US 2784132 A
Description (OCR text may contain errors)
March 5, 1957 E. N. MAISEL 2,784,132
AIR PERMEABLE FIBROUS BATT Filed May 11, 1953 ijo/wmar yy maw Z4? M Uited States Patent AIR PERMEABLE FIBROUS BATT Emanuel N. Maisel, Aurora, 11]., assignor, by mesne assignments, to Fiber Bond Corporation, Chicago, Ill., a corporation of Illinois Application May 11, 1953, Serial No. 354,003
2 Claims. (Cl. 154-54) This invention relates to an insulating batt of great resilience and loft, particularly suitable for use as an interl'ining for clothing, as an air or gas filter, and as a packing material for delicate objects.
This application is a continuation-in-part of my application Serial No. 290,481 filed May 28, 1952, now abandoned. I
It is known that fibers may be formed into a 'selfsupporting batt by coating the fibers with an adhesive which joins adjacent fibers of a batt. The fibers in this batt are assembled in layers with a random arrangement of fibers occurring substantially only within each layer.
This batt maintains its resilience and loft for only a relatively short period of time when subjected to repeated rough handling, as when it is dry cleaned as a batt or is incorporated as an interlining in clothing which is dry cleaned. The dry cleaning chemicals and the high temperatures of the subsequent steam pressing of the clothes are also destructive of the batts made in accordance with the prior methods. In accordance with the present invention the batts are made of non-matted, uncompressed fibers which are arranged randomly in three dimensions, namely, in all directions along the length, width and depth of the batt. The three-dimensionally-arranged fibers are non-matted and uncompressed and are held against matting and coinpression by a flexible adhesive, with the result that the batt has a softness, resilience and loft not heretofore attained in a batt. This batt has none of the disadvantages of the prior art batts. As hereinafter pointed out, it can be subjected to repeated dry cleaning and pressing operations without a breakdown of the arrangement of .the fibers or a substantial loss in its original resilience and loft. -LThe batt constructed in accordance with the invention comprises a plurality of non-absorbent, nonmatting fibers, preferably plastic fibers, either straight or curled, of various lengths of from about one half inch to two inches, held in three-dimensional, random, arrangement by means of a flexible adhesive. In making the batt, theindividual fibers are first arranged in a three-dimensional, random arrangement and are then wetted lightly with adhesive to'cause them to adhere to each other only at their spaced points of contact. The application of the adhesive and the drying thereof is e'ifected without crushing or compae'ting the fibers ofthe batt. In consequence, the resulti-ii'glbatt is uncompressed and has an unusually highdegieeof softness'and resilience and a very high loft. Al-
though the battmay be handled and out without' any backing sheet, the application of a-backing of cheese cloth orsimil'ar material facilitates such handling and cutting. .The batt is capable of retaining stitches, and one or more ,,batt's may be stitched together, either with or. without liiite'rv'e'ning sheets of cheesecloth or similar material, to form, a) batt of'any desired thickness. When 'thejbatt Tia-incorporated in a laminated fabric facing sheetsmay be 's'titched to both surfaces of the batt.
The adherence of the three-dimensional, randomly ar ranged fibers to each other at substantially only their points of contact imparts to the batt, and to laminated fabric in which the batt may be incorporated, excellent from a latex emulsion is preferred. Where the batt is to be subjected to a dry cleaning operation, a synthetic rubber should be used. A suitable synthetic rubber is a vulcanizable, rubbery copolymer of butadiene and acrylonitrile, for example, that sold by B. F. Goodrich Co.- under the trademark Carbopol.
In accordance with the present invention, I have found that if the three-dimensional, randomly arranged fibers are of plastic material and are lightly, wetted with a vulcanizable, synthetic rubber latex adhesive to adhere the fibers at the spaced points of contactfand the adhesive is then cured under controlled conditions, the result: ing batt may be cleaned and steam pressed over andover again without loss, or without substantial loss, of softness, resilience or loft. In brief, the curing of the vulcanizable adhesive is efiected by heating the adhesive coated batt to a temperature'of from about 210 to 250 F., preferably about 220 to 230 F., for at least one minute. Although this curing temperature may be above the fusing temperature of the plastic fiber, surprisingly, the fiber does not undergo deterioration. Y
A preferred illustrative embodiment of an insulating batt and laminated fabric incorporating the above and other advantages is shown in the accompanying drawing, forming part of this specification, in which: i f
Figure l is'a fragmentary -plan view of the insulating batt incorporated into a laminated fabric,-withportions broken away to show the laminated arrangement of diflierent layers of material; 1
Fig. 2 is a fragmentary cross sectional view, taken along the line 22 of Fig. l;
Fig. 3 is an enlarged detail view illustrating the threedimensional, random arrangement of uncompressed fibers in the batt; and
Fig. 4 is a further enlargement of a portion ofthe fibers shown in Fig. 3, showingthe fibers in a compressed state.
