US2333902A - Paper coating device - Google Patents

Description

Nov. 9, 1943. w. F. THIELE r-:TAL 2,333,902

PAPER GOATING DEVICE Original Filed May 31, 1939 2 Sheets-Sheet 1 N0 9, 1943- w. F. THIELE ETAL 2,333,902

PAPER COATING DEVICE Original Filed May 51. 1939 2 Shee1'.S-Sheerl 2 Patented Nov. 9, 1943 PAPER COATING DEVICE William F. Thiele, Wisconsin Rapids, Wis., and

Warren E. Beadle, Sr., deceased, late of Wisconsin Rapids, Wis., by Warren E. Beadle, Jr., administrator, Biron, Wis., assignors to Consolidated Water Power and Paper Company,

Wisconsin Rapids, Wis., a corporation of Wisconsin Y Original application May 31, 1939, Serial No.

Divided and this application December 8, 1941, Serial No. 422,040

Claims.

This is a division of our co-pending application Serial No. 277,460, filed May 31, 1939, on Paper coating device, and relates to improvements in apparatus for coating paper to provide a desirable printing surface thereon,l and refers specifically to an apparatus wherein the rate of the transfer of the coating material to the paper web can be accurately controlled.

In all coating apparati wherein the coating material is applied to the paper web by means of a roll, and wherein no after operations 'are performed on the coated surface after the coating has once been applied, two predominant difficulties are encountered. First, the rate of passage of the coating material to the coating roll is diilicult to control and it is essential that this rate be as uniform as possible; and secondly, it is diiicult to secure a coating material of uniform fine texture and free from lumps continuously passing to the coating roll.

In our invention, an apparatus is provided in which the rate of passage of the coating material to the coating roll can be minutely controlled, and the coating material is so acted upon prior and during passage to the coating roll that its texture is maintained uniform.

Other objects and advantages of our invention will be apparent from the accompanying drawings and following detailed description.

In the drawings, Fig. 1 is a diagrammatic side elevational view of a coating unit embodying our invention.

Fig. 2 is a diagrammatic view illustrating the manner in which coating units similar to that shown in Fig. 1 may be utilized to coat both sides of a web.

Fig. 3 is a diagrammatic side elevational view of the coating rolls illustrated in Fig. 1, illustrating means for their relative adjustment.

Fig. 4 is a diagrammatic plan view of the coating rolls looking upwardly at the view shown in Fig. 3. i

Referring in detail to the drawings, an embodiment of our invention is shown which is particularly adaptable for coating a strong web of paper such as cardboard, box board and heavy strong kraft paper. In this form of our invention rolls Land 2 perform the dual function of coating rolls and fountain rolls. Rolls I and 2 are independently driven and the peripheral speeds of said rolls with respect to each other may be varied throughout a wide range. A dam 3 is positioned adjacent each end ofthe rolls I and 2 which function as closures at the nip of the rolls. The dam 3 may be constructed of hard rubber or any material which is frictionless in the presence of the usual coating material. We have found that the material known to the trade as Eel-slip operates very successfully as closure dams when utilized with coating material for coating paper.

A roll 4 is Journalled in an intermediate portion of link 5. One end of link 5 is pivotally connected as at 6 to standard 1. The opposite end of link 5 is pivotally connected as at 8 to rod 9 which is threaded at its end and is engaged in the worm mechanism I0. The mechanism I0 is a conventional mechanism and functions to move rod 9 longitudinally upwardly or downwardly to adjust roll 4 toward or away from rolls I and 2.

A web II of cardboard, box board, kraft paper or the like, is adapted to pass beneath .rolls I and 2 and above roll 4, said latter roll being so adjusted as to permit the upper face of the -web to raise a predetermined degree around the surfaces of rolls I and 2. This adjustment, of course, is provided through the mechanism III.

In operation a predetermined quantity of coating material is continuously fed in the nip of rolls I and 2 and is confined thereby by means of the dams 3. Preferably web I I moves at a translatory speed greater than the peripheral speed of either rolls I and 2, and it is also preferable that roll 2 be driven at a relatively higher speed than roll I. In view of the fact that the web I I moves faster than the fastest moving roll 2, a. wiping action occurs between the web and the surface for the roll 2 whereby the coating material is smoothly and uniformly applied to the upper surface of the web I I. The amount of coating material that is first applied to the web II is determined primarily by the speed of the roll 2. Roll I while applying a small amount of coating tc the web II also acts as a wiping mediumvand spreads the coating material applied by the roll 2, roll I moving at a peripheral Speed relatively slower than the translatory speed of web II.

Referring particularly to Fig. 2 a diagrammatic arrangement is illustrated for coating both sides of a web I2 utilizing units similar to that illustrated in Fig. 1. It is contemplated that the web I2 pass from the presses of a paper machine (not shown) or a portion of the drier section thereof. The web passes beneath the rst unit I3 and the upper surface is coated as described in conjunction with Fig. 1. The web is then passed around idler roll I4 and is carried around a plurality of drier drums I5. From the last drum I5 the web is carried around drum I6 and is passed through the second coating unit I1 whereby the opposite surface of the web is coated. After leaving the second unit I1 the web is trained around drier Vrials such as the usual clay dispersions. of the standards 28 is provided with an aperdrum I8. idler roll I9 and around drums 20. The web may then be rolled or cut into sheets in any conventional manner. It can readily be seen that by this arrangement both surfaces of the web I2 may be coated.

