US3012289A - Method and apparatus for blending ceramic fibers with carrier fibers - Google Patents

Description

Dec. 12, 1961 J w WEBER 3,012,289

METHOD AND APPARATIJS FOR BLENDING CERAMIC FIBERS WITH CARRIER FIBERS Filed May 13, 1957 2 Sheets-Sheet l INVENTOR. v John W Weber H/ ATTORNEY Dec. 12, 1961 J. w. WEBER METHOD AND APPARATUS FOR BLENDING CERAMIC FIBERS WITH CARRIER FIBERS 2 Sheets-Sheet 2 Filed May 15, 1957 IN VEN TOR. John W. Weber H/ ATTORNEY United States Patent 3,012,289 METHOD AND APPARATUS FOR BLENDHNG CERAMIC FIBERS WITH CARRIER FIBERS John W. Weber, Norristown, Pa., assignor to The Carborundum Company, Niagara Falls, N.Y., a corporation of Delaware Filed May 13, 1957, Ser. No. 658,582 8 Claims. (Cl. 19146) This invention relates to a method and apparatus for blending ceramic fibers with cariier fibers for forming therefrom a web from which roving and then yarn is produced. From the ceramic yarn a woven fabric of ceramic fibers can be easily made. This invention is particularly adapted for producing a web of blended ceramic and carrier fibers which comprises about 25% carrier fibers.

Ceramic fibers are usually brittle and delicate and generally a mass of as-produced ceramic fibers has a content of shot which must be separated from the fibers before processing them in the production of ceramic fiber yarn. The shot in the mass of as-produced ceramic fibers is small beads, pellets and particles of ceramic material which result from the manufacture of the fibers. The brittle and delicate characteristics of ceramic fibers require that a carrier fiber be used along with the ceramic fibers in the manufacture of ceramic fiber yarn. Otherwise, during carding and forming a web from which the roving and then the yarn is made, the ceramic fibers break up into small pieces and very short lengths which cannot be converted into the web. The carrier fiber supports the brittle and delicate ceramic fibers and permits carding the ceramic fibers without subjecting a large proportion thereof to damage and to breaking up into unusable short lengths and small pieces. To provide a maximum support for the delicate ceramic fibers in the manufacture of ceramic yarn, it is desirable that the carrier fiber be intimately blended with the ceramic fiber. However, because of the brittle and delicate character of the ceramic fibers, it is essential that they receive a careful and a minimum handling and working when effecting a blend with the carrier fibers. Usually, the carrier fiber content in ceramic fiber yarn is about 525% and seldom is less than 5%, but may amount to as much as 40%.

Since many orders for fabrics made from ceramic fiber yarn specify that the fabric be resistant to high temperatures and be fire-resistant, it is essential that the carrier fiber content of the ceramic fiber yarn be as low as possible while still being able to support the ceramic fiber suificiently for the production of the yarn. For production of aluminum silicate yarn, I have found that the carrier fiber content in the yarn preferably should range between about 5-25% and that a 10% carrier fiber content produces a good ceramic fiber yarn. Heretofore, aluminum silicate yarn has been produced only by using 40% carrier fiber in the yarn which amount of carrier fiber is too high to meet the high temperature and fire-resistant specifications.

Some of the ceramic fibers to which my invention relates are aluminum silicates, sodium-calcium silicates, calcium aluminates, calcium silicates, sodium silicates, and glass. I

Some of the carrier fibers which may be used in my invention are acrylic fibers, rayon, cotton, wool, asbestos, glass, polytetrafiuoroethylene fibers, polyamide fibers and polyester fibers.

My invention effects an intimate blend of ceramic and carrier fibers wherein the ceramic fibers are carefully handled and processed so that there is a minimum breakup into unusable short lengths and pieces. The resulting blend of ceramic and carrier fibers produced from practicing my invention can be utilized to make good strong ceramic fiber yarn and fabricated textiles that meet high temperature and fire-resistant specifications. Specifically, my invention comprises a method of blending ceramic fibers and carrier fibers by carding the carrier fibers to form a web of carrier fibers. Next, a mass of ceramic fibers is opened to make a plurality of small tufts of the ceramic fibers and then these small tufts are deposited onto the web of the carrier fibers so that there is a plurality of small tufts distributed upon said web of carrier fibers. Then the web of carrier fibers and the small tufts of ceramic fibers are carded to form a Web of blended carrier and ceramic fibers.

