US2339431A - Fibrous glass product - Google Patents

Description

Jan. l18, 1944. SLAYTER 2,339,431

FIBROUS GLASS PRODUCT Filed Aug. 22, 1942 f2 .EM

Patented Jan. 18, 1944 UNITED STAT rrsaoUs Guss PRODUCT Gaines Slayter, Newark,- Oiiio, assigner to Corning Fiberglas Corporation, a corporation of Delaware Application August 22, 1942,|S.liill1`0.455,966v

Claims. 1 (Cl. 28-79) My invention relates to novel products made by needling brous materials into matted form.

In the manufacture of felted products such as felts for horse blankets, rug pads, automotive insulation, etc., it has long been the practice to use a needle loom to knit a brous mass into a felted batting and by the same operation attach it to a backing of burlap or the like. This needling is accomplished by pushing barbed needles through the brous mass and juxtaposed backing material and then withdrawing them. The needle barbs hook some of the surrounding flbers and carry them through the mass of loose bers and backing material and thereby tie the mass of bers into the form of a felt and at the same time bond the felted material to the woven fabric or the like used as' a backing. It is common. practice, for example, to needle coarse vegetable fibers such as jute or hemp onto a burlap backing.

I have found that mats of matted glass bers may be needled with advantageous results in the way of greatly increased density of the mats, thus improving the thermal insulating properties of the mats and adding to the number of applications of glass ber mats. These needled mats, however, may have roughened surfaces because of the needling operation and may have less than the desired degree of strength measured in directions generally parallel with the major faces of the mats. i

Also, coarser glass bers, that is, bers in the neighborhood of .0007 inch in diameter are more economical to produce and are therefore preferable for many heat-insulating purposes. Mats of bers of this size, however, are more difficult to needle because of the likelihood of breakage of the fibers into shorter lengths with consequent decrease in the coherence and strength of the finished mat. I

An object of the invention is to provide a mat of glass ,bers needled to greatly increase its density and having smooth surfaces and increased strength and coherence. the present invention this is obtained by` facing the mat on one or bothof its'major faces with a thin web of very fine glass bers of great length needled to the mat. The ne long bers of the Web are needled into-the mat, serving not only to hold the web to the mat but also increasing the coherence of the mat.

A further object of the invention is to provide a. novel needled product of glass fibers in the form of an integrated mat of bers without a. backing of woven fabric or other supporting material, capable of being handled and applied.

A further object of the invention is to provide a needled mat of inorganicv bers having mass y integrity andstrength in al1 directions. A further object of the invention is to provide In accordance with.

an integrated bat of inorganic fibers, said bat .being of predetermined shape maintained without the use of an adhesive bonding material or other extraneous means.

A further object of the invention is to provide a mat or bat adapted for high temperature insulation purposes which is free vfrom organic binders or other materials which, when the insulation is subjected to high temperatures, would cause smoke, objectionable odors or gases.

A further object of the invention is to provide a novel form of integrated mat or bat .in which the usual heat treating and curing operations are rendered unnecessary.

A further object of the invention is to provide a needled mat and method of making the same, by which the use of the usual paper and thread as in stitching methods is eliminated.

A further object of the invention is to provide as a product of manufacture, a needled mat of mineral fibers which is reproof and vermin proof.

A further object of the invention is to provide a novel form of battery plate separator consisting of matted glass wool, and a novel method and apparatus for making the separator. M

A further object of the invention is to provide a novel form of heat insulating product which may comprise -a bat or the like consisting of matted glass libers with a bonding material to give the mat the needed strength and rigidity for handling while being installed, in combination with a, matting of the bers in such manner that the material will be self-supporting and retainits shape when subjected to high temperature by which the adhesive bonding material is burned out or destroyed in whole ,or in part. j 1

Other objects of the invention will appear hereinafter. v i

Referring to the accompanying drawing:

- FigureA 1 is a partly diagrammatic sectional elevational of a needling apparatus for use in practicingI the present invention;

Figure 2 is a fragmentary sectional elevation on a larger scale illustrating 'a portion of a needled mat and also showing the manner in which the needles operate; and

Figure 3 is a similar view showing -a somewhat modified operation in wnichthe needles are projected only part way through the mat:

The needling machine may be of .conventional construction. As shown in rigure vl it comprises a battery of needles Il mounted in a supporting plate Ii of wood or other materiaL The needles may be arranged in rows and uniformly spaced.

