US2077726A - Apparatus for the manufacture of coated paper - Google Patents

Description

April 20, 1937. UQNG 2,077,726

APPARATUS FOR THE MANUFACTURE OF COATED PAPER Original Filed April 1, 1953 2 Sheets-Sheet 1 M AETORNEZ D. D. UONG April 20, 1937.

APPARATUS FOR THE MANUFACTURE OF COATED RAPER Original Filed April 1, 1933 2 Sheets-Sheet 2 IN V EN TOR.

J I 6/ B 602 0250 M "ZTTOR/VEYS;

Patented A r.- 20, 1937 2,011,12 srrsaarusron 'rnn mmnmc'runn or cos-ran mesa Diong D. Uong, Fltchburg, Masa, assignor to Fltchburg laper Company, Fitchburg, Mass a corporation of Massachusetts l application April 1, 1933, Serial No. 663,966. Divided and this application August 17, 1935, Serial No. 36,623

4mm. (cur-4a) This'applicatlon is a division of my prior ap- Fig. 4 is a detail side elevation of a portion plication Serial No. 663,966, filed by me April of one of the feeding plates;

1, 1933. Fig. 5 is an end view, looking in the direction of This invention relates to the manufacture of the arrow 5 in Fig. 4, and 1 paper presenting a coated surface at one or Fig. 6 is a detail view, looking in the direction both sides thereof. Such coated papers are comof the arrow 6 in Fig. 5. monly produced by the application of a suitable Referring to Fig. 1, I have shown portions of a coating material to previously formed paper, and paper making machine of a usual type and having in the usual'commercial practice a liquid coatinga Fourdrinier section A, a press roll section B material has been applied to the paper after and a drying section C. The Fourdrinier section the paper has been dried and removed from the paper making machine. Such application ofliquid coating material to substantially dry paper involves a separate and additional coating operation as well as a second drying operation, all at substantial additional expense.

It is the general object of my invention to provide apparatus for producing a coated paper by the application of a coating material in powdered form to a web of paper while it is still in the paper making machine and before the drying thereof is completed.

Preferably I apply the powder to the web at a. point where the web still contains a substantial amount of water, a condition found at the suction boxes and to a less extent at the press rolls. It may at times, however, be desirable to apply the powdered coating material even later in the paper making process, as for instance at a point between sections of drying cylinders.

In any event, the powdered coating material is to be applied uniformly to the paper web while it still contains suilicient moisture to coact with the powdered material and produce an effective coating on the paper.

A further object of my invention is to provide improved powder feeding mechanism for thus uniformly applying a powdered coating material to a paper web in a paper making machine.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of the invention is shown in the drawings, in which Fig. 1 is a diagrammatic side elevation of portions of a paper making machine having my invention applied thereto;

Fig. 2 is a sectional side-elevation of a preferred form of mechanism for applying the powdered coating material to the moist web;

Fig, 3 is a sectional elevation of the coatingapplying mechanism, taken along the line 3-3 in Fig. 2;

conveyor Ill on which the paper material or pulp is deposited and through which a portion of the water escapes or is sucked away.

The apron i0 and partially formed paper web W passes over a series of suction boxes H, under a dandy roll l2, and around-a. larger or couch roll iii. The partially formed paper web W then passes between successive pairs of press rolls l4, l5 and I6 in the press roll section B,after which the'web passes around a series of drying rolls or cylinders 20 in the drying section C, the cylheated to remove a substantial portion of the moisture still remaining in the web W.

The paper-making machine thus briefly described is of a usual commercial type and in itself constitutes no part of my present invention, which relates particularly to the mechanism M for applying coating material in powdered form to the paper web W as it passes through the papermaking machine.

The location of the mechanism M in the papermaking machine is subject to somewhat wide variation but as at present practiced, I preferably mount the mechanism M so that the powdered material is applied to the paper web W as it passes over the first pair of suction boxes H, at which point the paper web' may comprise eighty percent, or more of water.

While the position above the suction boxes is at present favored, the mechanism M may, if desired, be so mounted as to deliver the powdered coating material to the paper web W as it machine. Such a location is indicated in dotted lines in Fig. l, the coating mechanism M being web as it passes from the first pair of press rolls ll to the second pair of press rolls l5, at which point the web W contains substantially less moisture than at the suction boxes.

I may also position the coating mechanism entirely beyond the press roll section, as indicated in dotted lines at M in Fig. 1, at which point A comprises a fine mesh wire screen apron or inders 20 beingof relatively large size and steampasses through the press'roll section B of the positioned to apply the coating material to the the moisture content of the paper web may be as low as twenty percent.

The location of the coating mechanism will be selected with reference to the paper stock, the coating material, the type of surface to be produced, and other operating conditions.

