US2749814A - Process and apparatus for mechanically working fibrous materials - Google Patents

Description

June 12. 1956 A. J. HAUG 2,749,314

PROCESS AND APPARATUS FOR MECHANICALLY WORKING FIBROUS MATERIALS Filed Jan. 22, 1955 2 Sheets-Sheet l lNVEN TOR M J ATTORNEY June 12. 1956 A. J. HAUG PROCESS AND APPARATUS FOR MECHANICALLY WORKING FIBROUS MATERIALS 2 Sheets-Sheet Filed Jan. 22, 1953 United States Patent PROCESS AND APPARATUS FOR MECHANICALLY WORKING FIBRGUS MATERIALS Anton J. Hang, Nashua, N. Application January 22, 1953', Serial No. 332,726

9 Claims. (Cl. 92--27) This invention relates to a machine for processing fibrous materials, and more particularly to a machine for mechanically working fluid masses of fibrous materials of the type employed in the paper making art.

In conventional procedures for processing pulp fibers and preparing these fibers for the paper making process, an effort is made, in many cases, to mechanically work the fibers so as to produce separated fiber ends Without unduly shortening the fiber lengths. These separated fiber ends greatly facilitate felting action on the wire machine and thereby provide for a smooth felted sheet of fibers being formed. However, in conventional methods of thus forming separated fiber ends the tendency is for the fiber ends to occur only at the extremities of the respective fibers. Treatment of fibers in this way is commonly referred to as fibrillation. It would, of course, be very desirable to provide for a much greater occurrence of separated fiber ends throughout the fiber bodies and particularly at intermediate portions of the fiber bodies. In this connection, for example, it may be noted that conventional procedures for inducing fibrillation are not suitable for working cotton fiber, although there are definite advantages to be derived from employing such a fiber stock. When cotton fiber is processed by conventional fibrillation methods there results a stock which is either of very short fiber length, in which case the stock cannot be made into a sheet of satisfactory strength, or the stock may tend to lump and provide a sheet of cloudy appearance.

The present invention aims to deal with the problems indicated and to devise generally improved methods and apparatus for processing fibrous materials and inducing fibrillation in such materials, particularly fibrous matter, as cotton fiber. It is also an object of the invention to provide means for inducing a more uniform processing of fibers whereby swelling of the fibers is brought about and simultaneously accompanied by a stressing of intermediate body portions of the fibers, with the result that short separated fiber ends are caused to stand out from these intermediate body portions of the respective fibers substantially throughout their length.

These and other objects and novel features will be more fully understood and appreciated from the following description of a preferred embodiment of the invention selected for purposes of illustration and shown in the ac companying drawings, in which Fig. 1 is a side elevational view, partly in cross-section, illustrating onepreferred embodiment of the invention;

Fig. 1A is a plan cross-section taken on the line 1A-1A of Fig. 1;

Fig. 2 is a plan cross-section taken on the line 2-2 of Fig. 1;

Fig. 3 is a side elevational view of a rotating cone member forming a part of the mechanism shownin Fig. 1 and being shown entirely removed from this structure;

Fig. 4 is a bottom plan view of the cone member shown in Fig. 3;

Fig. 5 is an enlarged photographic showing of fibers in the condition in which they occur as they are introduced to the processing machine of the invention;

Fig. 6 is another enlarged photographic showing further indicating fibers corresponding to those shown in Fig. 5 but in a condition resulting from being treated in the apparatus of the invention.

In accordance with the invention I have discovered that surprising and unusual improvements in the art of fibrillating a fluid mass of fibers may be achieved by a novel cycle of fiber working operations continuously repeated at a relatively rapid rate.

I find that such a cycle is comprised by first subjecting a fluid mass of fibers to compressive forces which operate to cause fibers, or bundles of fibers, to twist and curl upon themselves, and by thereafter abruptly releasing the fibers from the effect of the compressive forces for short intervals during which the fibers seek to untwist or uncurl and revert to a relatively straightened condition.

As a result of this continuous twisting and untwisting action carried on for sustained periods, the fibers, it is found, become over-stressed all along their lengths and fiber shredding tend to develop at many points along the fibers with the formation of tiny fibriles or broken fiber ends which stand out from the main body of fiber in positions to exercise an extremely desirable felting action. Such a method of working fibers may be conveniently referred'to as spiral fibrillation, as distinguished from conventional types of fibrillation in which the fibers are mechanically Worked into short lengths and the fiber ends at the extremities of the short lengths are separated from one another to constitute the felting agency.

