US1387068A - Process of and apparatus for the manufacture and handling of metallic-leaf films - Google Patents

Description

8. P. OLSON. PROCESS OF AND APPARATUS FOR THE MANUFACTURE AND HANDLING OF METALLfC LEAF FILMS.

APPLICATAION man AUG.6. 1920. 1,387,068, v Patented Aug. 9, 1921,

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@51 tJ-t' OL'VLQAJ d? C. P. OLSON.

PROCESS OF AND APPARATUS FOR THE MANUFACTURE AND HANDLING OF METALLIC LEAF FILMS.

APPLICATION FILED AUG.6- 1920.

Patented Aug. 9, 1921.

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Mk Mk AQN N E N C. P. OLSON. PROCESS OF AND APPARATUS FOR THE MANUFACTURE AND HANDLING OF METALLIC LEAF FILMS.

APPLICATION FILED AUGIGI I920.

Am m @M A m \N d w m s I m mm W P MN m O I m -K k/I n I M 1111 II AQIIQ NI MN I I I I I R. Aw N %a a. k IQ mm Cu a B /VFW mm 3 I Q & w a I A A i 1 @NEEEQ STATES CARL P. OLSON, OF IRVINGTON, NEW JERSEY.

rnocnss or AND ArrAnArus non ran MANUFACTURE AND HANDLING or mn'rAnrarest ornate.

DIG-LEAF FILMS.

essons."

Specification of Letters Patent.

Patented Aug. 9, 1921.

Application filed August 6, 1920. Serial No. 401,642.

T 0 all whom it may 001mm" Be it known that I CARL P. OLSON, acitizen of the United states, residing in the town of Irvington, county of Essex, and State of New Jersey, have invented certain new and useful Improvements in Processes of and Apparatus for the Manufacture and Handling of Metallic-Leaf Films, of which the following is a specification.

This invention relates to a process of manufacture of imitation gold or silver leaf or the like and to apparatus for the practice of such process, and for handling the leaf as produced, and to the improved leaf obtained therewith.

Gold leaf is used extensively in the arts for embossing and 'gilding, and particularly for stamping titles and ornamentations upon book covers. Pure gold leaf, as so used, is of a thickness not greater than one ten-thousandth of an inch. This degree of fineness is required in the art to secure that frangibility of leaf requisite to produce sharply defined margins when letters or other designs are stamped therefrom upon leather or other like substances by means of dies. It has been an object long sought to produce commercially a leaf in imitation of those of the precious metals which should have as close an approximation as possible to the extreme tenuity characterizing them, while also preserving the requisite opacity of the solid metal. Imitation metallic leaf has been made commercially, using bronze powder as the metallic base, of a thinness of one four-thousandth (1)0025) of an inch. Such leaves have been made by coating a glass or the like surface with a volatile liquid as a carrier for the bronze powders held in suspension therein, the volatile liquid being alsoa solvent of nitro-cellulose which, after evaporation of the volatile solvent, remained with the bronze powders and acted as a binder therefor. Such imitation metallic leaves simulating gold and silver leaf have been made either by painting, dipping or sprayin the glass or similar polished support, thinly to coat it with theleaf-forming material, comprising a binder of nitro-cellulose and bronze powders, the term bronze powders being generic to finely divided base metals; also by floating the like suspenslon upon a water-bath. Leaves so made have surpassed in thinness those possible of manufacture by coating a sheet of tissue or the like permanent back to be incorporated in the leaf, as Well as those built up from successive layers of materials as by first coating a support with an adhesive and then powdering the binding coat, as well as those made by heating or rolling thebase-metals. All the above recited processes also have their commercial limitations as to size of leaf producible. One of the objects of the present invention is the production upon a commercial scale of imitation gold leaf in endless lengths as a continuous process with apparatus that functions automatically. 0nd object is the production of a leaf of greater thinness than heretofore producible upon a commercial scale. Further objects sought are the production of a leaf which shall have such a degree of opacity that the covering effect of the thicker leaf shall not be sacrificed, 'while the removal of the surplus material after embossing or stamping shall be easier and more certain by virtue of the extreme tenuity of the leaf, and shall render unnecessary either the incorporation of any brittling agent to the leaf-forming mixture to facilitate the clearing off of the surplus leaf, or the scrubbling which bookbinders customarily are otherwise forced to resort to when the leaf is tenacious. Other objects will be pointed out in the ensuing specification.

