US1826697A

US1826697A - Apparatus for coating

Info

Publication number: US1826697A
Application number: US312041A
Authority: US
Inventors: William H Charch; Norman A Craigue
Original assignee: Du Pont Cellophane Co Inc
Current assignee: Du Pont Cellophane Co Inc
Priority date: 1928-10-12
Filing date: 1928-10-12
Publication date: 1931-10-06
Anticipated expiration: 1948-10-06
Also published as: FR682966A

Description

3 Sheets-Sheet 1 IH- l @NTC ATTORNEY W'. H. cHARcH ET AL APPARATUS Fon COATING Filed oct. 12 1928 Oct. 6, 1931.

W. H. CHARCH ET AL APPARATUS FOR COATING Oct` 6, 1931.

Filed Oct. 12,l 1928 3 Sheets-Sheet 2 IN'VENTO'RS Oct. 6, y1661. w. H. CHARCH ET A1. 1,626,697

A APPARATUS FOR COATING Filed Oct. l2, 1928 5 Sheets-Sheet 5 I im' uw, 5H". 66] 6h16,

' MQ/YMQTTORNEY Patented ct. 6, 1931 UNITED STATES VPATENT OFFICE WILLIAM H. CHARCH, F BUFFALO, AND NORMAN A. CRAIGUE, OF KENMOR, NEW

YORK, ASSIGNOBS, BY MESNE ASSIGNMENTS, TO DU PONT CELLOPHANE COM- PANY, INC., 0F NEW YORK, N. Y., A CORPORATION 0F DELAWARE APPARATUS FOR COATING Application lel october 12, 1928. Serial No. 812,041.

This invention relates ,to coating and more particularly to an apparatus for coating films, webs or sheets of cellophane (regenerated viscose) with a moistureproofing composition, such as set forth in copending application Serial No. 308,873, and comprismg a cellulose derivative, a wax, a gum or resin,

a plasticizer and a solvent or solvent mixture.

Cellophane produced in the usual cast- 10; ing machine has a bead on each edge which is two to four times thicker thanthe center parts of the film. In the usual methods of coating other materials, it was impossible to coat a cellophane film, sheet or web withlsi out having a lar e excessof coating material on the edges of ille film and a zone about six to eight inches in width adjacent said edges. In order to obtain a uniformly coated cellohane film, web or sheet by these processes 1t was necessary to cut away or trim the bead prior to coating.

We have found that we can eliminate and overcome this disadvantage by wiping or removing the excess coating material at the edges and zones adjacent the beads prior to` removing the excess coating material from the entire width of the cellophane film, web or sheet.

It has been found that by raising the temperature of the coating composition on the base as rapidly as possible to approximately the same or higher than the melting point i of the wax in the composition and by maintaining the applied coating compositionvin a homogeneous state until all the solvent is eliminated accidental blushing can be prevented.

When cellophane is heated, it has a tendcncy to lose some of its moisture and to become somewhat brittle. This also occurs when cellophane is coated with a moistureproofing composition as herein used and subsequentlv dried by evaporating thesolvent or solvent mixture in a heated atmosphere.

We have found that we can overcome this defect by subjecting the cellophane film, web or sheet to a humidifying action prior to and/or after the coating operation. If .are two ducts 17 which supply the humidiying action the last trace of the solvent will also be eliminated and the coated film'substantially deodorized.

It is therefore an object of this invention to provide an apparatus for moistureproofmg cellophane films, webs or sheets with a coatmg composition comprising a cellulose derivative, a wax, such as parafiin, a gum or re'sm, a plasticizer and a solvent or solvent mlxture to produce a substantially transparent, odorless, fiexible, non-tacky material.

Another object of this invention is to p'rovide an apparatus for carrying out a method whereinthe waxingredient is prevented from precipitatin out and producing a blush.

Another o ject of this invention is to provide an apparatus for providing a substantiall ane coating on cellophane having ,l bea ed edges without removing said beaded edges. c

still further object is to provide an apparatus having two' sets of doctor blades, whereby the disadvantages occasioned by the beaded edges of the cellophane are eliminated.