Each needle isv formed with a multiplicity of downwardly'projecng barbs I2 (Figure 2). The plate li is mounted on a carrier i3 which is adapted to reciprocate vertically in guides Il on the machine frame l5. The carrier i3 is reciprocated by means of a rotating crank shaft I and crank I8. A pitman I1 iournaled on the crankis pivoted at I8 to a connecting frame I3, the latter having a pivotal connection 20 with the reciprocating carrier I3. Y

Upper and lower stripper plates 2I and 22 have a. stationary mounting in the machine frame and are spaced apart to permit the passage therebetween of a mat or work-piece 23. The upper stripper plate 2I is adjustable up and down to accommodate work-pieces of various thicknesses. The stripper plates are preferably made of sheet metal and as shown are provided with inclined marginal portions or anges 24 providing a flared entrance for the mat 23.

The stripper plates are provided each with a multiplicity of perforations 21 arranged in rows and .spaced to correspond with the spacing of the needles. These openings are preferably circular and of slightly larger diameter than the needles. The construction herein shown and specifically that of the stripper plates is particf ularly adapted for use in needling mats or masses of inorganic bers and especially mats or Webs consisting of very ne glass bers. It has been found that conventional needling machines which are ordinarily providedwith spaced stripper bars and in which the-needles operate in the open spaces between the bars, are unsuited for needling glass ber mats or other mats of inorganic materials. By the provision of stripper plates provided with perforations such as herein disclosed, highly satisfactory results are obtained in the needling of mats consisting of inorganic bers and particularly mats comprising very ne glass bers which are preferably of considerable length.

The mat as it advances toward the needling machine is supported on an endless conveyor or belt 25 and after passing beyond the machine is carried on a conveyor 26. The conveyors travel in the direction indicated by the arrowsv izo/feed the web through the machine. Betweenthe end of the conveyor 25 and the lower stripper plate 22, a roller 3I is rotatably mounted in suitable manner and rotated by suitable power means. A roll 32 of a web of long ne glass bers is supported on a spindle 33 beneath the roller 3l. The web 34 is fed from the roll 32. over the roller 3|' and onto the lower stripper plate beneath the mat 23 as the mat is fed onto the stripper plate. A'second roll 36 of a web of glass bers is mounted on a spindle 31 above the conveyor 25 and may be power driven in any suitable manner. The web 38 from the roll 36 is fed onto the top surface of the mat 23 and passes with the mat beneath the upper stripper plate 2|. In this way the mat is faced on both maior surfaces with the webs 34 and 38 which are needled to the mat 23 by the needling machine. If desired in the interest of economy, either one of the faces of the mat 23 may be covered with a web of long ne glass bers instead of both being covered as disclosed'in the drawing. The bers of the webs 34 and 38 are of great length being substantially continuous in length throughout the length of the webs. They are also of very small diameters, in the range of ,.0002 or less to .0004 inch in diameter. The vfibers of the mat 23 are relatively much coarser than the bers of the webs, being in the neighborhood of from .0006 to .001,0 inch in diameter. In the needling operation the long, ne bers of mat 23 and thus intermingled with the bers of the mat to increase greatly the coherence of the mat. Their increased flexibility permits the bers of the web to be bent from their normal positions without undue breakage and rearranged to extend substantial distances into the mat.

In the manufacture of a mat 23 the individual glass bers extend predominantly in sub-- stantially horizontal directions due to the manner in' which the fibers as they are produced are deposited on a continuously traveling horizontal support or conveyor. The bers as they accumulate are intermingled. and built into the continuously forming web or mat. Thus in the compieted mat as it reaches the needling machine, the glass bers are arranged mainly in substantial parallelism with the maior faces of the mat but are haphazardly arranged in planes parallel with the major faces.

As the needles descend and perforate the mat. the downwardly projecting barbs I2 hook the surrounding bers in the web and also some bers of the mat itself and draw them downwardly through or part way through the mat. If the.

needles are projected through and beyond the lower stripper plate, some of the bers may be carried therewith so as to extend through the plate. By this process each-needle draws a, multiplicity of the surrounding bers downwardly, y

causing them to interlace with the main body of bers and serve as ties for felting and tying the body of bers together in the form of afelted mat. When the needles are withdrawn they are stripped free ofthe bers, each'needle being 'stripped individually. The resulting product is a mat of coarser bers held in compacted relation and reinforced with pluralities of ner bers entending transversely of the major faces of the mat and through or part way through the mat at spa'c'eda'pegions. Such a product is economical comparatively short intervals resulting in a mat of greater density than where comparatively wide spacing is used. As the needled portion of the mat pases beyond the machine it may be cut into individual bats or units of any desired size and shape.