There are two general manners in which the amount of coating material Ycarried by the coating rolls can be controlled; l-By means of the variation in speed of the contacting rolls I and 2, each of which may be separately driven, and 2-By means of the pressure existent between the contacting rolls, means being provided for urging rolls I and 2 toward each other for controlling such pressure and means also being provided for controlling the degree of proximity of the rolls. Means by which these operations may be carried out are illustrated in the detailed views of Figs` 3 and 4. Thus a supporting frame having a pair of sides 2| support the rollers I and 2, the frame members being suspended from or mounted on a supporting surface or beam indicated at 22. Each side frame carries a depending standard 23 in the lower portion of which is mounted a bearing 24. A shaft 25 is journaled at each end in opposite bearings 24, said shaft carrying the roll I. The roll I is provided with a surface layer 21 which is preferably constructed of a medium hard rubber or other like semiresilient material. Standard 28 is pivotally connected as at 29 to each of the frames 2|, each of the said standards carrying a bearing 30 at the lower end thereof. A shaft 3| is journaled at each end in one of the bearings 3|), said shaft carrying the roll 2. The roll 2 is provided with a surface layer 33 which is preferably constructed of hard rubber or metal which effectively resists the wearing action of paper coating mate- Each ture 34 through which a link 35 is adapted to freely pass. One end of each link 35 is pivotal- 1y connected to a standard 23 upon each side of the roll I as shown at 36. The opposite end of each link carries a nut 31 which is threaded on the end f Said link and serves to confine coil spring 38 between the standard 28 and a washer 39 disposed adjacent the nut 31. A boss 40 is integrally formed upon each bearing 30 and is' internally threaded to receive screw 4I having a hemispherical head 42. The arrangement is such that screw 4 Lmay be so adjusted as to determine the minimum clearance between the surfaces of rolls I and 2 when standards 28 are urged toward standard 23 by means of springs 38. It can be readily seen that the hemispherical heads 42 carried by screws 4| abut against bearings 24 and thus limit the degree to which roll 2 may approach roll I. Referring particularly to Fig. 4, a motor 43 is directly connected to shaft 25 and the motor 44 is directly connected to shaft 3|. By means of these motors, the rolls I and 2 may be independently driven and the peripheral speeds of the rolls with respect to each other may be varied through a wide range. In addition, by rotating the various contacting rolls at varying relatively peripheral speeds. a wiping and smoothing action is obtained which tends to render the film eventually applied to the coating roll smooth and of uniform thickness. Further, by maintaining a relatively small amount of coating material in the nip of the fountain rolls or gate rolls, and by the peculiar agitation of said material, the coating material is never permitted to lie stagnant or dormant and lumps are never permitted to form.

We claim as our invention: v

1. A device for coating paper which comprises a pair of juxtaposed rolls. dams positioned adjacent the ends of said rolls to provide a zone at the nip of said rolls for carrying a quantity of cdating material, means for rotating said rolls to apply coating material to the surfaces of said rolls, the surfaces of said rolls being in contact with a surface of a traveling web of paper whereby coating material is transferred from said roll surfaces to said web surface and roll means on the opposite side of said web for holding it in contact with both roll surfaces during passage of the web.

2. A device for coating paper which comprises a pair of juxtaposed rolls, dams positioned adjacent the ends of said rolls to provide a -zone at the nip of said rolls for carrying a quantity of coating material, means for rotating said rolls to apply coating material to the surfaces of said rolls, the surfaces of said rolls being in contact with a surface of a. traveling web of paper whereby coating material is transferred from said roll surfaces to said web surface, and means for holding said traveling web in contact with both roll surfaces during passage of the web.

3. A device for coating paper which comprises a pair of juxtaposed rolls. dams positioned adjacent the ends of said rolls to provide a zone at the nip of said rolls for carrying a quantity of coating material, means for rotating said rolls to apply coating material to the surfaces of said rolls, the surfaces of 'said rolls being in contact with a surface of a. traveling web of paper whereby coating material is transferred from said roll surfaces to said web surface. and means on the opposite side of said web and intermediate said rolls for holding said traveling web in contact with both roll surfaces during passage of the web.

4. A device for coating paper which comprises a pair of juxtaposed rolls, dams positioned adjacent the ends of said rolls to provide a zone at the nip of said rolls for carrying a quantity of coating material, means for rotating said rolls to apply coating material to the surfaces of said rolls, the surfaces of said rollsbeing in contact with a surface of a traveling web of paper whereby coating material is transferred from said roll surfaces to said web surface, means on the opposite side of said web and intermediate said rolls for holding said traveling web in contact with both roll surfaces during passage of the web, and means for adjustably positioning said holding means toward said rolls to cause said web to wrap about a predetermined portion of the surface of each roll.

5. A device for coating paper which comprises a pair of substantially juxtaposed rolls, means for urging said rolls toward each other, means for limiting the minimum distance between said rolls, dams positioned adjacent the ends of said rolls to provide a zone at the nip of said rolls for carrying a quantity of coating material, means for driving said rolls at different peripheral speeds to deposit a predetermined quantity of coating material from said nip to the surface of one of said rolls, means for passing a paper web into contact with the surfaces of said rolls to coat a surface of said web, and means for varying the pressure between said web and said rolls.

WILLIAM F. THIELE. WARREN E. BEADLE, JR.,

Administrator of the Estate of Warren E. Beadle,

Sr., Deceased.

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