Further objects will appear from the following description, appended claims and accompanying drawings in which:

Figure 1 is a front elevation of the apparatus for carrying out this invention.

Figure 2 illustrates the arrangement of the doctor blade mechanism and accompanyin parts. i

igure 3 is a vertical section through Fig- -ure 2.

Figure 4 is a vertical section taken von line 4 4 of Figure 3 illustrating the larrangement 'of the doctor blades. l

Fi re 5 illustrates the casting on which ythe lade holder trunnion and clamp are mounted.

Figure 6 is a detail of the mechanism for moving the doctor blades apart permitting the machine to be threaded with the cellophane film, web or sheet.

b Figure 7 is a detail of the humidifying In carrying out our invention the cellophane inthe form of a continuous film, web or sheet, after being subjected to a humidiying atmosphere is passed through 100 a bath containing the coating composition, thence between doctor blades, and finally through a drying chamber. After the exit of the coated film from the drying chamber, it is subjected to a deodorizing or humidifying atmosphere, preferably at a temperature above room temperature, whereby the flexibility-of the Coated film is increased and the last traces of solvents eliminated thus rendering the coated film odorless.

Referring now to the drawings and especially to Figure 1, where there is disclosed one modification of a complete apparatus for carrying out this invention mounted on a suitable framework, the web or film of cellophane as it is withdrawn from a roll 1 is :passed through a humidifying box 2, thence across various spreader rolls 3 and into the coating bath 4. From the coating bath 4 the film is drawn up between a wiping mechanism 5 whereby the excess coating material is removed and thence immediately into a drying or evaporating chamber 6. After traveling through the drying chamber, the substantially dried coated film is drawn through a humidifying chamber 7 in which there are disposed deodorizers 8. Upon the exit of the treated film from the humidifier 7 it passes through the air and it is wound up on a roll 9.

The roll 1 consists of a continuous film or web 0f cellophane as it is produced in the usual casting machine. In other words, the film or web of cellophane has the usual beaded edges.

From the source of supply the cellophane passes through a humidifier. Various means may be used to humidify the cellophane The description of the following humidifier is merely illustrative and not limitative of the invention.

The humidifying box 2 is made of metal and is mounted on the framework in any suitable position between the supply roll 1 and the coating mechanism 4. It comprises a cylindrical portion 10 provided with an extension 11. In the cylindrical portion. 10 there is a slot 12 vproviding an entrance through which the cellophane passes into the interior of the humidifying box. The

y edges of the slot are preferably rounded to form beads whereby smooth edges are presented tothe cellophane and damage to the latter is eliminated. The extension 11 is also formed with a slot 13 having beaded or turned edges as described whereby the humidified cellophane passes from the humidifier. Mounted on( the cylindrical portion 10 of the humidifier is a roll 14 which together with roll 3 provide means for guiding the cellophane through the humidifier. Connected to or cooperating with openings 16 in the sides of the extension 11 of the box are two ducts 17 which supply the humidifying atmosphere from any suitable source.

the portions of the ducts extending within the box have their ends closed and provided with a slot or `perforation through which the humidifying atmosphere may be introduced into the box. The amount of humidifying atmosphere introduced is maintained by a damper 18 placed in the duct and controlled by a handle 19. The top of the humidifying box is provided with movable or slidable covers or lids not shown whereby access to the interior of the humidifying box may be readily had. In the bottom of the cylindrical portion 10 of the humidifier are drip connections or valves 21 whereby the. drippings produced during the operations may be removed. The passage of the film through the humidifier is of relatively short duration and its moisture content is somewhat increased. The increase in moisture serves to minimize to a certain degree the drying out of the film as it passes up through the drying chamber. This step alone is usually not sufficient to prevent an undesirable drying out of the film but in combination with the final humidifying step described below it has been found to be effective. This humidifying step also tends to eliminate wrinkles from the film and prevents a lapping over of the film as it passes through the doctor blades with consequent breakage which would ensue.