To these ends, my invention consists, first, (in a rocess of leaf-formation comprising essentially the steps (a) of overcoming the tendency of the heavier bronze powders to settle out of a leaf-forming solution by counteracting the, effect of gravity upon the liquid suspension; (7)) of applying this suspension, unusually rich in bronze and of substantially unvarying homogeneity, as a coating of minimum thinness "to a film-forming carrier whereby a leaf is produced of great tenuity and opacity; (0) of accelerating the evaporation of the volatile solvents by application of currents of heatedair to the coatmgato romote the film-formation.

y mvention' consists, secondly,- in the provision of substantially automatic means adapted to perform these several successive steps of the process, consisting essentiall of a source of power for driving the severa operative elements constituting the apparatus of my invention in timed relation, respec- Asec-- tively as follows: A stirrer in a tank of leafforming composition; a pump adapted to withdraw the composition therefrom and to supply it to a dipping roll which coats a moving carrier; means for varying the speed of said roll; a film-forming drum engaging said roll and means for regulating the speed of said drum; a leaf-removing roll cooperating with said drum; all the foregoing elements being driven indirectly from the said source of power; and means for heating preferably dry air; means causing said aircurrents to circulate over the drum, and to vary their volume and rate. In addition to the foregoing semi-automatic apparatus adapted to form and handle a continuous film in unlimited lengths, my invention consists in means for adapting said apparatus to form and handle leaf of any desired width up to the width of the drum, whose width is a matter of commercial design; and in the provision of means for handling the formed film ready'for cutting in desired lengths.

My invention finally consists in the novel product resultant as a leaf of unlimited length, of a thinness approximating one tenthousandth of an inch (.0001) and of a density and opacity simulating that of pure gold leaf, being characterized when viewed mlcroscopically by a disposition of its con stituent bronze .resembling lamination of the flaky particles, by unusual freedom from streaks, such as result from flowing on glass, and from. air-holes, such as result from floatmg on a bath, and from irregular distribution of the powder, such as results from the intermixture of non-volatile ingredients, and by unusual luster and brilliance due to the high percentage of the metallic ingredient incorporated in the transparent binder.

In practising the above outlined process in its preferred form, I employ the apparatus illustrated in the accompanying drawings forming a part of this specification and 1n wh1ch Figure 1 shows in elevation and principally in vertical section a leaf-formmg and conveying apparatus. Fig. 2 is a' plan view on the line IIII of Flg. 1, the

' drum casing being broken away and underlying parts being shown by dotted outlines. Flg. 3 is a like View on the line III-III of Fig. 1, showing the mixing tank, the coatmg roll, the cleaning rolls, the removal roll and conveyer. Fig. 4 is a vertical view, on the hue IV-IV of Fi 1, partly in section, showing the drum, t e conveyer and the driving means for each and the removal roll. F i 5 is a vertical View, on the line V-V of ig. 1, and partly in section, showing the mlxlng tank, pump, supply tank, coating roll and drum. ig. 6 is a detail view on the line VIVI of Fig. 1, showing one of the cleaning? rolls contacting with the drum. F ig. 7 isano ther detail view, on the line VI VII of Fig. 1, showing the steam-coil the means permitting interchangeability of these rolls. The same reference numerals are used to indicate the same or like parts throughout the several figures.

