US 3109331 A
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Nov. 5, 1963 I R. A. CORDRAY ETAL 3,109,331
METHOD OF TEXTURING METAL SHEETS Filed May 5, 1961 FIG.]..
INVENTORS R. A.CORDRAY S. R.C,ROOKS I ATTORNEY METHOD OF TEXTUREIG METAL SHEETS Richard A. tierdray, Hinldey, and Sheridan it. Qrcoirs,
Cleveland Heights, flhio, assigners to Republic Corporation, Cieveiand, Qhio, a corporation of New Jersey Filed May 5, 1961, Ser. No. 168,116 4 Claims. (Cl. 89-66) This invention relates to metallic sheets having a textured design and, to a method of producing said design on the sheets by means of a novel rolling process.
Sheet metal, particularly stainless steel, has recently gained wide acceptance in the architectural field for use as ornamental wall panels. The flat surface of these panels is quite unappealing to the eye and in the case of stainless steel, the reflective nature of the surface is often undesirable.
Accordingly, one of the objects of this invention is to provide a novel method for imparting a pleasing and unique texture on metallic sheets.
Another object of the invention is to provide a method for decorating metallic sheets with a non-repeating design by passing between a pair of plain-surfaced rolls a pair of metallic sheets having a texturing agent therebetween.
A further object of this invention is to provide a method for texturing metallic sheets by using recoverable designproducing agents which form a random pattern consisting of adjacent shiny and dull surfaced areas.
Still another object of this invention is to provide a metallic sheet having an intaglio textured surface.
Various methods have heretofore been devised to produce a decorative or textured surface on metallic sheets. However, these methods have not been widely accepted to certain inherent disadvantages. The prior practice has been to impart a decorative finish on sheet metal by either passing the sheet between rolls having a textured surface or else by passing the sheet, together with a matte of Fiberglas, steel wool, or other substances, between a pair of plain-surfaced pressure rolls. In the former instance, a few of the disadvantages are the cost and maintenance of the die roll and the repeating nature of the design. In the latter case, the resulting design is limited to the extent in which a random pattern can be imparted on the metallic sheet.
The invention will be more readily understood by reference to the accompanying drawing in which:
FIGURE 1 is a perspective view showing the steps of carrying out the subject invention with portions of the upper sheet broken away to illustrate the condition of the metallic sheets and texturing agents before and after passing between the pressure rolls.
FIGURE 2 is a perspective view of a textured metallic sheet produced according to the invention.
The textured finish is produced on the metallic sheets by forming a composite pack consisting of two thicknesses of metal with a filler or texturing agent comprising metallic or non-metallic powder sandwiched therebetween. After the powder is placed between the sheets, droplets of a liquid (prefer-ably oil or Water) are sprinkled at random on the powder layer before placing on the top thickness of metal. The composite pack is then passed between a pair of pressure rolls which causes the Wetted portions of the powdered layer to flow in a random pattern and to leave juxtaposed raised flat surfaces on both top and bottom pieces of the sheets. The powdered areas which are not wetted by the liquid are relatively immobile and the rolls cause substantial reduction in the thickness of the sheets by forming depressions in the metallic sheets. The inherent abrasive action of the dry powder not only cuts out areas in the sheets but also leaves these same areas with a dull finish. After the composite pack has passed through the pressure rolls the sheets are separated, the powder is brushed from the textured surface, and thereafter may be recovered for subsequent reuse.
Referring particularly to FIGURE 1, it will be noted that the composite pack generally designated 1 comprises upper and lower metallic sheets S and S, respectively.
As seen in the left-hand portion of this figure, a layer of metallic or non metallic powder P has been spread on the lower sheet S. A few drops of liquid are sprinkled on this powder layer in a random fashion after which upper sheet S is placed in overlying relationship to sheet S. The completed composite pack 1 is then passed between the pressure rolls R and R, whereupon the pressure creates the textured design as described hereinabove.
FIGURE 2 clearly shows a textured sheet produced according to the subject method wherein the raised shiny portions 2 will be seen to comprise a fern-like pattern extending longitudinally of the sheet S to produce an intaglio design. These portions 2 of the sheet have not been dulled or substantially reduced in thickness by the powder P due to the fact that the liquid which was sprinkled over the powder caused a lubricity at these points between the sheets and enabled the powder tobe oarried away by the roll pressure and prevented the powder from being ground into the surfaces of the sheet as the composite pack 1 was passed between the rolls.