From the humidifier the film is passed over and under spreading rolls 22 and 23 mounted on the frame and functioning to iron out wrinkles from said film and thence into the coating bath 4. If desired, prior to the passage of the humidified film into the bath` the film may be passed through a slot 24 adjacent which is a wiper 25, which removes anv drippings or globules of condensed moisture. It is obvious that the film may be wiped on one or both sides as desired.

Submerged in the coating bath 4 contained in any suitable receptacle 26 is a roller 27 which is adapted to be raised'to allow the threading of the cellophane through the machine. A jacket 28 surrounds the receptacle whereby the coating composition may be heated or cooled by the circulation of steam, cold air or water as desired. To obtain optimum results the temperature of the coating composition should be maintained between approximately 20o C. and 40 C. Above 40 C. an appreciable amount of sol- Vvent evaporates, causing an undesirable atmosphere.

' for wiping both sides of the cellophane sheet, film or web passing therebetween. Since the wiping elements for wiping the two sides are duplicates, only one will be described.

The wiping mechanism comprises doctor blades 29 and auxiliary doctor blades 30 mounted on blade carriers 31 carried on trunnions 32. The trunnions 32 are carried in bearings formed by semi-cylindrical bores 33 formed in castings 34 and caps 35 having bores 36 complemental to bores 33, secured to castings 34 by any suitable means. If desired, the caps may be provided with oil holes 37 whereby the trunnions may be lubricated.

The blade carrier 31 in its lower portion has a bore 38 therethrough, whereby the car,- rier 31 is mounted on the trunnions 32. The

upper extremity of carrier 31 is formed to provide a support 39 for` the main doctor blade 29 which is secured thereto by bolts 40. The rear edge of the doctor blade 29 engages a sh'oulder 41 through which screws 42 spaced at suitable intervals in the shoulder 41, pass. The end of screws42 are adapted to engage the rear face of the doctor blade 29, whereby adjustment of the screws will adjust the doctor blades. l.

Situated beneath the main doctor blades 29 I are the auxiliary or short doctor blades 30 mounted' as immediately hereafter described. Secured to ribs 43 of the blade carrier 31 and adjacent each end thereof by means of bolts 44, are two spaced-apart elements 45. A

plate 46 having a slot or hole 47 extending at an angle, i. e. 45'to said plate. is mounted on elements 45 forming an inclined carrier 46 for the auxiliary blades 30. The carrier 46 is provided with a plurality of holes 48 through which screws 49 are adapted to pass. The auxiliary blades 30 are provided with slots 50 through which the screws 49 pass and which permit sufficient movement of the blades for accurate adjustment. By means of the nuts 49 engaging the ends of the screws 49, the auxiliary blades 30 are locked in position.

The main doctor blades 29, mounted as. above described, extend across the width of the machine and constitute means for wiping the entire width of the cellophane sheet, film or web on both sides. It is essential that the wiping edge of the doctor blade 29 be even and kept in adjustment. To this end the edge of the blades is maintained and/or attained by the movement of the screws 42 above described. In wiping both sides of a cellophane film, web or sheet, we have found that if the main blades' 29 are ar- C3 ranged at an angle to the passing film and in to overlap and, since the blades are adjustable, the amount of overlapping is adjustable. lhls overlapping gives a good scrap- 1ng action and permits the blades to be spaced wider apart than in the usual arrangement.-

The wider spacing of the doctor blades is especially important since cellophane film varies in thickness.` If the blades were spaced too close to each other, a thick portion of the film passing between the blades would be damaged or torn. v

The auxiliary doctor blades 30 (a pair disposed at each end of the machine) adjustably mounted as above described. are adapted to engage the edge portions and zones adjacent thereto of the cellophane film. Accordingly, the doctor` blades 30 are made of such length as to only wipe the desired area of the cellophane film, web or sheet. Various lengths may be used. We have found that if the auxiliary blades 30 are twelve inches in length when a film forty inches wide is treated. satisfactory results are obtained. The blades 30 may be staggered and overlapped similar to the main blades 2.9, or the edges may be positioned in the same'plane.

