US2344603A

US2344603A - Machine for making cellulose sheets and the like

Info

Publication number: US2344603A
Application number: US350289A
Authority: US
Inventors: Czapek Emil
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-08-03
Filing date: 1940-08-03
Publication date: 1944-03-21
Anticipated expiration: 1961-03-21

Description

E. CZAPEK 2,344,603 MACHINE FOR MAKING GELLULOSE SHEETS AND THE LIKE March 21, "1944.

2 Sheefs-Shet 1 w ww Filed Aug. 3, 1940 March 21, 1944. CZAPEK 2,344,603

1 MACHINE FOR MAKING CELLULOSE SHEETS AND THE LIKE Filed Aug. 3, 1940 2 Sheets-Sheet 2,

INVE NTOR f/n/L CZHPEK ATTORNEY Patented Mar; 21, 1944 UNITED STATES,

PATENT OFFICE Emil Clapek, New York, N. Y.

' Application Allgllit 3, 1940, Serial No. 350,289

10 Claims.

This invention relates to machines or devices for producing improved cellulose sheets, films or the like. The application is a continuation in part of my co-pending application Serial No.

lation has been completed and the coagulation bath has penetrated the sheet to the pouring base. The film after removal has practically the same length and width as the formerly spread 158,746, flied August 12, 1937 issued as Patent No. solution and furthermore does not change these 2,234,964 on March 18, 1941. dimensions in the following bath.

7 Among the objects of the present invention, In the embodiment shown in Fig. 1, there is it is aimed to provide an improved machine for provided a feeder or nozzle for feeding or spreadproducing an improved cellulose sheet, film or ing a viscous cellulose solution directly onto a the like of an exceedingly uniform physical strucsupporting base enable the solution effectiveture throughout having a practically equal ten- 1y to attach or adhere to the supporting surface sion and shrinkage characteristic in length as and" thereupon effectively spreading the solution well as in width. into a thin layer. In the present instance, the It is still another object of the present invensupporting base is. the face 2 of the drum 3, tion to provide animproved machine for producwhich, however, also may consist of an endless ins an improved cellulose sheet, film or the like band or belt. of an exceedingly light thickness without stria- The drum 3 is rotatably mounted on the shaft 'tions and the like and having a width of forty. 4 extending through the trough 5; the arcuate inches or more by means of a continuously operwall 6 of which is spaced from the face 2 a uniating process. form "distance throughout, while the end faces It is still another object of the present in.- of the drum 3 are preferably closed and in envention to provide an improved machine for progagement with the plane end baflles Iv of the ducing an improved cellulose sheet, film or the trough 5. The drum 3 is preferably provided with like of unusual thickness with an exceedingly a metal cylindrical wall member-to provideothe uniform physlcaistructurelthmughout. supporting face 2, thewall being composed as an iThes'e afidbther features, capabilities and adinstance oif either iron, steel, nickel or the like, vantages of the present invention will appear or the wall provided with a coating of nickel, from the sub-joined detail description thereof chromium or the like and then either highly illustrated in the accompanying drawings, in polished to form a glossy or glistening surface, which or else dull finished or a graduation of one or Figure 1 is a side elevation more or less die the other according to the surface finish of the grannnatically of one embodiment; film, sheet or the like to be produced.

Fig. 2' is a side elevation of the feeding de- The cellulose solution is introduced by the vice used in the embodiment of Fig. 1; hopper .or nozzle l to the surface 2 of the drum Fig; 3 is a fragmental transverse section of the 3, the hopper I having along narrow feeder disf din device shown in Fig. 2; charge 8, the opening of which is adjustable by Fig. 4 is a side elevation more or less diathe ivotally mounted wall member 9. g a c y another embodiment; When enlarging or. narrowingtthe discharge Fig. 5 is a fragmental plan of the embodiment opening by shifting the wall part 9, accordingly wn n FIE- 4; more or less cellulose solution will now through Fig. 6 is a front elevation of one of the conveyor supporting idlers used in the embodiment of Fig. 4; and

Fig. '1 is a sectional view on line 7-1 of Fig. 3.