1 is a motor having upon its armature shaft the worm 2 meshing with the cogged wheel 3 whose shaft 4, suitably journaled in the framing of the apparatus, carries the cone-shaped member 5, over which runs the belt 6 to and returning around a second coneshaped member 7, the pair being reversely disposed to constitute a cone pulley adapted.

to vary the speed of its members by shipping of the belt by the shifter 8. An extension of the shaft 4 carries the belt 9 which in turn rotates the shaft 10 which in turncarries the beltll which drives a shaft 12 carrying the gear 13 engaging the bevel gear 14 mounted upon the shaft 15 extending downwardly and carrying the pad-- dles 16 for agitating the contents of the tank 17 having the outlet pipe 18 leading to the pump 19, comprising a rotatable springpressed vane 20 adapted to withdraw fluid from said tank, the vane being rotated about a shaft driven by the belt 21 from a pulley 22 upon the shaft 12. The pump 19 discharges through the vertically extended pipe 23 which empties into a V-shaped trough 24 having a return overflow connection 25 to the tank 17. The second member 7, of the cone pulley, has a shaft .26, suitably journaled in a bearing 27 on the frame 28, and terminated by a sprocket driving the chain 29 engaging a driven wheel 30 upon the shaft 31 upon which is mounted the rotatable drying drum 32 having the hub 33, skeleton 34 and periphery adapted to receive the film, 35. The shaft 31 also carries the sprocket wheel 36 by which the chain belt 37 is driven and in turn drives the sprocket 38 upon the shaft 39 which carries a drum 40 suitably journaled in the frame. This drLun carries the conveyer or. belt 41, which passes around a second cylindrical drum 42, suitably mounted in the frame. The film-forming drying drum 32 is surrounded as to the upper two-thirds of its periphery by a housing 43 extending below the periphery and in closing and practically sealing same against entry of air by suitable edging 44 of felt or the like. The housing thus affords a substantially closed chamber of diminishing height, the larger end terminating in a casing 45 surrounding a steam coil 50 having steam-connection 51 to a boiler not shown and a valved vent 52. An air drying medium is preferably employed to dehydrate the air circulating about the coil 50 and through the housing 43 to the narrowed vent end, below the axial plane of the drum, where the'housing is terminated by piping 53 connecting with and forming the entrance to a suction fan 54. The volatile fluid entering the casing as vapor at its larger end is under suction, induced by the fan connected to the piping, which draws the volatiles through the housing at a rate increasing as the cross sectional area diminishes.

The shaft 10 carries the lower member 66 of a cone pulley, the upper member of which, 67, is mounted on a shaft 68, a belt 69 con-- necting the two members. The front end of the shaft 10 is driven by the belt 9, and the rear end of the shaft 10 carries the belt 11, as before described; by shifting the belt 66, the rate of rotation of the stirrer and pump may be varied, the rate of the rotation of the shaft 68 being varied inversely by such shift of the shipper 70. Upon the shaft 68 is journaled a frame 71, supported upon the adjusting screws 72, mounted in the frame extensions 73. This rocking frame at its other end supports the coating roll 74 which is driven from the shaft 68 by the twisted belt 75 so as to rotate the coating roll in the same direction as the rotation of the drying drum 32. The shaft 10 also drives the belt 76 which in turn drives a series of drum-engaging rolls 77, 78 and 79, likewise journaled in the frame. The rolls 77 and 7 8 are brushes adapted to be rotated by the belt 76 in reverse directions to wipe the periphery of the drying drum. The roll 79 is a bufling roll, preferably of felt, to dry and polish the drum. A box 80 incloses these rolls to catch the dust or the like, if

any, removed by them. The speed of these rolls is controlled by that member of the cone pulley controlling the speeds of the stirrer and pump to accord therewith and is varied inversely as the speed of the coating roll which is controlled as to speed by the other member of the cone pulley, for purposes hereinafter developed. At the lower quadrant of the drum opposed to the coating roll is the take-off roll 81. This is a lazy roll, driven by peripheral contact with the film upon the drum. It is preferably of felt and j ournaled in the frame over a trough 82 holding a, wetting medium into which dip the rolls 83 journaled in the trough and which rolls contact with the roll 81, moisten-- ing it so that it in turn may adequately moisten the film which, when of cellulose base, will contract away from the drum and pass down the rectangular chute 84 whic guides it to the conveyer.

