US1646605A - Batting process - Google Patents

Description

Patented Oct. 25,1927. I a 1,646,605

UNITED, STATES PATENT or-Pica.

WILLIAM BURTON 'WESCOTT, OF QUINCY, MASSACHUSETTS, ASSIGNOR TO THE RUB- BER LATEX RESEARCH CORPORATION, OF BOSTON, MASSACHUSETTS, A CORPORA- TION-OF MASSACHUSETTS. i l i I BATTING PROCESS.

No Drawing. Application file 1. 1 ovember 18, 1922. Serial No. 601,911.:

This invention relates to batting processes a t to be brittle. These difiiculties are par- 65 and products thereof; and it comprises a ticularly apparent in the case of asbestos I method of obtaining firm batted fabrics from fibers which do not tend to interlock or form normally smooth, non-felting fibers,-such as any permanentv union on batting in water; 5 cotton, flax, jute, woody fibers, asbestos, etc. but they are also true with many other wherein such fibers are batted in water to smooth fibers such as cotton. I 60 which is'added during or after the batting It is the purpose of the present'invention a small proportion of latex under conditions to produce an open-textured felt-like fabric precluding the coagulation of said latex and from these smooth fibers; the fabric fibers the batted material is thereafter dried in resembling wool felt in that they are bonded such a manneras to convert the latex solids together at. meeting faces. Although the 6 into a homogeneous dried gel, such gel fa ric is not felted in the same mechanical uniting and bonding together at their meet-v way as wool felt yet its characteristics are ing faces the several fibers so batted; and it felt-like; and for the sake of convenience it further comprises as anew material, a tough, 1s herein called felt.- a

strong resilient felt composed of fibers in I have discovered that I can efiect apar- 7 random arrangement, such fibers being bondticularly desirable type of union between ed together at meeting points by latex solids smooth fibers in a batted fabric and produce in the form' of a dried gel, such gel being this result by the use of'limited amounts of vulcanized or unvulcanized as the case ma latex; latex being the milky juices of cerbe; all as more fully hereinafter set for tam plants. Latex in its natural state is not and as claimed. a articularly stable liquid, readily coagu- There is no particular difficulty in making latmg 1n the presence of many chemical firm, hard felts by simply batting wool and agents, such as acids, phenols, etc., and by like fibers of irregular or serrated outline a 'tation. It 'an'however be stabilized sufii-.

together in the presence of water. Wool as c1ently for use by the presence of a little a fiber. has an imbricated surface rendering ammon a or other alkaline body. While possible a locking engagement between fiber latex is not presumed, because of its susand fiber. It is, however, substantially imcep l nature, o rm t concentration or 0 possible to make similar felted materials by purification, I have iscovered and elsewhere batting together smooth fibers such as 'ootdescribed and claimed (application Serial ton, flax, jute, asbestos, etc. While the felt No.. 601,909) that both concentration and made by batting 'such fibers in water may unfication can be effected by submitting have some degree of consistency while the atextocentrifugal action under certain conmaterial iswet it has little strength after ditions with production of a product of drying. In or, er to make felts of smooth standardized nature. Either the stabilized fibers it is the custom to use a greater or ordinary latex or these preparations, which less proportion of rough fibers, wool or the are more 1n the nature of a rubber emulsion, like; and generally the strength of the felt may be used in the present invention.

' 0 is the better the greater the proportion of V In the batted fabrics produced under the wool or the like therein and the less the propresent invention ver little latex is necesportion of cotton or smooth fiber. In order sary to give a consi erable degree of meto make fabric of an strength from batted chanical strength and a firm union between smooth fibers in ran om arrangement, it is fiber and fiber. No such proportion is neces- 45 in general necessary to use an adhesive; glue, sary to give firm union as is required with starch,.etc. Resilient felt cannot however be adhesives and sizes; and resilient felts can made from batted fibers with the use of subbe produced with these small amounts of stantial amounts of such sizing materials. latex. B the use of certain expedients re- Many of these bonding or sizing agents are silient fe ts of varied character can be ro- 50 water-soluble and while they may give a duced. As in the case of wool felts, t ere batted fabric strength in a dry condition, is a union between fiber and fiber at their the wet strength 1s commonly very much crossing or contactin points; this union less. These materials which are not waterhowever being efiecte a dried gel of soluble, as with some of the rosin sizes, are latex solids instead of mec anically as ui'the case of Wool. Dried latex el being but little affected by water, and vu canized dried gel notl' at all, the wet strength of the felt is 11g 1.

Latex can be dried down to give a gel; this gel comprising not only the caoutchouc of the latex but also the other dissolved and'suspended solids (resins, proteids, etc.) as well. .The gel formation is irreversible; the gel once formed not going back into suspension. 'iorm's an apparently homogeneous material (unlike rubber formed by coagulation), this material being of high mechanical strength and of desirable properties. In particular it vulcanizesin a desirable way; its properties in this respect being more nearly like those of long milled rubber than of raw rubber.

Latex mixes freely with water and tions can be obtained in almost any desired concentration. Latex usually contains 20 to 30 per cent of caoutchouc. In the present invention I ordinarily dilute such a latex soluto form a considerably weaker liquid.

