US3043742A - Pulp tank structures for pulp molding machines and method - Google Patents

Description

July l0, 1962 `M. P. CHAPLIN 3,043,742

PULP TANK STRUCTURES FOR PULP MOLDING MACHINES AND METHOD Original Filed Sept. 29, 1953 2 Sheets-Sheet x 3 ATTORNEY July 10, 1962 M. P. cHAPLlN 3,043,742

PULP TANK STRUCTURES FOR PULP MOLDING MACHINES AND METHOD Original Filed Sept. 29, 1955 2 Sheets-Sheet 2 INVENTOR MER/.EP Cf/HPL/A/ ATTORNEY United States Patent 3,043,742 PULP TANK STRUCTURES FR PULP MOLDING MACHENES AND METHOD Merle P. Chaplin, South Portland, Maine, assignor, by mesne assignments, to Diamond National Corporation, New York, N.Y., a corporation of Delaware Original application Sept. 29, 1953, Ser. No. 382,985, now Patent No. 2,938,582, dated May 31, 1968. Divided and this application .lune 4, 1959, Ser. No. 818,157 6 Claims. (Cl. 162-228) This application is a division of my copending application, Serial No. 382,985, tiled September 29, 1953 and now Patent No. 2,938,582, on Method of and Apparatus for Making Molded Pulp Articles, the disclosure of said copending application being herein incorporated by reference.

Said parent application discloses integrated apparatus and methods of forming pulp articles and comprises all apparatus and method steps from initially suction forming an article on a suction die to and including the discharge of such article from the apparatus in a condition to be packaged and ready for the market. That apparatus and method embodies, inter alia, numerous novel features relative to the tank structure containing the pulp from which the article is suction formed or molded. That aspect of the parent case forms the subject matter of this divisional application and involves both the tank structure and the method of feeding and handling the pulp in such structure.

The primary object of the invention is to provide for the etlicient supply of pulp to the forming dies as they are passed through a pool of pulp in the pulp tank.

A further object of thev invention is to provide means whereby diiferent kinds of pulp may be successively applied to the forming dies as they pass through a single tank, in a simple, convenient and el'licient manner.

Another object is to provide a surface coating for the article during the initial step of its formation.

Another object of the invention is to provide for the formation of an article of relatively coarse fibres and also relatively 'tine libres as may be required for diierent purposes in the finished article.

Another object of the invention is to maintain in the forming tank an equally uniform flow or movement of the liquid generally in the same direction as the die movement but interspersed with controlled cross currentswhich result in an article wherein the pulp iibres extend in all directions and thus are more efficiently matted than where such pulp bres predominantly are laid in the direction of movement of the 4forming die through the pulp bath.

In its preferred practical form the tank structure ofthe present invention comprises a tank provided therein with a plate curved on the axis of movement of the forming dies and spaced therefrom. That plate is provided with openings forming a plurality of nozzles facing in the general direction of rotation of the forming dies, so as to impel the mixture against the trailing sides of the dies. Said plate is also provided with a plurality of other openings or orifices to direct the pulp passing therethrough against the leading faces of said dies and said nozzles and orifices are spaced from one another to elect turbulence conducive to uniform distribution and felting "ire will be apparent from the hereinafter detailed description and appended claims when read in conjunction with the accompanying drawings.

The accompanying drawings illustrate one practical embodiment of the invention, but the construction therein shown is to be understood as illustrative, only, and not as defining the limits of the invention. 4

FIG. 1 is a longitudinal section through a tank structure embodying the present invention showing an associated forming drum with dies thereon, said drum being shown partly in section and partly in elevation.

FIG. 2 is a fragmental transverse section on the line 2 2 of FIG. 1.

FIG. 3 is an enlarged fragmental section of a part of FIG. 1, showing the circulatory action produced by the baffle and orifice plate forming part of this invention.

FIG. 4 is a fragmental section on the line 4-4 of FIG. 3.

FIGS. 5 and 6y are respectively fragmental plane sections on the lines 5-5 and 6'6 of FIG. l.

