US2288072A

US2288072A - Method and apparatus for making bonded fibrous products

Info

Publication number: US2288072A
Application number: US215144A
Authority: US
Inventors: Howard W Collins
Original assignee: Owens Corning Fiberglas Corp
Current assignee: Owens Corning
Priority date: 1938-06-22
Filing date: 1938-06-22
Publication date: 1942-06-30
Anticipated expiration: 1959-06-30
Also published as: BE435039A; DE734065C

Description

June 30, 1942. H. w. coLLlNs 2,238,072

METHOD AND APPARATUS FOR MAKING BoNDED FIBRoUs PRODUCTS Filed June 22,1938 4 Sheets-Sheet l METHOD AND APPARATUS FOR MAKING BODED FIBROUS PRODUCTS Filed June 22, 1938 4 Sheets-Sheet 2 ...mw Wm.

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H. W. COLLIN S June 30, 1942.

METHOD AND APPARATUS FOR MAKING BONDED FIBROUS PRODUCTS Filed June 22, 19:58- 4 sheets-sheet s INV EN TOR. Collins,

A T NEYS.

June 30, 1942. 2,288,072

'METHOD AND APPARATUS FOR MAKING BONDED FIBROUS PRODUCTS H. w. com-.INS

4 Sheets-Sheet 4 Filed June 22, 1958 Nm. Nm.

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IN V EN TOR. E W Collins,

A TTOR EVS.

Pat'ented June 1942 I.

OFFICE METHOD vAND APPARATUS Fon MAKING BONDED Fraoos PRODUCTS Howard W. Collins, Newark, Ohio, 'assignon by mesne assignments, to Owens-Coming Fiberglas Corporation, a corporation f Delaware Application June 1938, Serial No. 215,144 1o claims. (o1. 154-27) The present invention relates to'methods and,

apparatus for making bonded fibrous products, and more particularly to the fabrication of bonded products comprising mineral fibers such as glass wool, mineral wool or the like.

In the production of a bonded felt of mineral or glass wool1 it has been customary to introduce the binder, in the form of liquid cement or granular powder, into the air or steam jets with which the material is being treated, before Vthe blast strikes the molten mineral or`rock wool, or into the fibrous particles as they are being blasted. However, in the Old methods, if sufficient adhesive is introduced to effect a strong bonding of the fibers, there is a tendency for the bonded material to adhere to and accumulate on the walls and other surfaces of the settling chamber. Such accumulations are periodically disengaged and producev objectionable scab in` the finished wool.

On the other hand, if the glass Wool process is used wherein the fibers are conveyed downwardly by the vehicular blast and deposited upon a belt by the blast'which passestherethrough, such as;

terial by means of a picker or the like and simul taneously, as the material iscollecting upon a belt or the like to distribute binder in subdivided substantially uniformly throughout the thickness thereof and throughout the individual tufts of fibers making up the mat..

"Still another object of onev phaseof the invention is to set up the binder with maximum speed and with optimum binding effect. In this connection, it is desired to provide means for adjustmay be produced without loss of binder or valform. One of the dimculties of this process is that the dust binder does not penetrate throughout the individual tufts of'the material. the binder may be distributed on the fibers on the outer layers of the tufts, and may appear While to have a good distribution throughout the mat,

into the interiors thereof and that a uniform distribution over all the fibers is lacking.

With the foregoing difficulties in mind, it is an object of the present invention to provide a method whereby a binder may be uniformly distributed throughout the thickness of a. fibrous mat, especially one formed of felted, long mineral or glass wool fibers.

Another Object of the invention is to provide a method of procedure whereby a mat of picked shingles, partition material,

boiler lagging, refrigerator insulation or the like,

uable cooperating constituents therein.

