US1287027A - Drier for coated paper. - Google Patents

Description

J. JANSON.

DRIER FOR COATED PAPER.

' APPLICATION men MAYI5. ms.

1,287,0Q7. Patented Dec. 10, 1918.

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DRIER FOR COATED PAPER.

Specification of Letters Patent.

Patented Dec. 10, 1918.

. Application filed May 15, 1918. Serial No. 234,808. A

To all whom it may concern:

Be it known that I, JOHN JANSON, a citizen of the United States, and a resident of Lawrence, county of Essex, and State of Massachusetts, have invented an Improvement in Driers for Coated Paper, of which the following is a specification.

This invention relates to drying apparatus for coated paper and more particularly to paper which has been coated on one side only. Prior to my invention paper, which has been coated on one side only, has usually been dried by suspending the same in long loops over sticks in a drying room, or by feeding the paper through a hot air chamher, in which it is subjected to a high degree of heat, so that it is preliminarily dried, and then passed about cylindrical driers, to finish the operation. The first method is objectionable for many well known reasons, and it has been sought to obviate these. ob jections by the second method, above referred to, and, while the latter method may be more advantageous in some particulars, it fails to obviate all of these objections.

In drying paper which has been freshly coated on one side only, by either of the methods above referred to, or by any other method which has been employed, so far as I am aware, and in which the web is passed through a hot air chamber, in carrying out the drying operation, the uncoated side is liable to become heated to an objectionable extent, and cause the surface to become brittle, so that it is liable to crack. when bent. With these methods, the paper also tends to dry more rapidly at the edges than at the middle portion, frequently causing the paper to curl and making it necessary to trim these portions off, causing w'aste.

Also paper is frequently coated on both sides by first coating it on one side and then the other, the paper being passed through the drying chamber after each-coat is applied, and, when this is done, the coating which was first applied is liable to be overheated, and rendered brittleor otherwise injured.

A further objection to these methods is that paper, thus dried, is liable to be stifli'ened to an objectionable extent, and in this connection, I have discovered thatthis is largely due to the fact that the paper is either held flat as it is passed through the drying chamber or, when dried while supported on sticks in loops, is held without being flexed for a considerable period, so that it becomes the drying operation is taking place, so that,

when this operation has been finished, the paper will be relatively soft and pliable, and all tendency to become unduly stiff and brittle is thereby avoided. A further object is to provide a drying means with which the subjection of the paper to a degree of heat which is liable to cause injury thereto is avoided and in which the evaporation is performed more through the application of air in a relatively large volume than through the application of air heated to a relatively high temperature, so that. the process is as far removed from being a baking process as practicable.

Another object is to provide a form of drier in which the operation may be carried on continuously, so that the drying of the paper may be finished on ordinary drying cylinders, and maybe constantly delivered to an automatic winder.

I accomplish these objects by the employ- 7 ment of the means shown in the accompanying drawing, in which Figure 1, is a side elevation giving a general view of the entire apparatus which I employ, and in which my invention is embodied.

Fig. 2, is a similar view on a larger scale, of the drier to which the paper is delivered immediately after it is coated.

Fig. 3, is an end elevation thereof.

- Fig. 4, is a detail view of one of the air nozzles.

Figs. 5 and 6 are detailed end and sectlonal views of a supporting means for the air deflector plates of the fans, which I may employ.

As shown in the drawings, my improved means for preliminary drying the paper comprises a series of standards a, in which ing discontinuous, web-supporting surfaces.

