marginal banding arrangement used in the pad 10 illustrated in FIGURES l to 5.

The scouring pad of the present invention may be manufactured utilizing the apparatus 60 shown in FIG- URES 9-11 wherein for example, a continuous strip 61 of plastic or expanded foam material is fed over roller 62 while simultaneously loose metal wool 63 is fed over another roller 64, the plastic foam and metal wool entering the nip of the rollers 62 and 64 with a stream of molten polyethylene adhesive 65 being fed intermediate the converging plastic foam and metal wool as best seen in FIGURE 9. It is also possible to add water to the polyethylene so that the adhesive will also become foamed forming a thickness of adhesive film as described before and shown in FIGURE 6. In passing into the nip of the rollers 62 and 64, the polyethylene adhesive 65 covers the inner face of the plastic foam and the metal Wool 63 is pressed against the adhesive being embedded therein in the marginal band pattern shown in FIGURE 1 by means of embossing surfaces 66 and 67 on roller 64, the former corresponding to the arrangement of the bands 23, 26 on the pad while the remainder of the mass is pressed into light adhesive contact with the adhesive as previously described. The heavy embossing which bonds the peripheral fibers of the metal wool mass down into the layer of adhesive is preferably limited to a width of approximately A2" extending around the pad in the band paths 23, 26 and slightly inwardly of the edges of the foamed backing sheet. The latter forms a narrow unembossed border around the extremity of the pad presenting a soft, thick edge of foam along the longitudinal edges and a soft thick edge of foam, adhesive and wool fiber bundles 27 at the transverse ends. The pad thus has soft edges all around which are soft and pleasing for the user to touch. On the other hand, if the embossing extended to the extreme pad edges, an undesirable knife-edge of adhesive and compressed steel wool fibers would be presented to the users fingers. The composite strip is then fed around soap applicator roller 68 with the metal wool side contacting the face of the roller. As seen in FIGURE 7, a reservoir 69 which is kept filled with a soap 70 in liquid or semi-liquid form by fill nozzle 71, is located adjacent roller 68. Soap is moved from the reservoir 69 onto the surface of 'roller 68 by wiping roller 72. The viscous soap is then carried around on the surface of roller 68 as shown and impregnates the metal wool.

The soap impregnated composite strip is thereafter fed through a drying chamber 73 to solidify the soap and cause it to adhere in flake form to the metal wool strands after which the strip passes through a cutter unit 74 which severs it into individual scouring pad pieces.

It will be apparent from the foregoing that the scouring pad of the present invention ofiers a number of advantages. Prior art pads such as those exemplified by the patent to Cameron 3,074,099 have many objectionable features. They are thin and, because of the close corrugations, hard and inflexible so that it is difiicult to wrap them around curved surfaces and bend them inside lips of pans. The bottom of each corrugation of the steel wool fiber is pressed into a firm layer of bonding material, a

7 design ideal to give a rigid thin structure. Moreover, the

corrugations of the Wool are so short and compact that the ribbon is virtually incompressible under the fingers and thus there is no squeezing action possible so that the excellent foam generating characteristics of a soft mass of steel wool which normally acts like a sponge are completely eradicated. Finally, should the knife blade, which severs the completed ribbon into the individual pads during manufacturing, out along the bottom of the corrugation where the wool is compacted into the adhesive, the resulting transverse side of the pad as presented to the housewifes fingers will be as hard and sharp as a knife edge. This must of necessity occur very frequently in the process of cutting these pads. The pad of the present invention, on the other hand, avoids all these objectionable features and in their place proifers advantages. The steel wool is left loose and fluffy, being compacted only in a minimum peripheral strip. This means that the wool is soft and springy so that it can be wrapped around any curve or shape, even letting pointed objects penetrate it, and so give good cleaning action. An ideal example is that the tangs of a fork can be readily cleaned with this fluffy pad but not with the corrugated pads. The soft and fluffy wool, holds more soap than the compacted, corrugated mat, a fact greatly appreciated by the housewife, and additionally it can be compressed and released in a sponging action to generate large quantities of lather even when there is only a minimum quantity of soap left in the pad. When the soap is exhausted, the housewife is left with a soft, pleasant appearing mass of steel wool neatly secured to a piece of foam which can readily be regenerated into a soap pad simply by wiping it on a tablet of kitchen soap in contrast with the corrugated version which leaves a thin hard sheet of compacted wool which readily rusts because of the galvanic action set up at the bottom of each corrugation, where the wool has been cold-worked and compressed into a layer of bonding agent. Finally the pad of the of the present invention is so bonded that the transverse knife cut always falls on uncompressed wool, leaving a soft end of severed fibers rather than the com pacted knife edge of compressed wool. This means that the whole perimeter of the pad is soft to the touch.

