US3114939A - Method of producing redispersible fibers and mat product - Google Patents

Description

METHOD OF PRODUCING REDISPERSIBLE FIBERS AND MAT PRODUCT D. LABINO Dec. 24, 1963 Original Filed Nov. 29, 1954 INVENTOR. DommcK LABINO United States Patent ()fifice 3,114,939 Patented Dec. 24, 1963 $114339 METHOD OF PRODUCKNG REDISPERdIBLE FIBERS AND MAT PRUDUCT Dominick Labino, Grand Rapids, Ghio, assignor to JGllilllS-r Manville Corporation, New York, N.Y., a corporation of New York Continuation of application Ser. No. 471,695, Nov. 29, 1954. This application Nov. 29, 1960, Ser. No. 72,456 13 Claims. ((11. 19156.3)

This invention relates to the production of mats of fibrous materials, and to the packaging thereof; more specifically the invention relates to the production of thin, light-weight fibrous mats of glass fibers, the coherency of the fibers of which mats is such that the fibers are redispersible in gaseous media, particularly air.

This application is a continuation of my co-pendmg application Serial No. 471,695, filed November 29, 1954, now abandoned.

Mats of siliceous or glass fibers are customarily formed by feeding filaments of siliceous material into a hot gas blast which serves to attenuate the filaments into fine fibers of short lengths. These fibers under the force of the blast are dispersed and may be collected in mat form on a surface moving transversely to the blast.

The fibers as they collect on the surface tend to form a woolly mat, and to secure a compact mat it is customary to wet the same as it is formed by spraying resinous materials, or water, on the fibers and/or mat surface. Wetting the surface tends .to compact the mat which is then packaged by rolling in paper or other suitable mater-ialthe adjacent plies of mat being separated by the packaging material.

The packaging material is necessary for the dried fibers of adjacent layers would cohere and prevent satisfactory unrolling of the mats.

It has been found to be desirable in some instances to redisperse the glass or siliceous fibers of a mat in a suspending gaseous medium such as air but even the watertreated mats have not been successfully employable for this purpose as the compaction occasioned by the water is sufiicient to provide an undue coherence of the fibers of the mat even when the same has been thoroughly dried.

It is a primary object of this invention to describe a novel procedure for the production of light-Weight mats of siliceous fibers which procedure enables the production of mats the fibers of which are redispersible in gaseous media.

It is an important object of this invention to describe a novel process for the formation of light-weight mats which procedure eliminates the necessity of a packaging material between adjacent plies of the mat.

It is a particular object of this invention to describe a novel mat product of siliceous fibers.

In the production of mats of siliceous fibers, the fibers of which it is desired to redisperse, it has been found that if, in the course of the formation of the fibers and of the mats themselves, the same are not wetted then redispersion in gaseous media is materially facilitated.

It appears that even a wetting with water followed by thorough drying is sufficient to increase the degree of coherence of the fibers such that they do not readily redisperse; however, if the fibers as they are blown, are maintained dry or simply free of wetting agents, the unwetted mats may have the fibers thereof redispersed in a current of air for example.

It has further been found that if the dry fiber mats are subjected to a pressure, most suitably a light pressure, that the fibers of a layer of mat tend to cohere to an extent sufficient to permit the mat to be rolled or layered directly upon itself, and that the layers are thereafter 2 readily separable from each other Without disruption of the mat form. That is, the fibers of adjacent layers, will not cohere materially and thus the necessity for rolling the mats in other materials, such as paper, is eliminated.

The elimination of the paper etc. simplifies the winding process, also the unwinding process and lends to economy of both packaging and shipping.

The mats of this invention are web-like in thinness and most suitably have a weight per square yard of between 15 to 60 grams although mats of glass fibers of a weight as low as 8 grams per square yard have been successfully manipulated. As the weight per square yard increases above about 60 grams the redispersibility of the fibers becomes more difi'icult simply due to the bulk of the mat.

The invention will be more fully understood by reference to the following detailed description and accompanying drawings wherein:

FIG. 1 is a schematic representation of apparatus useful in the practice of the invention;

FIG. 2 is a side elevational view of a portion of the apparatus of FIG. 1;

FIG. 3 is a plan view of the structure of FIG. 2;

FIG. 4 illustrates the product of the inventive process in rolled form; and

FIG. 5 illustrates a plurality of mats, made according to the process of this invention, stacked in laminar fashion.

Referring to the drawings there is shown at 1 in FIG. 1 a glass melting pot composed of platinum or a suitable alloy as platinum-rhodium for example. Pot .1 is surrounded with insulation material 3 and provided with a heating element, such as an induction coil 5, supplied with energy from a suitable source (not shown).

Pot it retains a body of molten glass 7 which exudes through apertures s in the base of the pot to be drawn into filaments 11. Filaments 11 pass over a guide roll 13 and are presented in substantially parallel relation to drawing rolls 15.