Fans e are mounted on standards f between the said drums, one fan being mounted be tween the first and second drum, and one between the second and third drum, and so on, if a greater number than the three drums shown, are employed. Each fan is mounted to rotate about an axis parallel to, but at a substantial distance below the plane of the axes ofthe drums and at equal distances from the two adjacent axes, and is composed of a series of flat, axially extending and radially disposed blades. An arc-shaped guard plate 9 is mounted in position to inclose a segmental portion of each fan, and in close proximity to the ends of the fan blades, said plates being preferably formed to extend throughout approximately a semicircumference, and, in practice, being designed to be set in a position to inclose the upper half of each fan. These plates 9 are mounted to be swung about the respective shafts on which the fans are mounted, so that they may be tilted from the horizontal position shown, if desired. While any suit able means may be provided for supporting said plates g, so that each may be circumferentially adjusted about the fan over which it is located, a preferable means is shown in detail in Figs. 5 and 6. As shown therein, each bearing 6', in which a fan shaft is mounted to rotate, is provided with a projecting boss 6 at one side thereof. Each plate 9 is mounted on radial arms 9', formed integrally with a collar 9 which is located on the boss, e and held in any position of adjustment by 'a set screw 3 With the plates 9 arranged as shown, when the fans are rotated, the air which is thrown out.

radially thereby will all be directed downward, but may be directed more to one side" than the other, if desired, by merely slightly,

tilting the plates.

A hot air box his provided, which extends over all of the slatted drums, and to which hot air, under pressure, is constantly supplied, and-the under side of said box is formed to provide concave recesses h, in each of which the upper portion of one of the slatted drums is located, the surface of each recess being formed concentrically with the axis of the particular drum which is located therein. A series of air-discharging slots 11 are formed in the portions of the hotair box in which said recesses h are located, each slot being extended throughout approximately the length of the drum and.

preferably being inclosed at its ends and one side by a fixed nozzle portion j and at the other side by a flap gate is, which is pivotally mounted in the nozzle portion 7 and adjustable therein, toward and from the latter by a set screw m, or other suitable means, as shown in Fig. 4, to vary the size of the discharge orifice. The air-discharging slots 1', and nozzles portions y are arranged with special reference to the distance between the slats of the drums and so that the circumferential distance between the nozzles is about one and one-half times greater than that between the slats. As thus arranged the radial lines extended through two adjacent slats will not, in any position of the drum, intersect two adjacent nozzles, but if one radial line through a slat intersects one nozzle, the radial line through the next slat will intersect the space between such nozzle and the next adjacent nozzle. air jets will, therefore, always be directed into a space between two slats.

- The operation of the drier, as thus far described, is as follows:

The web of paper .w, which has been freshly coated on one side only, is passed, with the coated side up, over the first slatted drum and then downwardly beneath the first fan 0, then up over the second slatted drum, so that the web is suspended in a loop between the drums, out of contact with the fan, but in sufficiently close proximity thereto to be under the direct influence ofthe air thrown out centrifugally by the fan blades, the fan being mounted at the middle of the lower portion of the loop and the fan blades being of such length that they terminate at a safe distance from the web, at all points, so that there is no danger of contact therewith. The web is, in; like manner, passed over the second drum and down about the second fan and up over the third drum, as shown. The drums are driven at a suitable speed, all in the same direction, and the fans are driven in the opposite direction to that Of the drums, as indicated by the arrows in- Fig. 2, the driving means employed being One or more of thewell known in the art, and adapted to vary the relativespeeds asmay be desired.

In operation. the jets of heated air are discharged against the freshly coated sur-' surface of the paper, caused bythe'force of the airjets, also produces frictionalengagement, in addition to that caused bv gravity, between the web and the slats of the drums, which is substantially increased by the action thereon between the slats,

which causes the web portions, extending from one slat to the next, to be pressed inward, so that such portions are forced against the sldes as well as the tops of the caused by the fan therein. The fans therefore, by forcing air against the coated surface of the web, as it passes in a loop from one drum to the next, have both a drying action thereon, and an action to increase the frictional engagement of the web with the drums. They also act to hold the web portions, suspended between the drums, dis tended as shown, as they pass from one to the next. The combined actions of air currents and gravity, as above described, cause a sufliciently strong frictional engagement between the drums and web to cause the latter to be fed along at the surface speed of the drums. Each portion of the-coated surface is thus subjected to the action of warm, or hot air currents, throughout the entire time during which it is passing beneath the hot air box, and, as air is forced in considerable volume against the coated surface, the moisture will be rapidly absorbed, and this is done without the application of heat tothe under, or uncoated side of the web, except from the coated side, danger of damage thereto from this source being eliminated. Excessive heating even from the hot air jets is also prevented by the fans, which force air at a somewhat lower temperature against the web between each set of air jets, so that the paper is somewhat cooled, as it passes between each drum.