While there is above disclosed only some embodiments of the scouring pad of the present invention, it is possible to produce still other embodiments without departing from the scope of the inventive concept herein disclosed, accordingly, all matter disclosed herein should be understood as being illustrative and not taken in a limiting sense.

What is claimed is:

1. A scouring pad comprising a flexible backing sheet of foamed polyurethane, a layer of non-porous waterproof adhesive covering one face of said backing sheet, and a mass of intertwined strands of a metal wool generally coextensive with and covering said layer of adhesive, said mass being characterized by having a soft lofty main body of metal wool enclosed by compressed bands of said met-a1 wool which are embedded in said layer of adhesive adjacent the marginal extremities of said backing sheet, the intertwined strands in said mass extending outwardly of at least a portion of said bands and upwardly therefrom in soft lofty bundles which terminate at marginal extremities of said backing sheet, the strands at the bottom of said main body and at the bottom of said bundles being in surface adhesive contact with said layer of adhesive.

2. The scouring pad of claim 1 further comprising a solid soap material distributed throughout said mass of metal wool.

3. The scouring pad of claim 1 wherein the metal wool is steel wool.

4 The scouring pad of claim 1 wherein the adhesive is polyethylene.

5. The scouring pad of claim 1 further comprising a colored pigment incorporated in said adhesive layer for masking visibility through said backing sheet so the mass of metal wool cannot be seen through said backing sheet.

6. A scouring pad comprising a flexible backing sheet of foamed polyurethane having parallel longitudinal and transverse margins, a layer of polyethylene adhesive covering one face of said backing sheet, and a mass of intertwined strands of steel wool generally coextensive with and covering said layer of adhesive, said mass being characterized by having a soft lofty main body of steel wool enclosed by compressed parallel longitudinal and transverse bands of said steel wool which are embedded in said layer of adhesive, said longitudinal bands being embedded in said layer adjacent the longitudinal margins of said backing sheet, said transverse bands being embedded in said layer inwardly a distance of the transverse margins of said backing sheet, the intertwined strands in said mass 7 8 extending outwardly of said transverse bands and up- 3,014,233 12/1961 Gibbons 15209.5X Wardly therefrom in soft lofty bundles of steel Wool which 3,074,099 1/1963 Cameron 15-506 terminate at the transverse margins of said backing sheet, 3,182,346 5/1965 Winston 15-506 X the steel Wool strands at the bottom of said main body and at the bottom of said bundles being in surface ad- 5 FOREIGN PATENTS hesrve contact with said layer of adhesive. 946,634 1/1964 Great Britain.

References Cit 954,456 4/1964 Great Britain.

UNITED STATES PATENTS CHARLES A. WILLMUTH, Primary Examiner. 2,020,668 11/1935 Wandel 156-290X 10 R. L. BLEUTGE,AssistantExaminer.

2,493,968 1/1950 Hepner l5--209.5 X

Claims (1)

1. A SCOURING PAD COMPRISING A FLEXIBLE BACKING SHEET OF FOAMED POLYURETHANE, A LAYER OF NON-POROUS WATERPROOF ADHESIVE COVERING ONE FACE OF SAID BACKING SHEET, AND A MASS OF INTERTWINED STRANDS OF A METAL WOOL GENERALLY COEXTENSIVE WITH AND COVERIGN SAID LAYER OF ADHESIVE, SAID MASS BEING CHARACTERIZED BY HAVING A SOFT LOFTY MAIN BODY OF METAL WOOL ENCLOSED BY COMPRESSED BANDS OF SAID METAL WOOL WHICH ARE EMBEDDED IN SAID LAYER OF ADHESIVE ADJACENT THE MARGINAL EXTREMITIES OF SAID BACKING SHEET, THE INTERTWINED STRANDS IN SAID MASS EXTENDING OUTWARDLY OF AT LEAST A PORTION OF SAID BANDS AND UPWARDLY THEREFROM IN SOFT LOFTY BUNDLES WHICH TERMINATE AT MARGINAL EXTREMITIES OF SAID BAKCING SHEET, THE STRANDS AT THE BOTTOM OF SAID MAIN BODY AND AT THE BOTTOM OF SAID BUNDLES BEING IN SURFACE ADHESIVE CONTACT WITH SAID LAYER OF ADHESIVE.

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