I have further discovered that by subjecting the fibers to the spiral fibrillation process of the invention I am enabled to provide for a desirable swelling of the fibers to an extent comparable with that obtained by conventional fibrillation and, at the same time, I am enabled to avoid breaking the fibers into undesirable short lengths and, with the relatively longer length thus achieved, better felting strength in the felted product may be realized.

In carrying out my improved method I have further devised novel apparatus for inducing spiral fibrillation, and the mechanism shown in Figs. 1 to 4, inclusive, is illustrative of one preferred form of such apparatus. In general, the apparatus includes a pair of cooperating fiber working members arranged in close proximity to one another to comprise a fiber conduit with at least one of the said members being rotatable. Built into these fiber working members are two distinct instrumentalities. One of these consists of special fiber-engaging means and operates to provide for a twisting and rolling of the fibers upon themselves; the other of which consists of fiber cornpacting means operating to apply compressive forces'for short intervals to the twisted fibers, and thereafter to abruptly release the twisted fibers from compressive forces so that an opportunity for untwisting and unrolling is provided.

I have discovered, that by forming in adjacent surfaces of the fiber working members two sets of small craterlike openings, there is produced a multiplicity of curved edges, and when one set of openings is rotated relatively to the other, the curved edges constitute special fiber engaging means having the ability to twist and roll fibers upon themselves in an unusual manner.

I further find that by constructing one of the fiber working members with elongated stepped or raised portions there is obtained a means of periodically applying compressive forces to the twisted fibers, and at predetermined points releasing these fibers from compressive forces.

Considering the above described features in greater detail, attention is directed to the structure illustrated in Figs. 1 to 4, inclusive, wherein numeral 10 denotes a base member in which is mounted a bearing 12. Adjustably supported in spaced relation above the base on threaded spacing bolts 14 is a bearing plate member 16 of generally triangular shape, as may be more clearly seen from an inspection of Figs. 1 and 2. Rotatably received in the bearing 12 is one end of a power driven shaft 18. This member at its intermediate portions is rotatably supported in a bushing 20, in turn secured in the plate member 16. Fixed to the shaft 18 is a pulley 22 driven by a belt which has not been shown. but which may be of a conventional type. Portions of the shaft 18 occurring between the bushing and the pulley extend through an oil trapping well 24, and by means of this arrangement the shaft may be fully lubricated.

Fixed to the upper end of the shaft 18 by means of a pin 26 is a fiber working member 28 constituting one of the pair above referred to, which fiber working member has a conically shaped formation with the base or larger section of the cone occurring at the bottom of the member, as viewed in Figs. 1 and 3. The cone member '28 has its base recessed to provide an annular cavity 136' into which projects the bushing 20, as well as annular supporting portions of the bearing plate 16 in which the bushing it fitted.

At its upper outer portions the bearing plate 16 is recessed to provide an annular shoulder 32 and an upstanding rim portion 34. Received on the shoulder 32 in fitted relationship within the rim 34 is a sleeve member 36 which supports an annular member 38 which constitues the second fiber working member of the above described pair. The member 38 preferably consists of a stationary tubular body having a conically shaped opening formed axially therethrough and of a shape and size adapted to enclose and lie in slightly spaced relation with respect to the outer surface of the conically shaped fiber working member 28, and to thus comprise an annular conduit having a fiber passageway 42. At its upper end the fiber working member 38 is provided with an inlet port 40 which communicates with the annular passageway 42 and constitutes a means of inducing fluid fibrous material into the machine, as has been diagrammatically indicated in Fig. l.

Securely attached around the outer surface of the conically shaped member 28 is a fiber engaging element 44 which may conveniently consist of a thin conical sheet or layer of metal which is interrupted at separated points therealong to form a series of spaced-apart crater-like openings 46 which provide curved fiber engaging edges lying in the plane of the cone surface. These openings 46 are better shown in Fig. 2. Similarly, the fiber working member 38 is provided at its inner surface with a conical fiber engaging member 48 consisting of a thin sheet of metal, or other suitable substance, which constitutes a liner and which is also interrupted throughout its surface at separated points therealong to form craterlike openings 50.