The dryin action is practically uniform over the entlre surface, so that diflicultiesdue to having one portion dried faster than another are avoided.

It is to "be furthernoted that, as the web is carried over the drums, down beneath and about the fans, it is being constantly flexed in opposite directions, and, as this flexing is caused while the drying operation is in progress, the paper and its coating have no opportunity to become stiffened. This fear ture is of special advantage when a second coating is applied either to a previously coated side or to the opposite side.

The surface speed of the drums and the drying action on the web, as it is fed thereby, is such that, by the time it passes from beneath the hot-air box, the coating is set,

so that it may be carried into engagement with a slatted guide roll 'n beneath which the web is passed, said roll 11. being arranged to cause the web to be held down close to the surface of the last slatted drum, and in contact therewith. as long as is practica le.

While the coating has become set at this point, further drying and hardening thereof is preferably performed by other means. To this end the web is then carried between two tension rolls 0, which are arranged to grip the same with suflicient force to enable the web to be pulled taut at the delivery side thereof, and then it is passed about two drying cylinders p, of common form, its coated surface being held in contact therewith by 'an endless belt in a well known manner, so that, when the web passes from the last drying cylinder, the coating will be thoroughly dry and hard.

From this point the web ispassed to a double acting winder, onto one roll or the 'other of which the web is wound, and then re-wound'on the roll 8, so that the operation is continuously carried on. The particular means employed for driving the mechanism above described, are well known in the art and require no'description.

, It will be understood that, while a series of three slatted drums are illustrated, my invention is not restricted to the use of this number, as only two or more than three of such drums may be employed. The use of -more than two drums being a matter of ducoated surface of the web.

2. A drier for coated paper having means constructedand arranged to feed a web of paper. without engagement with its upper surface and comprising a series of rotatably mounted supports spaced apart so that the web is suspended therebetween in a loop and is oppositely flexed, as it is carried thereover, when said supports are rotated, means to rotate said supports and means simultaneously to force heated air against said upper surface of the web, to cause a drying action thereon and increase the frictional engagement of the web with said supports. 3. A drier forv coated paper comprising a series of suitably spaced parallel rolls over which a web of paper is passed, with its freshly coated side uppermost, and between which it is loosely suspended, means to rotate said rolls in the same direction, to feed the web by the frictional engagement thereof'with the under side of the web and to flex the same oppositely, as it is fed, and means simultaneously to apply heated air -to said upper sidof the web.

4. A drier for coated paper comprising a pair of rotating drums adj acently disposed in parallelism, and over which the web of paper is passed and between which it is suspended in a loop, with its freshly coated side uppermost, and means for forcing heated air against the upper side of the web, to increase the frictional engagement thereof with the drums and to cause a drying action on the coated surface.

- 5. A drier for coated paper comprising a pair of rotating drums adjacently disposed in parallelism, and over which the web of paper is passed and between which it is suspended in a loop, with its freshly coated side uppermost, means to force air against the web as it is carried over the upper portions of said drums, and means to force air downwardly against the inner side of the loop, suspended between the drums, at its lower end, whereby the action of the drying air at both points increases the frictional engagement of the web with. the drums.

6. A drier for coated paper comprising a pair of drums adjacently disposed in parallelism and over which the web is passed and from which it is suspended in a loop therebetween with its coated surface uppermost, means to rotate said drums in the same direction, means to deliver a series of hot-air jets against said surface at points at which it is supported by each drum and means to force air against the inner surface of said looped portions of the web in directions to hold the same distended.

