US 3182346 A
Description (OCR text may contain errors)
y 1965 A. A. WINSTON 3,182,346
CLEANING ARTICLE AND METHOD OF MANUFACTURE Filed April 29, 1963 INVENTOR ADOLPH A. WINSTON United States Patent 3,182,346 CLEANH'JG ARTICLE AND METHOD OF MANUFACTURE Adolph A. Winston, Darien, Conn, assignor to General Foods Corporation, White Plains, N.Y., a corporation of Delaware Filed Apr. 29, 1963, Ser. No. 276,585 7 Claims. (Cl. 15-209) This invention relates to a new and improved scouring article and method of manufacturing the same. More particularly, the invention is concerned with creation of a laminated structure of metal wool filaments on a backing sheet.
Steel wool has heretofore been sold in the form of balls, ribbons and like bodies wherein the metal wool filaments are assembled into a unitary construction adapted to be gripped by the user in scouring pots, pans and similarly soiled utensils. Such metal wool bodies or pads are likely to undergo splitting of the metal filaments giving rise to unpleasant slivers which are offensive to the hands of the user. The art has long sought to provide a mass of metal wool filaments suitably mounted on a backing material such as paper or cloth so that the metal wool can be handled through the intermediation of a backing sheet and manipulated without danger of filament slivers cutting the skin of the user. The main limitation of prior art structures was that metal Wool fibers could not be faithfully mounted in any practical manufacturing operation in such manner that they were stationed permanently and uniformly on the backing member throughout the anticipated period of use. Since metal wool filaments are preferably mounted on a backing member in a corrugated pattern to provide greater scouring effect, nadir portions of the undulations proximate the backing member present an uneven surface to any adhesive employed to bond the individual metal filaments to the backing. Accordingly there is a tendency for the corrugated metal filaments to be unanchored as produce or unravel in use and thereby lose the desired corrugated pattern.
In accordance with the present invention a disposable cleansing and scouring article is provided by laminating corrugated metal filaments to a compressible spongiform ply. Such lamination is carried out by first feeding an endless ribbon of matted metal filaments into the pinch between a pair of corrugating rolls. The corrugated ribbon is then trained into the nip between a pair of laminating rolls. A continuous strip of deformable resilient spongiform material is trained around one of the laminating rolls and brought into proximate relation to the corrugated filaments at the nip between the laminating rolls. A heat activatable resinous material, e.g. polyethylene, is deposited in the form of a vertically descending molten film of substantial thickness between the juxtaposed strips of spongiform material and the corrugated metal wool filaments.
Due to the compressibility of the spongiform material and the plasticity of the molten resin, the concave undulating nadir portions of the corrugations displace the resin into the surface of the spongiform strip while being surrounded by the resin as the juxtaposed plies pass through the nip between the laminating rolls. By virtue of the ability of the metal wool to dissipate the heat of the resin, the laminating film is rapidly reduced in temperature to a point where it sets to permanently anchor the filaments and the film per se in place on the backing ply. While heat transfer from the resin is effected rapidly, setting of the resin occurs only after resin penetration at the surface of the spongiform sheet and around the nadirs in the corrugated metal filaments.
In carrying out lamination, the extrusion orifice through which the hot molten plastic material is caused to issue should be located proximate the nip between the oppositely rotating laminating rolls whereby the plastic material falls in free-film form at a sufficiently elevated temperature so as not to undergo premature solidification, i.e., firming to a point whereat the resin cannot orient itself to migrate around the metal filaments and enetrate the surface of the spongiform material. The molten free film may be solidified after lamination by cooling one or both of the two laminating rolls over which the spongiform sheet and the metal filaments pass so as to assure that the laminated structure will be transferred unitarily without delamination to the succeeding stations of the fabricating operation. These stations will involve impregnation of a soap foam or molten soap in the laminated structure, drying the soap and then cutting the soap-impregnated product. For such subsequent operations the free-film of thermoplastic resin, as in the case of polyethylene, should be substantially set shortly after lamination so that any extraneous liquids, such as the fats contained in liquid or molten soap, do not detract from the extent of filament anchoring.