Below the drawing rolls and le'ftwardly (FIG. 1) is a burner 17 from which emanates a hot gaseous blast 19; the gaseous blast strikes the parallel-arranged filaments as they pass the lower end of guide 20 and the filaments are blown toward hood 21 and highly attenuated into fine fibers 23 of relatively short length.

At the right hand end of the hood 21 a wire mesh or perforated belt 25 passes upwardly, closes the hood end and receives the blown fibers thereon. The belt is itself continuous and adapted to be trained over rolls indicated at 2'7, 29, 31, the latter of which is driven through means which include motor 28, sprockets 30, 32 and chain 34.

Mounted in any suitable manner within the belt is a sheet metal housing 33 which provides an open end 35 closely adjacent the belt for the development of a vacuum pressure at the belt surface. A conduit 36 is provided in the rear of the housing for the exhaustion of air by an appropriate motor and vacuum pump combination.

The fibers 23 under the influence of the blast and the vacuum pressure at the moving belt surface deposit in a thin web or mat on the belt and are carried upwardly. The thickness and weight per square foot of the web are easily controllable by simply moving the belt at greater or lesser speeds and in accordance with the rate of glass filament feed to the burner. Rightwardly, supported slightly above the surface of the longer strand of the belt, is a roller or simply a statiouary rod 37 which engages the underside of the web and lifts the same in order that it may be drawn to the pressuring and winding equipment indicated generally at 39.

As shown in FIG. 1 a relatively large support roll 41 is provided to receive the web. Roll 41 is provided with a sprocket 42 which is connected with motor 28 by chain 40 and sprocket 38. Roll 41 is preferably driven at a speed slightly in excess of that at which the mat is formed and accordingly there is imparted thereby a slightly drafting action whereby the mat is stretched slightly to efiect an orientation of the fibers. Roller 43 suitably bears under the influence of gravity upon the driven roll 41 and pressures the mat. The pressuring action is supplemented by the drafting action which also aids in causing the fibers to lie down smoothly.

Rolls 45, 47 are similar to roll 41 and are suitably provided with sprockets and chains for driving from and in synchronism with roll 41. The roll 49 rotates freely and is spaced sufiiciently from roll 41 in the direction of rolls 45, 47 to permit effective drafting to take place as the mat stretches out.

Rolls 45, 47 are each provided with pressure rolls 51, 53, respectively, and the mat issuing rightwardly is wound while supported on suitably driven rollers 55, 57 without the interposition of paper or other separating material.

The uniformity of thickness of the mats 7% of this invention is important both in connection with fiber redispersal and the rolling of the mats '70. The uniformity is generally more difficult to attain as these thin mats become very wide and there is a distinct tendency for the mat edges to be thinner than the center when a single gas blast is employed; with a plurality of gas blasts issuing from a like plurality of burners, such are sometimes employed on very wide mats, the resultant mat may even be ridged.

As shown in FIGS. 2 and 3 the housing 33 may be provided internally with a plurality of built-in guides to accommodate a series of panels which are each wholly or partially insertable into the air stream flowing from the open end 35 of the housing to the conduit 36. The guides, indicated at 59, 61, 63, respectively, engage panels 65, 67, 69 frictionally. The panels are separately vertically movable into the guides and the relationship between the extent of the insertions of each determines the pressure condition across the belt face (FIG. 1). Accordingly the panels serve to regulate the fiber deposition and to provide for mat uniformity.

The freshly Wound roll of mat 79 is indicated at 71 in FIG. 4 and while fiufiiness is present quite unexpectedly the same does not restrict the redispersal of the fiber of the mat. The redispersal is itself benefited most particularly by the absence of wetting of the fibers of the mat; the packaging of redispersible fibers is benefited both by the absence of the wetting and the pressuring of the mat as it is being packaged.

While the invention has been described in particularity with relation as to a redispersible roll package, it will be understood that the invention also finds utility in the formation of a selfsustaining mat, for use as an intermediate product in a process which may be subsequently dispersed. It is also contemplated that a plurality of mats 70 of this invention may be stacked or layered in laminar fashion and subsequently be redispersed into individual layers without destroying the integrity of the layers.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions and accordingly it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

What I claim:

1. A method of forming an unwoven siliceous fibrous mat, comprising in combination: melting a supply of siliceous material; forming fine fibers from the melt; dispersing the formed fibers in a gaseous stream; collecting said fibers as a substantially uncompressed Web; and subjecting the resultant web to a simultaneous stretching and compressing step to orient the fibers thereof without subjection to intermediate compression.

2. The method as described in claim 1 which comprises the further step of subsequently rolling said web upon itself.

3. A method of forming a redispersible package of un woven siliceous fibrous mat comprising in combination: melting a supply of siliceous material; forming fine fibers from the melt; dispersing the formed fibers in a gaseous stream; collecting said fibers as a substantially uncorn pressed web; subjecting the resultant web to a simultaneous stretching and compressing step to orient the fibers thereof without subjection to intermediate compression; and subsequently layering a plurality of said webs contiguous to each other to form a laminate comprised solely of said Webs.

