US3076236A

US3076236A - Apparatus for making mats of blown mineral fibers

Info

Publication number: US3076236A
Application number: US781225A
Authority: US
Inventors: Labino Dominick
Original assignee: Johns Manville Fiber Glass Inc
Current assignee: Johns Manville Fiber Glass Inc
Priority date: 1958-12-18
Filing date: 1958-12-18
Publication date: 1963-02-05
Anticipated expiration: 1980-02-05

Description

D. LABIN Feb. 5, 1963 APPARATUS Foa uAxING MATS oF BLowN MINERAL FIBERS ShutbShnt 1 Filed Dec. 18, 1958 INVENTOR.

A TTORN E YS D. LABINO Feb. 5, 1963 APPARATUS, OR MAKING MATS OIv BLOWN MINERAL FIBERS 2 Sheets-Sheet 2 Filed Dec. 18, 1958 INVENToR.

2G66 e if ,@d -e A TTORNE YS United States Patent O 3,076,236 APPARATUS FOR MAKING MATS OF BLOWN MINERAL FIBERS Dominick Labino, Grand Rapids, Ohio, assigner, by rnesne assignments, to Johns Manville Fiber Glass, Inc.,

Cleveland, (Ehio, acorporation of Delaware Filed Dec. 18, 1958, Ser. No. 781,225

7 Claims. (Cl. 19-156.3)

This invention relates broadly to a method and apparatus for increasing the capacity of a machine for making mats of mineral libers by the flame drawing process. More specifically, it relates to a method and apparatus for increasing the capacity of the liber generating portion of said apparatus. j

Though the method and apparatus disclosed herein are particularly adapted for the production of glass fiber mats in the manner hereinafter disclosed, the principles involved are equally adaptable to the production of mats comprised of other blown mineral libers.

It is common practice in the industry to collect the fibers on a foraminous belt to a considerable thickness and then compress the mat to the desired thickness and density. lt is also common practice to arrange the bush.- ings and the blast producing burners in a tier or row spaced from and parallel to the initial end of the collection belt and this arrangement provides space for only a limited number of bushings and burners whose maximum liber producing capacity deter-mines the lineal rate of advance of the collection belt. In other words, the productive capacity of commercial mat making machines is limited to the volume of libers produced.

This invention discloses a method and apparatus for materially increasing the volume of blown fibers deposited on the collection belt, thereby permitting a corresponding increase in the rate of advance of the belt for any comparable mat thickness.

It is therefore an object of this invention to provide a method for increasing the liber generating capacity of a mat making machine.

It is another object of this invention to provide additional ber generating apparatus for a mat making machine and means for depositing the additional oers onto a collection belt.

Other objects and advantages of the invention will become more apparent during the course ofthe following description, when taken in connection with the accompanying drawings.

in the drawings, lwherein like numerals are employedy to designate like parts throughout the same:

FG. l is a plan view of a mat making apparatus illustrating one form of the invention;

FlG. 2 is a projected side elevation of the apparatus ofFIG.1; Y l, l,

FIG. 3 is a plan view of a modiiied form of the apparatus shown in FIG. l;

FIG. 4 is a side elevation of the apparatus shown in FIG. 3;

FIG. 5 is a cross section taken on the line 5-5 of FIG. 3; and

PIG. 6 is a perspective View of the `mat produced by either form of the apparatus.

Referring to FIGS. l and 2 of the drawings, the numeral 1h designates a mat making apparatus in general. The conventional apparatus is comprised of a plurality of bushings 11 closely spaced in a tier or row substantially the width of the collection belt described hereinafter. The shape of the bushings, the material from which they are made and the method of applying heat thereto is in this instance immaterial.

The bushings 11 melt a supply of glass, usually in the form of marbles which are deposited at intervals to com- 3,076,236 Patented Feb. 5, 1963 ICC pensate for the volume of glass withdrawn from each bushing in form of streams 12 of molten glass which ow through a multitude of orilices penetrating the base of each bushing.

