Патент USA US2406718код для вставки
Patented Aug. 27, 1946 2,406,718 r. UNITED STATES PATENT OFFICE. EMBOSSING BOWL Y i „ „ , . . , Raymond E. Thomas, Newburgh, N. Y., assignor to4 . , E. Ldu Pont Vde Nemours & Company, Wil g _ n,mingtom Del., a corporation of lDelaware ' ' Application July 31, 1943„Serial No. 496,947 4 Claims. l (Cl. 101-407) 1 This invention ¿relates »to the embossing of Vsheet materialïandïmore particularly to increas tion of the engravedroll. The deterioration is manifested by a crumbling and f‘dusting-off” of the outer surface of the paper> bowl and, in time, by the spalling _of larger pieces which render the ing the vlongevity of paper coun-ter rollers, known asbowls, in the roller embossing operation of ' sheet'material. _~ _. Inv producing surface pattern leffects on sheet ' bowl unfit for use. y Y Y _ ‘ Y This invention has for anl object a method for material by means yof embossing, two methods are commonly used; namely, platel embossing and treating paper embossing bowls to render them more resistant topowdering or'fiaking of the roller «eml'aossingv Y In the »plate embossing meth paper surface upon continued operation. YAri ïod the’s'heet material is' pressed between a metal 1.0 other object is to lengthen the useful lifeof paper plate bearing theï'desired design in Vrelief and a embossing bowls beyond their ynormally expected operating period. Other objects will appear softer fibrous base which has the »counter of the design onthe metal‘piate. ' . 4 ' 4hereinafter as the description of theV invention » ' In the roller 'embossing method engraved metal -rolls are used 'in_coniunction with softer counter n "rolls or bowls, which‘areusually m'adeof paper. Y proceeds. In the normal operation of >a roller, embossing rmachine the customary method for using a new The îpaper bowls are "made by Yplacing paper discs paper bowl is to wet the bowl with water and to or washers at right -an'g‘les’to'the axis of a metal ’mandril and then‘forcing 'the paperV discs into intimate contact yby means of pressure, after which .the discs are secured in position by use of rigid metal end supports connected to ¿the man ~dril. The'paper vbowl carries a 'pattern counter bring the metal embossing roller in contact with the bowl, 4first'under low pressure and then with gradually increasing pressure until full operating pressure is attained. This method o_f “cutting to Íthe pattern on thelmetal roll. ` ' ' ' ' in” a design allows a clear, well defined counter impression of the' engraved roll to be reproduced on the bowl. The machine then’may be used to In producing an embossed pattern by the rollerA 25 emboss sheet material for a considerable period ' embossing `method onÍs'h’eét material, it isv passed of time without giving any trouble with the bowl under ordinary operating conditions. Occasion *between the'metalroller'andíthe' paper bowl using 'suiiicient :pressure ' and -heat'to secure the desired pattern. ' . l” "` The heat is íapplied 'customarily by ‘heating -the metal'roll althoughiitiisîsometime's advantageous j-to fpreheat the material vbefore it contacts the A»rollers ‘and vuse Ya cool metal roll, to secure the . desired pattern. For y“deeper patterns more heat _ ally the engraved roller andthe bowl may get out of register and give embossed designs which are 30 not clear cut and distinct. This is corrected by Y’ wetting the bowl with water, thereby swelling the paper übers and obliterating the previous design. ‘The original process of “cutting-in” the design may then be repeated. ' or-'lpressure-usually areappliedíthan 'for shallower designs: For -pyroxylin ’coated fabrics, Vpressures '» After embossing a considerable quantity of sheet material in a roller embossing machine, the of 35 -to '50 Vtonsfat `they area of contact of the bowl begins to show signs of deterioration caused r.metal-and’paperrolls, and *temperatures of 200° by the pressure, heat and abrading action of the F. to 300° vF'. are used. 