As indicated in the drawing, the mat 23 may be of considerable thickness, although I have found that the present method is suited for felting comparatively thin mats also. Very satisfactory results have been attained by this method of felting or needlin'g webs ranging in thickness from .006 to .100 inch or more to mats of a fraction up to several inches in thickness and having a nal density of 6 to 12.7 pounds and more per cubic foot. With mats of greater thickness, a lighter density is often desirable, as, for example, in a mat one inch thick, the density may be 6 pounds per cubic foot or less. .These gures. however, are given merely as examples of what has proved satisfactory and not as limitations.

Figure 3 illustrates a modified operation in which the needles penetrate only part way through the mat. After needling the mat inv this manner, it may be reversed and again needled by causing the needles to enter the opposite side the webs are carried well into the body of the to complete the felting so that it is extended entirely through the mat. By the use of this method .none of the bers is drawn downward beyond the surface of themat. This avoids any unevenness or fuzziness of the .lower surface in the mat such as is sometimes produced by operating in the manner shown in Figure 2. The Figure 3 method is adapted for any but very thin composite mats. l

It is to be observed that the needling method illustrated in Figures 2 and 3 provides a felted composite mat without any lextraneous backing or. supporting material. 'I'he present invention renders unnecessary the usual woven fabric or other supporting material to which mats oi crganic bers are needled in conventional opera-- tions. Thereis thus herein provided a felted mat or mass consisting wholly of glass bers without any organic or other binding material.

For some purposes it is desirable to provide a needled mat or bat which in addition to the needling'is bonded throughout by an adhesive binder. As an example, a mat designed for use as a high temperature insulation may be'bonded with an ,adhesive material which gives needed strength and rigidity for handling, shipping, installing, etc. When such mat has been installed for insulating a stove, furnace, hot pipe or the like, the

bonding material or that portion thereof which is subjected to lhigh temperatures may be destroyed by the heat without impairing the mechanical bonding which has been effected by the needling operation. 'I'he insulating material is thus held intact and in position after the adhesive 4binder has been impaired or destroyed. For some purposes the webs 34 and 38 maybe inthe form of a thin mat of glass bers bonded together by an adhesive binding material such as latex, shellac, starch, ammonium alginate, or other bonding material.

This application is a continuation-impart of my copending application Serial Number 274.660,'

led May 19, 1939.

Modications may be resorted to within the spirit and scope of my invention.

I claim:

1. As an article of manufacture, a composite brous structure comprising a mat of glassfbers,

' the lmajority of the bers extending in prallelism with the major faces of the mat, 'said mat@ being facedfon opposite maior faces with webs of glass bers thatL are ner than the bers of said mat. said webs being substantially less in thickness than the mat, 'and bers of said webs at spaced regions being arranged transversely to the majorfaces of 'said mat and to extend into the body of the mat substantialdistances to hold the mat and facing webs dn a unitary structure.

webs of glass bers that are one and one-half to ve times thinner than the bers of said mat,

the ner bers of said webs extending at localized points substantial distances into said `mat toV mechanically bond the mat together, and binding materiaL throughout said mat aiding in holding the bers together. y Y

4. As an article of manufacture, a mat of glass -bers, the majority Vof the bers extending in parallelism with the major faces of the mat,

\ other of the bers of the mat extending transversely of the mat at localized points distributed throughout the mat and therebymechanically bonding the mass of bers into an integrated mat having strength and -mass integrity, and` a web of glass bers that is substantially thinner than the mat overlying the mat, said web being :go-composed of glass bers substantially ner than the bers of said mat and bonded together with a binding material, the bers of said web at said localized points extending substantial ldistances into the body of bers forming-said mat to-thereby hold the web to the 'mat and mechanically bond the mat into an integral structure.

5. A heat insulating mat comprising a bat of ne glass be'rs, the majority of the bers exg,l

tending in directions substantially parallel with 40 the major faces of the mat, a web of glass bers covering a major face of said mat, said web being thinner than said mat and being composed of bers that extend substantially continuously throughout 'the web and that are substantially` 4 preventing disintegration of said mat and separation .of said web therefrom upon destruction voli of said bonding material.

' GAMES mm ner than the,bers of said mat. and bondingmaterial dispersed throughout the mat and bond-

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