US3056172A - Method and apparatus for reconstituting fibrous material - Google Patents

Description

Det. 2, 1962 w. H. PRENTlcE Erm. 3,056,172

METHOD AND APPARATUS FOR RECONSTITUTING FIBROUS MATERIAL Filed April 13, 1959 WILL/AM H. P05/vm? V/Ncsur l( mx IN VEN TORS @f-QM A rTokA/EYS United States Patent Office 3,056,172A Patented Oct. 2, 1962 3,056,172 lifiETiGD AND APPARATUS FOR RECONSTI'IUT-` ING FIBROUS MATERIAL William H. Prentice, Newark, and Vincent V. Link,

Hanover, Ohio, assignors to Owens-Corning Fiberglas Corporation, a corporation of Delaware Filed Apr. 13, 1959, Ser. No. 805,872

8 Claims. (Cl. 19-96) t This invention relates to method and apparatus for processing and reconstituting siliceous fibrous material, and more particularly to reconstituting mats, batts,

lankets, and boards of fibrous glass into small, relatively open, aggiomerations of fibers of variable lengths.

ln processing fibrous glass mats, batts, blankets or boards for various end uses such as appliance insulation, house insulation, acoustical insulation, pipe insulation and the like, various `amounts of trim materials are produced when converting the aforementioned forms to the introduction and installation of fibrous insulation in the usual mat, blanket, batt, or board forms.

The trim materials produced in Various standard fibrous glass forming processes vary widely in density, depending upon whether they are trimmed from mats, batts, or blankets, or whether they are gathered during a boardforming process. The range of densities resulting from the aforementioned variables may `be considered from about 1,42 pound per cubic foot to 14 pounds per cubic foot or above. The binder content in the trim materials is in the cured stage whether the fibrous glass material is in blanket or board form.

ln the past, no satisfactory method for reconstituting haphazard or regulated mixtures of lower density fibrous materials and the higher density board-like products has been found, and attempts to process mixtures of trim of this nature were not always successful in producing a product with the necessary properties for a satisfactory blowing wool thermal insulation. These materials failed in meeting standards for a commercial product in many respects, such as too great variations in density from sample to sample of the product, and because of large unreeonstituted chunks of interbonded fibrous material remaining in the product.

These difculties have been substantially overcome through the utilization of the method and apparatus of this invention.

Therefore, it is a principal objectrof this invention to provide method .and apparatus for reconstituting siliceous fibrous materials of varying density concomitantly into tufts of suitable size and thermal characteristics for utilization as blowing wool.

It is a further object of this invention to provide method and apparatus for reconstituting siliceous fibrous material into tufts of fibers suitable for utilization in pneumatically operated insulation distributors.

It is a further object of the present invention to provide novel method and apparatus for producing tufts of siliceous fibers, particularly glass fibers, the original stock of the fibers being in the form of mats, batts, blankets, and semi-rigid boards, or from the trim materials of fibrous materials in the aforementioned form.

A further object of this invention is to provide method and apparatus for reconstituting binderless or bonded fibrous material, or mixtures thereof.

A further object of this invention is to provide method and apparatus whereby trim materials from fibrous glass processes may be shredded in the form of useable tufts of fibers.

It is an ancillary object of this invention to provide novel method and apparatus for reconstituting fibrous material in an economic manner at high speeds.

Other objects and advantages Within the contemplation of the present invention will become `apparent from the following description taken in conjunction with the drawings, in which:

FIGURE 1 is a side elevational view partially broken away, and partially in section, of an embodiment encompassing the principles of this invention; and

FIGURE 2 is a perspective drawing partially broken away of the feeding and shredding components of the assembly illustrated in FIGURE 1.

Referring to the drawings in greater detail, FIGURE 1 discloses siliceous fibrous material 10 of varying densities with the binder additive in the cured stage or possessing no binder at all. The siliceous material may be in the form of mats, batts, blankets, boards, or trim material from such forms. The materials may be deposited on top of the endless conveyor belt 11 manually, or mechanically from suitable storage bins not shown. Mechanisms such as surge bins with coacting automatic weighers may be used to control the blend of fibrous material introduced to the conveyor.

The endless conveyor belt 11 is driven by a suitable mechanical means such as a drive wheel 13 mounted on a drive shaft 14 and actuated by and linked to a suitable drive mechanism not shown.

Mounted above and aligned with the endless conveyor belt 11 is another endless conveyor belt 12 which is rotatcd in a direction opposite to the endless conveyor belt 11 to provide movement of the opposing belt faces, in the same direction as shown by the arrows indicating the respective movements of the belts.