4. A method of forming a redispersible package of unwoven siliceous fibrous mat, comprising in combination: attenuating simultaneously a plurality of continuous siliceous filaments into fine fibers with a hot gaseous blast to form hot dry fibers; collecting said fibers as a substantially uncompressed Web; subjecting the resultant web to a simultaneous stretching and compressing step to orient the fibers thereof without subjection to intermediate compression.

5. The method as described in claim 4 which comprises the further step of subsequently rolling said Web upon itself.

6. A method of forming a redispersible package of unwoven siliceous fibrous mat comprising in combination: melting a supply of siliceous material; forming fine fibers from the melt; dispersing the formed fibers in a gaseous stream; collecting said fibers as a substantially uncompressed web; subjecting the resultant web to a simultaneous stretching and compressing step to orient the fibers thereof without subjection to intermediate compression; and subsequently layering a plurality of said webs contiguous to each other to form a laminate.

7. A method of forming a redispersible roll of unwoven siliceous fibrous mat having a substantially uniform density, comprising in combination: simultaneously attenuating a plurality of continuous siliceous filaments into fine fibers with a hot gaseous blast; collecting said fibers under the influence of said blast and a source of vacuum as an uncompressed web; regulating the vacuum applied across the width of the web being formed to provide a web having a substantially uniform thickness; subjecting the resultant web to a simultaneous stretching and compressing step to orient the fibers thereof without subjection to intermediate compression.

8. A method of forming a redispersible roll of un- Woven siliceous fibrous mat having a substantially uniform density, comprising in combination: simultaneously attenuating a plurality of continuous siliceous filaments into fine fibers with a hot gaseous blast; collecting said fibers under the influence of said blast and a source of vacuum as an uncompressed web; regulating the vacuum applied across the width of the web being formed to provide a Web having a substantially uniform thickness; subjecting the resultant Web to a simultaneous stretching and compressing step to orient the fibers thereof without subjection to intermediate compression; and subsequently rolling said web upon itself.

9. A method of forming a redispersible roll of unwoven siliceous fibrous mat having a substantially uniform density, comprising in combination: simultaneous- 1y attenuating a plurality of continuous siliceous filaments into fine fibers with a hot gaseous blast; collecting said fibers under the influence of said blast and a source of vacuum as an uncompressed web; regulating the vacuum applied across the Width of the web being formed to provide a web having a substantially uniform thickness; subjecting the resultant web to a simultaneous stretching and compressing step to orient the fibers thereof without subjection to intermediate compression; further subjecting the resultant web to at least one compressing step.

10. A method of forming a redispersible roll of unwoven siliceous fibrous mat having a substantially uniform density, comprising in combination: simultaneously attenuating a plurality of continuous siliceous filaments into fine fibers with a hot gaseous blast; collecting said fibers under the influence of said blast and a source of vacuum as an uncompressed web; regulating the vacuum applied across the Width of the web being formed to provide a web having a substantially uniform thickness; subjecting the resultant Web to a simultaneous stretching and compressing step to orient the fibers thereof without subjection to intermediate compression; further subjecting the resultant Web to at least one compressing step; and subsequently rolling said web upon itself.

11. A redispersible unwoven siliceous fibrous package comprising a plurality of adjacent fluify non-cohering layers, each of said layers consisting of a plurality of dry oriented siliceous fibers.

12. A flufi'y siliceous fibrous mat consisting of a plurality of oriented fine dry siliceous fibers, said mat having 6 a weight of between about 8 to 60 grams per square foot.

13. A siliceous fibrous package comprising a plurality of flutfy contiguous layers, each of said fluffy layers consisting of a plurality of oriented fine dry siliceous fibers, said fibers being sufiiciently coherent in respect to other fibers within a layer to form the layer, and said layers being sufiiciently incoherent in respect to each other to maintain the integrity of the individual layers when separated from each other.

References Cited in the file of this patent UNITED STATES PATENTS 1,864,317 Powell June 21, 1932 2,318,244 McClure May 4, 1943 2,518,744 Barnard Aug. 15, 1950 2,787,542 Labino Apr. 2, 1957

Claims (1)

1. A METHOD OF FORMING AN UNWOVEN SILICEOUS FIBROUS MAT, COMPRISING IN COMBINATION: MELTING A SUPPLY OF SILICEOUS MATERIAL; FORMING FINE FIBERS FROM THE MELT; DISPERSING THE FORMED FIBERS IN A GASEOUS STREAM; COLLECTING SAID FIBERS AS A SUBSTANTIALLY UNCOMPRESSED WEB; AND SUBJECTING THE RESULTANT WEB TO A SIMULTANEOUS STRETCHING AND COMPRESSING STEP TO ORIENT THE FIBERS THEROF WITHOUT SUBJECTION TO INTERMEDIATE COMPRESSION.

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