The streams of glass 12, while still in a iiuid state, are fed into the nip of a pair of rolls 13 rotating in synchronized relation to attenuate the streams of glass 12 into filaments 14 which gravitate in spaced parallel relation over the face of an elongated guide 15. A plurality of burners 16, usually one for each bushing as shown, though not restricted thereto, directs a hot, gaseous blast along the lower face of the guide to further attenuate the lilaments 14 and shred them into staple fibers 17 of varying lengths but substantially uniform diameter.

The bushings 11, the attenuating rolls 13, the guide 15 and the burners 16 constitute a normal complement of fiber generating apparatus for producing a mat, the number of bushings 11 and burners 16 used being directly proportional to the -width of the mat. The bushings and burners are insulated to promote greater operating eiiiciencies Vand therefore are rather bulky so that only a limited number can be placed in the space available, roughly the width of the collection conveyor. Thus, the volume of fibers produced is limited and the speed of the liber collection conveyor is a function of the volume oi fibers produced and the depth of the mat. In other words, the productive capacity of the mat making machine is limited by the fiber producing capacity of the generating apparatus.

The blast directs the fibers 17 in a substantially horizontal flight within the contines of a draft shield 18 onto a foraminous belt 19 advancing in the direction of the arrow 2i?. The area in which the fibersare deposited upon the belt 19 is hereinafter designated as the collection area 21. A vacuum chamber 22 underlies the belt 19 to span the collection area 21 and assists in felting the fibers on the belt in random array. Also, in the collection area 21, a binder solution 23 is distributed within the thickness of the mat by a spray apparatus 24. A dry binder may also be used with a suitable applicator.

The mat 25 impregnated with the binder solution 23 is advanced by the collection conveyor 19 and transferred to a second conveyor 26 which carries the mat 25 through an oven 27, where the binder is cured. While within the contines of the oven 27 the mat Z5 may be compressed by a device such as a belt 23. Upon emergence from the oven 27 the cured mat 29 is packaged as in a roll 30.

rihe apparatus described above comprises a conventional commercial machine for manufacturing a mat of bonded glass fibers. The production capacity of a machine or this type is limited by the volume of fibers deposited on the belt 19 in the collection area 21. Due to space limitations, governed by the width of the conveyor 19, no suitable arrangement of bushings and burners was known prior to this invention which would generate an increase volume of fibers for deposition in the collection area.

By this invention, that problem has been solved in a novel manner. Experimentation has proven that additional bushings, indicated by the numeral 31, may be placed outside the lateral contines of the conveyor belt 19. The additional bushings may be in substantial vertical and horizontal alignment with the bushings 11 or may be displaced from that alignment for convenience, the only important consideration being that the streams of molten glass descending from the additional bushings 31 move in an unobstructed path.

The streams of molten glass, also indicated by the numeral 12, are fed into the nip of the rolls 13 for attenuation into filaments 14. These lilaments 14 pass over the face of guides 32, positioned below the additional bushings 31 and above the guide 15, where the amazes filaments are further attenuated and transformed into staple fibers 33 upon impingement by a hot, gaseous blast emanating from a plurality of burners 34. The guides 32 are limited in length to span only the additional bushings 31. extending each end of the tier of bushings 11 comprising the normal complement.

The additional bushings 31, the guides 32 and the burners 34 are respectively substantial counterparts of the bushings 11, the burners 16 and the guide 15 and the fibers 33 produced thereby are substantially equivalent to the fibers 17. Therefore, the Volume of fibers produced by each bushing and burner set will be substantially equal to the volume of fibers produced by any other set. Likewise the gaseous blast generated by each of the burners 34 directs the fibers 33 in a flight paralleling the flight of fibers 17, but in an elevated relation thereto due to the elevation of the guides 32 and the burners 31 with respect to the guide 15 and the burners 16. However, since the bushings 31, the guides 32 and the burners 34 are positioned outside the transverse span of the collection belt 19, the flight of the fibers 33 is also outside the span of the belt and parallels the fiight of the bers 17.