My invention is especially suitable for blending aluminum silicate fibers with carrier fibers such as rayon and cotton. Generally, the aluminum silicate fibers range in size from about 2-20 microns.

In the accompanying drawings, I have shown one embodiment of my apparatus which can be used in practicing my invention in which:

FIGURE 1 is a schematic side view of a carding machine for producing the web of carrier fibers and of an opening machine for making the small tufts of ceramic FIGURE 2 is a schematic side view of an enlarged portion of FIGURE 1 including a revolved section of a segment of the periphery of the dofier to show the position of the cutter band thereon;

FIGURE 3 is a section view along the line III-III of FIGURE 2;

FIGURE 4 is a schematic side view of a carding machine which forms the Web of blended ceramic and carrier fibers; and

FIGURE 5 is a schematic side view of a train of conveyors for carrying the web of carrier fibers with the small tufts of ceramic fibers distributed thereupon from the carding line and opening machine of FIGURE 1 to the carding line of FIGURE 4.

As shown in FIGURES 1 and 4, my apparatus for blending ceramic fibers with carrier fibers comprises a first carding line 1 which forms a continuous web of carrier fibers from a mass thereof, an opening machine 2 which produces the small tufts of ceramic fibers from a mass of as-produced ceramic fibers, and a second carding line 3 which forms a web of blended carrier and ceramic fibers. The delivery end of the opening machine is located adjacent to the delivery end of the first carding line so that the opening machine deposits 21 plurality of the small tufts of ceramic fibers across and along the web of carrier fibers as the web leaves the first carding line. The train 4 of conveyors shown in FIGURE 5 receives the Web of carrier fibers with the small tufts of ceramic fibers distributed thereupon and carries the web and small tufts distributed thereupon to the second carding machine.

The web of carrier fibers preferably comprises randomly oriented fibers with a substantial or a major portion of the fibers arranged longitudinally of the Web and with the balance of the fibers arranged laterally and diagonally of the web to impart strength thereto.

A small tuft of the ceramic fibers produced by the opening machine comprises a plurality of loosely associated fibers which have been torn ofi of a mass of as-produced fibers, which have been subjected to a small amount of combing relative to the amount of combing received on a carding line, and which have been partially separated from one another to approach individualization and from which the shot has been separated. I have found that tufts which weigh from about l1 /2 to about 4 /26 grains are satisfactory for the production of a good Web of blended ceramic and carrier fibers.

The web of blended carrier and ceramic fibers produced by the second carding line is similar to the web of carrier fibers with a substantial or a major portion of the blended fibers being disposed longitudinally of the web and with the balance of the blended fibers being arranged laterally and diagonally of the web to impart strength thereto.

As shown in FIGURE 1, the first carding line 1 has a conventional automatic weighing self feed 5 comprising a feed apron 6 which delivers a mass 7 of carrier fibers to a spike apron 8 having a plurality of spikes arranged in rows across the width of the apron with the spikes in one row being staggered relative to the spikes in the next succeeding row. As shown, the spike apron is inclined vertically so that it delivers the carrier fiber to a conveyor apron 9 located beneath the upper end of the spike apron. The spikes on the spike apron tear off tufts it} of carrier fibers from the mass as the spike apron travels in the direction of arrow 11 and in engagement with a portion of the mass. The spike apron carries the tufts to the top of the automatic weighing self feed where they are removed from the spikes and drop down into the weighing pan for discharge 'onto the conveyor apron 9.

This conveyor apron delivers the tufts to a set of feed rolls 12 which, in turn, transfers the tufts onto a lickerin roll 13. Each of the feed rolls and the lickerin roll has card cloth or wire secured to its periphery and extending substantially across its length. The card cloth or wire, like the other card cloths or wires referred to hereinafter, has a plurality of teeth arranged thereon with the teeth being adapted to tear down and break down tufts of fibers into smaller tufts or clumps before passing the broken down and torn down tufts to a succeeding component of the carding line. On a carding line such as lines 1 and 3, the card cloth or Wire on the various elements of the line has progressively smaller and finer teeth extending from the feed rolls to the carder with its main cylinder, worker and stripper rolls to be described hereinafter.