It is also Within the contemplation of the invention to provide a procedure and apparatus for producing bonded Vproducts in any desired shape, one specific shape being cylindrical for pipe coverings, although other shapes such as corrugated, flat, or special shapes, for use in automobile dash or panel insulation, wall boards, siding material,

'in securing a uniform distribution of binder throughout the cross-'section of a fibrousmass; Fig. 5 is an elevational View of the portion of the apparatus adapted to apply or distribute the binder uniformly throughout the flbrousmass: Fig. 6 is an elevational view, shown partly in section, of a preheating unit for preheating the binder prior to pyrolyzing the same;

Fig. 7 is an elevational side view, shown in cross-section, of the apparatus shown in Fig. 5; Fig. 8 is a fragmentary cross-sectionalend `view of a portion of the apparatus shown in Fig. 7, the section being taken along the line. 8--8 of Fig. 9 is a partial, cross-sectional view of the pyrolyzing or heat treating apparatus showing a mat being treated between platens;

mineral wool fibers may have binder distributed 554 Fig. 10 is a similar view of a modified embodiment of a heat treating or pyrolyzing apparatus adapted to produce a corrugated shape; and

- of binderin the opposite face.

- or corrugated wool. The fibers in either case may descend from the flberizing apparatus. I into a forming hood I6 and lay.. themselves upon a belt I'I where they form into a loosely -belted mat I8.. As the bers accumulate and form a web upon the belt Il, they may be sprayed by means of a spray gun I9 with a suitable lubricating medium such as oil, stearic acid emulsion or the like, `or the coating described in'Williams and Bone Patent No. 2,083,132,l

lThe problem now is to incorporate binder uniformly throughout .the mat I8.` If binder is sprayed upon the mat, from one side thereof, the fibers in the mat actas a filtering medium,caus

ing the major portion of the binder to deposit in the exposed face of themat and leave a dearth For this reason, application of the binder to a fabricated mat has heretofore proved unsuccessful, especially when a dense or closely packed mass was being treated. I have discovered, howeventhat uniform distribution may be achieved throughout the mat and that the filtering problem may be overcome by applying the binder alternately first to one side of the matand then upon the other. To

assist the penetration of the binder in subdivided form, I preferably apply it in an air stream, drawing the air through the mat and permitting the fibers to filter out the dust. Liquid or 4 tures, especiallyjsince no drying problem is inthe binder laden air through the mat. In this operation', the binder laden blast of air preferably is directed into the mat from the side thereof that is presented in convex relation to the spray nozzles andthe incoming binder, thereby stretching out each side of the mat in turn at the point of forceful introduction of the binder and facili-- tating deep penetration by the binder dust.

B y sucha process of applying the binder a1- ternately through both faces of the mat, uniform distribution throughout the mat may be achieved. The mechanics of this are diagrammatically illustrated in Figs. 2 to 4. As will be observed in Fig. 2, a diagram is shown wherein the vertical ordinate represents the thickness of the bat, and each place along the ordinate designates the corresponding point in the 'mat Horizontal abscissas designate by length of arrowsthe concentration of the binderat the corresponding point in the bat.

In Fig. 2 the resulting concentration of binder through any portion of the mat caused by the iirst application of binder applied from below, is shown. Thus, the horizontal arrows show a Varying concentration of binder from the bottom to thetop of the mat caused by the major portion of the binder being filtered out near the bottom of the mat and progressively less to the top.

Fig. 3 shows, on the other hand, the concentration of binder caused by the second application of binder blown in the opposite direction.

i thickness of the mat.

I have discovered that while reversing of the flow of air through the mat may blow away a volved and these binders may be set up to any desired consistency-.by means of a heat treathyde, methylmethacrylate, wax`, sugars, glyptols,

linseed olil, glue. sodium silicate, casein. pitches,

tar, stearin, tallow, low melting metals or the minor portion of the binder which may have been deposited by' a prior application and accumulated along'the outer surface thereof, the main bulk of the binder remains in position where it was first :filtered out and deposited upon the fibers. It is thus possible to reverse the flow any number of times without materially disturbing the binder like, etc., maybe used. To increase fire resist.

ance, various compoundssuch as sodium carbe added. `In the present application an air cirwhich has once been deposited upon the fibers.