A substantially S-sh-aped conduit 35 is positioned to receive the flight of fibers 33 generated by each additional set of bushings 31 and burners 34 and to uniformly distribute these fibers 33 over an area of the belt 19 in the collection area 21 on top of the fibers 17 previously collected in the area 21. Though not absolutely required, it is preferred that the conduits 35 have a smooth interior surface and long sweeping bends. However, it has been demo-nstrated that the air taken in with the blast from the burners 34 moves at high velocity through the -conduits 35 carrying the individual fibers 33 in a fluid suspension which conforms to the contour of each conduit 35. The radius of the bend is not critical and the absolute smoothness of the interior surface of the conduits, though desirable is not mandatory.

The number of bushings 11 and burners 16 shown in FlG. 1, and the number of additional bushings 31 and burners 34 have been chosen only for purposes of illustration and the number of each or the ratio therebetween is not to be interpreted as being a limiting factor.

As shown in FIGS. l and 2, the flight of the fibers 17 is distributed over substantially all of the lower transverse portion of the collection area 21 and the flight of the fibers 33 formed by each of the additional bushings 31 and the burners 34 are directed through a conduit 35 for distribution in an area spanningT a complementary one-quarter transverse portion of the upper half of the collection area 21. As previously described, the fibers 33 are deposited in a layer on top of the layer of fibers 17, so that the individual layer thickness and the combined layer thickness is uniform.

In the example shown in FIGS. l and 2, four bushings have been added to an existing 6 bushing machine, thereby increasing the volume of fibers by two-thirds which for any given mat thickness will permit a corre- -sponding increase in the lineal speed of the collection and oven conveyors, numbered 19 and 2-6 respectively, to result in a corresponding increase in the mat making capacity of the machine.

FIGS. 3, 4 and 5 show a modified form of the invention. In the specific embodiment shown in the drawings, the capacity of the machine, generally indicated by the numeral 36, is trebled.

As is shown in FIG. 3, the fiber generating apparatus is grouped in three tiers with the tiers defining three sides of a quadrate. The fourth side of the quadrate is defined by the fiber collecting belt disclosed hereinafter. Each of the tiers is spaced vertically in relation to the other tiers, as is shown in FIG. 5, for a purpose to be disclosed hereinafter and the fibers generated by the apparatus comprising each tier are directed into the area defined by the quadrate.

The tiers of fiber generating apparatus, taken in a clockwise direction around the quadrate and also in a descending order relative to elevation, are generally indicated by the

numerals

37, 38 and 39. Each tier is comprised of a plurality of bushings and blast generating burners, a pair of attenuating rolls and a filament guide. The distribution of bushing and burner sets between tiers is equal in all instances, though not necessarily restricted to eight in each tier as shown.

The bushings, burners, attenuating rolls and filament guide comprising each fiber generating tier are identical in construction. However, to differentiate between corresponding parts in different tiers, corresponding parts in different tiers are designated by different reference numbers.

The tier 37 is comprised of a plurality of bushings 40 for melting a supply of glass contained therein to a fluid state at which the glass gravitates in the form of small streams 41 through orifices formed in the base of each bushing. The streams of glass 41, while still in a fiuid state, are fed into the nip of a pair of rolls 42 revolving at a rate which will attenuate the streams of molten glass 41 into filaments 43 of uniformly fine diameter and direct these filaments 43 in spaced parallel array onto the face of a guide 44. A plurality of burners 45, usually one for each bushing, direct high velocity, hot gaseous blasts across the lower face of the guide 44 to further attenuate the filaments 43 and to transform the filaments into staple fibers 46 of a uniform diameter and varying lengths.

The fibers 46 produced at each burner 45 are directed by the high velocity blast generated by the burner into the open end of a conduit 47 which bends at right angles in the horizontal plane passing through the center line of the burner. As shown in FIG. 3, the conduits 47 lie in parallel, spaced relation with their individual mean radii progressively increasing in increments corresponding to the spacing of the burners 45. The blast from each of the burners 45 draws a large volume of air into the conduit to develop a high velocity air stream for transporting the fibers 46 through each conduit 47 and to subsequently deposit the fibers on a forming belt in a manner to be disclosed.