The openings 46 and 50 cooperate with intervening smooth surfaces of their respective body portions 48 and 44 to constitute an annular fluid conduit, the surfaces of which are adapted to guide and gradually compress fibers as they pass downwardly from the inlet port 40 to the base of the cone member. As the cone member 28 rotates, the concaved and curved edges of the openings 50 seek to engage and hold fibers at one side while the convex and curved edges of the openings 46 seek to engage the fibers from an opposite side and twist and turn the fibers upon themselves. In some cases the fibers may be twisted individually and in other cases they may be twisted in bundles or groups.

' A further important feature of the apparatus described is the provision on the conical member 28 of stepped portions 62 and 64 which constitute fiber compacting means, as noted above, and which extend from top to bottom of the conically shaped body on two opposite outer sides thereof, as shown in Figs. 2, 3 and 4. These stepped portions increase radially with respect to the central axis of the conicallyshaped body from top to bottom thereof and provide fiber releasing spaces, as 66, best shown in Fig. 2. It will be apparent, therefore, that when the member 28 is rotating, these stepped portions provide for a progressive application of compressive forces which increase in magnitude for a limited period and act on twisted fibers which pass down between the annular passageway 42. Periodically, however, the compacted fibers are abruptly released from these compressive forces as they pass around into the spaces 66. If desired, the magnitude of the annular passageway 42 may be varied by suitable adjustment supporting structure for either one or the other of the two fiber working members 2S and 38. For example, the bearing plate 16 may be vertically adjusted on the supporting bolts 14 to raise or lower the member 38, and various other arrangements may be resorted to.

When the fibers reach the bottom of the passageway 42 they pass into another annular fiber discharge passageway 54 which is formed in the upper side of the bearing plate 16 in a position to communicate with the passageway 42, as is better shown in Fig. 1 of the drawings. At one side of this annular discharge passageway there is further provided an outlet chute 56 through which processed fibers may leave the machine and to facilitate exit of the fibers I may provide a clearer element 58 consisting of a vertically depending angle piece attached by a bolt 60 to the bottom of the conical member 28, as shown.

In accordance with the invention I employ the above described apparatus to successfully work various fibrous material and particularly cotton fiber. In operation a fluid mass of cotton fiber of some desired consistency is fed into the inlet port 40, and due to the conical shape of the fiber working member 28, and also due to gravity, the fibrous material is gradually drawn toward the lower end of the fiber passageway 42; then into the discharge passageway 54; and finally out through the discharge chute 56.

The member 28 is revolving in the direction indicated by the arrows in Fig. 2 at a relatively high speed during this movement of the fibers and, because of this fact, the fibers usually in bundles, although in some cases individually, are rolled into twisted bodies or nodules with the crater-like openings of the fiber working member 38 acting to hold the nodules at one side so that rolling action can take place in response to the twisting action exerted by the crater-like openings in the revolving fiber working member 28. The nodules thus formed are of appreciable size and tend to increase in magnitude as they pass down through the fiber passageway 42. However, it is pointed out that they must work through a gradually diminishing clearance and therefore are subjected to increased pressure as they work down through the machine. It will also be apparent that these nodules in their passage through the machine are constantly undergoing a periodic increasing and decreasing pressure cycle due to the stepped portions on the fiber working member 28. The release of pressure in this cycle provided by the stepped portions permits the nodules to change position and to open and start to untwist or unroll in seeking a normal straightened position. This action has the effect of controlling the forming of the nodules so that they are not allowed to build up to too large a size.

The combined action of the fiber engaging surfaces and the stepped portions is to twist and curl the fibers all along their length, dividing the fiber bundles and fibrillating individual fibers without breaking them, as may be more clearly observed from a comparison of the fiber bodies shown in Figs. 5 and 6. The fibers of Fig. 5 represent stock of cotton fiber type prior to processing in the machine of the invention and occurring in a condition in which it is known that unsatisfactory felting will take place if the fibers are passed over a wire machine.

Fig. 6 shows fibers of the same stock after having been passed through the machine of the invention. A very important difference may readily be observed by closely inspecting the fibers in the two figures and comparing them. Whereas the fibers of Fig. have separated fiber ends only at the extremities of the fiber bodies, in the case of the stock of Fig. 6 it will be seen that there are tiny separated fiber ends which stand out from the fibers at many points along the fibers, and particularly at intermediate parts of the fibers where it is important to incerase the occurrence of these fiber ends.

In actual tests of material treated by the spiral fibrillation of the invention, it has been found that relatively weak fibers, such as cotton fibers, can be worked to produce a stock which has appreciably greater felting strength without necessarily shortening the fibers themselves. As a result, it has been found practical to utilize cotton fiber in the paper making process with the production of a satisfactorily smooth felted sheet of material. It should be understood, however, that the machine may be used to obtain specific desired results with all kinds of paper making fibers in order to incorporate increased strength and improved binding qualities.

