US2589008A - Apparatus for forming fibrous mats - Google Patents

Description

N A N N A L M a APPARATUS FOR FORMING FIBRQUS MATS 2 SHEETS-SHEET l Filed July 5, 1947 INVENTOR,

George M lam/7017 A TTORNEYS March 11, 1952 Filed July 5, 1947 G. M. LANNAN APPARATUS FOR FORMING FIBROUS MATS 2 SHEETS-SHEET 2 2 fl a g JNVENTOR. Gear e /7. 10/2/70 Patented Mar. 11, 1952 APPARATUS FOR FORMING FIBROUS MATS George M. Lannan, Newark, Ohio, assignor to Owens-Corning Fiberglas Corporation, a corporation of Delaware Application July 3, 1947, Serial No. 758,925

6 Claims.

l l The present invention relates to a production of mats of fibrous material and more particularly to a process and apparatus for forming mats of glass fibers.

It is an object of the present invention to provide fibrous glass mats of haphazardly arranged glass fibers that will be replete with voids or air spaces to obtain high acoustic and thermal insulating properties.

It is a further object of the invention tomake mats of fine glass fibers that will be highly resilient, have a high degree of integrity and are highly uniform in character for use as a reinforcement for plastics.

It is another object of the invention to provide fibrous glass mats that, while being resilient, have also a certain resistance to compression, making them suitable for cushioning, padding and as clothing inter-liner material.

A still further object of the invention is to provide an apparatus for mixing or combining into a mat fibers of either organic or inorganic materials.

A still further object of the invention is to provide a process by which mats of fibrous materials may be formed.

A still further object of the present invention is to provide an apparatus for forming mats of fibrous material which is simple in construction and capable of producing efiiciently at high speed any desired type of fibrous mat in an economical manner.

Other objects and purposes of the invention will become apparent during the course of the following description. I

In the present invention glass fibers have been selected as one fibrous material particularly adapted for operation in the apparatus and because of their inorganic nature, high strength characteristics and other features inherent in the fibers. Glass in fibrous form may be produced by many well known processes. Glass fibers designated generally by the term glass wool are usually produced by flowing streams of molten glass and engaging the molten streams in a high speed gaseous blast to attenuate the streams to fibers. Fibers formed in this manner mayvary in length from a fewinches to many feet and are customarily collected on a moving foraminous belt in the form of a mat or bat. Material of this form has been found useful as thermal and acoustical insulation when impregnated with a binder and molded into substantially rigid or self -sustaining shapes.

A, second form in which glass fibers are used commercially includes strands or yarns of continuous length which may be woven into textiles. Glass fibers in this form are produced by flowing streams of molten glass, gathering the streams together to form a strand and winding the strand on a support at a high speed to attenuate the streams to very fine fibers. Each of the streams is continuously attenuated and the strands formed thereby may be produced in unlimited lengths. A binder is usually applied to the strand as it is formed to preserve integrity of the strand and prevent separation of the filaments during later processing operations. The single filaments in the strand may number from to 200 and have a nominal diameter of from .0002 to .0004 inch while single glass wool fibers may average from .0005 to .0006 inch in diameter but may if desired be much smaller, say .0003 inch.

Strands formed by the above continuous forming process both in woven and unwoven forms have found great utility as a reinforcement for molding resins and are widely used in laminated plastics because of their high strength, and nonhygroscopic characteristics. In addition, these strands of continuous type fibers may be cut into short lengths to form mats in which the strands are present in the form of..haphazardly arranged bundles of fibers.

The present invention not only provides for the production of mats from a single type of fibers but contemplates combining fibers formed by both the glass vwool and continuous fiber forming processes. In addition organicfibers may also be processed in accordance with the present invention or combined with the glass fibers;

The glass wool fibers, as an example may be formed in accordance with the process shown in the patent to Slayter and Thomas, No. 2,133,236, dated October 11, 1938 and continuous type fibers may be formed in accordance with the showing in the patent to Slayter and Thomas No. 2,234,986, dated March 18, 1941.