The mat I8 having the binder distributed therein may then be directly pyrolyzed or otherwise treated with heat, or reacting fluids to set up the binden If desired, several layers of the oulation system has been shown which is most I suitable for dry binders, suchl as powdered asphalt, clay, sugars, or the like, although other sprayingor binder applicators may be used in connection'with the present invention according t to the nature of the substance applied.

' supply pipe 21. A suction box 28 may be provided in the drum 25 to facilitate the passage of 75 mat I8 may be lbuilt upf or laminated to form a mat of suitable thickness.

On the other hand, the mat I8 after having been treated with binder by the

drums

22 and 25 may be passed directly through vfeed rolls 29 into a picker 30. The pickerserves to tear the mat "apart, and ordinarily if the fibers are'of sufiicient or similar products 49.

To-fa'cilitate pyrolysis', the binder laden mat I8n may be heated, by means of the preheater 33 adapted to circulate hot air through the mat by a feed mns vze: tothe rotating "picker anwmch 'tears upthe mat and permits it to fall upon the belt 3|'.

ordirectly\to vthe belt 3|, without being picked.

means of a blower 34 through conduit 35, heat supply chamber 36, the mat |83, and the belt 31 to the conduit 40 and back -to the blower 34.

The mat I8a may then be subjected t0 pyrol lyzing heat within a confined -zone between cater- -pillar platens 4| mounted upon ro11ers'42.- 1 'I'he platens 4| `may be heated by any suitable means such as steam jets, burners 43 or the like.; The;

pyrolysis .generally takes from three to fifteen peel the mat I8 from the drum 25 and guide it minutes in temperatures ranging from several hundred degrees to 700 or 800 F., according to the degree ofpyrolysis desired. As shown in Fig.

9, the platens preferably contact and partially compress the mat. e

The mat I8 then progresses into a cooling chamber 45,and maybe acted upon by the cater. pillar belts 46 which may be air or water-cooled to withdraw the vheat from the mat |83. The mat |83, now in the form of a board or sheet having great toughness, strength and resilience, as

desired, may be slit by Ameans of a rotating knife or the like 48 'to-forniblocks,

Referring nowrnorev particularly to Figs. 5 to 8, wherein more detailed views of portions of the apparatus are/shown, it will be noted that the conveyor belt |1 feeds the mat |8 under the perforated drum 22. The drum 22 is mounted upon bearings 55 fixedV to the framework 56. Within the drum 22 is the suction box 23 communicating with a blower 58 through the conduit 59. The mat I8 `th'en passes over the perforated drum 25 mounted upon bearings 60 fixed to the framework 56.

Spray nozzles are mounted below the drum 22,*and asshown in Fig. 8, preferably extend across the entire Width o f the mat. Similar spray nozzles 26 are mounted over the perforated drum 25 to treat the other side of the mat. .The

' in subdivided form-may be dusted into the air streams through the blower 6| and for this purpose a feed hopper 63 with suitable feed adjust` ing means may be provided.

, The suction boxes 23 and28 cause the binderv particlestobe drivenv into the mat where they are ilt'ered out and distributed through the mat, The vehicular air is then withdrawn by the into the feed rolls 29. A second guide` plate 16 pivoted also at its lower edge may be placed in the position shown in Fig. 7 to close oil the front end of the chamber 8| when the picker is in use. )When the picker is not in operation, however,

and themat I8 passes directly from the drum 25 e to the belt 3|, the guide plate 15 is lifted away from the drum to its position 15a shown in dotted outline, and the guide plate 16 is moved down to assume the position 16 shown in dotted outline. The mat |8 then moves from the drum 25 onto the chute 16 in its position 16a and passesdown to the belt 3| by which it is conveyed into boards, slabs, batir the preheater, more fully described hereinafter.I If desired, the mat I8 may be built up in laminated form withpaper, cloth, gypsum plaster, sheet metal, metal foil, or laminated ,witha plurality of layers similar to itself, or laminated with picked material, or the like, as desired, prior to the preheating step.