In Figs. 2 to 6 I have shown the details of the form of coating mechanism M which I have devised for applying powdered coating material to the paper web W. As shown in the drawings, the coating mechanism M comprises a casing 22 mounted on suitable supporting frame members 23 adapted to be easily secured to the main frame at the paper-making machine at a desired loca- A pair of distributing rolls 24 and 25 are supported in bearings 26 on the frame members 23 and are rotated by the driving belt 21 in the direction of the arrows a in Fig. 2. A hopper 30. is mounted above the casing 22 and is provided with feed plates 32, adJustably secured to blocks 34 and 35 which in turn are mounted on pairs of slide bars 36 which function as fixed guides for the blocks 34 and 35.

The blocks 34 at each side of the hopper are connected by links 40 and 4| to eccentric pins 42 rotated with a pulley 43 by a belt 44. As the pulley 43 is rotated, it will be obvious that the feed plates 32 are given slight reciprocating movements in reversed directions, thus tending to evenly distribute the powdered material lengthwise of the plates and to feed the material downward through the relatively narrow opening between the lower edges of the feed plates 32. The width of this opening may be adjusted by adjusting the plates 32 in the blocks 34 and 35, for

which purpose adjusting screws 45 are provided.

The feed plates 32 converge downward as shown in Fig. 2, and the lower edges of the plates are preferably beveled as indicated at 46 in Fig. 5. The lower portions of the plates 32 are also preferably grooved as indicated at 41 in Figs. 4 and 6, and the beveled edges 46 are preferably provided with finer grooves as indicated at 43 in Figs. 4 and 6. As the plates 32 are relatively reciprocated, the grooved lower portions of the platestend to pulverize the powdered coating material, should any lumps or hard portions occur therein.

By the use of these reciprocating grooved feed plates a fine uniform stream of powdered material is delivered to the roll 24 within the casing 22, and a considerable portion of this material is passed along by the roll 24 to the roll 25, as indicated at Fig. 2.

After leaving the roll 25, the powdered material circulates in different directions within the casing 22 and is finally deposited in a substantially uniform manner on the moist surface of the paper web W. The rolls 24 and 25 are preferably provided with knurled surfaces as indicated in Fig. 3 for more eflectively'advancing and distributing the powdered material.

It will be evident from the foregoing description'that the mechanism M for applyina he P dered material to the paper web is a self-contained unit which may be readily mounted in any convenient position in a. paper-making machine, as indicated at M, M, M and M in Fig.

1, the particular position selected depending on the nature of the product and desired coating and on the operating conditions.

It is deemed essential that the paper web should have sufllcient substance so that the powdered material. will remain largely on the surface of the web, and furthermore that the. web shall contain sufilcient moisture to coact with the powdered material in producing an effective coating. Under ordinary conditions the moisture content will run from twenty to ninety percent in the web at the point of powder application. The powdered material itself may be varied to suit operating conditions and the particular type of coating desired, but will commonly consist largely of an adhesive material mixed with some form of pigment of different colors.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:-

1. A powder-applying mechan'ismfor a papermaking machine comprising a casing, a hopper mounted thereon, feeding devices for said hopper, and a pair of distributing rolls mounted in said casing and substantially spaced from the side walls thereof, said rolls having roughened and substantially continuous peripheral surfaces and being positively rotated in the same direction, one of said-rolls being positioned directly in the path of the. falling powder and being effective to agitate and divert said powder and the other roll beingmounted at one side of said first roll and being horizontally displaced therefrom in the direction in which the falling pow-- der is diverted by engagement with said first roll and receiving portions of said diverted falling powder directly from said first roll.

2. A powder-applying mechanism for a papermaking machine comprising a casing, a hopper mounted thereon, and feeding devices for said powder comprising a. pair of adjacent plates mounted at opposite sides of said hopper and means to reciprocate said plates longitudinally, said plates having a plurality of substantially vertical grooves formed in their inner surfaces and lower end surfaces.

3. A powder-applying mechanism for a. papermaking machine comprising a casing, a hopper mounted thereon, and feeding devicesfor said powder comprising a pair of adjacent and substantially vertically grooved plates mounted at opposite sides of said hopper and means to reciprocate said plates longitudinally and to cause said plates to move simultaneously in opposite directions.

4. A powder-applying mechanism for a papermaking machine comprising a casing, a hopper mounted thereon, and feeding devices for said powder comprising a pair of adjacent and substantially vertically grooved plates mounted at opposite sides of said hopper, means to reciprocate said plates longitudinally, said plates being inclined relatively to each other, and means to adjust said plates in the planes thereof to vary the powder delivery opening between said plates.

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