The present invention is illustrated in the accompanying drawings in which:

Figure 1 is aschematic View, of novel apparatus by which the present invention may be carried out; V I Figure 2 is a side elevational View of a part of {the apparatus shown in Figure 1;

The present invention is readily adaptable for producing mats of any desired fibrous material which may be either organic or inorganic fibers or a combination of such fibers depending upon the end use of the material. Combination materials may be produced to provide any desired characteristics inherent in the materials being combined. As an example, mats of glass wool fibers have low tensile strength particularly when very thin and it is sometimes desirable to incorporate and bond therein short lengths of high rial a dry resin which upon the application of heat or in the presence of a solvent becomes softened-- and adheres-the mat fibers together. Such resins maybe in either fibrous or powdered form: In addition, the mat material may be bonded byincorporating as hereafter described a' small percentage, say 10 per cent or so,.of short-lengths of continuous-type strand's which are heavily coated with a heat reactable resin. The resin coated strands are interspersed throughout themat and upon the application of heat the resin is caused to soften and flow and thereby effect a complete'bonding'of the mat material. 7

Ingeneral, the'stepsby which mats are formed in accordance with the present invention'will now-be described, reference being made especially to-Figure 1 of the accompanying drawings. One apparatus found suitable for the processing/of the fibrous material includes a primary fiber opening and feeding mechanism" A Informing a' 'mat of'a single fibrous material'the bulk fibers are supplied to the feeder A which delivers athin layer of the materi'alto the first picking stage B. The fibers which at this point may'bein nonuniform clumps or irregular masses are fed into the-picking roll which opens or tears apart the masses and separates'the fibers into small tufts or bundles of fibers. separated fibers as they are discharged from the picker collect inthe form of 'a' loosely felted mat The-mat as it forms is continuously fed to* second picking stage C where the fibers-"are again separated and recollected. The. greateruniformity' of the sheet of material thus beingfed is transmitted tothe final mat so that the resulting'producthas the highest degree of uniformity in thickness, density and texture. The: impor tance of the two stage picker operation is readily apparent when materials which are dissimilar in character are to be combined into .a single mat. The operation of the picking rolls is such that the different materials are mixed and blended. into. a uniform product.

The mat of material flowing from the stage C. comprises an unbonded heterogeneous arrangement of fibers to which itisnecessary to incorporate a binder in order to preserve the integrity of the mat; ing themat from one or both sides with a suitable adhesive containing solution and then passing the mat through a heated oven D to dry or cure the binder.

rial which is mixed with the mat fibers before These opened or partially The binder may be-applied-byspraypassage through the picker, or the dry powder may be sifted into the formed mat and subjected to heat to set the adhesive.

After passage of the mat through the oven the mat may be rolled or cut into sheets for storage or shipment or it may pass directly into other fabricating operations. 7

Referring particularly toFigure liof. the drawings the fibrousmaterialis placed in a hopper H) which forms a part of the feeding mechanism A. A movable belt H forms the floor of the hopper "land moves the fibers in a rolling motion to a fiber picker belt l2. The movement of 'the'belt' ll provides a continuous feed to the belt 'IZ? aslong as any fibrous material remains thereon: The picker belt 12 is provided with a plurality; of spikes or needle points l3 which pick an even mat from the mass in the hopper as it advances and passes it over to a feeder belt l which carries the material into the first picking stage mechanism;.B.;j Asa:thepickerrbeltrlhrconveys :the fibrous; materialiunward: a; short; belt removes any undulyrlarge. massesiromthmbeltj2 so that a substantially uniformjayer:ofrfibersis carried tothefeeden'belti I,5..

In. order. to remove the fibrous materiallfrom the picker belt 12 as-,-it.is carried from-.thehopper. iil'iaxstripper ljB-comprisingjaplurality of blades IQ of leather, rubber, or the like has -beengpror vi'ded. Rotation of, the stripperl8- causes. the blades-I9 or paddles.to wipe the material from the spikes i3-so thatit is deposited onthe feeder belt-15. A

The feeder belt l5 conveys;the fibrousmateriai as. a substantially uniform sheet .2-iof. loosely matted fibers in the;- direction of. the: mixing or picker: station E. The-belt is, preferably; con: tinuously driven by means of a motor ;22,-and gear, reduction unit 23 through a,chainlktmcarryythe mat beneath,afeedregulatingmoll. 25.. The; feed r0113 25 isrweighted. toaprovide tension on the fibers and is mounted on arms26 pivoted to the framework of the picker mechanism.