The present invention essentially uses a pour-v ing base onto which a viscous cellulose solution such as a cuprammoniumcellulose solution is poured evenly by means of an exact fitting nozzle or feeder. Thereupon, the solution which adheres to the base and cannot be subjected to stretching or'extending, passes by moving or M tating at the base into a coagulation bath. In

the coagulation bath which is in continuous movement. the p r d sheet l be agulated to a strip and only then removed when the coagucall? adjustable n pl tc'cj' or baffles Ml ha ing.

the opening 8 onto the pouring base 2. The hopper itself is supported in a bracket or in two levers I! which are pivotally connected to rotate about the two pivots IS on the frame constituting a part of the wall 6 and are provided'with two rollers l4 resting on the edges of thedrum I. The hopper is adjustably mounted in the bracket l2 and rests on the pouring base by means of two rotating rollers M6. The position of the hopper is regulated through screw ll.

In order to prevent any vagrant discharges 'from the sides of the feeder l for the several adjustments possible, there'i-are provided the vertivertically extending slots I88 cooperating with the wing nuts I49.

Attached to the lower edge of the wall it of the nozzle is a blade bar i5 which has been tapered into a knife-like edge and by a set of screws l6 and 160 the position thereof may be adjusted. The adjustment must be to the finest extent and very exact, as the thickness of the film is adjusted and regulated hereby.

The thickness of the finished film is determined by the amount of cellulose solution 20, which the knife-like lower edge of the blade l5 leaves on the pouring base 2.

The width of the slot 8 of the feeder will be adjusted through changing the position of wall a to insure supplying onto the base 2 sufficient cellulose solution in advance of the edge of the blade l5, so that the cellulose solution will be sufflciently and edectively spread out on the pouring base 2 below the feeder. The position of wall 9 is adjusted by actuating the eccentric 590. The width of the opening of the feeder l depends upon the thickness of the film to be manufactured, on the velocity of the drum 3, and on the viscosity of the cellulose solution.

The drum rotates in the direction of the arrow H6. The cellulose solution is spread directly on the dry surface by rotating the drum 3, without passing through a free intermediate space and thereupon passes into trough 5 and is here coagulated by the fluid contained therein. The position of the hopper l is such that the blade H5 in advance of the slot 8 is disposed below the upper level of the drum 2 and on the side of the drum 2 with reference to the arrow HG so that it will cooperate or is operatively associated with a downwardly moving portion of the surface of the drum 2 relative to the upper level of the drum 2 to enable accumulating the supply medium on the drum and toprewet the surface of the drum 2 before the surface so wetted comes beneath the lower edge.of the blade l5.

The trough 5 will be supplied with a treating fluid introduced through the inlet H with a treating fluid consisting essentially of sodium hydroxide, ammonia and copper, which is discharged through the outlet liif It will be noted that the inlet I1 and the outlet l8 are disposed at the upper level of the fluid in the trough 5 and at the opposite ends thereof, the inlet ll jfist below the position where the film 19 leaves the drum 3 and the outlet i8 a short distance below where the solution 20 is initially poured on the outer face 2 of the drum 3.

The concentration and the velocity of 'thefluid flowing through trough 5 is determined by the The thus produced sheet orstrip l9 may be removed from the surface 2 without difhculty. It is completely coagulated and still of the same length and width as at the beginning of the process. The strip 89 passes now for a short time 10 through another trough containing a coagularoller 2! from which. it 'passes into the container 22 so that the face of the layer heretofore in engagement with the face 2 of the drum 3 may now be effectively coverecL with a, coagulation fluid similar to that contained in the trough 5.

In order effectively to dry the surface 2 and thereby remove any deposits, moisture and the like either from the strip H9 or from the trough 5 after the strip passes onto the roller and in the area of. the surface 2 disposed between w the roller 2i and the nozzle I, there are provided scraping means, such as the scrapers M2 and i M3 consisting in the present instance of the blades pivotally mounted on the shaft M4 and M5 so that as here shown they rest by gravity on the surface 2 and in opposition to the direction of movement of such surface 2.