The fiber forming apparatus comprising the tier 38 is comprised of bushings 4S, equalling the number of bushings 40 in tier 37 and also spaced at intervals equalling the spacing of the bushings 40 in tier 37, a pair of attenuating rolls 49, a filament guide 50 and burners 51 corresponding in number to the bushings 48 contained in the tier 38. As shown particularly in FIGS. 4 and 5, the burners 51 discharge their fiber production at a level below the conduits 47 associated with the fiber producing apparatus of tier 37 and, as previously stated at right angles to the direction of discharge of the fibers produced by the apparatus of tier 37. A straight conduit 52 is positioned to receive the fibers produced by each of the burners 51 and to deliver them onto the forming belt at a level slightly below the discharge of each of the right angled conduits 47. In other Words, the discharge end ofl each right angled conduit 47 is in vertical alignment above a straight conduit 52.

The fiber forming apparatus of tier 3S and the straight conduits function in the same manner as the apparatus of tier 37 except the flight of the fibers is in a straight line and at a level below the fibers produced by the apparatus of tier 37.

The bushings and the burners of tier 39 also correspond in number to those contained in

tiers

37 and 38 and are spaced at intervals as previously defined for

tiers

37 and 38. The fiber producing apparatus components comprising tier 39 are indicated as follows: bushings 53, attenuating rolls 54, filament guide 55 and burners 56. All components are spaced at a level below corresponding elements of tier 38 by an amount equal to the difference in elevation between corresponding components of

tiers

37 and 38.

A plurality of conduits 57, identical in configuration to the right angled conduits 47, enter from the side of the quadrate opposite the point of entrance of the conduits 47. Each of the conduits 57 respectively discharges in vertical alignment with the discharge from a corresponding pair of previously aligned

conduits

47 and 52.

In brief, the apparatus for generating fibers are grouped in three

tiers

37, 38 and 39 defining three sides of a quadrate and are positioned at different levels so that each tier discharges into three sets of

conduits

47, 52 and 57 which discharge the fibers 46 produced by the generating apparatus of all the

tiers

37, 3S and 39 at the fourth side of the quadrate.

The total volume of fibers generated by each tier is directed by the associated set of conduits into a flight wherein the volume of fibers is uniformly distributed over a span defining the width of the mat. Also, as disclosed, each flight is vertically spaced with respect to the other flights so that each night contributes one-third of the thickness ofthe mat. v

As shown in FIGS. 3 and 4, the fibers 46 discharged from the

conduits

47, 52 and 57 enter into the confines of a trough 58, which shields the flight of the fibers from extraneous air currents, and are deposited in layers on the surface of an endless foraminous belt 59 advancing in the direction of the arrow 60 (FIG. 4). The area in which the fibers 4-6 are deposited on the belt 59 is hereinafter defined as the collection area 61. A vacuum chamber 62 is placed behind the belt 59 in the collection area 61 and the vacuum applied at this point assists in felting the fibers in random array into a mat 63.

The remainder of the mat making machine is conventional and is comprised of an applicator 64 for distributing a binder 65 to the fibers 46, preferably in the collection area 61, an oven for curing the binder and means for packaging the finished mat. The oven may also include means for compressing the mat tothe desired thickness and density.

The increased volume of fibers produced by the generating apparatus of either form of the invention disclosed herein permits a corresponding speed-up of the conveyor system used in further processing ofthe rnat thereby increasing the productive capacity of the mat making machine. Referring to the particular forms of the invention shown, the specific apparatus disclosed in FIGS. 1 and 2 will increase mat production by two-thirds while the apparatus of FIGS. 3, 4 and 5 will treble vthe production of a standard machine.