The endless belt 12 is resiliently mounted on suitable springs or the like to provide a convergence with the material being conveyed by endless belt 11. rThe spring mounting provides for positive engagement of the siliceous fibrous material being conveyed on endless belt 11 and effects a positive feed of the materials to the upper and lower feed rolls 15 and 16. The endless conveyor belt 11 is generally longer than the spring mounted endless conveyor belt 12 to provide for free fiow thereon of the materials to be reconstituted.

The endless conveyor belts 11 and 12 may be run at different speeds. For example, it maybe desirable to run the endless conveyor belt 12 faster than the endless conveyor belt 11 to provide for differences in the angle in which the material will leave the conveyor belts. 'However, it is generally the practice to run both belts 11 and 12 at the same speed. The speed of the belts is generally the same or slightly less than the surface speed of the feed rolls 15 and 16.

The materials for the endless conveyor belts 11 and 12 are not deemed critical. They may be fabric or metallic mesh, and a neoprene coated fabric has proved eminently satisfactory.

The siliceous fibrous material 10 is delivered by the endless conveyor belts 11 and 12 into the bite of opposed, rotating feed rolls 15 and 16. The lower feed roll 16 is fixedly mounted on a drive shaft 18 which is suitably journaled and driven -by a linkage and drive mechanism not shown.

The upper feed roll 15 is mounted on a drive shaft `17 and may be driven by the same linkage and drive mechanism as the lower feed roll 16', or it may be provided with an independent linkage and drive mechanism.

Whatever suitable linkage and drive mechanism is ernployed, or whether .they are employed independently or not, it is necessary that the feed rolls be rotated in opposite directions with the lower feed roll being rotated in a clockwise direction and the upper feed roll in a counterclockwise direction.

The upper feed roll is resiliently mounted to provide a fioating action under a downwardly exerted force supplied by suitable mechanisms, such as coil springs, operating on the feed roll 15 at the points where it is journaled. This floating action provides adjustment for differences in thickness and density of the material that is being fed by the rolls and further provides a positive feed of the material to tearing action of the teeth 33.

In addition to the positive action of the fioating roll, the feed rolls are fluted to provde gripping ridges 19 and 20 which run longitudinally along the outer circumference of the feed rolls. These ridges 19 and 20 engage themselves into the fibrous material 10 being fed therethrough, and in addition to providing a positive feed, they retain the fibrous material 10 against the tearing action of the teeth 33 impinging against the fibrous mass. The feed rolls 15 and 16 are generally rotated at the same r.p.m., though it may be possible to change the angle of feed from the rolls by operating one roll at a slightly greater speed than the other. This rpm. differential may be effected without substantially tearing the fibrous material 10 fed therethrough.

Suitable feed roll guard plates 21 and 22 are disposed above and below the feed rolls 15 and 16 for safety purposes and to seal against air flow.

The tearing and shredding mechanism consists of a series of rotatable wheels 30 mounted on a common drive shaft 31. A series of teeth retaining bars 32 are secured by weldment or other suitable means to the outer circumference of the wheels 30 transverse to the wheels and generally parallel to the common drive shaft. The area between the bars is open and the bar and wheel assembly might be said to resemble a squirrel-cage.

The circumferential area open between the bars 32 may be partially or totally closed with suitable plates, but it is preferred to have an open area to reduce the mass at the outer periphery of the wheels becauseof the high rotational speeds at which the tuft tearing assembly operates, and further, the open structure tends to prevent jamming and promote tumbling recirculation of tufts which are not propelled from the shredding zone.

Perpendicular to the bars 32 and extending radially therefrom are teeth 33, the shank of each being threaded through a bar 32 and affixed with a suitable retainer nut 34. The assembly of the wheels 30, bars 32, and teeth 33 is enclosed about its lower periphery by a shredding plate 35 which has lbeen provided with multiple openings 36 and about its upper periphery by curved guard plate 37. The shredding plate 35 and curved guard plate 37 are suitably mounted at hinge 38 and a seal is provided at the hinge mounting to prevent escape of the material carried by the teeth 33 and to restrict air ow. The opening between feed roll guard plate 22 and shredding plate 35 is covered by seal 40. Seal 41 provides a similar closure between feed roll guard plate 21 and curved guard plate 37.