After leaving the roller 2i and in order to facilitate guiding the strip l9 through the bath 23 in the container 22, the strip next passes down under the roller as near the lower end of the container 22, then up above the roller 25 before-being passed into the water 28 in the next container 29 where any of the'bath fluid adhering to the outer faces of the strip is is 5 now effectively washed ofi and some of the coagulation bath fluid which has generated the strip or been diffused into the same will be diluted and removed in part. For convenience; the strip is after leaving the roller 2'! first passes around the roller 30 adjacent the lower end of the tank 29, then around the upper roller 3!, again down around the lower roller 32, again up and around the upper roller 33, again down and around the roller 36 and then up out of the tank 29 around the roller 35 before being introduced into the components of the influential solutions and fluids,

hereinafter set forth in detail.

The film layer l9 will adhere to the surface 2 of the drum 3 during the entire coagulation process and does not permit that any part of the fluid in trough vl5 penetrates between the face 2 and the adhering surface of the layer l9. Only after the coagulation has been completed, will the coagulation fluid penetrate through the coagulated layer l9 and thereby arrive at the surface 2 of the drum 3 which it now wets. Furthermore, oniy. -after this has been accomplished will the sheet Is be taken from the drum 3.

For a proper coagulation of layer l9, it is important that the coagulation fluid in trough 5 flows past layer N. In order to effect a good flow or movement of the fluid, trough s-is so shaped that only a small space intervenes beacid bath 36 contained in the tank 31.

The strip is will be guided into and out of the acid bath 35 by means of the rollers 38 to 43 inclusive, in the manner well known in the art, where the strip I9 will be regenerated and the copper effectively removed.

After the strip l9 has been completely freed of the copper, it is now passed through several baths of clean, clear water and impregnated with softeners or plasticizers and dried. For

drying the strip 89, the same is passed either through a well-known drying cylinder, not shown, or subjected to a stream of warm air supplied by a suitable blower or the strip subjected to a 7 combination of .both such drying treatments.

Preferably, in the embodiment just described, as shown in Fig. l, the inlet 44 is connected to an extended tubular spray I50 having a plurality of branches extending adjacent to the path of tween the pouring face 2. and the opposite wall of g is movement ofthe strip l9 and provided with disdroxide in'the proportions heretofore recited and dissolving'the other agents by the coagulation ofcharge openings directed at the face of the strip I9 In the embodiment illustrated in Fig. 4, instead of permitting the strip here designated I I9 to extend freely from'one rollerto the other, while passing through the secondary coagulation bath I23 in the tank I22 and while passing through the water I28 in thetank I29, it will Ib supported on the'endless band 46 with the surface of the strip II9 exposed which formerly adhered to the face I02 of the drum I03. when so supported on the endless band 46, it

will be noted that the rollers I40 in the lower portion of the tank I22 will be chambered at I so that the exposure of the face of the strip III here sought will not be interrupted.

Furthermore, in this embodiment, instead of permitting strip II9 to extend freely from one roller to the other while passing through the acid bath I36 in the tank I31, it will here pass directly from one roller to another, see the upper row of .rollers 41 and the. lower row of rollers 48 staggered relative to one another and overlaption bath absorbs the ammonia. and the copperof the cellulose solution at once and the concen-- ping one another effectively to support the strip II9 throughout its passage through the tank I31.

Here, too, the acid bath is constantly being renewed and being fed to the several inlet pipes- 49 with discharge openings directed at the faces of the strip II9, as they pass from one roller to the other. The tank I31 is also provided with an outlet 50 to permit the bath fluid to pass therefrom so that the copper, if in excess of five 'per cent, may be removed therefrom and fresh acid supplied to the predetermined concentration.

It is of course obvious that the

baths

23 and 29 as well as the baths I23 and I29 may .be renewed continuously as well as the other baths.

, While it is desirednot to be limited to the proportions, hereinafter set forth, it is claimed that the proportions here used in the process disclosed and machines used are new and particularly advantageous.

As an instance, excellent results have been achieved when the steps now to be described and proportions indicated are selected.

First, it is well to note that it is desirable to observe the chemical proportions hereinafter set forth so that the coagulation may take place correctly and tension-free into the inside of the solution in order to facilitate faultlessly removing the finished strip I9 from the base 2 when the strip has already so solidified that there will be no disadvantageous changes by the ensuing treatments in

tanks

22, 29, 31 and the like.