In the drawings, the reference numeral 2 indicates a batt of non-absorbentnon-matting fibers 3. "The fibers preferably are curled or crimped, but straight fibers of the same type may be used. The fibers maybe natural fibers such as hogs hair, or they may be synthetic fibers such as nylon, rayon, acrylic fiber (a copolymer of vinyl chloride and acrylonitrile) commercially available; under the trademark Dynel, acrylic fiber (formed from, a polymer of acrylonitrile) commercially available under the trademark Orlon, or polyvinylidene chloridepolyvinyl chloride copolymer fiber commercially available under the trademark Saran. Nonorganic fibers such-as glass fiber, commercially available under the trademark Fiberglas, may also be used. Any of these fibers may be used alone or mixed with 'eachother.
The fibers-are preferably of various lengths, from about one half inch to two inches, and are intermingled in random arrangement so that they lay at various angles, both horizontally and vertically, to form a three-dimensional batt with the individual fibers contacting each other at their separate points of contact throughout the batt. Relatively few pairs of individual fibers 'contact at more than one point, and each fiber of the batt contacts a rea d a n 1.
plu y o f ot lier fibegs atspaced points which may be in the same or in difierent plaii es.
The batt is sprayed or otherwise coated lightly with an elasticadhesive on either one orboth surfaces, preferably both surfaces. y The an ount of adhesive issujfiicient to coat atleast the outer fibers of the batt so that they adhere to each other and to the transversely: extending fibers at their pointsofcontact qnly, asindicated at} rhespscs between the fibers should be I substantially free of ad; hesiveto maintain the softnessnnd insulating properties of the batt. The small amount of the adhesive which passes through the interstices between the outer fibers wets the underlying fibers, and causes them to adhere at their points of contact, The amount of adhesive applied is not sufiicie nt to fill the voids hetween the fibers. Apart from incidental impregnation of some fibers with adhesive, the fibers are in the main unimpreg'nated and hence retain their natural springiness and impart to the batt the desired i n eand e i l .7 i
The spaced joining of the three-dimensional, random arra ment 013 t e fi r vs tm tfi s. d re tt snstths fib r g ue t s s sa lv r l d m Also, the elastieadhesiveapplied thereto substantially increases tss is q vt s att: Thebatts maybe made of any desired thickness, say w a hrss-s sh hs a n h o 0.0? m re inches, When the batts are of about three-fourths of an inch or less inthickness, the fibers throughout the entire batt may bepenetrated and coated with adhesive by a spraying operationapplied to the outer surfacesthereof It is not essential that the adhesive reach fibers in the center of the batt because the adhesive serves to tie the whole batt together by joining fibers extending transversely of the batt the longitudinally entending fibers at both end portions of the transversely extending fibers. A A H h Any elastic adhesive material such as natural rubber, synthetic rubber, or adhesive resinous or other plastic material may beused, Natural rubber, however, is not recommended when theiend product in whichgthe batt is incorporated is to be dry cleaned as it is attac ke'd by the .shsm s v din t vent o a div ani s istsy sle n so e nla c yn t rubber should be used. The adhesive material may be applied in solution or in emulsion form. lnthe case of either natural or synthetic rubben for example; it is applied in the forrnof an aqueous suspension or latex, with or'without yulcanizing agents, and the adhesive coating is then dried to precipitate the rubber. Any conventional, cornrnercially available, ammonium-stabilized, natural rubber latei; may be used in accordance withrny invention, alone or in combination with a synthetic rubber latex. A suitable, synthetic rubber latex which may be used as the adhesive is the rubbery copolymer of jbutadiene and acrylonitrile sold under the trademark Carbopol. If desired, there maybe incorporated into the natural rubber latex or the mixed natural and synthetic rubber latex small amount's, about 0.25 to 3.0% of a resinwhich serves to addnuick tack and strength to the adhesive. Examples of resinous adhesives that may be used include solutions of polyvinyl chloride or polyvinyl acetate or copolymers thereofin organic solvents. v y The adhesive applied to the fibers is dried to a nontacky state, either naturally or artificially, without com- .pacting the batt. This prevents theadhesive coating on any fiber from adhering to any other fiber except at the points where the fibers are in contact with each otherin the uncompressed, three-dimensional, random arrange- .ment in which the batt is initially formed. If the batt is compressed any time after the adhesive is dried, the fibers vWhich are brought into contact by the compressionwill not adhere to each other, and the resiliency of the fibers cause them to spring back to their original positions when the compressing 0 1 i ffi yat s r; As preyiofsly stated, it is importantthat tho, ran
"three dimensionally arranged fibers as adhered to each other only at the points of contact to which the adhesive is" originally applied. The adherence of the fibers to' each other at their points of contact keeps the fibers in place and thereby maintains the loft and resilience of the batt. In Figs. 3 and 4 a plurality of random, three-dimensionally arranged fibers 3 are shown with adhesive 4 sheathing the fibers and adhering them together at their points of contact. The adhesive is dried in this position of the fibers. In Fig. 3 fibers of the batt are shown in their normal uncompressed relationship and in Fig. 4 the same section of fibers is shown when the batt is temporarily compressed. As soon as the compressing force is released, the fibers shown in Fig. 4 will spring back to the positions shown in Fig. 3 because of the resiliency of the individual fibers and the elastic nature of the adhesive.