Due to compressibility of the spongiform backing ply, the metal wool corrugations are not flattened incident to application of the laminating pressure called for in bringing the metal filaments into intimate contact with the spongiform material and the molten thermoplastic laminant. To afford retention of the corrugated pattern, therefore, the backing sheet should be of a highly compressible character such as is offered by urethane plastic foam and like resilient spongiform compositions to be hereinafter described.
When viewed in cross section, the composite structure will be seen to have corrugated depressions therein complementary to the nadir portions of the corrugated metal wool filaments, the intermediate laminating film being in the form of a continuous corrugated membrane. It is a feature of the present structure that the crests at the working surface of the metal wool filaments are substantially free from contact with the laminant film; while the nadir portions of the filaments are maintained in an immobile orientated pattern by being anchored at the concave portions of the corrugations only. The anchored metal filaments offer the maximum scouring effect, through the cutting action of the flexible filaments, as they orient themselves freely when contacting soil on the working surface of a pot, pan or other utensil requiring cleansing,
The invention will now be more fully understood by reference to the accompanying drawings showing a preferred method for manufacturing the article of the present invention and also describing the article.
In the drawings:
FIGURE 1 is a schematic side elevation of equipment for laminating the metal wool filaments to a spongiform backing sheet; FIGURE 2 is a perspective view of a laminated corrugated scouring article produced by the apparatus depicted in FIGURE 1; and FIGURE 3 is a side elevation taken partly in elevation and partly in section along line 33 in FEGURE 2, a part of the side section in FIG- URE 3 being magnified to better illustrate the features of the present invention.
Referring now to FIGURE 1, the apparatus shown therein consists of an unwind roll it? mounted for rotation on journals 12 housed on stand 14. A roll of highly compressible resilient urethane foam 16 ribbon is trained around guide rolls 18, 20, 22, and 24 adapted to lead the foam ribbon 16 over metal laminating roll 26.
A ribbon of metal wool shown generally at 28 is introduced to the nip between a pair of oppositely rotating corrugating rolls 30, 32, to create corrugations in the metal wool ribbon 28, the corrugated metal filaments and the undulations therein being more particularly described hereinafter with respect to FIGURES 2 and 3: die 34 mounted on the discharge end of an extruder (not shown) is mounted superjacent the nip between corrugating roll 30 and laminating roll 26 whereby a polyethylene filrn36 is fed to the laminating nip in a manner to be more particularly described hereinafter.
The corrugated metal wool filaments are thus laminated to the foam ribbon 16 through the intermediation of molten resin film 36 and are conducted away from the laminating station of take-off rolls 38, 40, substantial solidification of the laminant being achieved in the vicinity of the laminating station, which solidification may be assured by cooling laminating roll 26 internally.
The laminated corrugated metal wool filaments and foam ribbon composite shown generally at position 42 is conducted beneath a pair of soap rolls 44, 46 operated in the directions shown by the arrows to deposit from soap nozzle 49 a uniform ribbon of hot molten soap onto the corrugated side of composite 4-2, the soaped laminated structure being conducted under the control or" guide roll' 48 into a conventional vertical drier generally shown at 50 wherein the moisture is removed from the soap by training the composite over a plurality of pulleys (not shown) under the influence of circulating hot air.
The dried composite issuing at 52 from drying chamber 50 is then conducted by guide rolls 54, 56 into flying cutter 58 wherein the ribbon is divided into pads of the dimensions shown in FEGURE 2.
Referring now to FIGURE 2, the pad thus produced will be seen to consist of a corrugated metal wool ply 100 laminated through the intermediation of a solidified thermoplastic anchoring ply 102 to a compressible spongiform ply 104. As will be seen from FIGURE 3, and more particularly the magnified section thereof, the undulations of the metal wool filaments are alternately anchored in place by laminant 102 as at 1'06 and freely displaceable and unanchored as at E08 providing a void space between the crests of the laminant at 110 and the intermediate thermoplastic ply 102. As seen in FIGURE 3, the concave undulations of the metal Wool filaments are immersed in the thermoplastic substantially no that the material of ply 102 surrounds a substantial portion of the nadirs of the filaments as at 112, thereby assuring permanent anchoring of the filaments to the laminant.