The operation of the apparatus described is dissolvable commercially as described in Letters Patent No. 992,743, in the ratio of two ounces of soluble cotton to three ounces of amylacetate and one pint of benzin, I prefer to increase the ratio by employing two pintsof amylacetate to one ounce of cotton. The preferred proportions are, by weight, one ounce of soluble cotton, dry, and eight ounces of bronze powder of the grade known as finest pale gold, or, substantially 10 per cent. of cotton to 90 per cent. of powder. This mixture is one that flows freely when solvent of the cotton is in excess of the amount needed to effect its solution. With this mixture, the speed of revolution of a drying drum five feet in diameter should be approximately five feet per minute, or revolution per minute, with a drying temperature between 150-180 Fahr. The belt 6 having been adjusted to deliver the correct rate of drum-rotation, the tilting table 71 is adjusted by the screws 72 so that the coating roll 74 affords a minimum clearance between its surface and that of the drying drum 32. The film-forming periphery of this drum is preferably of hard, polished material. In practice, burnished has been successfully used with a coating roll of like metal. The temperature having been established by the coils 50 and the suction fan 54 being in operation, the belt 69 is initially regulated by hand, so that, with a given solution the stirring and pumping may be more vigorous for a heavy solution, and the speed of the coating roll proportionally slower, the rates adapted to produce the best results being matter determined by the fluidity of the leaf-forming mixture. This mutual dependence is due to the discovery that a mixture high in bronze may be used to make a denser leaf if the suspension of the bronze is maintained during the coating process. To this end, an active agitation of the mixture in the tank is necessary and the pumping thereof from near the base of the tank is desirable, as well as a pumping action that will drive the mixture up to the roll in a constantly ascending column rich in suspended powder. This rich mixture is taken up by the coat ing roll, and due to its viscosity a layer of the mixture adheres thereto of approximately one-fourth inch in depth, with which layer the drying drum contacts. By locating the coating roll below the drum, the line of their closest approach is below the axial horizontal plane of the drum and above copper.

the axial horizontal plane of the roll, and this relative location of the two cylindrical surfaces permits gravity to act upon the layer of solution to thin it, and thus the desired object of yielding the thinnest possible continuous film is promoted. Other expedients, as by dipping the drying drum directly into the mixture or using-a coating roll above the horizontal medial plane of the drum, result in the deposit of superfluous material'which adheres to the drying surface and desired. I

With a coating of the thinness attainable with the apparatus and by the process described, the film dries with great. rapidity under the current of air whose volume is diminished as its rate of motion is accelerated by the narrowing channel afforded by the form of the casing and the suction of the fan, and is delivered as a ribbon-like sheet in substantially endless length, to the conveyor upon which it is deposited as a continuous film, ready for cutting and immediate packaging without the need of rehandling, as in the present practice. In lieu of a conveyer, the film may be received upon any suitable support, but I prefer the conveyer shown, as it affords opportunity for inspection of the film and permits its readier control.

Having thus explained the principles of my invention and the best mode now known to me of applying same, and believing these principles to be capable of application by other means than those shown and described, I do not wish to be understood as limiting the scope of my invention to the structural embodiment of means illustrated, nor to the particular methods of operation set forth, save as my preferred practice.

In the appended claims, the term leaft is employed to designate the imitation metallic leaf as used commercially, resulting from the cuttin up of the film to desired sizes; the term 1m is employed to denote the continuous web formed in endless length by the drying of the composiion coated upon the film-forming drum; and the term coating to denote the composition as applied to the drum prior to hardening by evaporation into'a film. It may also be noted that the term bronze powder is used in its generic sense.

Having thus described my invention, I claim:

1. The process of forming imitation metallic leaf as a continuous film, consisting in agitating a film-forming suspension of bronze-powder to such degree that the powder does not appreciably settle in the suspending medium; dipping said suspension while in an agitated condition, applying produces a thicker-coating than same as acoating to a revolving surface on v a line lower than the axis of rotation of said surface, subjecting the coating so formed to a current of preheated air, and removing the resultant film while the surface is revolving.

2. The process of forming imitation gold leaf as a continuous film, consisting in agitating a film-forming suspension of bronze powder, delivering same while undergoing agitation to a rotating distributer, delivering same therefrom to a revolving surface, subjecting the coating so formed to a current of preheated air and removing the dried coating from said surface as a film of unlimited length.

