Патент USA US2410884код для вставки
Nov. 12,' 1946. ' s. LAWRENCE, JR - 2,410,334 COMPOSITE FABRIC Filed Jan. 26, 1943 INVENTOR BY Z‘ J», I: ATTORNEYS 2,410,884 Patented Nov. 12, 1946 UNITED STATES PATENT OFFICE ‘COMPOSITE FABRIC Beardsley Lawrence, .lr., Huntington, W. Va., as signor to Utility Fabrics Company, Inc., Hunt- , ington, W. Va., a corporation of Massachusetts ' Application January 26, 1943, Serial No. 473,633 4 Claims. (01. 154-46) , This invention relates particularly to fabrics comprising open texture web of heterogeneously distributed strands bonded together at inter sections-thereof and another web or webs of loosely’ arranged ‘unspun long ?ber that are bonded to the strands of the ?rst web to formv an integral tough sheet. - .: It is a purpose of this invention to provide a fabric which has good tensile strength, good 2 l , resistance of the individual strands and permits yielding .of the individual strands with distribu- . tion of the tear strains to a plurality of strands thereby, providing veryv high tear resistance. The structural combination, moreovér, is pliant and easily ?exed. , , . _ Strand fabrics embodying thisinvention have a variety of uses, being suitable in some forms ' for packaging of vegetables and fruits, in others, resistance to tear but which is not excessively 10 when waterproof for tarpaulins and the like, as substitutes for burlap and for various other uses. faces are provided. ' ,stiff or leathery and in which smooth ?ne'sur- ' It is a further purpose of this invention to. Any?bers of the character described in the unspunweb whether- of cotton or otherwise are . provide stout fabric that is ineXpensive‘to .pro- : duce and that is capable of a variety of uses 15 referred to herein as “long” ?bers in order to distinguish such ?bers from paper stock and the particularly _ where strength, toughness, ?ex like. However, it is an advantage of this in ibility and smooth ?ne surfaces are required. Generally speaking, according to this inven-. vention that relatively inexpensive low grade tion, ?ne closely laid unspun ?ber webs of cotton or other like ?bers having a length of from 3/8" ?bers may be used. ‘Such ?ber may be animal, . vegetable, -_ synthetic or mineral- Examples of to 5/3" ?ber'lengths formed by carding or garnet suitable. ?bers are hair, wool, bast ?bers, musa ?bers, asbestiform ?bers,. rayon,v cellulose, syn thetic ?bers, etc. In any event, the ?bers used ting and weighing from 200 to 400 grains per I yard and having a thickness of from 2 to 8 ?ber diameters, or split starched vwadding are com , in the unspun ?brous web material are “long bined with loosely, and openly or heterogeneously 25 ?bers” .as this termyhas been de?ned above Moreover, while the fibersv are ordinarily bonded laid ?ber webs of sisal, jute,‘ pita or'other like together in the webs they are nevertheless dis ?bers which have been formed by garnetting or posed in a loosely mattedrelation [as ‘distin-. carding to form fabric meeting the purpose of ' guished from a dense compacted and rigid mass this-invention. The threads, ?bers or strands in the heterogeneous web may be from 3A" to 30 or sheet of ?bers such as short ?bers formed on a paper-making screen or densely‘ felted ?bers. 4" long as contrasted with the 3A3” to %" long When the ?bers in the unspun ?brous web mate ?bers in the unspun web. The weight of the rialhave been subjected to a carding machine latter web may vary according to the material used; theapproximate weight-of sisal may be from 12 to 20 oz. per square yard but greater or lesser amounts can be used depending upon the strength desired in the ?nished fabric. The unspun and heterogeneous webs may be impreg nated with the same or different binders or only the heterogeneous web might be impregnated with a binder and unspun webs adhered thereto simply by the stickiness of the impregnant on the heterogeneous web. The unspun webs of long ?bers thus arranged action they have a very desirable condition of indiscriminate interlacing and curvature of in- dividual fibers which renders the web material stretchable and yieldable without rupture in any direction. ~ ‘ . With regard to the‘ strands, other ?bers than the-heavy sisal, jute‘ and ‘the like ?bers can be employed. »Thus,ianimal, vegetable, ‘mineral or synthetic ?bers such as those mentioned above may be employed. The ?bers may be made into rovings which either are unspun or slightly with the ?brous strands afford numerous ad 45 twisted. When it is stated hereinthat the ?bers in the strands are “bunched” it is to be under vantages and improvements. Thus,» it is a fea stood that the ?bers are arranged contiguously ture and advantage of integrated