A breast 14 receivesthe tufts from the lickerin roll and performs a further break down and a combing of the tufts. This breast comprises a main cylinder 15 and two worker rolls 16 and a stripper roll 17 interposed between and nearly in contact with the two worker rolls. The Worker rolls and the stripper roll are nearly in contact with the periphery of the main cylinder. The main cylinder and each of the worker rolls and the stripper roll have card cloth or wire whereby each combs and Works the tufts to break them down into smaller masses and to approach individualization of the fibers preparatory to forma ing a web. The worker rolls rotate relative to the direction of rotation of the main cylinder so that they remove some of the tufts therefrom and the stripper roll rotates relative to the direction of rotation of both worker rolls and of the main cylinder so that it removes the fibers from both worker rolls and returns them to the main cylinder. The main cylinder has a surface speed greater than the surface speeds of the worker rolls and the stripper roll and the stripper roll has a higher surface speed than the worker rolls. The relative speeds of the main cylinder of the two worker rolls and of. the stripper roll in combination with the card cloth or wire on the worker and stripper rolls and on the main cylinder effect a combing and working of the tufts to reduce them in size and to bring about an individualization of the fibers.

-A transfer roll 18 with card cloth or wire mounted thereon removes the carrier fibers from the breast and deposits them on the main cylinder 19 of the carder 20. The carder, like the breast, has worker rolls 21 and, in the case of the carder, a stripper roll 22 associated with each worker roll. The main cylinder, stripper rolls and worker rolls'of the carder are disposed nearly in contact with each other as shown'in' FIGURE 1 and, like the main cylinder, stripper roll and'the worker rolls of "the breast, have card cloth or wire thereupon with the card cloth or wire of the carder having more rows of teeth per inch and more teeth per row. The carder operates in the same manner as the breast with the main cylinder having a higher surface speed than the surface speeds of both the worker rolls and stripper rolls and with the stripper rolls having a higher surface speed than the surface speed of the worker rolls. The carder combs and works the carrier fibers to produce a Web of carrier fibers wherein the worker rolls remove tufts or clumps of fiber from the main cylinder and comb and work these tufts or clumps; then the stripper roll takes the worked clumps and tufts and performs a further combing and working thereof before returning the combed and worked fibers to the main cylinder. The progressive working and combing of the tufts by the main cylinder 1-), the worker rolls 21 and the stripper rolls 22 form a continuous web 23 of fibers on the main cylinder 19. The worker rolls are so arranged relative to the main cylinder that fibers which have been formed into a web escape being picked up by the worker rolls and pass onto a dotfer roll 24.

The doffer roll 24, assisted by a fancy roll 25, interposed between the doffer roll and the worker roll 21a and disposed nearly in contact with the main cylinder 1?, removes the individual fibers from the main cylinder. Three cutter bands 26 arranged around the periphery of the doffer roll, evenly spaced, divide the continuous web 23 into four widths 23a, 23b, 23c, and 23d of substantially equal dimension. Both the fancy roll and the doffer roll have card clothing.

The fancy roll digs out and partially frees the individual fibers from the main cylinder, thereby permitting the dofier roll to remove the fibers from the main cylinder in web form.

An oscillating doifer comb 27 extracts the four widths of web from the dofier roll and a lattice apron 28 receives the widths and carries them to a position'adpacent the delivery end of the opening machine. There, the small tufts 29 of ceramic fibers are deposited across and along each width of the web just before the web is carried downwardly to right angle deflector vanes 30 which impart a right angle turn to the direction of travel of the continuous widths of web (FIGURE 3).

As shown in FIGURE 1, the opening machine 2 has a lattice apron 31 which conveys a mass 32 of as-produced ceramic fibers to an, automatic weighing self feed 33 equipped with a vertically inclined spike apron 34. This spike apron has a plurality of rows of spikes arranged across its width with the spikes in one row being staggered relative to the spikes in an adjacent row. The spike apron 34 travels in the direction of arrow 35 and as it passes in engagement with the mass of ceramic fibers, the spikes thereon tear off tufts 36 of fibers and carry them to the top of the apron. One arrangement of spikes on the apron 34 which has produced satisfactory results comprises a spacing of 1%" between spikes on a row and a spacing of 1 /4" diagonal dimension between spikes on adjacent rows.

One eccentric rotating comb 37 located about halfway up the apron 34 and positioned adjacent thereto and a second eccentric rotating comb 38 disposed near the top of the apron and positioned adjacent thereto progressively reduce size of the tufts. The two eccentric rotating combs also assist in removal of shot from the ceramic fibers. At the bottom of the spike apron is a receptacle (not shown) which collects the shot removed from the mass of ceramic fibers by the spike apron and by the two combs.