The feed rolls 29 may be )powered in synchronism with the drurns22 and 25, and the belt |1, by being mechanically connected to the drive on the shaft 64. The mechanical connection may include chain 11, a sprocket 18, and spur gears 19 which are fixed to the feed rolls 29.

The picker 30 is mountedupon a shaft 84 and housed within a chamber 8| having a hinged cover 82 which may be swung open to provide access thereto. A chain'85 actuated by a motor 86 drives the picker at any desired speed. If electrostatic effects within the picker chamber 8| are excessive, causing the picked material to accumulate in bunches along the side walls, it is desirable to apply a water spray nozzle 83 adapted to raise. the 'humidity within the chamber and thus counteract the electrostatic effect.

A compressing or leveling off roller 32 is I vmounted upon a frame 61! at the discharge end of the' chamber 8|.

blower 58-1through the conduit 59 to a suitable f chamber, lter or cyclone (not shown) where the residual bindermay be removed. If desired, the air and residual binder may be returned directly to the blower 6| where additional binder may be added to bring up the concentration of the air to the desired degree.

The conveyor belt |1 at its forward end of travel runs over a drum which is mounted on a shaft 64 and driven by' a chain 65 suitably act 'I'he roll 32 may be adjusted or raised into inoperative position by `means of an adjusting device 88 of suitable design, and may be driven by the chain train in'- cluding chain 89, shaft 90, sprocket 9|, chain 92, and shaft 93 which is actuated by the belt 3|. Thus,the roll 32 is actuated by and in synchronism with the belt 3|. The drive mechanism for the belt .3| will be brought out more fully hereinafter. ,v Referring now to Fig. 6, the belt 3| carries the mat |8a to the intake end of the preheat chamber 33, through which it is carried upon the perforated or apron conveyor 31. The transfer from the belt 3| to the conveyor 31 may be facilitated by means vof a transfer roll l99. At the intake side of the chamber 33 is a compressing roller |00 which may level oi and/or compress, if desired, the mat |8a to predetermined dimension and density. Mounted over the conveyor 31 and spaced therefrom is a perforated plate |0| adapted to admit heated air uniformly over the surface of the mat I8ab from the airy supply chamber 36.

The hot air is supplied by means of a heater |02 within a chamber |03 arranged alongside of the conveyor belt 31. The air is drawn fromV the chamber |03 to a conduit 40 by means of circulates constantly through the mat and is con` stantly maintained at suitable temperatureby means of the heater |02. Ordinarily the mat is preheated to about 300 F. although more or less heat may also be used.

The /blower 34 may be actuated by a motor |01 mechanically connected by means of belt |08.

After emerging from the preheat chamber 33, the mat may pass under a compressor or leveling roller |08.

The entire system may be driven synchronously by a motor I| mounted at the upper end of a preheat chamber 33. The motor ||0 supplies power to a jackshaft by means of a chain H2. The jackshaft supplies power through the chain ||3 to the drum l I4 over which the conveyor 31 travels, thus actuating .the said conveyor 31. At the other end of its travel the con` veyor 31 runs over the drum I I5, and thereby actuates shaft H6 which in turn rotates the shaft ||1 by means'of a chain H8. The shaft the blower 34 from where it is blown through"- aaaaova confined zone, as for example, between the heated platens shown. It has been found that pyrolysis within a confined zone' is ordinarily desirable to prevent the volatile constituents of the binder from escaping and thus apparently. cause them to condense on theilbers and serve to plasticize the residualcarbonaceousconstituents. The flexlural strength, toughness, feel and resiliency of the product have been found muchI improved by such procedure.

v It is to be observed that the mat may be pyrolyzed or molded into various shapes, 'as desired. As shown in Fig. 9, a planular shape suit- I |1 has mounted on it, drum Il! over which runs able for boards, sheets, or light weight bats may be formed, or, as shown in Fig. 10,.the mat I 8b may be set into a corrugated shape between undulating platen forms 4 I. Such a product finds use, for example, for roong material and may be placed under a metal corrugated roof. In this event, however, the corrugations are slightly less pronounced than shown in the drawings to conform with the corrugated metal.