As will also be seen inFIGURE 3, the laminant per se assumes a wavelike cross-section by reason of the substantially complementary pattern of the laminant to the various nadirs of the individual metal wool corrugations. This corrugated laminant ply-102 will also be seen to be substantially anchored to the compressible plastic foam ply 104, which adhesion is in part attributed to migration of the molten laminant into the voids or pockets at the surface of the foam ribbon during the lamination process. To achieve this preferred anchoring of the laminant resin, it is maintained sumciently high in temperature above its solidification point as it is extruded in'free film 36 that a substantial migration of the polymer can occur. However, the temperature is preferably not sufiiciently elevated to a point whereat it cannot be rapidly solidified after lamination of the corrugated ply to the compressible plastic foam.
In achieving the desiredlaminated structure, the amplitude of the corrugations, the thickness of the foam ribbon, the thickness of film 36 and the ultimate ply thereof 102, the compressibility of the corrugated metal wool ribbon and the foam ribbon, and the speed-of lami-.
nation are all interrelated factors which should be taken into account in adjusting nip clearance to achieve the desired laminated structure. A narrow nip clearance will .imbed the metal filaments too deeply into the laminant and the resilient backing whereby an insuflicient amount of corrugated steel or other metal wool is available for scouring. On the other hand, a nip clearance that is too wide will not result in sufiicient immersion of filament nadir portions to firmly anchor the metal wool to the backing. The nip clearanceshould be sufiicient to promote substantial immersion of the nadir portions of the corrugations in the laminant and permit anchoring of individual metal filaments while leaving substantial freedom to the crest portions thereof. In all such laminations this is achieved by bringing the corrugated metal wool ribbon into compressing relation to the foam ribbon under conditions whereby the latter will yield undervthe laminating pressure transmitted through the molten adhesive and result in a sinusoidal pattern in the solidified laminating ply. Hence the foam ribbon should be sufiiciently compressible to allow distortion sufficient to receive the nadir portions of the metal wool corrugations during the laminating operation.
The metalwool material may be aluminum, steel, or any other metallic fiber having a cutting edge produced therein incident to filament productions, although the invention is not restricted to use of metal filaments derived by any particular method.
The preferred foam ribbon has become possibly known as urethane or polyurethane foam and is generically chemically identifiable as a foamed isocyanate resin. The preparation of polyurethane foams from free isocyanate radical-containing polyurethane products results from the reaction between (1) an alkyd or other. active hydrogencontaining organic polymeric material and (2) organic compounds containing, as the sole reacting groups; a plurality of isocyanate groups is described in German Plastics Practice, by De Bell et al., 1946, pp. 316 and 463- 465. Disclosures of reactants and methods which may be employed to produce polyurethane foams of use in preparing the foam ribbon are United States Patents 2,282,-
827 (Rothrock), 2,284,637 (Catlin), 2,284,896 (Hanford et al.), 2,292,433 (Hanford), 2,333,639 (Christ et al.), 2,358,475 (Pratt et al.), and 2,374,163 (Rothrock); and United States patent applications Serial Nos. 340,168 (Detrick et al.), filed March 13, 1953, now Patent No. 2,787,601; 369,240 (Barthel), filed July 20, 1953, now Patent No. 2,788,335; 381,745(Mitchell), filed September 21, 1953, now Patent No. 2,850,464; 383,370 (Barthel), filed September 30, 1953, now Patent No. 2,833,730; 395,843 '(Roussel), filed December 2, 1953, now Patent No. 2,842,506; and 405,036 (Mitchell), filed January 19, 1954, now Patent No. 2,814,600.
However other foamableresinous thermoplastic compositions capable of offering the desired compressibility and foam structure may be employed such as rubber sponge, cellulose sponge and like compositions 'well known in the art. Although the invention preferablyemploys compressible foamed resins whose structure in the superficially dry state per se is such that the material is sufiiciently deformable to receive the nadir portions of the metal wool corrugations, it is also within the spirit of the present invention'that any compressible spongiform plastic material which may be relatively uncompressible in the dry state and rendered temporarily compressible in the wet state (such as axwet cellulose sponge) may be used in such wet state as the ribbon 16 is fed to the nip between the laminating rolls; the wet laminated ribbon may be thereafter dried incident to removing moisture from the soap applied'to the composite 42.