At the top of the spike apron 34 is a driven stripper roll 39 with projections arranged across its length and around its periphery for removing the tufts 36 of ceramic fibers from the spike apron and dropping them into a weighing pan 40 which deposits the tufts into a hopper 41 at regular intervals. When the weighing pan has received a certain number of tufts which equal a predetermined weight, a lever mechanism (not shown) opens the bottom of the weighing pan andthe tufts drop down into the hopper 41. The hoppe feeds the tufts to a second feeder 42 having a vertically inclinde spike apron 43 with its spikes being disposed similarly to the spikes of the spike apron 34. On the spike apron 43 there is 1%" between adjacent spikes in a row extending substantially across the width of the apron and 2" diagonal dimension between adjacent spikes in successive rows. From the tufts produced by the first feeder, the spike apron 43 tears off smaller tufts 29 and carries these tufts up to its top where they are removed from the spikes of the apron 43 and then delivered onto a conveyor 45. These smaller tufts 29 generally are from about one-tenth to one-third the size of the tufts 36 made by the spike apron 34 and weigh between about 1 to 6 grains.

Adjacent the top of the spike apron 43 is an eccentric rotating comb 46 which is substantially the same as the two eccentric rotating combs associated with the spike apron of the first feeder. ThiS eccentric rotating comb 46 performs substantially the same function as the two combs heretofore described.

A second stripper roll 47 extracts the smaller tufts 29 from the spike apron 43 and transfers them to a downwardly inclined slide 48 having three deflector vanes 49 spaced across its lower end. The deflector vanes divide the smaller tufts into four streams 50. The slide 48 discharges these four streams of tufts onto the horizontally disposed conveyor 45 arranged to move the streams to a point above the continuous traveling widths of web of carrier fibers and there to deposit the tufts 29 upon each width of web so that there is a plurality of tufts extending across and along any given length of a width of web. The small tufts are delivered onto the widths of web just before the lattice apron 28 carries each width over its end 2841 whereupon each width is conveyed downwardly and given a 90 twist before reaching the right angle deflector vanes 30.

As each width passes underneath a right angle deflector vane, it makes a right angle turn and, in the case of width 23a, it is laid upon a horizontal conveyor 51. As shown in FIGURES 2 and 3, as the widths move downwardly to the right angle deflector vanes 30, the small tufts 29 fall ofi of that portion of the width onto which they were deposited and drop down onto a different portion of the same width, which portion has already passed underneath a right angle deflector vane 30. Each of the other three widths and the small tufts deposited thereon are subjected to the same operation with the widths being twisted 90 and passed around a right angle vane deflector.

The right angle vane deflectors are arranged in tandem so that the four widths of web and the small tufts form a stack or pile 52 of successive layers of a width of web and of small tufts. In other words, width 23a becomes the bottom layer and the small tufts deposited thereon become the second layer with width 2312 becoming the third laye and its tufts the fourth layer. Correspondingly, width 230 becomes the fifth layer, its tufts the sixth layer; width 23d becomes the seventh layer and its tufts the eighth layer.

The train 4 of conveyors shown in FIGURE carries the pile or stack 52 of layers of web and of tufts to a feed apron 53 of the second carding line 3. The delivery component 54 of this line of conveyors has its upper end pivoted to a portion 55 of a frame which supports the conveyors (all of the frame not being shown) and its lower end connected to an endless chain 56 so that the pile of web and of small tufts is laid transversely upon the feed apron 53 in continuous lengths as shown in FIG- URE 5.

The second carding line is substantially the same as the first and has a set of feed rolls 57, a breast 58 with a main cylinder 58a, worker rolls 59 and stripper rolls 60, a carder 61 with a main cylinder 62, worker rolls 63, stripper rolls 64. a top dofl'er roll 65 and doffer comb 66, and a bottom dofler roll 67 and dotr'e comb 68. Between the top and bottom doifer rolls is a fancy roll 69.

Referring to FIGURE 4, the feed apron 53 of the sec ond carding line delivers the stack or pile 52 of layers of web and of small tufts of ceramic fibers to a set of feed rolls 57 which transfer the pile to the main cylinder 58a of the breast 58.