'Coated‘fabri'cs utilizing operation. This deterioration manifests itself in :synthetic resins'of a >more 'thermoplastic nature 40 a hardening, crumblingor “dusting-off” of the fare sometimes embossed >at ’pressures as high as. » surface of the bowl. At first the dust is a poten 80 tons and temperatures as lowas 60° F. The tial source of damage to the material merely be K .metal roll is -driven by» a series of gears, chains, cause of the dirt contamination involved, but orother'mechanical means, while the >paper bowl soon the 4deterioration progresses to such an ex - may be turned 4either by 'the friction against the 4.5 tent that a satisfactory grained material cannot be ysecured because of the poorly defined counter ¿.Jnetalfroll and the sheet material or by a seriesï» of gears, chains; vor other mechanical meansV act impression of the bowl. In certain cases where ing in conjunction with the means used to drive an embossing cylinder of a smaller size is avail the metal roll. ` ‘ » , ‘ able the bowl may be “turned down” on a lathe In ,the embossing-of sheet material, such as a 50 in the yconventional manner. In most cases the „coatedfabrid the pressure and heat of the opera- î' paper is removed to a depth o'f a quarter of an îtion tend in time ¿to cause such deterioration of K .the paper bowl as to .render it uselessibecause the -embossed impressions arenot’ sufûciently clear A cut and will not Agive aftru-e embossed reproduc ,¿ inch. The Ysame process is-thenfollowed as with ‘a new ybowl in preparing and using it for emboss ing. In time the"‘turned down” bowl will deteri .Orate on the surface and must be discarded unless 2,406,718 3 . 4 ing of material with a deep character, or grain, was beginning to show "dusting off” of the sur face. This would normally have resulted in the replacement or “turning-down” of the bowl. In this case, however, the bowl was given a liberal brush coating of the following solution while the a still smaller sized cylinder is available in which case the “turning-down” procedure may be re peated again. Normally at this stage the bowl must be replaced. It has been found that the life of a bowl may be prolonged considerably beyond the stage when embossing cylinder was operating in contact with “dusting-01T” has begun by the use of a composi the bowl under approximately 50 tons pressure and 270" F. temperature: tion which prevents the paper fibers of the bowl surface from crumbling. This is accomplished by utilizing an aqueous solution of a water soluble 10 polyvinyl alcohol resin, suitably plasticized so as to prevent embrittlement of the surface. The water soluble resin may be applied to the sur-» Bowl preservative composition nPart A: " face of the manufactured bowl or may be in Water corporated into the paper before it is placed 15 on the bowl mandril. A convenient method is to impregnate the formed paper sheet before it `is cut into sections; another method is to incor-> porate the resin directly'in the slurry from which Per cent Polyvinyl alcohol _________________ __ ' _ ____ __ 4.00 40.50 Part B-Glycerine ____________________ __ 26.50 Part C`--Water _______________________ __ 29.00 100.00 20 The above composition was prepared by mak ing a slurry of the polyvinyl alcohol and cold water of part A. This slurry was then mixed for use with another cylinder after the bowl while being heated in a steam jacketed kettle to first shows signs of failure, the impregnating com give a lump-free clear dispersion. Part B was position mentioned above also is of value as it then added while the mixture was stirred, and tends to minimize the depth of deterioration. the water of part'C was added hot with continued Normally deterioration, embrittlement and-hard stirring to give the finished composition. ening will take place to a greater depth than the When applied to the bowl which was operating l@ inch removed on the lathe. When the im in the normal manner in conjunction with the pregnating solution is used, this deterioration does not take place to any extent at depths of 1A; inch 30 embossing cylinder as described above, the heat of the cylinder served to evaporate the water and or more and in this manner affords a resilient the sheet of paper is formed.V , In the case in which a bowl is “turned down” -surfaceon a “turned down” bowl. give a bowl whose outer surface was saturated with the polyvinyl alcohol, glycerine mixture. In the preferred embodiment of the invention This mixture served to bind the paper ñbers to a solution of polyvinyl alcohol, dissolved in water and Vplasticized with glycerine or similar water 35 gether and prevent the crumbling and “dusting oif” which causes the bowl to become useless. soluble