mounting permits movement of they roll: toward and away from the surface of thefeeder belt,l5 as mats of varying thickness are fed therebeneath;

As'the mat of fibers-issues frombeneaththe roll. 25-it isengaged by a picker roll. 28 whichis. cylindrical in form and is, provided with rows of pointed spikes or' needles 30 which tear, small tufts of fibers from the end of the mat 2.1.. 'Ijhe needles 30 are arranged .inrows spaced.-.uniformly radially of the roll and therows-are set in stag;- gered relation, consecutive rows being 0fiS t -&D-rproximately. of .the distance-between the needles of each row. With, this arrangementof the. spikes the fibers are pulled from thematina substantially uniform-manner.

Rotation. of the -roll 2.8 inaclockwise direction 7 tends to throwthefibers forwardly into a settling chamber 32. Should the spikes 30 of: the roll. 28

dislodge a greater mass. of fibers than normally required, a non-uniformmat would be produced- Tog-uardagainst this possibility asecond roll. 34 is provided. The roll 34 is mounted above the. roll.28:-and is provided with spikes 35-arranged m. uniformly spaced rows. about the. periphery of;

the-roll. The roll-.35;is'positioned slightlyto the rear. of} the; roll .ESand-is alsoi rotated in a clock W159i direction. Therollsjzfl and 34- areispacedj apart: oniy,-sufficiently to. permit clearance; of the: spikessince the two rolls arerotated atdifferentspeeds as will be brought-out-in detail presently;

Any large: tufts o1- fibrousz material picked ,:up;.by

5 the roll 28 and which extend beyond the ends of the spikes 30 will be engaged by the spikes 35 of the other roll and torn apart or thrown rearwardly onto the incoming mat.

Should such a mass of fibers adhere to the spikes 35 and be carried around as the roll rtates, a third roll 33 has been provided. This roll 38 is constructed similarly to the previously mentioned picker rolls and carries spikes 39 arranged in rows about the periphery. The rolls 34 and 38 are mounted in a common horizontal plane and are spaced apart so that the spikes intermesh throughout substantially their entire length. Thus any tuft or mass of fibers carried by or between the spikes 35 are engaged by the spikes 39. The axial spacing of the spikes carried by each rollare such as to provide a clearance of of an inch or less so that the tufts of fibers are completely disrupted and dispersed. The roll 38 is rotated in a counter clockwise direction at approximately twice the speed of the roll .34.

As shown in Figure 2 the rolls 2B, 34, and 38 are driven by means of a chain 43 trained over sprockets 4|, 42, and 43 carried respectively by the supporting shafts ofthe rolls 28, 34, and 38 A variable speed motor 45 may beemployed to drive the rolls through a belt 46 trained over a pulley 41 mounted on the drive shaft of the roll 28. As an example of the relative speeds of the rolls it may be assumed that the roll 28 rotates at the rate of 1200 R. P..M. The roll 34 is geared to rotate at approximately 800 R. P. M. and the roll 38 is. geared for rotation at approximately 1600 R. P. The speed of rotation of the rolls may be regulated by means of the motor 45 depending upon'the type of fibrous material being processed and the facility with which the material is dispersed.

As the. fibers. discharged from the picking mechanism enter the settling. chamber 32 they are collected on an inclined foraminous belt 55 mounted on rollers for continuous movement. A suction chamber 53 is provided beneath the surface of the belt so that the fibers are drawn downwardly. and collect on the belt in the form of a'pad 54. The belt 50 or conveyor corresponds substantially to the feeder belt l5 previously described and carries the fibers collected thereon t the second stage picker mechanism C.