The solution 20 introduced through the nozzle I consists essentially of an amount of cellulose corresponding to 5 to 8 per cent by weight of the entire solution, an amount of ammonia corresponding to 45to 85 per cent by weight of the cellulose content, an amount of co per corresponding to 36-to 43 per cent by weight of the Y of 0.1 to 1.2 per cent by weight of the bath.

The easiest manner of adding the agents supplementary to the sodium hydroxide is by starting the process with a coagulation bath of sodium hya smaller ,amount of the cellulose. The coagulatration of the proportions in-this way will be quickly standardized which has to be observed during the process.

The transformation of the, cellulose solution 20 -into a solid strip is done by dipping the pouring base 2 covered with the layer ill by rotatingor other movement of the base 2 into the coagulation bath in trough 5. Themellulose layer I9 is here coagulated from one side while the'other side adheres closely and unmovably to the base. 2 until the coagulation is completed.

.The effect or rather the changes which take place in the layer I9 while passing through the trough 5 with the recited' proportions of the ingredients both in the solution and in-the 'fluid' constitute the important steps in the process for obtaining uniform and tension-free strips. It has been found essential and advantageous that the ammonia which during the oagulation difluses from the cellulose layer I9 into the coagulation fluid'inthe'trough 5 is'immediately .washed out. Therefore, it. is better that the coagulation fluid passes in a stream along the solution layer I9 throughout its entire extent and in an opposite direction to the movement of the pouring base 2.-

Only by-maintaining the coagulation bath in motion in this way can the ammo'nia content be watched so that a. detrimental accumulation o the boundary surface will-be avoided.

The rate of flow of the fluid through the trough 5 will be determined by the respective components or ingredients of the solution introduced through the nozzle I, the ingredients of the fluid in trough 5, the velocity of the movement of the base 2, the

thickness of the layer I9, and finally the extent 7 and width of the fluid passage formed by the trough 5 and the base 2. Therefore, when the velocity of the now is proper, it will be. possible to maintain the total concentration of the ammonia in the coagulation fluid below 0.8 per cent by weight, and the risk of a detrimental accumulation of ammonia on the boundary surface or in pockets will be avoided.

Since duringthe process by continuous coagulation "additional quantities of ammonia will steadily enter into the coagulation bath from the cellulose layer, the ammonia has to be continuously removed from the coagulation bath so that the concentration of ammonia will not exceed 0.8

per cent by weight. This is accomplished as an instance when the fluid isremoved from trough 5 through the discharge I8, the ammonia thereupon distilled off so that it will again be reduced weight ofthe fluid.

to 0.1 to 0.5 per cent by weight of-the fluid and this fluid then cooled off and returned to the trough 5 through the inlet. II. j

The accumulation of copper in thefluid content of the trough I can ordinarily be ignored if care is exercised occasionally to remove the cop-,

per content when it exceeds 0.1 to 1.2 per cent by The next step will be the washing of the its I9 in order to rinse oil the adhering part'of'the coagulation fluid as well as to dilute and partly remove the coagulation fluid seeped into the strip I9.'

- The rinsing or soaking of the strip I latter it has been removed from the-base 2,. eventually.

as set forth passes a second coagulation bath when it will be subjected'to a bath'of either-water or a weak solution of sodium hydroxide. The rinsing may only be continued until the constituents of the strip 89 have been reduced to 20 parts by weight of copper, 3 parts by weight of ammania, and 22 parts by weight of sodium hydroxlarit ies, striations and the like.

The washed film thereupon ispassed into an acid bath in which the cellulose will be entirely regenerated and the copper will be removed from the strip. It has been found advantageous to use a sulphuric acid bath of more than 2 and less than 5 per cent by weight at temperatures of more than '75 and less than 125 degrees Fahrenheit.

In this bath the shrinking of the strip takes place initially. Hereby a satisfactory uniform treatment of the strip IS without inducing any tensions, shrinkages Or the likein the same can be obtained, if the preliminary coagulation. and washing has been done in a careful manner, and the concentration, temperatures and the like have been followed closely, as mentioned.