The composition ofthe'laminant ply should be one like low density polyethylenethat is readily film forming and may be converted into a molten sheet susceptible to rapid solidification after the application of laminating pressure to the corrugated ply and the backing ply. Typically any one of the known polymerized olefin resins such as polyethylene, polpropylene and polystyrene, etc. may be used with or without a tackifying or plastisol'additive, all of which is well known to those skilled'in the art. The adhesive composition shouldbe preferably thermoplastic and be of'sufiicientviscosity to migrate around the monofilaments and 'occupy the pores'a't the'surface of the undulating indented compressed portions of the backing ply.
The laminant should also be capable when set of retaining a shape complementary to that produced incident to distortion under the laminating pressure applied thereto.
The advantages of the present invention are that the aforesaid composite structure is produced with corrugations of either a sinusoidal or any other undulating pattern capable of providing a good scouring efiect without sacrificing good bonding of the nadir portions of the corrugations to the backing material. By reason of the spongiform backing material called for in producing this laminated structure, the individual voids and vesicles therein provide improved soap retention for the life of the pad, and hence improve the overall scouring efiectiveness of the article throughout its anticipated period of use. The backing acts as a reservoir feeding soap to the working surface of the metal wool facing ply 100 at a rate which makes its scouring and cleansing activity more effective, particularly in view of the mobility of the crests of the well-anchored filaments. By virtue of the consistency aiforded in bonding the metal wool corrugations to the backing and the simplicity of the laminating process, this procedure lends itself to acontinuous, low-cost, troublefree manufacturing operation assuring a uniform laminated structure with a minimum of plant supervision.
What is claimed is:
1. A composite scouring article comprising a corrugated metal wool ply; a compressible spongiforrn backing ply; and an intermediate laminating ply of thermoplastic resin adhesive; the laminating ply having undulations therein complementary to the nadir portions of the corrugations in the metal Wool ply and anchoring individual filaments thereof in the composition of the laminating ply at the nadir portions thereof; the backing ply having undulating indented compressed porous portions therein complementary to those of the laminating ply, the composition of the laminating ply being adhered to the compressed undulating portions of the backing ply and ccupying the pores at the surface thereof.
2. A scouring article according to claim 1 wherein the crest portions of the metal wool filaments are free of contact with the composition of the laminating ply so as to be mobile at the working surface of the scouring article.
3. Process for laminating a compressible spongiform backing ply to a metal wool ply which comprises pressing said metal wool ply into a corrugated form having alternate nadir and crest portions, introducing said backing ply to the corrugated metal wool ply through the intermediation of a molten thermoplastic laminating resin deposited between juxtaposed surface of the backing ply and the metal wool ply, applying on the nadir portions of said corrugated metal wool ply laminating pressure to the juxtaposed plies sufficient to cause the nadir portions of the corrugated ply to transmit laminating pressure through the intermediate molten laminant and produce complementary depressions in the backing ply whereby the laminant ply assumes a pattern substantially complementary to the pattern of the nadir portions of the corrugated metal wool ply and the molten laminant is caused to anchor the filaments in place.
4. The process of claim 3 wherein said backing ply and said corrugated metal wool ply are juxtaposed continuously in the form of ribbons fed respectively to the nip between 21 pair of laminating rolls.
5. The process of claim 4 wherein said molten thermoplastic resin is extruded as an unsupported free film which contacts the juxtoposed plies just prior to the application of laminating pressure thereto.
6. A scouring article according to claim 1 wherein the undulations in the backing ply are equal in pitch and unequal in amplitude to the undulations of said corrugated metal wool ply.
7. A scouring article according to claim 6 wherein the undulations in the backing ply are of lesser amplitude than that of the undulations of said corrugated metal wool ply.
References Cited by the Examiner UNITED STATES PATENTS Re. 25,200 7/62 Robinson et al l56-244 2,493,968 1/50 Hepner 15-209 X 2,897,109 7/59 Voigtman 156-244 X 3,074,099 1/63 Cameron 15-506 3,080,688 3/63 Politzer 15-297 X CHARLES A. WILLMUTH, Primary Examiner.