This main cylinder and its worker and stripper rolls have card cloth extending substantially across its length and wrapped around its periphery. As shown in FIG- URE 4, there is a stripper roll for each worker roll and the main cylinder, worker and stripper rolls operate in the same manner as the comparable components of the breast 14 of the first carding line. This breast 58 combs and works the web of carrier fibers and small tufts of ceramic fibers in the initial blending of the ceramic fibers with the carrier fibers and, in addition, converts the small tufts 29 of ceramic fibers into smaller clumps or tufts so that the carde 61 may more easily form a web of blended ceramic and carrier fibers.

A transfer roll 70 with card cloth secured to its periphery and extending substantially across its length receives the combed and worked web of carrier fibers and small tufts and clumps of ceramic fibers from the breast 58 and transfers them onto the main cylinder 62 of the carder 61. The carder 61, like the carder 20 of the first carding line, has a plurality of worker rolls 63 and stripper rolls 64 arranged substantially the same as those of the carder of the first carding line. Specifically, the main cylinder 62 has four worker rolls and four stripper rolls with a stripper roll associated with each worker roll. The main cylinder and each worker and stripper roll have card cloth which enables them to comb and work the small tufts of ceramic fibers into a web of blended carrier and ceramic fibers while avoiding breaking up the ceramic fibers into lengths and pieces too short to card. Also, this carder, like the carder of the first carding line, progressively reduces the small tufts and clumps of ceramic fibers so that the tufts and clumps approach an individualization of fibers and so that they blend with the carrier fibers and form a web 71 of blended carrier and ceramic fibers.

The top doffer roll 65 and the bottom doffer roll 67 remove the individual fibers from the main cylinde and oscillating dofler combs 66 and 68 positioned as shown in FIGURE 4 relative to each doffer roll extract the Web of blended fibers from the dotfer rolls whereupon two conveyors 72 and 73 pick up the web and carry it to a tape condenser (not shown). The tape condenser forms roving from the web and then winds the roving onto spools (not shown). The bottom dofl'er roll removes that portion of the web of blended fibers which escapes the top doffer roll.

Between the top and bottom dofler rolls is the fancy roll 69 which digs out of the main cylinder the web passed by the top dotfer roll, thus enabling the bottom dofi'er roll to easily remove the portion of the web which remains on the main cylinder. The card cloth for the fancy roll is generally fillet wire.

There is a stripper roll 74 associated With the top doffer roll and a stripper roll 75 also associated with the fancy roll. The stripper roll 74, associated with the top doffer roll, removes any individual fibers which may have been picked up from the top dofier roll and which have escaped the doffer comb and transfers such individual fibers back onto the main cylinder. The stripper roll 75, associated with the fancy roll, performs a like function, namely, it transfers from the fancy roll any individual fibers which may have been picked up and returns it to the main cylinder.

I have found that the following card wiring for the main cylinder, worker and stripper rolls, fancy roll, and dotfer rolls of the second carding line produce a good web of blended and carrier fibers: a card wire of about 6-12 rows of teeth per inch across the main cylinder and the worker and stripper rolls of the breast; a card wire of about l2l6 rows of teeth per inch across the transfer roll; a card wire of about 14-22 rows of teeth per inch across the main cylinder of the carding machine; a card wire of about 12-20 rows of teeth per inch across the stripper rolls and worker rolls of the carding machine; a card wire of about l220 rows of teeth per inch across the top dofier roll and across the stripper roll associated therewith; a card clothing of about 22-28 rows of teeth per inch across the fancy roll; a card wire of about 12-18 rows of teeth per inch across the stripper roll associated with the fancy roll; and a card wire of about 18-24 rows of teeth per inch across the bottom dofier roll.

Conventional chain and belt drives operate the first and second carding lines and the opening machine together with the train of conveyors which transport the stack of layers of web and of tufts from the opening machine and the first carding line to the second carding line. These drives have not been shown or' described since they are well known'and their description would only serve to unnecessarily complicate and lengthen this specification.