The auxiliary doctor blades 30 may be made of various materials. We have obtained satisfactory results when they were made of flexible materials such as spring brass with beaded edge, leather, thin steel and the like. y

To thread the machine, it is necessary that the

blades

29 and 30 be opened up or spread apart. For this purpose an externally geared handle mechanism 51 is provided. The handle mechanism 51 is mounted on

pads

52 and 53 of the castings 34 and, since both mechanisms are similar, only one will be described. A gear casing 54 is provided with an extension 55 by means of which the casing is securedto the pad. The casing 54 is also provided with bearings or journals 56 and 57 In the journal 56 a stub shaft 58 is polsitioned. On one end thereof a handle mechanism 59 is fastened by any suitable means. 0n the other end of the shaft 58 there is keyed a gear 60 which is adapted to mesh with a gear 61 carried on an extension 62 of the trunnion 32 and supported in the journal 57. It is obvious that rotation of the handle 59 will rotate the trunnion 32 whereby the blade holder will be moved and the blades separated. In order to indicate the amount of

l blades

29 and 30 are closed. To insure that the blades return to their original adjusted positions, adjustable stops 64 are mounted on bosses 65 of the blade holders. The stops comprise bolts 66 screwed in threaded holes 67 in the bosses 65. Nuts or bolt-heads 68 on the extremity of bolts 66 are adapted to engage a stop-block 69 mounted on the pad 70 of the casting 34 by means of a bolt 70 and positioning dowels. By means of a nut 71, or other suitable means, the stop 64 may be, after adjustment to any desired position, locked.

After the

blades

29 and 30 have been brought back `to their original adjusted position, means are provided to maintain the

blades

29 and 30 in position during the operation of the machine. The means for attaining this result comprises hand clamp devices 72. Specifically, the hand clamp 72 'comprises clamping members 73 and 7 3 adapted to engage the trunnion 32 and a screw 74 operated by rotation of the head 75, whereby7 the clamping elements 73, 7 3 are tightened or loosened. By means of ears 76 and bolts 77 and 77 respectively, the clamps are mounted on the end casting 34.

As above mentioned, the entire wiping mechanism 5 is slidably mounted whereby it may7 be adjusted to any desired position in relation to the coating bath. Various means may be used to attain this result. In the drawings. We have shown one for effecting this result. Extending through the lower portion of the casting 34, is a channel 78 in which a bar 79 is positioned. One end 79 of thebar 79 is bent upwardly and has a bolt 80 extending through a threaded hole 81 therein and through a threaded hole 82 in the casting 34. ln its horizontal arm, the bar is formed with a vslot 83 through which af bolt 83 connecting the casting 34 to theframe extends. Rotation of the bolt 8() moves the entire mechanism, the limits of said movement being governed by the length of slot 83. Suitable means may be mounted on the bolt 80 whereby rotation of the screw is prevented when not desired.

In the `arrangement of the doctor blades, above described, it has been found that the tension on the lm is of eXtreme importance and is one of the factors which regulates the quantity of the coating which is left on the film after passing through the blades. Low tensions result in considerably less friction on the film by the blades and consequently considerably more coating is left on the film than would result whenhigher tensions areY employed. .T he thickness of the coating may be varied as much as 100% and over by just varying the tension on the film. For this reason it is necessary to employ a device which will maintain the tension of the film through the doctor blades at some predetermined adjustable tensionf Various means may be employed. We have found that by controlling the tension of the roll 1 from which the film is supplied, We can obtain a suitable tension through the doctor blades. We therefore apply to the spindle on which the roll is carried any suitable braking means applying a progressively increasing tension as the supply on the roll decreases. Since the specific details of the brake means form no part of this invention, further description thereof is deemed unnecessary.