The rotation of the picking rolls just described sets up currents of air which move generally in the direction of .the rolls causing some of the fibers in the material to be carried thereby. In order to offset this difficulty Ihave provided air jets 55 arranged above the roll 38 and beneath the roll 28 to direct blasts of air in the direction of the settling chamber 32. This movement of air not only counteracts the tendency of the fibers to follow the surface of the rolls but augments the action of the suction chamber 53 in uniformly dispersing the fibers. The wall 56 which forms the roof of the settling chamber 32 may be suitably curved to provide a streamlined flow to carry the fibers over at least a major portion of .the settling area; The wall 56 which may also form a closely fitting cover for the rolls extends forwardly and terminates adjacent the picker mechanism C. It is believed that a more uniformlayer of fibrous material may be ob-' tained if the fibers are permitted to float in.a circulating air stream before settling to the belt 50.. I

The pad 54 is fed by the belt 50 into the second stage picking mechanism 0, the construction of which'is a counterpart of the mechanism B and in a settling chamber 58, the bottom of which is formed by a travelling foraminous belt 59. A suction chamber 60 is provided beneath the belt in the area of the chamber to collect the fibers into the final mat structure. A gate roll 6| is arranged at the end of the settling chamber to initially compress the mat 59 as it is conveyed forwardly.

When it is desired to apply binder to the matted fibers spray guns indicated at 63 are arranged above the mat to apply binder to the surface of the mat or saturate it. Binder may be applied to the bottom of the mat by spray guns indicated at 64 arranged at the end of the belt 59 if desired. As an example, the binder may include emulsions of phenol formaldehyde, methyl methacrylate, polystyrene or polyvinyl acetate. Such materials may be present in the finished product in amounts ranging from 7 to 12 per cent by weight of the fibers.

The binder impregnated mat is then cured on dried by passing the mat through a suitable oven 65 associated with a conveyor flight 66.

Suitable mechanism may be provided for circulating heated air through the mat to cure the binder thereon. As the mat leaves the oven it may be either coiled into a roll, cut into sheets or passed directly into other fabricating operations.

Mats formed in the present manner may be employed as a base for roll roofing, shingles or siding in which the mat after passing from the present apparatus is impregnated with an asphalt composition and further processed into the desired material.

The following examples illustrate the operation of the apparatus in connection with the forming of mats of various fibrous materials. One type of mat found especially suitable for the reinforcement of plastics because of the high fiber density obtainable comprises short lengths of strands of parallelly arranged glass fibers bonded together into substantially discrete bundles. These bundles of fibers may be in random lengths of from 1 inch to 3 inches but preferably all should be within the range of 1 to 2 inches.

Masses of these fibrous bundles are deposited in the primary'opener and fed to the picker rolls. The action of the picker rolls is such that the bundles of fibers are separated from one another without destroying the integrity cf the individual bundle. The mat formed by the first picker section while substantially uniform vin crosssection is reprocessed through the second set of rolls by which it is again disrupted and the bundles of fibers collected into a final mat of uniform density. A binder or impregnant may be applied to the mat by spraying orthe ike.

Glass wool fibers may be processed through the present apparatus either in the form of loose unbonded fibers or as the scrap from thermal insulating board manufacturing processes in which the fibers are compressed and bonded to? gether into products of high density. In either case the fibers lie predominantly in planes parallel to the surface of the sheet or board. Processing this material through the present picker mechanism is accomplished by feeding the loose wool or boards directly into the picker rolls where the fibers are torn into tufts and collected in a sheet. This type of material while lacking in tensile; stren th as compared to the fibrous material previously described has been found suitableforthermal and acoustical insulation and provides amaterial in whichthe fibers extend in all directions.

The. tensile strength of mats of the above material may be increased by concomitantly processing therewith short lengths of continuous typetextile glass fibers or strands. This is readily accomplished by distributing the continuous type fibers in the desired percentage by weight on the mass of wool fibers before processing and feeding the combined material through the rolls. For. instance, a mixture of 80 per cent wool fibers and 20 per cent textile may be combined into a product having increased properties, In the final product the short length strands are randomly dispersed throughout the depth of the and compressed.

Mats of very fine staple length glass fibers are produced in light densities of from 20 to 40 square feetper pound for thermal and acoustical insulation as well as for padding and clothing interliner-material. The individual fibers range in diameter from .00003to .00015 inch and form a highlyresilient mat. This material at times has a tendency to condense when held under compression for a length of time, This condition may be remedied by processing the previously formed mat through the present apparatus and including a small percentage of cut strands of continuous type fibers in the manner previously described. The strands which are bundles of fibers bonded together provide resistance to compression and prevent a'matting together of the fibers. These strands of material may be added to the mat without materially otherwise altering any of its characteristics.