My invention is the first method which successfully blends aluminum silicate fibers with carrier fibers to form a web of blended fibers from which commercial roving and then yarn may be produced. Heretofore, the best efforts in the manufacture of aluminum silicate yarn effected yields of only -50% of the ceramic fiber used and could only produce the ceramic yarn with a carrier fiber content of about 40%. Thus, prior to my invention, the best efforts produced a yarn which could not meet high temperature and fire-resistant specifications and which was economically unfeasible for commercial production due to the'extremely low yield of ceramic fibers. My invention eifects a web of blended aluminum silicate and carrier fibers from which aluminum silicate roving and yarn can be produced with yields as high as 70-75% of the total ceramic fibers processed being utilized in the final product and with a carrier fiber content in the final product being as low as about 5%. Hence, my invention has made possible production of aluminum silicate yarn which not only is economically feasible to make but can easily meet high temperature and fire-resistant specifications. In addition, the lower carrier fiber content in the v yarn produced by practice of my invention results in a I roving and yarn having greater strength at very high temperatures than yarn heretofore made. a

Practice of my invention now makes available for the first time articles made from aluminum silicate yarn which have highly important properties and advantages. For example, fire curtains or flame and heat barrier fabrics made from aluminum silicate fibers withstand temperatures in the range of about 2000 F., whereas such curtains and fabrics previously made from asbestosclot have been suitable for temperature ranges of about 1000* High'temperature gaskets and packings made from aluminum silicate woven fabrics have the same high temperature advantages overthose made from asbestos cloth. In addition, aluminum silicate gaskets and packings have greater heat insulating properties than those made from glass fibers. a

In the field of high temperature protective clothing, aluminum silicate fabrics have a higher temperature range than those made from asbestos cloth and have a better insulating property than those made from glass cloth.

Braided or wrapped sheathing made from aluminum :silicate yarn has superior electrical insulating characteristics than sheathing made from a combination of asbestos and glass fibers and from glass fibers alone. Specifically, wire wrapped with aluminum silicate sheathing has less corona and, in addition, the aluminum silicate sheathing withstands higher temperatures while maintaining its electrical insulating ability.

While a certain embodiment of my invention has been shown and described, it will be understood that it may be otherwise embodied Within the scope of the appended claims.

1' claim:

1. A meth d of forming an intimate blend of carrier fibers and of ceramic fibers from carrier fibers and from ceramic fibrous material that contains a substantial proportion of shot that must be separated to obtain substantially shot-free fibers to permit processing of the ceramic fibers, comprising carding said carrier fibers to form a carded web of carrier fibers, picking a mass of said ceramic fibrous material to separate the shot and fibers and to form tufts of ceramic fibers, picking said tufts of ceramic fibers to form smaller tufts of ceramic fibers, depositing said smaller tufts of ceramic fibers onto said carded web of carrier fibers so that there is a plurality of said smaller tufts of ceramic fibers distributed upon said web of carrier fibers, and carding said already carded web of carrier fibers with said smaller tufts of ceramic fibers distributed thereon sufficiently to break up said tufts and substantially to individualize the ceramic fibers and to intimately blend the ceramic fibers of the tufts with the carrier fibers of the carded web to form a web of intimately blended carrier and ceramic fibers.

2. Apparatus for blending ceramic fibers and carrier fibers comprising a first carding means for carding a mass of carrier fibers to'produce a web of carrier fibers, a first picking means for making tufts of ceramic fibers from a mass of ceramic fibers, a second picking means for reducing said tufts from said first picking means to smaller tufts, said second picking means being arranged to receive the tufts from said first picking means and being arranged to deliver said smaller tufts onto said web of carrier fibers so that said smaller tufts are distributed upon said web, and a second carding means for carding said web of carrier fibers and said smaller tufts of ceramic fibers to form a web of blended carrier and ceramic fibers.

3. Apparatus for blending ceramic fibers and carrier fibers comprising a first carding means for carding a mass of carrier fibers to produce a continuous web of carrier fibers, said first carding means having means for dividing said web into at least two widths, a first picking means for making tufts of ceramic fibers from a mass of ceramic fibers, a second picking means for reducing said tufts from said first picking means to smaller tufts, said second pick ing means being arranged to receive the tufts from said first picking means and being arranged to deposit said smaller tufts onto each of said widths of said web of carrier fibers so that the smaller tufts are distributed upon any given length of each of said widths,.a second carding means for carding each of said widths of said web and said smaller tufts of ceramic fibers to produce a web of blended carrier and ceramic fibers, conveyor means extending between said first carding means and said second carding means for moving said widths of said web from said first carding means to said second carding means,

said second picking means being arranged to deliver said smaller tufts onto each of said widths as said widths move from said first carding means to said second carding means, said conveyor means having means for placing one of said widths upon another with a layer of said smaller tufts interposed between as said widths travel from said first carding means to said second carding means.