I may also provide modified forms of fiber working apparatus in which the fiber engaging surfaces and stepped portions already described are combined with different types of fiber working members.

It will be seen that I have provided a novel method and apparatus for mechanically working fibrous materials, whereby a special type of fibrillation can be carried out and by means of which a wide range of fibers can be treated to impart greater felting strength and combining qualities when used in the paper making process. By means of this invention ditficult types of subject matter, such as cotton fibers, can be successfully utilized and various other advantages realized.

While I have shown preferred embodiments of the method and apparatus of the invention, it should be understood that various other changes and modifications may be resorted to in keeping with the spirit of the invention as defined by the appended claims.

Having thus described my invention, what I desire to claim as new is:

1. A machine for processing a fluid mass of fibrous material comprising a pair of tubular fiber working members concentrically arranged in close proximity to one another but in such spaced-apart relation as to define a relatively narrow conduit through which fibrous material may pass, inlet port means for guiding fibrous material into the said conduit, means for producing rotative movement of at least one of said fiber working members, fiber engaging surfaces formed in said fiber working members, said surfaces being interrupted to form a plurality of spaced-apart crater-like openings which have curved edges lying in the plane of said surfaces, said curved edges being adapted to cooperate with one another to roll without breaking the fibers into twisted formations, and one of said fiber engaging surfaces being provided with stepped portions which gradually approach and then abruptly depart from immediately adjacent portions of the other of said fiber engaging surfaces to provide spaces in which fibers rolled into twisted formations may seek to uncurl.

2. A machine for processing a mass of fibrous material comprising a pair of tubular fiber working members eoncentrically arranged in spaced-apart relation to define a fiber passageway which varies in magnitude, means for producing rotative movement of one of the said fiber working members, one of said fiber working members comprising a casing member having a conically shaped opening extending axially therethrough, the other of the said fiber working members comprising a conically shaped body presenting a surface generated by a line that moves around an axis while continuously changing its angle with respect to the axis.

3. A machine for processing a mass of fibrous material comprising a base, a bearing member mounted in spaced relation to the base, power driven rotor means supported in the base and guided in said bearing, a casing secured at the upper side of the bearing and having a conically shaped opening formed therein, a conically shaped body lying in spaced relation to the casing in the conically shaped opening and fast on said power driven rotor means, said conically shaped body being formed with interrupted fiber engaging surfaces, said fiber engaging surfaces being generated by lines that move around a common axis while continuously changing their angles with respect to the axis to form fiber uncurling spaces and said bearing being further constructed with an annular fiber discharge passageway communicating with the space between the conically shaped body and said opening.

4. A machine for processing a fluid mass of fibrous material comprising a pair of fiber working members arranged in spaced-apart relation to one another to define a relatively narrow annular passageway through which fibrous material may be moved, inlet port means for dividing fibrous material into said passageway, means for producing rotative movement of at least one of the said fiber working members, fiber engaging surfaces formed in said fiber working members, said fiber engaging surfaces including a surface generated by a line that moves around an axis while continuously changing its angle with respect to the axis.

5. A structure as defined in claim 4 in which the said generated surface further terminates abruptly in a step defined by a change in angle of the said generatrix line along an inward radial path.

6. A structure as defined in claim 4 in which the said generated surface terminates in a plurality of steps defined by changes in angle of the said generatrix line along inward radial paths.

7. A structure as defined in claim 4 in which the said generated surface further terminates abruptly in a step defined by movement of the said generatrix line along an inward radial path for a short distance, each of said fiber engaging surfaces being further interrupted to form a plurality of spaced apart crater-like openings which have curved edges lying in the planes of said surfaces, said edges being adapted to cooperate with one another to roll the fibers into twisted formations.

8. That improved method of processing fibrous ma terial which comprises conducting a fluid stream of fibrous material through an annular conduit, engaging constituent fibers of the said material, and twisting the fibers upon themselves, and simultaneously exterting a progressively increasing pressure on the twisted fiber portions.

9. A method as described in claim 8, including the further step of periodically releasing pressure on the twisted fibers and guiding them into a region in the annular conduit where the twisted fibers are free for a short interval to untwist and seek a substantially straightened position.

References Cited in the file of this patent UNITED STATES PATENTS

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