It is also possiblev to. produce pipe covering from the corrugated material shown in Fig. 10. 'Ihis may be done by cutting the corrugated material through the adjacent bends in the material to produce a series of semicylindrical sections |8, such as shown in Fig. l1. 'I'hese may then be placed in pairs over a pipe to provide insulation therefor.

The present invention may handle and laden with binder fibrous mats of any desired thickness and density. Ordinarily it has been found that a relatively thin mat, as for example, about The shaft |.I1. is also mechanically connected to .compressor elements, including the belts 3| and f 31 and coacting compressor rolls in synchronism with one another.

From the preheat chamber 33, the preheated mat IB passes into the pyrolyzing unit between thefplatens 4|^which completes the heat treatan inch or so in thickness, and having a relatively light density, as for example one and a half to two pounds per cubic foot is preferable, since they may be laden with binder at high speeds with this present process. Glass wool mats having relatively long ber lengths and diameters ranging from about .0002 inch to .0008 inch are ordinarily preferable. When crimped wool is used, the larger diameters .and lighter densities generally are most suitable.

If desired, however, mats of much greater thickness and/or density may also be used. as for example a two or four inch thick mat of the density normally and .conveniently producible on the flberizing machine. .The time of application, howment and tends to set up the binder to the desired consistency.

The heat treatment of the binder may vary according to the material treated and thetidesired result. Thus, temperatures from about-f180- F.

to -about 900 F. may be used for powderedl asphalt binders according to the type of material desired. A wall board or partition may have a curing temperature of about 250 F, to 600 F. An ordinary bat for refrigerator insulation or similar material may be treated with relatively low temperatures. A light density automobile dash or panel insulation lmay also be treated lightly, if desired. High temperature material such as boiler lagging or pipe insulation may be pyrolyzed to about 800 to 900 F. s

The curing time may vary widely, as` for example, from about three minutes to fifteen min- -utes, inversely proportionabas a generalrule to temperature and shorter time are used for maximum temperature resistance.

The material is preferably pyrolyzed within ever, varies directly with this thickness of the mat, so that when thicker mats are used, more time is required to apply the subdivided binder. '-I'he amount of bindermay also vary widely, that is, from afew per cent to a large amount Asuch as forty or fifty per cent or more. The densities of the nished product may also vary widely, as for example a few pounds per cubic foot to about 20 or more pounds.

It is also to be observed that the application of binder on alternate sides of the mat may be made any number of times, as for example, three, four or even more times on each side in order to distribute the binder uniformly throughout the mat. The mat or perforated drums may also be agitated, preferably in the direction of the thickness of the mat, in order to facilitate entry of the binder throughout the mat. This may be ldone simultaneously as the dust laden air is passing through the mat, or later.

Modifications may be resorted to within the spirit and scope of the invention as defined in the appended claims.

. Iclaim:

1. Apparatus for incorporating a binder into a mineral fibrousv mat which comprises ,a drum having a perforated surface over which one major surface of said mat passes, means for drawing air laden with binder in subdivided form through said mat and said perforated surface, a second perforated surface upon which the other major surface of said mat passes, and a second means for drawing air laden with binder in subdivided form through said mat in a direction opposite to the first application of binder laden air.

2. Apparatus for incorporating a binder into a mineral fibrous mat which comprises a drum having a perforated surface over which one major surface of said mat passes, means for drawing air laden with binder in subdivided form through said mat and said perforated surface, a second perforated surface upon which the other major surface of said mat passes, a second means for drawing air laden with binder in subdivided form i through said mat in a direction opposite to the first application of binder laden air, a picker for shredding said mat, and means for accumulating said shredded material in successive increments and withdrawing the same continuously Ain the form of a newly formed mat.