4. in an apparatus for forming an intimate blend of carrier fibers and of ceramic fibers from carrier fibers and from cerarnic fibrous material that contains a substantial proportion of shot that must be separated to obtain substantially shot-free fibers to permit processing of the ceramic fibers, a first picking means for opening a mass of ceramic fibrous material to separate the shot and the fibers and to make a plurality of small tufts of substantially shot-free fibers, a second picking means for reducing said tufts from said first picking means to smaller tufts, said second picking means being arranged to receive the'tufts from said first picking means and being arranged to deposit said smaller tufts onto an already carded web of carrier fibers for blending therewith.

5. A method for forming an intimate blend of carrier fibers and of ceramic fibers comprising carding carrier fibers to form a carded web of carrier fibers, picking a mass of ceramic fibers to form tufts of ceramic fibers,

icking said tufts to form ceramic fiber tufts of reduced size and that weigh from about 1 grain to about 6 grains, delivering the last-mentioned tufts upon said carded web of carrier fibers to form a layered structure in which there are at least 5% of carrier fibers based on total fibers, and then carding said layered structure intimately to blend said carrier fibers and ceramic fibers and to form a web from said intimate blend.

6. A method of forming an intimate blend of ceramic fibers and carrier fibers comprising, carding a mass of carrier fibers to form a uniform carded web of such fibers, placing said carded web in a horizontal position, picking a mass of ceramic fibers to form a plurality of small loose tufts of said ceramic fibers, depositing said small loose tufts by gravity in a uniform open layer upon said horizontally disposed carrier web to make a uniform composite of small loose tufts of ceramic fibers and web of carrier fibers, and carding said composite to further separate the ceramic fibers of the small loose tufts and intimately blend the ceramic fibers and the carrier fibers of the carded Web.

7. A method of forming an intimate blend of carrier fibers and ceramic fibers including the steps of carding a mass of carrier fibers to form a uniform carded web of such fibers, placing said carded web in a horizontal position, picking a mass of ceramic fibers to form tufts of ceramic fibers, picking said tufts to form smaller tufts, depositing said smaller tufts by gravity in a uniform open layer upon said carrier Web to provide a uniform composite of tufts of ceramic fibers and web of carrier fibers, and carding said composite to further separate the ceramic fibers of the tufts and intimately blend the ceramic fibers and the carrier fibers of the carded Web.

8. Apparatus for forming an intimate blend of carrier fibers and ceramic fibers comprising, a first carding means for carding a mass of carrier fibers to produce a carded web, a horizontally disposed conveyor adjacent said first carding means and adapted to receive a carded web therefrom, a picker for opening a mass of ceramic fibers to provide a plurality of'small tufts of ceramic fibers, said picker being arranged to deliver said tufts by gravity upon said horizontal conveyor so that the tufts are distributed in a uniform open layer upon said web, and second carding means in receiving relationship to said conveyor for carding said web of carrier fibers and said tufts of ceramic fibers distributed on said web.

References Cited in the file of this patent UNITED STATES PATENTS 1,015,764 Potter Jan. 23, 1912 1,179,458 Ryan Apr. 18, 1916 1,235,327 Kinsley July 31, 1917 2,665,453 Senior et ai. Jan. 12, 1954 2,682,085 Novotny et a1 June 29, 1954 2,816,327 Hunter et al Dec. 17, 1957

Claims (1)

1. A METHOD OF FORMING AN INTIMATE BLEND OF CARRIER FIBERS AND OF CERAMIC FIBERS FROM CARRIER FIBERS AND FROM CERAMIC FIBROUS MATERIAL THAT CONTAINS A SUBSTANTIAL PROPORTION OF SHOT THAT MUST BE SEPARATED TO OBTAIN SUBSTANTIALLY SHOT-FREE FIBERS TO PERMIT PROCESSING OF THE CERAMIC FIBERS, COMPRISING CARDING SAID CARRIER FIBERS TO FORM A CARDED WEB OF CARRIER FIBERS, PICKING A MASS OF SAID CERAMIS FIBROUS MATERIAL TO SEPARATE THE SHOT AND FIBERS AND TO FORM TUFTS OF CERAMIC FIBERS, PICKING SAID TUFTS OF CERAMIC FIBERS TO FORM SMALLER TUFTS OF CERAMIC FIBERS, DEPOSITING

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