strand fabrics either in unspun relation or in a loosely twisted embodying this invention that strains become relation as distinguished from ?bers in highly distributed over a maximum number‘ of the ?bers with the effect of greatly increasing the load 50 twisted and dense types of cord. It is not with out the scope of this invention to ‘use more highly bearing properties of ‘ the. fabric. Tensile twisted strands such as various types of ?brous strains are. taken predominantly by the hetero» cord material. If the strands are tightly spun, geneously distributed strands, and the unspun it is difilcult to impregnate the?bers at the cen web structure with which the strands are in ters of the strands thoroughly and this renders tegral, enables such strains to be distributed over the unimpregnated ?bers subject to deteriora a plurality of strands’ so that the tendency to tion by moisture. When the ?bers are initially rupture is minimized. Moreover, tear strains impregnated they contain about 10Q% to about also are taken predominantly, by the strands 200% of bituminous or other like binder based and in this case, also, the unspun web material of loosely bonded long ?bers augments the tear 60 on the weight of the ?bers in the strands or rov 2,410,884 4 ings. ‘ ‘ ' . Preferably, though not necessarily, the B. The latter may be saturated with or coated strand elements are of larger diameter than the with a, thermoplastic binder such as a. bituminous long ?bers. resinous or other binder, having a softenting ' . point between about 140° F. and 160° F. This nature of this invention, further purposes, fea 5 binder may be applied to the web B by spraying onto the web, dipping the latter into the binder tures and advantages of this inventionwill be Or else the binder may be applied in other man apparent in connection with the following de ners such as with printing rolls or doctor blades. scription of certain typical embodiments which The binder serves to bond'the strands at their are described for exemplary purposes in connec 10 intersections. tion with the accompanying drawing, wherein: ' The saturated web Bis unrolled from roll 8, Fig. 1 is a perspective view, largely schematic, - v‘passed over idler roll I and around roll 8. Simi of integrated strand fabric embodying this inven larly,‘ a web A--i is unwound from roll 9 and tion; passed around idler roll 4 to roll 3 where it en Fig. 2 is. a perspective view, largely schematic, Having thus indicated in a general way the ' of an alternative embodiment of this invention; 15 gages a face of web B. The combined webs A--i Fig. 3 is a perspective view, largely-schematic, of another alternative embodiment of this invention; and ' Fig. 4 is a schematic view illustrating the steps of combining unspun long ?ber-bearing‘ webs with strand webs to produce various of the em bodiments shown in Figs. 1 to 3 inclusive. The unspun web A of cotton ?bers of %" to %" ?ber length of the character described is made into web form using a conventional cards and B pass around roll I and between the latter and roll 2. Also, a second web A—! is unwound from roll 1. and passed around roll I and around ' roll 2, passing between it and roll I and engaging 20 the opposite side of web B from the web A-I. The combined webs A-i, B, A--2 pass between the pressure bight of the heated rollers I and 2 producing the ?nished fabric K of Fig- 1. While the webs A--l and A—2 may be unsat 25 urated before being combined with the web B as ing or garnetting machine. These webs weigh from about 200 to about 400 grains per square yard and have a thickness of 'from 2 -to 8 ?ber diameters. The web thus produced is in the form of a thin matted mass of irregularly interlaced 30 long ?bers loosely arranged. Suitable loosely matted webs of long fibers can also be made in other ways such as by making garnetted wadding which may, for example, be Just described, they also (although this is not pre ferred) may be previously saturated with the same or similar binder used for web B, or they may be saturated with binders unlike the binder used with webB, such as latex, starch, cellulose or.vinyl resins or the like. Also, the webs A-|, A--2 may be left unsaturated until after, their ‘ combination with web B, and then the whole ‘fabric K may be saturated or coated with latex. composed‘of cotton ?bers about % inch to about 35 oils, resins or other plastics preferably of the non % inch in length. Thus. for example, garnetted thermostatic class. *' In a further alternative the webs A-l, A-2 wadding containing about 400 grains per square , may be peptized so as to cause the ?bers there yard may be lightly starched on opposite sides of to adhere and in