Organic fibrous materials including such vegetable fibers as ramie, jute, sisalhemp or cotton, andnatural fibersasuch as wool, hair or fur may be processedby the present apparatus either aloneor in any desired combination. Such inorganic fibrous materials as long or short fibered asbestos, rock wool or slag wool may also be processed and mixed with the organic fibers or glass. fibers. Of the vegetable fibers ramie is preferred because of the greater fiber length and strength. These, as well as other fibers may be employed to provide bulk to glass fiber mats and conversely glass fibers may be employed to reinforce. mats of ramie orother-fibers.

Modifications may be resorted to without departing from the spirit of the invention or the scope of; the appended claims.

c aim;

1.,An apparatus for forming mats of fibrous material comprising primary fiber opening means, a-fiber feeder belt for conveying a mass of material deposited thereon from said opener to afirst picking stage, said first picker including a. detent roll cooperating with said belt to feed he fibersfrom dhelt. pi k n o 1p d an-Zita u a e th a l xt n ing spikes and rotatable in a clockwise direction for. removing tufts of fibers from the mass, a kick-back roll mounted above and rearwardly, of the picking roll and provided on its surface with radially extendingspikes aligned with the spikes of said piskingroll, said rollrotatable in a clockwise direction ata speed lessthan that of the picking roll to remove excessively large tufts of fibers 7 from the spikes of the picking roll, a high speed picking roll associated with said kick-back roll disposed in a common horizontal plane therewith and provided on its surface with spikes. intermeshing with the spikes of said kick-back roll, said high speed roll rotatable in a counter-clockwise direction at a speed approximating twice that of the kick-back roll to disrupt tufts of f1- bers carried thereby, said high speed roll and said picking roll together effecting the discharge of the picked materialsforwardly and upwardly. into a settling chamber, means for rotating. said picking rolls, means for collecting the fibers into a sheet including a continuously moving inclined foraminous belt having a suction chamber therebeneath, means for passing said sheet of material through a second picking stage. similar to the mechanism of said first stage to rearrange and redistribute said materials, means for collecting the fibers into a continuous mat-like body, and means adjacent said first pickin roll and said high speed picking roll for directing streams of air under pressure in the direction of flow of the material.

2. An apparatus for forming mats of fibrous material compirsing primary fiber opening means, a fiber feeder belt for conveying a mass of material deposited thereon from said opener to a picker, said first picker including a detent roll cooperating with said belt to feed the-fibers from said belt, a picking roll provided on its surface with radially extending spikes and rotatable in a clockwise direction for removing tufts of fibers from the mass, a kick-back roll mounted above and rearwardly of the picking rolland provided on its surface with radially extending spikes aligned with the spikes of said picking roll, said roll rotatable in a clockwise direction at a speed less than that of the picking roll to remove excessively large tufts of fibers from. the spikes of the picking roll, a highspeedpicking roll associated with said kick-back roll disposed in a common horizontal plane therewith and provided on its surface withspikes intermeshing with the spikes of said kick-back roll, said high speed roll rotatable in a counter-clockwise direction at a speed approximatingv twice that of the kick-back roll to disrupt tufts of fibers carried thereby, said high speed rolland said picking. roll together effecting the discharge of thepicked materials forwardly and upwardly into a, settling chamber, means for rotating said picking rolls, and means for collecting the fibers into a sheet including a continuously moving inclined foraminous belt having a suction chamber therebeneath. a

3. An apparatusfor forming mats of fibrous material comprising primary fiber 7 opening means, a fiber feeder belt for conveying a mass of material deposited thereon from said opener to a first picking stage, said first picker including a detent roll cooperating with said belt to feed the fibers from said belt,.a picking roll provided on its surface with radially extending spikes and rotatable in a,clockwise direction for removing tufts of fibersfrom the mass, a kick -back roll mountedabove andrearwardly of the picking roll and provided on its surface with radially extend; ing. spikes aligned with the spikes of said picking roll and in tangential relation thereto, said roll rotatablein a clockwise direction at a speed less than that of the'picking roll to removeand dis.- charge excessively large tuftsof fibers from the spikes of the picking roll, a high speed picking roll associated with said kick-back roll disposed in a common horizontal plane therewith and provided on its surface with spikes intermeshing with the spikes of said kick-back roll, said high speed roll rotatable in a counter-clockwise direc* tion at a speed approximating twice that of the kick-back roll to disrupt tufts of fibers carried thereby, said high speed roll and said picking roll together effecting the discharge of the picked materials into a setting chamber, means for rotating said picking rolls, means for collecting the fibers into a sheet including a continuously moving inclined foraminous belt having a suction chamber therebeneath, means for passing said sheet of material through a second picking stage similar to the mechanism of said first stage to rearrange and redistribute said materials, and means for collecting the fibers into a continuous mat-like body.