3. The process of forming imitation goldleaf in unlimited lengths consisting in agitating a film-forming suspension of bronze powder, delivering same in an ascending stream to a distribute'r, coating same upon a rotating surface, subjecting the coating so formed to a current of preheated air, and removing the dried film from said surface as a continuous film.

4:. The process of forming imitation goldleaf as a continuous film'of unlimited length and of thinness and density approximating that of gold-leaf, consisting in coating a rotating surface with a substantially homogeneous and rich suspension of bronze-powder in a solution of nitrocellulose, the proportion of solvent being largely in excess of that necessary to dissolve the nitrocellulose and the quantity of the powder being by weight in excess of both, driving off the solvent with a moving volume of preheated air in contact with the surface of the coating, causing the outer surface of the dried coating to contract by wetting, and continuously stripping said coating as a film from the rotating surface. I

5. The process of making imitation metallic leaf from a suspension of bronze powders in a solution of nitrocellulose, consisting in coating a revolving surface with the suspension, drawing a current of heated air over said coated surface at aconstantly accelerated rate of motion while in contact with-said surface, and confining the air during its contact with said surface.

6. In an apparatus for producing imitation metallic leaf, the combination of a revolving film-forming drum, a motor adapted to drive same and an adjustable speed-varying element between the two; a film-composition tank having an agitator therein and a connection to a pump adapted to withdraw the composition from said tank and to raise it to a reservoir adjacent said drum, and an overflow return from said reservoir to said tank; a shaft driven indirectly by said motor and in turn driving a gearing operatively connected to said agitator. and to said pump and an adjustable speed-varying element between said shaft and said gearing; the two said speed-varying elements being mutually responsive, and an adjuster adapted to control said elements simultaneously.

7. In apparatus for produ cing imitation metallic leaf, in combination, a' film-forming revolving drum, means adapted to coat the periphery of said drum with a film-forming solution, said means being located below the horizontal plane of the drum and including a pump adapted to cause an ascending strgam of said solution to be supplied to said coating means, a housing inclosing the upper half of said drum, a heating source adapted to supply superheated air to said housing, and meansadapted to draw said air from said heating source through said housing and in contact. with the film upon the periphery of said drum.

8. In an apparatus for making imitation metallic leaf, the combination of means adapted to supply a film-forming solution continuously to the periphery of a revolving drum as a thin coating, said means comprising a revolving cylinder the axis of which is parallel to the axis of the drum and the periphery of which is spaced apart from the periphery of said drum, with means adapted to revolve both said drum and said cylinder at independently regulable speeds and means adapted to vary the spacing between the two peripheries, cylinder being of relatively small diameter and located below the horizontal axial plane of the drum and approximately theregrom upon the upwardly moving side.of the rum.

9. In an apparatus for making imitation metallic leaf, the combination of means adapted to supply a film-forming solution continuously in an agitated state to a revolving cylinder located adjacent to and bus imitation metallic film as the said,

the suspension so dipped to a beneath a revolving cylindrical drum, the axes of revolution of said cylinder and drum being parallel and adapted to turn in the same direction, means adapted tovary the distance between said axes, means for driving both, and a speed-controlling means interposed between said driving means and said drum and cylinder adapted to vary their relative speeds inversely.

10. In apparatus adapted to form imitation metallic leaf as a continuous film, means adapted to coat a predetermined width of the periphery of a revolving drum with a film-forming solution containing a volatile solvent, said drum and means for driving same at predetermined speed, a source of heated air, and means adapted to cause the circulation of said air successively channel leading from through an inclosed over the periphery of said heating source,

said drum, and through an exhaust in diminishing volume and at an increasing rate.

11. The process of forming a homogenea continuous fabric consisting in mixing bronze powder with a film-forming solution, agitating the mixture until substantially all 0 the bronze powder is suspended by'the solution, continuing this suspension agitation during the dipping step ensuing, dipping the suspension while undergoing agitatlon, applying continuously revolving film-forming surface on a line below the horizontal axial plane on the rising quadrant of the revolving surface, circulating a current of preheated air over the film-coating so applied to the revolving surface and in contact therewith for more than half its revolution, dried fihn therefrom while revolving.

I CARL P. OLSON.

and removing the 30

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