Preferably also the bath 36 is being continually renewed, the bath fluid entering the tank 31 through the inlet 44 and leaving the tank 31 through the outlet 45 so that the bath fluid :flows past the strip i9. -.In order to have the acid solution spread uniformly onto the strip, the inlet ll is connected to an extended tubular spray 46 and branchways. The copper dissolved in the acid solution will be removed from the fluid which is discharged through outlet 45, and the fluid will again be replenished with fresh acid and reheated to the desired temperature. The copper content of the acid solution should not exceed 5 per cent by weight of the bath fluid.

After the stripl9 has been completely freed of copper,it is now passed through several baths of clean, clear water-and impregnated with softeners and plasticizers and dried.

Strips made according to the present process and by the present machine are characterized by not having been stretched, extended-or shrunk to anyappreciable extent during the process of coagulation and washing resulting in a uniform physical structure throughout, free from striations, streaks and irregularities of any kind.

0n account'of the uniform treatment on the base in the first stage of the process when the transformation from the liquid into the solidified state takes place,'the process is especially suited for the manufacture. of thin strips and has been developed'especia-lly for this purpose.

In accordance with present process, it is possible to manufacture strips not only having a weight of less than 0.35 ounce per, thousand square inches, but also having a weight of less than 0.20 ounce and less than 0.10 ounce per thousand square inches, all characterized by being without striations,'streaks and irregularities of any kind.

However, this process is also suited for the.

a sufilcient supply has been received by and supported onto said surface without any free air space between the nozzle, layer and dry supporting surface. In other words, the thickness of the layer being spread out efiectively fills up the space between the. nozzle, spreading blade is and the supporting surface 2. I

It is obvious that various changes and modifications may be made to the details of construction without departing from the general spirit of the invention as set forth in the appended claims.

What I claim is:

1. Thecombination with'a movable support of a pouring device adapted for the production of thin films having a thickness uniform in the length and, in the width by pouring a cellulose solution on said support including a hopper for containing a cellulosic solution adjustably disposed on the edges of said support and having an elongated feeder at its lower end, the feeder having a discharge opening operatively associated with said support, a blade extending the entire width of the feeder and adjustably connected Y to said. feeder, and end baffles adjustably conmanufacture of unusually thick films. As the coagulation of thick layers develops very slowly, it is necessary to retard the velocity of the drum 3 so that the coagulation may be finished on the base. Since, however, the coagulation in this process always takes place on the base, it is uniform and without tensions and stretchings. Therefore. this process is also particularly adapted nected to the sides of the hopper for engaging the surface of said support and extending parallel to the path of movement of said support.

2. The'comblnation with a movable support of a pouring device adapted for the production of thin films having athickness uniform in the length and inthe width by pouring a cellulose solution on said support including a hopper for containing a cellulosic solution, two pivotally mounted levers having their free ends engaging said support, said hopper being adjustably suspended by said levers and having an elongated feeder at its lower end, the feeder having a discharge opening adiustabie for controlling the escape of the cellulose solution, a blade extending the entire width of the feeder and adjustably connected to said feeder, and end bames disposed at the outer sides of the hopper, extending parallel to the path of movement of said support, and adjustably connected for engaging the surface of said support independently of the predetermined position of the feeder and the blade.

3. The combination with a movable support of a pouring device adapted 'for the production of extremely thin films having a thickness uniform in the length and in the width by pouring a cellulose solution on said support, including a hopper for containing a cellulosic solution adjustably disposed on the edges of said support and having an elongated feeder at its lower end, the

justably disposed on the edges of said support and having an elongated feeder at its lower end and a movable back wall, the feeder having a discharge opening operatively associated with said support, means to regulate the opening of the feeder discharge to control the escape of supply medium by moving said back wall, a blade extending the entire, width of the feeder, means adjustably connecting said blade to said feeder ,at several points for precisely regulating with uniformityv the distance between the lower edge of the blade and the surface of said, support throughout the length of the blade, and end baffles adjusted on the outer sides of the hopper and extendin parallel to the path of movement of said support, to effect the closure of the space laterally between the feeder discharge, the blade and the surface of the support immediately adsurface of said drum, said .device including a hopper having an elongated feeder and a regulatable' outlet at its lower end, and having two supporting rollers engaging the surface of .the drum, a blade adjustably connected with the feeder at several points on the advance side of the feeder' and operatively associated. with the surface of the drum for spreading the deposited solution evenly in a thin'film layer, the discharge edge of the blade being in substantial alinement with. the contact points between said rollers and drum, means for precisely regulating with uniformitythe distance between the lower edge "of the blade and the surface of the drum independently of the position of thehopner, and end baffies adjustably connected to the feeder at its sides to prevent any vagrant discharge from the sides of the feeder.