7 A drier for coated paper comprising a series of drums adjacently disposed in parallelism and having discontinuous, web-supporting surfaces, means to rotate said drums in the same direction, means to deliver a series of hot air jets against the upper surface of the web, as it is supported by the drums, to depress the same into the spaces between said supporting surfaces of. the

drum and increase the frictional engagement thereof with the web and to cause a drying action thereon.

8. 'A drier for' coated paper comprising a series of drums adjacently disposedin parallelism, and each composed of a cylindrically disposed series of slats for supporting a web of paper thereon, said slats being spaced apart, to permit the web to be loosely suspended therebetween, means torotate said drums in the same direction, and means arranged to direct jets of hot air against the upper surface of the .web, opposite said drums, to cause a drying action on said surface and press the web inwardly between the slats, to flex it oppositely and increase its frictional engagement with the slats.

9. A drier for coated paper having means for supporting and feeding a web of paper with its coated side uppermost, said means comprising a series of drums adj acently disposed in parallelism and each composed of a cylindrically disposed series of web-supporting slats, with spaces of substantial width .therebetween and means to supply hot air under pressure, having a series of jet orifices concentrically disposed about the upper porin proximity thereto, and in positions in Y which the air discharged from one or more of said orifices will be constantly directed between two or more of said slats.

11. A drier for coated paper comprising a pair ofweb-supporting and feeding drums, adjacently disposed in parallelism and over which the web is passed and from which it is suspended therebetween in a loop meansfor forcing air downwardlyinto the loop thus suspended, as the web is carried from one roll to the other.

12. A drier for coated paper comprising a pairof web -supporting, and feeding drums, adjacently disposed in parallelism and over which the web is passed and from which it is suspended therebetween in a loop, and a fan mounted to rotate within the loop thus suspended and arranged to force air against the lower portion thereof, to hold the loop distended and cause a drying action on its inner surface.

13. A drier for coated paper comprising a. pair of web-supporting, adjacently disposed drums, mounted to rotate about parallel, horizontal axes, in the same direction, and

from which the web is suspended therebeand A hot-air box extending over said drums, in

proximity thereto, and having recessed portionsin its under side to receive the upper portions of said drums, and air-discharge ports in said recessed portions arranged to direct jets of air against the upper surface of the web, as it is carried by said drums, to

pre$ the web against the drums and cause a drying action on said surface.

15. A drier for coated paper comprising a series of web-supporting drums adjacently disposed in parallelism and over which the a winder for receiving the Web from said drying cylinders.

16. A drier for coated paper comprising means to feed the web of paper with .its coated side uppermost, means to force air at a relatively high temperature-against the coated surface of the web at one point in its travel and then to force air at a lower temperature thereagainst at a succeeding point in its travel, to cause evaporation of the moisture in its coated surface without causing excessive heating of the we.

17. A drier for coated paper comprising a. pair of web-supporting, adjacently disposed drums, mounted to rotate about parallel, horizontal axes,

in the same direction,

and from which the web is suspended there- 80 between in a loop, a fan mounted to rotate within thelower portion of the loop about an axis parallel to that of said drums and having radially and axially extending blades terminating short of the surface of the loop, 86 a curved deflecting plate extending over and circumferentially of the fan, and means permitting circumferential adjustment of said plate to direct the air forced out by the fan in different directions within the loop. 18. A drier for coated aper comprising a series of suitably spaced carrier rolls, on which the web rests, with its coated surface uppermost, and between which it is loosely, suspended, and means to rotate said rolls in 46 the same direction to feed the web by the frictional engagement thereof with under side of the web, means to exert a drying action on the web as it is fed, apair of gripping rolls to which the Web is delivered from 60 said carrier rolls, to permit the web to be placed under tension as it is drawn therefrom, and a winder to receive the web delivcred from said gripping rolls.

In testimony whereof I have signed my name to this specification.

JOHN JANSON.

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