4. An apparatus for forming mats of fibrous material comprising a picker, said picker including a picker belt, a detent r011 cooperating with said belt to feed the fibers deposited thereon from said belt, a picking roll provided on its surface with radially extending spikes and rotatable in a clockwise direction for removing tufts of fibers from the mass, a kick-back roll mounted above and rearwardly of the picking roll and provided on its surface with radially extending spikes aligned with the spikes of said pickin roll and tangential thereto, said roll rotatable in a clockwise direction at a speed less than that of the picking roll to remove excessively large tufts of fibers from the spikes of the picking roll, a high speed picking roll associated with said kick-back roll disposed in a common horizontal plane therewith and provided on its surface with spikes intermeshing with the spikes of said kick-back roll, said high speed roll rotatable in a counter-clockwise direction at a speed approximating twice that of the kick-back roll to disrupt tufts of fibers carried thereby, said high speed roll and said picking roll together effecting the discharge of the picked materials forwardly into a settling chamber, means for rotating said picking rolls, and means for collecting the fibers into a sheet including a continuously moving inclined foraminous belt having a suction chamber therebeneath.

5. An apparatus for forming mats of fibrous material comprising a picker, said picker including a fiber feed belt, a detent roll cooperating with said belt to feed the fibers deposited thereon from said belt, a picking roll provided on its surface with radially extending spikes and rotatable in a clockwise direction for removing tufts of fibers from the mass, a kick-back roll mounted above and rearwardly of the picking roll and provided on its surface with radially extending spikes aligned with the spikes of said picking roll, said roll rotatable in a clockwise direction at a speed less than that of the picking roll to remove excessively large tufts of fibers from the spikes of the picking roll, a high speed picking roll associated with said kick-back roll disposed in a common horizontal plane therewith and provided on its surface with spikes intermeshing with the spikes of said kick-back roll, said high speed roll rotatable in a counter-clockwise direction at a speed approximating twice that of the kick-back roll to disrupt tufts of fibers carried thereby, said high speed roll and said picking roll together effecting the discharge of the picked materials into a chamber, means for rotating said picking rolls, and means for collecting the fibers into a sheet.

6. An apparatus for forming mats of fibrous materials including a feed conveyor on which masses of fibers are deposited in random relation, a first rotatable picking roll cooperating with said conveyor and provided on its surface with a plurality of outwardly extending spikes for removing tufts of fibers from said mass, a second spiked picking roll in tangential relation with said first roll and rotatable in the same direction as said first roll and at a lower angular speed for removing tufts of excessive size of fibers fromsaid first roll, a third spiked picking roll disposed substantially in the plane of said second roll and having the spikes in meshing relation, said roll rotatable in the opposite direction at substantially twice the angular speed of said second roll for completely disrupting the tufts of fibers carried by said second roll, means including an upwardly inclined conveyor for collecting the fibers discharged by said rolls, the upper end of said conveyor terminating substantially in the plane of the axis of said first roll, and means adjacent said first and third picking rolls for directing jets of air tangentially of said rolls.

GEORGE M. LANN AN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 128,697 Barbour July 9, 1872 437,303 Josephy Sept. 30, 1890 765,135 Gardner July 12, 1904 1,420,162 Toles June 20, 1922 1,719,035 Wehnert July 2, 1929 1,928,699 Neal Oct. 3, 1933 1,948,395 Powell -J Feb. 20, 1934 2,233,433 Smith Mar. 4, 1941 2,467,291 Brelsford et al. Apr. 12, 1949 2,477,555 Roberts et al July 26, 1949

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