When diluted,'of course, relatively small amounts of acids or other coagulants will .suflice to produce a clotting, even as against the influence of ammonia.- or other alkali present and'with many of use is 'here contemplated, there is enough acidity present in the fiber to neutralize the stabilizing agent of ordinary latex.. As I do not desire any such coagulation in the present invention, I customarily maintain in batting liquids distinctly" but falntl allialine at the time the latexisi adde With the rubber emulsions produced by purification of the latex, with removal of some or most of the non-caoutchouc solids of the latex, the susceptibility to coagulation by the action of acids is not so great andnot so much care need be exercised in maintaining the batting materials alkaline as in usmg ordinary stabilized latex. 'Thq,amount and the strength of solution used of latex depend upon circumstances; but I ordinarily and where it is desired to obviate adjust both so as to produce between 1 and 5 per cent of latex solids in my final dry product. Coagulation of latex is a localized operation and always produces localized coagulation of a'stringy nature." This is not desirable since it is my object in the present invention to produce substantially uniformly distriuted filmiform dried gel-.uponthe fibers throughout the article. Wherever the fiber is wetted by the latex solution and then driedQdried latex gel is produced. With 1 such small amounts of this latex .gel as is contemplated in this invention in an uncompressed felt, the space relations of the fibers remain unchanged bythe present operation; and a resilient felt can gel produced in the felt is more or less tacky;

The' gel on drying.

the fibers whose l the latex in and on the be produced. The

in the felt. If vulcanization be effected without compression, the volume relation- Ship of the felted mass remains unchanged. There is produced a felt with the fibers firmly united at their meeting points, but otherwise in the relation in which they are left by the batting. \Viththe rubber gel in its tacky condition, on compression the volume relationship can be altered to any extent which may be desired; that is,a*denser felt can be produced at will. With and vulcanization, the fibers their new relation. Within limits, the compression resilience of the felt can be adjusted. as may be desired. Latex though an emulsion has the property of (infusion to a largeextent and advantage can be taken of this to produce felts with a graded impregnation; one side only of the moist batted felt being treated with the latex. This gives a material having more of the dried gel, in one face than in the other; and in the latter face there ma" be but little. On brushing or combing, a textured face is produced. In making some classes of goods, a plurality of impregnations may be desirable. For example a batted felt may be made with the aid of a i-mited amount of latex and the felt dried and vulcanized (without pressure or much pressure) to obviate tackiness of the gel and give a resilient felt. This may then be reimpregnated from one face and then vulcanized under some pressure. The operation produces a fabric with one side open textured and resilient and the other of denser character. It may be dense, tough and impervious to water.

In the practice of the present invention the fibers may be simply batted together in water containing a'small they may be first batted in water in the usual way and then given a treatment with latex solution, before or after drying.

Where'batting is accomplished in the presence of water containing latex, on drying,

into the gel condition. As stated, this gel is irreversible. On further drying, it forms a tough, dry filmiform gel in and on the fibers. Where a maximum compression resiliency in the final product is des1red,I commonly subject the felt after drying to a grad ually lowered gas or atmospheric pressure and then allow the pressure to return toatmospheric as rapidly as possible. On slowly owering the pressure, which may remain between films of latex gel and the underlying fiber, is'removed; the air and moisture escapin through the inter stitial ducts; On su denly renewin the pressure thefilm of dry e1 is pressed firmly againstthe underlying fi er and. a very good type of bond is secured. It has been compression are fixed in.

fiber finally passes.

found proportion of latex; or

any air or moisture that an alternation of 2 or 3 of such successive pressure oscillations with slowly lowering pressure and rapidly renewed pressure, etfect a thorough forcing of the rubber gel into the most intimate contact with the fiber;

A slow reduction of pressure is advantageous and a rapid rencval of the pressure is also advantageous, and particularly in resilient felted articles in which it is not desired to obliterate the voids.

Felts made as above described may be subsequently vulcanized or not. If not vulcanized, since the deposited dried rubber gel is more or less tacky, an applied pressure causes a certain amountof adhesion and may obliterate or materially lessen the voids thus reducing the compressive resiliency. If the material be vulcanized Without con'ipression, this tackiness is obviated and a high compressiveresiliency may be obtained. If it be desired to vulcanize the material, a certain amount of fine or colloidal sulfur may be incorporated in batting at the same time as the latex. 01' cold vulcanizing agents such as sulfur chlorid may be employed after drying the bat. Or any other suitable vuleanizing process, such as the Peaoheycold vulcanization process may be used.

Where a dense, tough felted mass is desired, the impregnated felt may be, after thorough drying, cured with vulcanizing agents under mechanical pressure as betweq platens of a press. Sometimes it. is desirable to introduce inert compounding materials into the batting during the manufacture. \Vith the latex treatment that of filler without forfeiting mechanical strength in the finished product. i

What I claim is the batted fiber will. ordinarily take up a considerable proper- 1. In the felting of; smooth fibers the process which comprisesbatting such. fibers, coating and impregnating the batted fibers with latex, drying, and during drying producing a slowly reduced atmospheric pressure.

2. In the felting ofsmooth fibers the process which comprises batting such fibers, coating' and impregnating the batted fibers with latex, drying, and during drying alternately producing a slowly reduced atmospheric pressure and quick-and rapid restoration ot atmospheric pressure.

In testimony whereof,'I have hereunto affixed my signature.

WILLIAM BURTON 'WEseoT'r