polyhydric alcohol is applied to the sur The bowl which was treated as described above face of the bowl in sufñcient quantity to im was used in normal operation for more than two pregnate the surface layers thoroughly. The months before it was necessary to replace it. This bowl is thenV subjected to the “cutting-in” process previouslydescribed. The heat and pressure of 40 added service represents a definite economic advantage. the “cutting-in” process evaporates the water The primary use of the invention is' to in and leaves the paper fibers of the bowl impreg crease the useful life of paper bowls used in nated with the polyvinyl alcohol-glycerine mix the roller embossing of sheet material. The in ture. In the drawing, Figure 1 represents a( diagram 45 vention will also find wide use where paper or other water absorbent materials are subjected to matic section of an embossing bowl prepared repeated or prolonged high pressures and high ~- according to the present invention. Figure 2 is temperatures. ' ` a diagrammatic section of the bowl of Figure 1 The treatment of roller embossing bowls with in combination with a conventional embossing roll bearing a design. In both ñgures the same 50 plasticized polyvinyl alcohol solutions inhibits deterioration of the surface of the bowl to such numerals refer to the same parts of which 4 is a an extent that it may be used far beyond its nor mandril provided with a flange against which a mal period of usefulness. Another advantage large retaining washer I is placed. The paper is that when applied to new bowls and occasion discs which have been impregnated with poly vinyl alcohol or which subsequently may be coated 55 ally during the normal life of the bowl, deteriora tion will not only be retarded but will also not with it are threaded onto the mandril. When take place to as great a depth. 'I‘his latter be sufficient of the paper discs have been mounted havior permits the bowl to be more readily “turned on the mandril another similar washer l is placed against them and forced together tightly by down” to a Isamaller size and still have a resilient, means of nutI 3. After the paper discs have been 60 undeteriorated surface. Other advantages will be apparent to those Skilled in the art. suñiciently compressed and treated with a poly It is apparent that many widely different em vinyl alcohol solution containing a plasticizer, bodiments of this invention may be made without the bowl is run under high pressure at elevated temperature against the embossing roll to cut in departing from the spirit and scope thereof, and a counter design in the peripheries of the com 65 therefore, it is not intended to be limited except pressed paper discs. Subsequently a fabric 5 may as indicated in the appended claims. be embossed by passing it between the bowl and I claim: 1. An embossing bowl capable of being cut in the embossing roll as shown in Figure 2. The by a counter embossing roll to form a clear well coated fabric is then wound up in a conventional manner on wind-up roll 6. 70 defined impression and also highly’resistant to The following description of the preferred em temperatures up to about 300° F. comprising a large number of centrally perforated paper discs bodiment is given as an illustration. This de scription is not to be construed as limiting the impregnated at least on their periphery with a invention to this preferred embodiment. A bowl which had been used in the ßmbOSS water soluble polyvinyl alcohol composition, a 75 mandrel passing through the said perforations 2,406,718 6 and end plates forholding the discs in com pressed relation. . 2. The bowl of claiml 1 in which the paper is impregnated with a composition consisting of polyvinyl alcohol, glycerine and Water. I3. The bowl of claim 1 in which the paper is _ impregnated with a composition containing 4 parts of polyvinyl alcohol and 26.5 parts of glycerine. i ` 4. A method of treating paper embossing bowls 10 v which comprises impregnating the paper with an aqueoussolution of polyvinyl alcohol and a plas ticizer and thereafter cutting in the surface of the said bowl by running it in contact under pressure at an elevated temperature with a coun ter embossing roll until a clear Well defined coun ter impression of the embossing roll is repro duced on the bowl. v RAYMOND E. THOMAS.