From the wiping mechanism 5 the coated film is caused to pass into a drier 6^located in close proximity to the wiping mechanism, whereby the coated films approach the temperature of the drier as rapidly as possible and before any substantial evaporation of solvent. This is to minimize the amount of solvent evaporated at the lower temperature and to prevent blushing. "Blushing, as

above described, is the result of the separation of Wax in very minute particles from the other solid ingredients of the coating composition, and is evidenced by the hazy, translucent or opaque films.l Paraiiin or other wax possesses a definite and limited solubility in the coating compositions whichl We use. said solubility depending primarily upon the temperature. At the temperature approximately that of the melting point of the waX or higher, its solubility is many times grgater than it is at lower temperatures. Accordingly, we maintain the temperature of the drier at or above the melting point of the wax in the composition. l

The drier 6 comprises a casing having heated coils 85 on both sides thereof. Disposed at various points in thel drier are doors 86 hinged to the casing and provided with wire glass windows 87, whereby access to the interior of the drier may be easily had and, due to the wire glass windows 87, the interior of the drier may be at any time viewed. The

temperature of the drier is preferably main-y tained in the vicinity or at the entrance of the film at 80 C. to 100 C., and the remainder of the drier is maintained at such a temperature that the parafiin or other wax will not be precipitated out. The upper sections of the drier are maintained at a temperature of not lower than 60 C. to 65 C.

From the drier, the coated film is introduced into a humidifier having means`8 disposed at lvarious points therein whereby moisture may be introduced in the chamber and restore ory impart flexibility to the coated film. Various means may be used to attain this result. We have found that steam introduced through pipes, the openings of which are covered with canvas, produces satisfactory results. We have also found that satisfactory results are obtained if the humidification is carried out at a temperature higher than room temperature and preferably above 40 C. To attain .this result, the

humidifyin chamber is provided with heating coils. he humidifier -is alsoprovlded with doors having windows sinular to the vdrier 6. The drier 6 andand the humidperature corresponding closely to the melting point of the wax, but slightly lower by 5 to 10 C., the moistureproof properties seem to disappear to a great extent. Also, during the process considerable moisture is lost by the film during its initial drying. In this final step the film picks up additional moisture sothat its moisture content is brought back to that necessary for a flexible and pliable film.- During this final step substantially all-the solvent is eliminated and the film rendered odorless.

When the film finally issues from 'the warm humidifying chamber and into the air, it becomes self-cooled, its temperature drops and the moistureproof properties of the coatlng are restored. Upon cooling, the coating seals the base materlal andA the molsture which the base has picked up.

From the humidifier the coated film passes through the air and is wound on a roll.

In the above method the material treated is described as a continuous film or web. The invention is not limited thereto since it is obvious that sheets of various sizes may be treated by the herein-described method.

vIn the claims the expression a temperature approximately that of the 4melting point ofsaid wax is used. This expression is intended to cover the temperature as set forth in thedescription, viz.. a temperature approximately the same or higher than t-he melting point of the wax in the composition.

Though the hereinbefore description relates specifically to the coating of celloas defined in the following claims.

phane, it is obvious to anyone skilled in the art that'the essential features of this invention may be used for coating numerous bases with divers compositions.

Since it is obvious that various modifications may be made in the apparatus abovedescribed, we do not intend to limit ourselves to the exact details above-described except We claim: 1. An apparatus for coating sheets, films, webs and the like comprising means to apply a coating `composition to the material to be coated, means toonly remove the excess composition from the zones adjacent the longitudinaledges of the material and means to remove Athe excess com osition from the entire width of the materlal to be coated.

,2. An apparatus -for coating sheets, films, webs and the like comprising means to apply a coating composition to the material to be coated and means to remove the excess of said coating composition, said means being webs and the like comprising means to apply a coating composition to the material to be coated, a pair of short doctor blades to wi the excess composition from the zones adyacent the longitudinal edges of the material, and a pair of doctorblades to wipe the excess composition from the entire width of the material.