Where the batt is to be subjected to relatively high temperatures, as is the case where the batt is incorporated in articleswhich are steam pressed, the fibers of the batt may deteriorate to the extent that the batt loses its softne ss, resiliency andloft. Some of the synthetic fibers of the kind above described, such as Dyne'l, for example, whensubjected to temperatures above about F., ordiiiarily begin to shrivl and lose their desirable properties. This action occurs even below the fusion point of the fibers. When the fibers are raised to temperatures above the fusion point, the fibers of the batt fuse together and the batt completely loses its softness, resiliency, shape and loft. The temperatures utilized in conventional steam pressing operations are sufficiently high to deleteriously afiect the relatively low melting point synthetic fiber: such as ,Dynelfi except when they are properly protected in accordance'with the present invention. Thus, Dynelf and like relatively low melting point plastic'fibers may be protected against the deteriorating etfec'ts of superheated steam such as'is encountered in steam pressifig operations, by the use of a vulcanizable synthetic rubber bonding medium which has been cured under controlled conditions, as follows: The batt of three-dimensional, randomly arranged fibers having been lightly sprayed with a vulcanizable synthetic rub'er latex, is carried into an oven on an endless carrier (not shown). Any source of dry heat may be applied to the batt in the oven, as for example the heat generatedby a battery of infrared bulbs positioned about one foot above the batt. The infrared bulbs supply heat in the region of the batt and throughout the bjatt. The heat of the batt should be raised to from about 210 to 250 F., preferably about 220 to 230 F., for at least about one minute, thereby effecting the desired curing of the rubber. The curing of the rubber for longer periods of time, say two to five minutes, is not harmful. Nor is it necessary. One minute of nine is' generally adequate. During this curing operaticn, the water in the synthetic rubber latest isevaporated and the desirable protective and adhesive properties of the synthetio rubber coating are developed. The drying oven, of course, should include circulation to carry away the moisture accumulating therein.
One striking fact ab ut the curing operation isto be noted. Dynel fibers, for example, will ordinarily shrivel and otherwise deteriorate at temperatures above about 180 F. Yet, the very curing operation which is neessary to bringou't the properties of the synthetic rubber coatingwhich will protect the fibers againstv ternpastures o f 18 0 F. and above, is well above 180 F.,
namely, from 210 to 250" F., and the Dynel does not deteriorate, I Although the ba t isprejferably sufiiciently thin that the sprayed adhesive will coat and sheath the fibers in the center of the batt, it is not absolutely necessary to c 'oat the batt fibers thrbughout the batt to protect the fibe'rsin the central portion of the batt from the efi earthenwar ry", c ea w re a n after an by the outer coated fibeis Or n-e batt assay the coated ends of the transversely extending fibers which protect and insulate the uncoated fibers in the center of the batt and also tie them integrally into the batt.
' The batt of the uncompressed, three-dimensional, randomly arranged fibers when formed is placed on the endless carrier which passes through the drying oven and the adhesive is applied to the batt, preferably as a spray, before the batt reaches the oven. The batt can be sprayed simultaneously from both sides thereof, a perforated endless carrier making this possible. It is preferred, however, to spray the adhesive initially only on the top surface of the batt and then carry the sprayed batt through the drying oven for curing of the adhesive. Thereafter, the batt is turned over and the uncoated side is sprayed with adhesive, and the twice coated batt is again passed through the drying oven to cure the freshly applied adhesive.
The batt formed as described above is uncompressed, yet is self-sustaining and has considerable strength in its lateral, longitudinal and transverse dimensions. It can be handled and be cut without the addition of any backing material and is capable of retaining stitches. The batt may be stitched directly to woven fabrics to form a laminated fabric.
The batt is an excellent air retainer and the insulating value thereof is very high. Because of the random, three-dimensional arrangement of the fibers, there are innumerable intercommunicating voids in the batt and air can pass through the batt, but only at a relatively slow rate. The batt can be compressed or cleaned without loss of loft or balling of fibers.