A particular advantage of this invention is that the fibrous material 10 may be of great variance in density. For example, low density, 2 to 3 pounds per cubic foot mat may be superimposed or mixed with high density, 11% pounds per cubic foot board on the endless belt 11 and the superimposed material fed into impinging relation with the teeth 33. The teeth 33 claw the superimposed iibrous materials into tufts 42 and move the tufts over a perforate surface so that tufts of certain size pass through openings in the surface. Tufts which their initial contact therewith are carried around by movement of the teeth and again over the perforate surface. This action continues until all tufts pass through openings in the surface. The majority of tufts may pass through the openings in the surface during their first contact therewith.

Apparently in this operation the teeth 30 engage and impinge, generally tangentially, the fibrous material 10 being fed and gripped by the feed rolls 15 and 16 and small tufts 42 of fiber are torn from the fibrous material in a manner to break the bonds between fibers and thereby form relatively open tufts. The tufts are carried along on the teeth 33 to the zone of the perforate shredding plate 35. There the tufts are brought into impacting er1- gagement with the shredding plate 35 where a shredding or grating action takes place to further break bonds between fibers and to interfelt the tufts which when they are suitable size pass through the openings 36 in the shredding plate 35 in interfelted tuft-like form 47. The tuft-like material 47 passing through the openings 36 in the shredding plate 35 freely falls through the collecting hood 43 onto an endless conveyor belt 44 actuated by drive roll 45 mounted on drive shaft 46, which is connected to a suitable drive mechanism not shown. The deposition of the tufts onto the endless belt 44 may be aided by a suction box, not shown.

It is desirable to provide as many openings 36 in the shredding plate 35 as is compatible with maintaining the structural strength of the plate, and in maintaining sufficient working surface in the bridging webs between the openings to establish a Working effect on the fibrous material carried over the intersurface of the bridging network. In processing 1/2 pound to 14 pound density fibrous glass material a bridge between the openings 36 was most effective.

The size of the openings 36 in the shredding plate 35 are a function of the size desired in the tufted product. The openings 36 are preferably circular, though rectangular, square, or triangular openings are suitable. If triangular openings are used, the preferred orientation is with the apex facing in the direction of fiow of the fibrous material over the shredding plate 35. The area of the openings 36 of course affects the degree `of shredding and interfelting of the tufted material brought in contact therewith and are generally of a smaller area if the fibrous material being reconstituted is of very light density. The opening area 36 serves to govern the size of the worked tufts that may be passed therethrough and prevents any clumps or large chunks of tufts from passing therethrough. Tufts which contain clumps or large fibrous chunks are subjected to a recirculating or tumbling action by the teeth 33 to size them to the proper dimension for passage through the openings.

In operation, the fibrous material being fed and retained between the feed rolls 15 and 16 is engaged by and irnpinged by the rapidly moving picker teeth 33 which tear, comb, and open groups of fibers, from the mass of fibrous material being fed by the feed rolls, into tufts of fibers which are engaged about and extend downwardly from the outward extremities of the teeth 33. The tufts which are engaged `on the individual teeth are rubbed between the outer extremities of the teeth 33 and the inner surface of the shredding plate 35. This rubbing and shredding action serves to further break resin bonds between the fibers in the tufts, interfelt, and add integrity to the individual tufts. This shredding or grating action on the tufts held on the outer extremities of the teeth 33 sizes the tufts to the proper dimension to pass through the openings in the shredding plate 35. If the tufts have not been sutiiciently compacted or interfelted to pass through openings 36 in the shredding plate 35, they are either carried around by the teeth and recirculated to the tearing and the shredding action, or if they are dislodged from the teeth carrying them, they are engaged by the teeth on succeeding bars do not pass through the openings in the surface during and tumbled and rubbed for passage through the openings 36in the shredding plate 35. This action insures that no large unopened chunks of heavy density material are incorporated as constituents of the tufts, and that no large clumps, or chunks of fibrous material pass into the tufted mass being collected.

The teeth employed in this mechanism may be modeled after conventional types of picker teeth such as lag-type, chisel-type, or hook-type. The hook-type tooth has proved particularly adaptable to reconstituting fibrous glass materials. The tooth generally has a hook point at its outward extremity, and a relatively sharp leading edge which broadens out, as from the apex of a triangle, towards the rear of the tooth. Hook teeth are particularly effective because they positively empale the fibrous material around and extending downwardly from their outer extremity, and provide for a positive shredding action on the tufts between the teeth 33 and the shredding plate 35.

The dimension between the outermost extremities of the teeth 33 and the inner surface of the shredding plate 35 is of a critical nature in that to provide a proper shredding effect the distance between the inner surface `of the shredding plate and the extremities of the teeth should be smaller than the general expanded condition of the tufts of fibrous material carried by the teeth 33.