4. An apparatus for coating sheets, films, webs and the like comprising means to apply a coating composition yto the material to be coated, a pair of short doctor' blades to wipe the excess composition from the zones adjacent the longitudinal edges of the material, i

and a pair ot doctor blades to wipe the excess composition from the entire width of the material, and means to adjust said doctor blades.

5. An apparatus for coating sheets, films, Webs and the likecomprising means to apply 'a coating composition to the material to be coated, a pair of short doctor blades to wi e the excess composition from the zones ad]a cent the longitudinal edges of the material,

and a pair of doctor blades to wipe the excess composition from the entire width of the material, said doctor blades being arranged in staggered relation.

6. n apparatus for coating sheets, films, webs and the like Vcomprising means to apply a coating composition to the material to be coated, a pair of short doctor blades to wipe the excess composition from the zones ad]a cent thelongitudinal edgesof the material, and a pair of doctor blades to wipe the excess composition from the entire width of the material, the wiping edges of the second mentioned doctor blades arranged in overlapping relationship.

7. An apparatus for coating sheets, films, Webs and the like comprising means to apply a coating composition tofthe material to be coated, a pair of short doctor blades to wi e An apparatus for coating sheets, films,

webs and the like comprising means to apply and a pair of doctor blades to Wipe the excess composition from the entire width of the material, and means to open up and separate the doctor blades of each pair to permit threading therethrough.

Mr9. An apparatus for coating sheets, films,

Webs and the like comprising means to apply a coating composition to the material to be coated, supports, a plurality of short doctor blades mounted on said supports and constituting means to Wipe the excess composition from the zones adjacent the longitudinal edges of the material, and a pair of oppositelyl disposed doctor blades mounted on said supports and adapted to wipe the excess composition from the opposite sides of the entire Width of the material.

10. An apparatus for coating sheets, lms, webs and the like comprising means to apply a coating composition to the material to b coated, supports, a plurality of short doctor blades mounted on said supports and constituting means to Wipe the excess composition from the zones adjacent the longitudinal edges of the'material, and a pair of oppositely disposed doctor blades mounted on said supports to wipe the excess composition from the opposite sides of the entire width of the mas, terial and means to adjust said doctor blades.'

11. An apparatus for coating sheets, films, Webs ahd the like comprising means to apply a coating composition to the material to be coated, supports, a plurality of short doctor blades mounted on said supports and'constituting means to Wipe the excess composition from the zones ad'acent the lon itudinal edges of the materia and a pair cfg opp sitely disposed doctor blades mounted on sai supports to wipe the excess composition from the opposite sides of the entire width of the material, and means to adjust each of Said doctor blades. L

12. An apparatus for coating sheets, films, `Webs andthe like comprising means to apply a coating composition to the material to be coated, supports, a plurality of short doctor blades mounted on said supports and constituting means to Wipe the excess composition from the zones adjacent the longitudinal edges of the material, and a pair of oppositely disposed doctor blades mounted on said supports to Wipe the excess composition from ,GO the opposite sides of the entire Width of the material, and means to at least partially rotate said supports whereby the blades are separated.

13. An apparatus for coating sheets, films, Webs and the like comprising means-to apply a coating composition to the material to be coated, movable supports, a plurality of short doctor blades mounted on said supports and constituting means to Wipe the excess composition from the zones adJacent the longitudi-i nal edges of the material, and a pair of oppositely disposed doctor blades mounted on said supports to wipe the excess composition from the opposite sides of the entire width of the material, and means to prevent movement of said supportsduring operation.

14.- An apparatus` for coating sheets, films, webs and the like comprising means to apply a coating composition to the material to be coated, supports, a plurality of short doctor blades mounted on said supports and constituting means to Wipe the excess composition from the zones ad] ac'ent the longitudinal edges of the material, and a pair of oppositely disposeddoctor blades mounted on said supports to wipe the excess composition from the opposite sides of the entire Width of the material and means to position said supports transversely of the material.