6. Thecomblnation of a frame, a coagulating bath, a drum rotatably mounted in said bath with 'a. segment of said drum exposed, levers pivotally connected to said frame having rollers at their free ends engaging 'the surface of said drum, ahopper mounted above the exposed portion of said drum, adjusting means for adjust- 'at'ed with a downwardly moving portion of the drum surfacelto accumulate-the supply medium -on and pro-wet the drum surface before said surface comes beneath the feeder discharge openin and a sharp edge blade adjustably connected to the advanceside of thefeeder at sevoral points to spread out the supply medium accumulated on. the drumsurface evenly to a uniform film layer. 1

- I: The combination of a coagulating bath, a-

1 drum. rotatably .mounted in said bath with a segment of said drum exposed, a hopper including a feeder at its lower end, mounted above and spaced from the exposed segment of said drum, said hopper having a movable back wall and the feeder having a discharge opening operatively 5 associated with a downwardly moving portion of the drum surface permitting the supply medium after passing the discharge opening to accumulate on and pre-wet the drum surface-before said surface comes beneath the feeder discharge opening, a tapered blade at the advance side of the feeder discharge openingand means adjustably connecting said blade to said feeder at several points to facilitate precisely regulating with uniformity the distance between the lower diminished edge of the blade and the surface of said drum throughout the length of the blade to spread out the supply medium accumulated on the drum surface to a thin mm layer. 8. The combination of a coagulating bath, a drum rotatably mounted in said bath with a segment of the drum exposed, a feeder having a discharge opening operatively associated with said drum,- means for adiustably mounting said feeder toposition the discharge opening above the downwardly moving portion of the drum surface, a blade adjustably connected to the lower end of the feeder at the advance side of the feeder, means for precisely regulating with uniformity the distance between the lower edge of the-blade and the surface of said drum portion, e'nd baffles connected to the sides of the feeder and extending parallel to the path of movement of the drum surface,-and means for adjustably connecting said end baflies to position said end baffles in effective engagement with said drum surface independently of the predetermined position of the feeder and the blade to effect the closure laterally of the space between 40 the feeder discharge opening, blade and drum surface.

9. The combination of a movable supporting base, a feeder adjustably disposed on the lateral edges of said supporting base and having its discharge end disposed at the base, a blade adjustably connected with the feeder on the advance .side of the feeder discharge opening, end bailles adjustably connected to the sides of the feeder effectively to engage the surface of the face throughout their widths and bounding both ends of the blade and of the lower end of the feeder discharge opening; all. to enable supplying a cuprammonlum cellulose solution directly onto said supporting base and to enable spreading such solution, so accumulated between the discharge opening, the blade, the baflies and the supporting base, into a thin layer on the base, a coagulation bath for carrying out the coagulation of the cellulose solution, the received layer being supported by said movable base during the coagulation treatment in said bath, and means for detaching the coagulated cellulose structure 4 from the supporting base after the. cellulose structure passes .out of the coagulating bath.

1 0. The combination of a metallic cylindrical -rotatable supporting base having a highly polposed at the base, a blade adjustably connected with the feeder on the advance side of the feeder discharge, end baiiies adiustably connected to the sides of the feeder effectively to engage the sur- (5 face of the base throughout their widths and ished surface finish, a feeder adiustably disposed on the lateral edges of said supporting base and having its discharge opening end discoagulation of the cellulose solution, the received layer being supported by said movable base during the coagulation treatment in said bath,

and means for detaching the coagulated cellulose'structure from the supporting base after the cellulose structure leaves the coagulating bath.

I EMIL CZAPEK.