Referring to the drawings, 8 designates a forming drum or cylinder about the circumference of which is positioned a succession of spaced apart forming dies 9. The drum is mounted to rotate on a horizontal axial shaft 4 and this drum, as well as the dies thereon, may be of any conventional form common to the art of suction molding drum construction; The dies are foraminous or perforated and suction is provided internally of the drum to cause the accretion of fibres onto the several dies or.

forms 9 as they pass through and are thus submerged for a time in a pool of pulp or fibre material.

Pulp or libre mixture in a very dilute form, mixed with water or other liquid, is prepared by various methods and means well known to the art. This dilute mixture in proper relation to libres and liquid is introduced into a tank 3i. The level of liquid fibre mixture is maintained reasonably constant at the approximate level indicated at 3a, 3a.

As shown in FIG. 1, a pump 3b, driven by any suitable means, such as a motor 3c, through a belt 3d, delivers this liquid-fibrous mixture to a pressure chamber 3e through any suitable connecting passage such as 3f. From this pressure chamber 3e the liquid-fibrous mixture is discharged with some force into space 3g through directed and controlled openin-gs constituting nozzles 3h and ori'- tices 3i in a nozzle and orifice. plate 3]'. A 'sufficient quantity of ibre mixture is supplied to establish a circulation or flow inthe same general direction as the movement of forming dies in their passage through this mixture, shown in FIG. 3 as counter clockwise. The surplus liquid mixture ows over a dam 3k at the discharge end of the orifice and nozzle plate, returning to a tank 3L, from which it is again recirculated by pump 3b. Additional liquid-libre mixture is constantly supplied to this tank 3L from any convenient and suitable source. Tank 3L may be located below the tank 3, asis here shown, or it may be mounted in any other convenient place or position so long as it permits the overliow from the formin-g tank 3 to return to it by gravity.

The quantity of liquid-bre mixture furnished by the pump 3b and circulated through the areas 3e and Sgis considerably in excess of that required for the formation of articles on suction dies 9 passing through this area, so that adequate circulation and mixing thereof is maintained, as well as av definite liow of this liquid mixture at generally the same speed and in the same direction that the forming dies move throu-gh it. This direction of ow is partly due to the quantity of material being furnished by the pum-p 3b, partly to the fact that the dies are moving through the mixture in the tank in the same direction as this iiow, and partly to the direction of iiow being urged or accelerated by the shape of the nozzles 3h which direct the flow in the direction of the die movement. However, in order that the fiow through the nozzles Shibe not too directional, or have a tendency to straighten the fibres out in a unidirectional manner, orifices 3i direct intersecting streams at approximately right angles to the streams directed through nozzles 3h.

The general direction of stream through nozzles 3h may be `controlled by proper shaping of the deflecting member overlying each nozzle and the size of the nozzle opening. Similarly the size of orifices 3iV may be modified so that any suitable or adequate dispersion of fibre mixture may be obtained. Thearrows in FIGS. 3 and 4 very clearly show the intermingling of the streams flowing through the nozzles 3h and the orifices 3i. One or more orifices 3i are located to intersect the stream from each nozzle -to break it up in the marmer generally shown by said arrows', so that the pulp fibre mixture is distributed evenly over -all sections of each forming die 9 on which the fibres are deposited to form the article. Any desired number of these nozzles and orifices may be provided.