15. An apparatus forJ coating sheets, films,

Webs and the like comprising means to apply a coating composition to the material to be coated, supports, a plurality of short doctor blades mounted on said supports and constituting means to Wi e the excess composition from the zones a jacent the longitudinal edges of the material, a plurality of oppositely disposed doctor blades mounted onsaid support-s to wipe the excess composition from the opposite sides and the entire Width of the material, means to separate said blades toy permit threading of the material through the apparatus and means to limit the return of said blades to their predetermined wiping position upon bringing together said blades..

16. An apparatus for coating sheets, films, Webs and the like comprising means to apply a coating composition to the material to be coated, supports, a plurality of short doctor blades mounted on said supportsl and constituting means to wipe the excess composition from the zones adjacent the longitudinal edges of the material, a pluralityI of oppositely disposed doctor blades adapted to wipe the excess composition from the opposite sides and the entire width of the material, means to move apart'said supports to permit threading of the material through the apparatus and means to limit the return of said supports to their original predetermined positions.

17. An apparatus for coating sheets, films, Webs and the like comprising means to apply a coating composition to the material to be coated, supports, a plurality of short doctor blades mounted on said supports adapted to wipe the excess composition from the zones ad]acent the longitudinal edges of the material, a plurality of oppositely disposed doctor blades to Wipe the excess composition from the opposite sides and the entire Width supports to permit threading of the nia-4 terial through the apparatus and means limiting the forward movement of said supports. 1 An a paratus for coating sheets, films, webs and t e like comprising means .to aply a coating composition to the-material to e coated, supports, a plurality of short doctor blades mounted on said suplports to wipe the excess composition from t e zones adjacent the longitudinal edges of the material, a plurality of opposite disposed doctor blades adapted to wipe t e excess composition from the opposite sides and the entire width of the material, means to move apart said suplports to permit threadin of the material t rough the apparatus an adjustable ,means limiting 'the forward movement o said supports.

19. An'apparatus for coating sheets, films, webs and the like comprising in combination successive and separate means to humidify the material to be coated, means to remove wrinkles in the material, means to apply a coating composition and means to remove the excess coating composition and means to dry said coating. f

20. in apparatus for coating sheets, films, webs and the like comprising in combination successive and separate means to humidify the material to be coated, means to apply a coating composition to said treated material, means to remove the excess composition from said material at the zones adjacent the longitudinal edges of the materia means to wipe the excess composition from the entire width of the opposite sides of said, material and meansto dry the coating.

21. An apparatus for coating sheets, films, webs and the like comprising in combination successive and separate means to humidify the material to be coated, means to apply a coating composition to said treated mate-l rial, means to remove the excess composition from said material at the zones adjacent the longitudinal edges of the material, means to remove lthe excess composition from the entire width of said material, means to dry said coating and means to humidify the coated material.l

. ,22. An apparatus for coating sheets, films, webs and the like comprising in combination successive and separate means to 'apply a coating to the material to be coated, means to remove the excess composition from the coated material at. the zones adjacent the longitudinal edges thereof, means to remove the excess composition from the entire width of said material, and -means to dry the coat? ing disposed in close'proximity to the applymg means.

23. An apparatus for coating sheets, films, webs and thelike comprising in combination successive and separate means to apply a coating composition to the material to be coated, means to remove'the excess composition from said coated material at the zones adjacent the longitudinal edges thereof, means to remove the excess composition from the entire width of said material, means tot dry the coating disposed in 4close proximit to the applying means, and means t0 humi ify the coated material. 24. An apparatus for coating sheets, films,

webs and the like comprising inf combinationsuccessive'and separate means to humiditythe materlal to be coated, means to apply a coating to said material, means to remove the excess composition fromthe coated material at the zones adjacent the longitudinal edges thereof means to remove the excess composition from the entire width of the coated, material, andmeans to dry the coating disposed in close proximity to the apply- `ing means.

25. An apparatus for coating sheets, films, webs and the like, comprising means to apply a coating composition to the material to e coated, a pair of short doctor blades to wi e the excess composition from the zones adjacent vthe longitudinal edges of the material,a pair of doctor blades to wipe the excess composition from the entire Width of the material, and means to control the ten-v sion' of the material passing through said doctor blades.