The resilience and loft retaining qualities of the batt are due primarily to the random, three-dimensional arrangement of the fibers, and to the thin, elastic adhesive coating which fastens the batt fibers together only at their spaced points of contact. The use of crimped or curled fibers increases the resilience of the batt over that attained with straight fibers. A cross section of a batt formed from crimped or curled fibers appears as a series of bridges in all directions and planes, thus giving greater loft than the same amount of straight fibers. The use of fibers of different lengths provides a better fiber distribution throughout the batt and also provides more points of contact.
When the batt is to be incorporated in a laminated fabric, facing sheets and 7 are applied to opposite surfaces and secured to the batt by a line of stitching 8. If the batt is provided with a backing 6 of cheesecloth or similar material, the outer facing sheet, which is generally a woven fabric, is positioned adjacent backing sheet 6. The backing sheet imparts strength to the batt and aids in preventing the ends of the fibers of the batt from projecting through the interstices of the woven fabric. The laminated fabric is uniformly resilient throughout its area and does not require quilting to hold the fibers in sections.
The vast number of voids or air spaces in the batt im parts thereto such a high degree of porosity that the batt breathes, and therefore it can be advantageously used as an interlining for garments or as an air filter. The batt conforms readily to the contours of irregularly shaped objects without loss of the cushioning properties of the batt and hence it is admirably suitable for use as a packing material, particularly for fragile and other readily breakable objects.
The importance of having a random, three-dimensional arrangement of uncompressed fibers cannot be overemphasized. The adhesive coated fibrous batting previously utilized included fibers arranged randomly generally along only two dimensions, that is in single planes or layers, and, in general, there was more or less of matting and compression of the fibers. In contrast, the arrangement of fibers which I use are random in all directions throughout the length, width, and depth of the batt, and there is no matting and compression of the fibers. There are innumerable fibers which extend transversely, i. e.
throughout the depth, of the batt'an'd these fibers aid in tying the batt into an 'integral' strucure and in imparting to the batt its unusual properties of softness,:resiliency and loft. By the term random, th'i jee-dimem sional arrangement used in theclaims and specification, is meant just such an arrangement of; :fibers 'as above described.
Although I. have described a, preferred embodiment of'thefinvention in considerable detail, it will;;be understood that the description thereof is intended to be illustrative, rather than restrictive, as many details may be modified or changed without departing frorii'the spirit or scope of the invention. Accordingly, I do not desire to be restricted to the exact structure and method described. For example, instead of applying the light adhesive coating to the fibers after they have been intermingled to form an uncompressed, three-dimensional, random arrangement of the fibers, the adhesive coating may be applied to the fibers before they are intermingled. The former procedure is the preferred procedure.
I claim: 3 a
1. An uncarded, uncompacted fibrous batt capable of passing air therethrough, said batt having a thickness up to about two inches, and a resilience and loft capable of being maintained on compression of the batt and subsequent release of pressure, said batt comprising a plurality of normally uncompressed plastic fibers of from about one-half inch to two inches in length, in intermingled, random, three-dimensional arrangement throughout the length, width and depth of the batt, there being individual fibers extending transversely throughout the depth of the batt to opposite upper and lower surfaces thereof and tying the batt into an integral structure from said upper and lower surfaces, said transversely extending fibers being bonded at spaced points to other fibers in the batt, a thin coating of a flexible adhesive about said transverse fibers and other fibers and throughout the batt, said adhesive bonding'adjacent fibers in regions immediate their spaced points of contact, whereby the fibers are fixedly joined together at said spaced points to tie the batt into an integral structure, there being inter communicating voids between the said fibers throughout the batt and no fibers in said voids, said voids being substantially free of adhesive, and said batt being of substantially uniform resilience and loft throughout.
2. An uncarded, uncompacted fibrous batt'capable of passing air therethrough, said batt having a thickness from about one-half of an inch up to about two inches, and a resilience and loft capable of being maintained on compression of the batt and subsequent release of pressure, said batt comprising a plurality of normally un compressed fibers of from about one-half inch to two inches in length, in intermingled, random, three-dimensional arrangement throughout the length, width and depth of the batt, there being individual fibers extending transversely throughout the depth of the batt to opposite upper and lower surfaces thereof and tying the batt into an integral structure from said upperand lower surfaces, said transversely extending fibers being bonded at spaced points to other fibers in the batt, a thin coating of a flexible adhesive about said transverse fibers and other fibers and throughout the batt, said adhesive bonding adjacent fibers in regions immediate their spaced points of contact, whereby the fibers are fixedly joined together at said spaced points to tie the batt into an integral structure, there being intercomrnunicating voids between the said fibers throughout the batt and no fibers in said voids, said voids being substantially free of adhesive, and said batt being of substantially uniform resilience and loft throughout.
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