On the other hand, that powder which is not contacted by the liquid remains immobile and forms depressions 3 in the opposed surfaces of the sheets due to the roll pressure. The surface of the depressed areas 3 will be dulled due to the abrasive action of the powder P.
Not only does the random sprinkling of the liquid on the powder produce an irregular pattern, but it will be seen that when the drops of water between the sheets S and S approach the point between the rolls the pressure cause-s these drops of liquid to be compressed and squished into further unpredictable or random patterns which generally follow the longitudinal dimension of the sheets due to the progressively advancing pressure of the rolls.
Although water or oil is the preferred liquid to be used, it will be understood that any liquid may be used which will not attack the metallic sheets or the powder and does not wet the powder. It will be seen that if a wettable liquid were used, then the powder beneath the sprinkled liquid would have no lubricity and would not be carried away from the pattern of the liquid when squished by the roll pressure.
Not only stainless steel, but also aluminum and mild steel, among other metals, can be satisfactorily textured according to the subject method.
It has been found that various types of powders may be used to achieve different texturing effects. Although a powder made of the same metal as the sheets to be textured is preferred, any number of metallic and nonmetarllic powders may be utilized to produce the texturing design. Sever-a1 metallic, silica, alumina, and organic resinous powders have been used with success. The powder must not be too soft or have too high a degree of lubricity. The powder must have a hardness rating of 3 or higher on Mohs scale, otherwise the powder would be too soft to absorb the roll pressure to satisfactorily cut out the depressed areas 3-. The mesh size of the powder can vary between -l4 to 400 mesh.
The amount of roll pressure used in the process of this invention has been found to effect the quality of the textured sheet. For example, when the roll pressure is too high the powder tends to abrade the surface of the raised design thus dimming its lustre and lessening the arc-9,331
textured appearance of the sheet. Conversely, when the roll pressure is too low the powder does not suificiently abrtde the sheet to create the depressed areas, a result similarly undesirable. The rolling of the sheets in accordance with this invention results in their elongation the amount of which is directly proportional to the roll pressure. Although greater or lesser roll pressures can be used to create certain effects in the finished sheet, it has been found more advantageous to maintain the roll pressure between amounts which would result in elongations of between about 4% and about 59%.
Since certain changes in the practice of this invention may be readily made without substantially departing from its spirit or scope, it is to be understood that all the foregoing be interpreted as being merely illustrative and is not to be construed as limiting or restricting the inven' tion as particularly pointed out and defined in the appended claims.
1. The method of texturing metallic sheets capable of elongation by roll pressure which comprises, applying a layer of metallic powder on top of a first metallic sheet, sprinkling drop-s of liquid at random on said powder, said liquid being inactive with said sheet and providing lubricity between said powder and sheet to act as a carrier to randomly distribute said powder, placing a second metallic sheet over said first sheet to form a composite pack,
passing the composite pack between a pair of pressure rolls whereby the drops of liquid are spread out in a predominantly longitudinal direction to form random patterns free of powder and said powder not in contact with said liquid remaining stationary and compressed to form depressed areas in the sheets, and separating the rolled sheets.
randomly distribute said powder, placing a second metallic sheet over said first sheet to form a composite pack, passing the composite pack between a pair of pressure rolls whereby the drops of liquid are spread out in a predominantly longitudinal direction to form random patterns free of powder and said powder not in contact with said liquid remaining stationary and compressed to form depressed areas in the sheets, and separating the rolled sheets.
3. The method defined by claim 1 wherein said metallic powder is of the same metal as said sheets.
4. The method defined by claim 1 wherein said sheets and powder are of stainless steel and said random patterns are shiny-surfaced while said depressed areas are duI-Ieurfaced.
References (Iited in the file of this patent UNITED STATES PATENTS 111,307 Bliss Jan. 31,1871 152,741 Goddard July 7, 1874 437,095 Church Sept. 23, 1890 483,240 Sagendorph Sept. 27, 1892 936,389 Wadsworth Oct. 12, 1909 1,516,098 Heyer Nov. 18, 1924 1,792,829 Goin Feb. 17, 1931 1,821,343 Honer Sept. 1, 1931