3. Apparatus' for forming a strong, tough fibrous product which comprises means for producing amat of glass wool, a perforated rotatable drum over one major surface of said mat passes, means for blowing air laden with binder dust through said mat and into said drum, means associated with said drum for exhausting said air, a second perforated rotatable drum over which the opposite major surface of said mat passes, means for blowing air laden with binder dust through said mat and into said second drum in the direction opposite the direction of the rst dust laden air,- and means associated with said second drum for exhausting the air passing thereinto.

4. The method of incorporating binder within a loose, fiuy mat of fibrous material which comprises bending said mat, establishing a region of negative pressure at the concave side of said bent mat, and blowing a gaseous medium laden with binder in subdivided form'through the bent mat from the convex side thereof to cause the fibers to filter out and retain the binder.

5. The method of incorporating a dry binder material in a loose, fluffy mat of fibrous glass which comprises establishing a stream of gaseous mediumf'laden with dry binder in the form of dust passing through the mat by flowing a gaseous medium laden with such binder into the mat from one side thereof while exhausting the medium from the other side, reversing the direction of the blast of binder laden gaseous medium through the mat by blowing said medium into the mat from the oth'er side while exhausting the medium from the rst side, whereby the dry binder dust is evenly distributed throughout the thickness of. the mat. V

6. The method of incorporating dry binder within a loose, fluffy mat of fibrous gla'ss which cdmprises bending said mat transversely to its length, passing a gaseous medium laden with binder in subdivided form through said mat from the convex face thereof, bending said mat in the trate into the mat alternately from opposite sides, whereby the individual fibers of the mat filter out and retain the binder particles.

'7. Apparatus for producing a bonded mat which comprises means for depositing mineral .fibers and producing a mat continuously thereof,

means for conveying said mat away from the deposition zone, a rotatable cylindrical drum 4spaced from the deposition zone in the direction ,of the mat for directing a blast of binder-laden air into said mat, and an exhauster at the other side of the perforate drum surface, whereby a blast of binder laden -air is established through said mat while on said drum to cause the binder to be filtered out by the bers in said mat and distributed through the thickness of said mat..

8. Apparatus for producing a strong, tough s board of .brous material which comprises means opposite directionl and transversely to its length,

for producing a loose, fluffy mass of glass wool in mat formation, -a pair of rotatable cylindrical drums spaced from said rst named means and having perforate surfaces over which said mat is passed respectively in opposite directions, and spray nozzles adjacent each drum arranged to direct a blast of gaseous medium laden with dust binder through the drum surface for pass- 'ing a stream ofv gaseous medium laden with binder through said mat, with said blast alternately entering each major face of said mat While presented in convex relation to said spraying nozzles.

9. 'I'he method of incorporating binder within a loose, fluffy mat of fibrous material which comprises bending said mat, establishing a region of negative pressure at the concave side of said bent mat, directing a blast of gaseous medium laden with binder in subdivided form through the bent mat from the convex side thereof to cause the fibers to lter out and retain the binder, then bending the mat in the opposite direction, establishing a region of negative pressure at the now concave side of the bent mat, and passing a gaseous medium laden with binder in subdivided -stream of gas l-aden with dry binder in dust form passing through a continuous glass wool mat, by

' flowing a gas laden with such binder into the mat from one side thereof while exhausting the gas from the second side, reversingthe direction of the `blast of binder laden gas through the mat by blowing said gas into the mat from the second side while exhausting the as'from the first side, whereby the dry binder du t is evenly distributed throughout the thickness of the mat,-then shredding said mat by means of a picker, collecting the shredded material into the form of a new mat having the fibers arranged to extend promiscuousLv in substantially all directions, and then treating said n'ew mat to cause said binder to be set and produce a strong, tough fibrous product.

H OWARD W. comms.