The teeth 33, in addition to mechanically impacting the tufts through the openings 36 in the shredding plate 35, by their rapid movement apply centrifugal force to the tufts of fibers to move them through the openings though the movement is believed to be mainly mechanical.

The relationship of the speed at which the fibrous material to be reconstituted is fed into engaging impingement with the teeth 33, the nature and density of the fibrous material, the number and working length of the teeth 33, the number of teeth containing bars 32, the lineal speed of the teeth impinging the fibrous material, the distance between the extremities of the teeth 33 and the working surface of the shredding plate 35, the size openings 36 in the shredding plate 35 all effect the nature of the tufts formed by this invention. Satisfactory operations have been obtained by proper varying of the aforementioned conditions either singly or severally. Generally, the most satisfactory results are obtained when the surface speed at which the fibrous material to be reconstituted is fed, is much lower than the surface speed at which the teeth impinge the fed fibrous mass, and the working distance between the outward extremities of the tuft containing teeth 33 and the inner surface of the shredding plate 35 is less than the dimensions of the tufts torn from the fibrous mass. For a given surface speed of the feed rolls 15, 16 there is an optimum surface speed at which the teeth 33 will impinge the fibrous material, which will yield a product of significantly lower bulk density. For example, the most satisfactory results in reconstituting fibrous glass in the 1/2 to 111/2 pound per cubic foot density range for blowing wool were achieved utilizing the following:

Working distance between inner surface of the shredding plate and the outward extremities of the teeth Mt". Number of teeth containing bars equally spaced about the circumference of the wheels 8 Diameter from center of drive shaft to pin extremities 26".

The tufted materials after exit through the openings 36 in the shredded plate 35 may be collected by suitable 75 means and packaged for use as thermal insulating materials such as blowing wool, or with additional resinous type binders the tufts may be molded under heat and compression to suitable products such as insulating board, cushioning board, blocks, or the like.

While this invention has been described primarily in connection with reconstituting siliceous fibrous material, and particularly fibrous glass, it is readily apparent that other fibrous materials such as mineral, organic, natural, or synthetic fibrous materials may be similarly processed. It is also apparent that within the scope of this invention various modifications and differing arrangements may be made other than are herein disclosed.

We claim:

1. The method of reconstituting siliceous fibrous material comprising establishing a supply of fibrous material, feeding fibrous material from the supply in a continuous manner, clawing the continuously fed fibrous material to tear away and open a plurality of tufts of fibrous material therefrom, rubbing and grating the opened tufts of fibrous material by movement of the tufts in contacting relation over a perforate surface to interfelt the fibrous material in the tufts to form smaller tufts for passage through the perforations of the surface, and passing the interfelted tufts through said perforations.

2. A method for reconstituting fibrous material including the steps of feeding a mass of fibrous glass materials of varying densities concomitantly, tearing tufts of the aforesaid fibrous glass material from the mass, and rubbing and shredding the tufts of fibrous glass material in contact with a perforate surface to interfelt the fibrous glass material in the tufts and reduce their size for passage through the perforations of the surface, and recirculating to the perforate surface any tuftsof the fibrous material which have not been sufficiently interfelted and sized to pass through said perforations.

3. The method for processing and reconstituting fibrous material, including the steps of continuously feeding to a given zone fibrous glass, from a brous glass mass containing fibers interbonded to different degrees of density, clawing said continuously fed fibrous glass in said zone, and disecting said fibrous glass into tufts, shredding and rubbing said tufts of fibrous glass in a restricted zone bounded 'by a perforate surface to interfelt the fibers within the tufts into relatively open agglomerated form restricted at least to a predetermined maximum graded size, screening tufts of the desired size through said perforate surface, and rubbing the unscreened tufts across and against the perforate surface to reduce their size for passage through the perforations.

4. Apparatus for reconstituting siliceous fibrous material comprising feeding means to continuously feed a fibrous mass of said material, tearing and opening means comprising a rotatable surface with a plurality of rows of spaced teeth affixed thereto and extending radially therefrom adjacent said feeding means oriented to irnpinge said mass, and to tear away and open a plurality of fibrous tufts from the fibrous mass, a perforate shredding plate in a concentric, closely spaced relationship with the tearing means to cause a coaction therewith to interfelt the fibers of said tufts.