26. An apparatus for coating sheets, films, webs and the like comprising means to apply a coating composition to the material to be coated, a pair of short doctor blades to w1 je the excess composition from the zones `adjacent the longitudinal edges of the material and a pair of doctor blades to wipe the j excess composition from the entire width of the material, and means to regulate the tension of the material passing through the doctor blades, `said doctor blades bemg arranged in staggered relation.

27. An apparatus for coating sheets, films, webs and t e like comprising means for applying a coating composition to the material to be coated, a pair of short doctor blades to wie the excess composition from the zones adjacent the longitudinal edges of the material and a pair of doctor blades to wipe the excess composition from the entire width of the material being treated, and means to individually adjust each of said doctor blades.

28. An apparatus for coating sheets, films, Webs and` the like comprising means for applying a coating com osition to the material to be coated, a pair o short doctor blades to wi e the-excess composition from the zones adjacent to longitudinal edges of the material, and a pair of doctor blades to Wipe the excess composition from the entire Width of the material being treated, the wiping edges of each pair of said doctor blades overlapping, and means to individually adjust each of said doctor blades.

29. An apparatus tor coating sheets, tilms, Webs and the like comprising in combination successive and separate means to apply a coating to the material to be coated, means to remove the excess composition from the coated material at the zones adjacent the longitudinal edges thereot, means to remove the excess composition trom the entire Width ot -said material, and drying means to quickly heat the coated film.

30. An apparatus tor coating sheets, films, webs, and the like comprising in combination successive and separate'me'ans to apply a coating composition to the material to be coated, means to remove the excess composition trom said coated material at the zones adjacent the longitudinal edges thereot, means to remove the excess composition trom the entire Width ot the saidmaterial, drying means tquickly heat the coated film, and means to humidity the coated material.

3l. An apparatus tor coating sheets, films, webs and the like comprising in combination successive and separate means to humidity the material to be coated, means to apply a coating to said material, means to remove the excess composition trom the coated material at the zones adjacent the longitudinal edges thereof, means to removethe excess'composition trom the entire Width ot the coated material, and drying means to quickly heat the coated film.

32. An apparatus tor coating sheets, films, webs andthe like comprising in combination successive and separate means to humidity the material to be coated, means to iron out the Wrinkles in saidrmaterial, means to apply a coating composition to said treated material, means to remove the excess composition trom said material at the zones adjacent the longitudinal edges ot the material, means to wipe the'excess composition trom the entire Width ot the opposite sides ot said material, and means to dry the coating.

33. An apparatus tor coating sheets, films, webs and the likecomprising in combination successive and separate means to humidity the material to be coated, means to iron out the wrinkles in said material, means to apply a coatingcomposition to said treated material, means to remove the excess composition trom said material at the zones adjacent the longitudinal edges ot the material, means to remove the excess composition trom the entire Width ot said material, means to dry said coating, and means to humidity the coatedmaterial. p

34. An apparatus tor coating sheets, tilms, webs and the like comprising in combination successive and separate means to remove the Wrinkles in said material, means to apply a coating composition. to said treated material, means to remove the e..ess composition trom said material at the zones adjacent the longitudinal edges ot the material, means to wipe the excess composition trom the entire width ot the opposite sides ot said material, and m'eans to dry the coating. e

35. An apparatus tor coating sheets, iilms, websand the like comprising in combination successive and separate means to remove the l 4cnnnnlcn'rn 0F CORRECTION.

Patent No. 1,826,697. y Granted october 6, 1931, 1o

WILLIAM H. cannon ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, lines 48 and 49, strike out "lf are two ducts 17 which supply the" and insert instead If the coated material is subjected to a; and that the said Letters Patent should be read with this correction therein that the same may confonn to the record ofv the `oase in the Patent Office.

Signed and sealed this 3rdl day of November, A. D. 1931.

. v M. J. Moore, (Seal) Acting Commissioner of Patents.