It is sometimes desirable to have a relatively thin surface coating on one surface of the article for purposes of appearance, strength, utility7 or to facilitate or aid in some subsequent operation on the product itself. To enable articles of this kind to be made by the apparatu-s of this invention, a removable baffle plate 3m may be fixed in the forming tank 3 in the position shown in FIGS. l and 5. This baffle plate serves to deflect a portion .of the fibre mixture supplied through pipe 3f, in the direction Vof die movement, leaving ya relatively quiescent pool 3n of mixture above it. For the fibre mixture supplied through pipe 3f to reach this pool, it would have to flow, which it will not, in a direction contra to die movement, back past the end of this bafiie plate 3m, and also contrary to the general direction of ow of the mixture through 3g. It is thus possible to supply a different fibre -mixture to the pool `area 311 by means of -a pipe Sq and from this pool an initial deposit of fibres may be deposited on the dies 9 as they pass through this area. The quantity of mixture supplied `through pipe 3g is just sufficient to maintain this pool 3u at the same level 3a as that of the pulp level in that end of the main tank 3, and to counteract any tendency for the mixture in this tank to fiow in the reverse direction into the pool 3u. Baflies of different lengths may be used so that lthe size of pool 3u may be increased or decreased as may be desired to produce varying kinds and thicknesses in initial libre deposits on the forming dies. Continued travel of the dies through the space 3g of the tank 3 superimposes additional fibrous material over the material initially accreted on the die surface by continued suction, as `already described.

When some brous materials are utilized, particularly those of waste or other woods of the lower and less expensive grades, it is sometimes impractical to defibre them `as much as is possible where new wood pulps are employed, without losing too much of their strength and 'serviceability. When such materials are molded by suction, there may be a deficiency of the small size fibrous materials in the liquid fibre mixture, thereby leaving a somewhat more open and porous article structure than and lstill utilize waste wood and other inexpensive fibrous materials, it'is possible, iaccording to this invention, to

` supply materials which will properly and effectively close these voids, Yparticularly on the exposed surface or surfaces of the articles while they Iare retained on the vforming die on which they are originally accreted. This l may accomplish by inserting a bafiie plate 3p (FIGS. l .and 6) at the discharge end of the tank 3, sufficiently spaced above the nozzle and orifice plate 3j-so that the regular overiiow of liquid fibrous materials can readily pass beneath this 4baiiie plate 3p, overiiow the end of the plate at 3k, and return .to the tank 3L, to be reciroulated by pump 3b. Due to the rotation of the forming drum 3 and for other reasons, the liquidlevel 3a' at this end of the .tank will be the same or slightly higher than the level 3a at the other end of the tank. 'Ihus the stock fed through openings in the baille 3j will not enter the zones above the baiiies 3m and 3p.

This bafiie plate 3p is removable, but when in use, fits tightly to the end, and both sides of the tank 3, as shown in FIGS. l and 6, to form, in effect, a smalllocalized area therein. Fibrous materials, generally of a fine texture, and of a kind which will interlock with the other materials already accreted on the forming die, are supplied through pipe 31' in sufiicient quantity to provide a filler for the voids which may exist in the accreted article `at this point and effect an adequate filling and surfacing of the entire exposed area of the article as the forming die leaves the fibre mixture in the machine tank. By so depositing such materials through a continuous suction method at the extreme end of the accreting cycle, it is possible to surface-seal the molded article, fill voids therein and prevent undue quantities of air from being drawn through it, thereby enabling the suction to act with more effect to solidify the freshly formed structure, eliminate air voids therein, `and this without requiring the use lof any extraneous means.

After an article has been suction formed on one of the dies 9, as stated, continued rotation of the drum carries the article out of and beyond the tank 3. Since suction is continued through the die, an even solidification is obtained `over the entire article surface `due to atmospheric air pressure `against the exposed surface thereof.

The article thus formed may be subjected to further operations or manipulations while on the forming drum and, as the drum rotates, said article is removed from the drum for use or further. treatment as may be desired and as more particularly described in the parent application.

The foregoing detailed description sets forth the in` vention in its preferred practical forms but the invention is to be understood as fully commensurate with the :appended claims.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

l. Method of molding liber pulp articles which comprises: causing a suction forming die cylinder to rotate in partially submerged position in `a substantially `arcuate pool of pulp, feeding pulp into said pool under pressure through spaced apart pulp inlets at the bottom thereof in a controlled direction substantially corresponding to the direction of rotation of the `die cylinder, and simultaneously feeding additional pulp into the same pool through other interspaced pulp inlets also at the bottom thereof and directing the feed of such added pulp in a different controlled direction than that at which the pulp is fed Vfrom the first mentioned inlets.