5. Apparatus for reconstituting fibrous glass materials comprising means for continuously feeding a fibrous glass mass, a rotatable surface adjacent said feeding means, claw shaped teeth affixed to and extending radially from the rotatable surface to continuously and consecutively impinge the fibrous glass mass to tear tufts therefrom, a perforate shredding surface concentrically spaced about the lower half of said rotatable surface and at predetermined distance from the outer extremities of the aforesaid radially extending teeth, said predetermined distance being smaller than the maximum dimension of the aforesaid tufts.

6. The method for reconstituting siliceous fibrous material comprising continuously feeding a mass of the siliceous fibrous material, tearing away from the fed material and opening with a claw like action clumps of the aforesaid material, transporting the clumps of fibrous material to a perforate surface, grating said material by moving the clumps of material over the perforate surface in intimate engaging relationship therewith, and concomitantly piercingly impinging the bers of said clumps repeatedly to interfelt the fibers and to reduce said clumps to a smaller size, screening through said perforate surface clumps of fibers reduced in size to a degree sufficient to pass through the perforations, and recirculating the remainder of the clumps passed over said surface to return them to said surface for regrating to the size for ultimate passage through said perforations.

7. Apparatus for reconstituting siliceous fibrous mater rial comprising feeding means for continuously supplying a siliceous fibrous mass, a perforate surface disposed adjacent said feeding means, a rotating clawing means adjacent said feeding means and disposed above said perforate surface oriented in relation to the feeding means to effectively claw the fibrous supply during rotation and thereby tear a plurality of fibrous tufts from said fibrous mass, said perforate surface disposed to receive the tufts formed by said clawing means, said rotating clawing means disposed in suiciently close proximity to the perforate surface to coact therewith on said tufts to sweep ingly rub said tufts across said perforate surface to interfelt the fibers within said tufts and to form smaller tufts for passage through the perforations of said surface.

8. The method of reconstituting siliceous fibrous material comprising establishing a supply of siliceous brous material, feeding said material from said supply in a continuous manner, repeatedly clawing the continuously fed siliceous brous material to tear and open a plurality of tufts of fibers therefrom, piercingly mpinging and rubbing the tufts in a restricted zone bounded by a perforate surface to interfelt the fibers thereof into a liuted but more integrated compacted size for passage through the perforations of said surface, and passing the interfelted tufts through said perforations.

References Cited in the file of this patent UNITED STATES PATENTS 275 Griswold July 17, 1837 438,198 Spangler Oct. 14, 1890 1,847,990 Stoner Mar. l, 1932 2,216,612 Dimm et al. Oct. l, 1940 2,635,298 Lepkowski Apr. 21, 1953

Claims (2)

1. THE METHOD OF RECONSTITUTING SILICEOUS FIBROUS MATERIAL COMPRISING ESTABLISHING A SUPPLY OF FIBROUS MATERIAL, FEEDING FIBROUS MATERIAL FROM THE SUPPLY IN A CONTINUOUS MANNER, CLAWING THE CONTINUOUSLY FED FIBROUS MATERIAL TO TEAR AWAY AND OPEN A PLURALITY OF TUFTS OF FIBROUS MATERIAL THEREFROM, RUBBING AND GRATING THE OPENED TUFTS OF FIBROUS MATERIAL BY MOVEMENT OF THE TUFTS IN CONTACTING RELATION OVER A PERFORATE SURFACE TO INTERFELT THE FIBROUS MATERIAL IN THE TUFTS TO FORM SMALLER TUFTS FOR PASSAGE THROUGH THE PERFORATIONS OF THE SURFACE, AND PASSING THE INTERFELTED TUFTS THROUGH SAID PERFORATIONS.

4. APPARATUS FOR RECONSTITUTING SILICEOUS FIBROUS MATERIAL COMPRISING FEEDING MEANS TO CONTINUOUSLY FEED A FIBROUS MASS OF SAID MATERIAL, TEARING AND OPENING MEANS COMPRISING A ROTATABLE SURFACE WITH A PLURALITY OF ROWS OF SPACED TEETH AFFIXED THERETO AND EXTENDING RADIALLY THEREFROM ADJACENT SAID FEEDING MEANS ORIENTED TO IMPRINGE SAID MASS, AND TO TEAR AWAY AND OPEN A PLURALITY OF FIBROUS TUFTS FROM THE FIBROUS MASS, A PERFORATE SHREDDING PLATE IN A CONCENTRIC, CLOSELY SPACED RELATIONSHIP WITH THE TEARING MEANS TO CAUSE A COACTION THEREWITH TO INTERFELT THE FIBERS OF SAID TUFTS.

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