It is to be understood that the forms of the invention herewith shown and described are to be taken as illustrative embodiments only of the same, and that various changes in the shape, size and arrangement of parts, as well as various procedural changes, may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. In apparatus for producing a. m'at of glass fibers; an upwardly directed collecting belt, a plurality of first fiber generators positioned substantially within the width of said belt and spaced rearwardly from said belt, means associated with said first liber generators for discharging fibers toward said belt to be collected thereon in mat form, a plurality of second fiber generators spaced from said first fiber generators, said second fiber generators positioned substantially outside the width of said belt, and a plurality of stationary conduits extending from said second liber generators to within the width of said belt, said conduits being at an elevation different from that of said means associated with said first ber generators and arranged so that fibers from the second fiber generators are discharged toward the belt at an elevation different from that at which fibers are discharged from the rst fiber generators.

2. Apparatus for producing a mat of glass fibers ase defined in claim 1, wherein the second fiber generators are arranged at an angle to the first liber generators, and the conduits are spaced relative to one another so as to deposit fibers substantially uniformly over the Width of said belt.

3. Apparatus for forming a mat of glass fibers as defined in claim 2, wherein the second fiber generators are arranged in different groups spaced vertically from one another and at opposite sides of the collecting belt.

4. Apparatus for forming a mat of glass fibers as defined in claim 3, wherein the conduits in each group extend laterally toward one another and are bent toward the collecting belt and uniformly spaced from one another.

5. Apparatus for forming a mat of glass fibers as defined in claim 1, wherein the conduits are curved intermediate the ends thereof and have their ends adjacent the collecting belt spaced substantially uniformly across the width of said belt.

6. Apparatus for forming a mat of glass fibers as defined in claim l, wherein an individual conduit is provided for each of the second fiber generators and a common conduit is provided for the first fiber generators.

7. Apparatus for forming a fibrous mat as defined in claim 1, wherein the first fiber generators are arranged in a line extending transversely to the collecting belt, the second fiber generators are positioned at each end of the line of rst fiber generators, and the conduits from the second ber generators are S-shaped in plan view.

References Cited in the file of this patent UNITED STATES PATENTS 2,732,885 Van Der Hoven Ian. 31, 1956 2,751,962 Drummond June 26, 1956 2,753,598 Slayter July 10, 1956 2,758,952 Toulmin Aug. 14, 1956 2,770,844 Lambert Nov. 20, 1956 2,868,684 Labino Jan. 13, 1959 2,996,102 Schuller Aug. 15, 1961 FOREIGN PATENTS 1,097,788 France Feb. 23, 1955

Claims

1. IN APPARATUS FOR PRODUCING A MAT OF GLASS FIBERS, AN UPWARDLY DIRECTED COLLECTING BELT, A PLURALITY OF FIRST FIBER GENERATORS POSITIONED SUBSTANTIALLY WITHIN THE WIDTH OF SAID BELT AND SPACED REARWARDLY FROM SAID BELT, MEANS ASSOCIATED WITH SAID FIRST FIBER GENERATORS FOR DISCHARGING FIBERS TOWARD SAID BELT TO BE COLLECTED THEREON IN MAT FORM, A PLURALITY OF SECOND FIBER GENERATORS SPACED FROM SAID FIRST FIBER GENERATORS, SAID SECOND FIBER GENERATORS POSITIONED SUBSTANTIALLY OUTSIDE THE WIDTH OF SAID BELT, AND A PLURALITY OF STATIONARY CONDUITS EXTENDING FROM SAID SECOND FIBER GENERATORS TO WITHIN THE WIDTH OF SAID BELT, SAID CONDUITS BEING AT AN ELEVATION DIFFERENT FROM THAT OF SAID MEANS ASSOCIATED WITH SAID FIRST FIBER GENERATORS AND ARRANGED SO THAT FIBERS FROM THE SECOND FIBER GENERATORS ARE DISCHARGED TOWARD THE BELT AT AN ELEVATION DIFFERENT FROM THAT AT WHICH FIBERS ARE DISCHARGED FROM THE FIRST FIBER GENERATORS.