2. The method of molding fiber pulp articles in `a pulp molding apparatus wherein a rotary former having dies is positioned Within a tank having' a substantially arcuate plate spaced below the rotary former to provide between the plate and the former a pool of pulp mixture, said method comprising: feeding pulp into the bottom of the pool through a plurality of spaced yapart nozzles in the plate in the direction of the trailing faces of the dies of the former, and simultaneously feeding additional pulp into the bottom of the pool through `a plurality of interspaced feed orifices in the plate in the direction of the leading faces of the dies.

3. In a pulp molding apparatus wherein a rotary former having forming dies is positioned within la tank containing a liquid-pulp mixture with a substantially a1'-l I plate being provided therein with a plurality of nozzles facing in the general direction of rotation of the former to feed the mixture into the pool against the trailing faces of the dies, said plate `also having a plurality o-f orices to feed additional pulp mixture into the pool in a direction of the leading faces of said dies, said nozzles and orifices being interspaced with one another in the direction of travel of the dies. y

4. Apparatus according to claim 3, wherein the streamsl passing through the nozzles and orices are directed at substantially right angles to one another.

5. In a pulp molding apparatus wherein a rotary former having for-ming dies is positioned within a tank containing a liquid-pulp mixture with a substantially arcuate plate within the tank below the rotary former to provide between the plate and the former a pool of pulp mixture, the improvement which comprises: a bafe mounted at the inlet end of the tank and projecting an appreciable distance in the direction of rotation of the former into the pulp pool between the plate and the former, means for feeding one kind of fiber-pulp mixture into the pool above said bafe, and means for feeding another type of fiber pulp mixture into the tank below the plate, said plate being provided therein with a plurality of nozzles facing in the general direction of rotation of the former to direct feed of pulp from below the plate into the pool above the plate in the general direction of rotation of the former, and said plate also having a plurality of interspaced orices to direct a further portion of such mixture from below the plate through said orifices vinto the pool in an `angular direction intersecting the direction of feed of the pulp mixture through the nozzles.

6. Apparatus according to claim 5, wherein the opposite end of the tank is provided with an overow above the plate for maintaining a substantially constant pulp bre mixture level in the pool and is also provided at the same end of the tank with a bafe extending into the tank above the overflow with means -for introducing a predetermined kind of pulp into the tank above the latter baille.

References Cited in the le of this patent UNITED STATES PATENTS 1,360,684 Roberts Nov. 30, 1920 1,707,429 AChaplin Apr. 2, 1929 1,838,904 Chaplin Dec. 29, 1931 1,884,583 `Crawford Oct. 25, 1932 1,907,046 Darrah May 2, 1933 2,528,189 Temperley Oct. 31, 1950 2,951,784 Moore Sept. 6, 1957

Claims (1)

1. METHOD OF MOLDING FIBER PULP ARTICLES WHICH COMPRISES: CAUSING A SUCTION FORMING DIE CYLINDER TO ROTATE IN PATIALLY SUBMERGED POSITION IN A SUBSTANTIALLY ARCUATE POOL OF PULP, FEEDING PULP INTO SAID POOL UNDER PRESSURE THROUGH SPACED APART PULP INLETS AT HTE BOTTOM THEREOF IN A CONTROLLED DIRECTION SUBSTANTIALLY CORRESPONDING TO THE DIRECTION OF ROTATION OF THE DIE CYLINDER, AND SIMULTANEOUSLY FEEDING ADDITIONAL PULP INTO THE SAME POOL THROUGH OTHER INTERSPACED PULP INLETS ALSO AT THE BOTTOME THEREOF AND DIRECTING THE FEED OF SUCH ADDED PULP IN A DIFFERENT CONTROLLED DIRECTION THAN THAT AT WHICH THE PULP IS FED FROM THE FIRST MENTIONED INLETS.

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