effect become welded together and then split midway thelthickness thereof. The soft ?brous surface at the plane of the split 40 and thereafter causing the peptizedsu‘bstance to ' harden. For example, a peptizing agent such as is then used on the inside adjacent to the strand‘ zinc chloride or sulphuric acid may be used which elements. In such case, the starched surfaces has the effect of gelatinizing cellulosic ?bers such make the web material easier to handle while the a soft inner surface is suitable for surrounding and as cotton ?bers so that the will adhere to maintaining in position the strand elements of 45 gether. Preferably, only th'giglffaces of the ?bers are peptized so that after the ?bers have become the fabric. The ~starched surface of the wadding adherent and set, the resulting fabric will not , ,oes not materially interfere with the impregna be excessively stiif. After the ?bers have been ion of the composite fabric and tends to make su?iciently peptized, the peptizing agent is re the outer surface of the fabric haveless stickii 50 moved, e. g. by washing or. neutralization and the ?bers are permitted to set in situ inbonded relation to each other. The impregnated strands “openly laid ?ber webs of sisal, jute or other like , of the web B are not affected by the peptizing v ?bers which have been formed by carding or gar agent and are encased between webs A--|, A--! netting, is also prepared. The ?bers or‘ strands in . this web B are from %" to 4" long as contrasted 55 which are substantially free of the bituminous or ness. . A web B of coarse, loosely heterogeneously' an - with the %" to %" ?bers in web A. The weight _ other binder. Such structure is especially desir of this web B varies with the ‘material used. The approximate weight of such a web when made from sisal would be from about 12 to about 20 ‘ with an article which is to be maintained out of direct contact-1 with the bituminous or other able when thefabric is to be used in connection ‘ounces per square yard. . Greater or less amounts 30 binder material that is used in the heterogeneous can be used depending upon the strength desired in the ?nished fabric. The fabric may be constructed by using vari ous combinations of webs A and B. strands of web B. If the ?bers are synthetic such as rayon, cellulose, acetate, etc., a suitable solvent can be used as the peptizing agent, e. g. acetone, and it can be removed by drying which may be In a prefered form of fabric K a web Bis sand 65 accelerated by heating or by washing out. Another way of accomplishing the bond be wiched between .two webs A-l, A-‘2 as‘ shown tween these webs A-i, B and A—! is to coat the in Fig. 1. The fabric K may be formed in the manner illustrated in Fig. 4. In the latter, I and ' sides of webs A—-| and A—2 that will come in contact with the web B in the operation of Fig. 4, 2 represent a pair of heated pinch rollers and 3, 4, 5 and 6 represent idler rollers. A roll 8 of ‘70 with the same thermoplastic material as would the material of web B saturated with binder and ordinarily be used to saturate the web B, and rolls ‘I and 8 of the material of webs A-l, A-2 leave web B unsaturated and uncoated and com are provided. ' bine the so-treated webs A—I, B and A—-2 with the heat and pressure in the apparatus of Fig. 4. The webs A-l, A-,-2 of rolls ‘I and 8 maybe unsaturated before being combined with the web 75 By omitting the roll 1 from the apparatus of 2,4;05884 5 v . the invention. For example, if such fabrics are used for. bag material, the added strength makes such bag material highly resistant. to sudden strains incurred as by dropping of a ?lled bag which would cause ordinary bags to‘ split open. Bags embodying the fabrics of the invention do not split open when dropped because of the fabrics’ great toughness and resistance to tear Fig. 4 bearing web A-Z, the _fabric L of Fig. 2 is produced which consists simply of a combined web A-l and a web 13. The web A-l of this fabric L may be treated in any of the ways of the ' web A—I' described in connection with the fab ric K. In the completed fabric K or L, the web B, by reason of its ?bersor strands being longer and stronger than those ?bers used in webs A—-i and A—~2, provides the strength. in all directions. Webs A—l and 10 . A-2 by virtue of their ?bers being ?ne and close While this invention has been described in connection with certain speci??c embodiments ly laid, provide sheets which hold the ?bers of thereof, it is to be understood that this has been web B in place and also provide a fabric with a , done for illustrative purposes only and that the practice of this invention. may be varied within smooth ?ne surface which is desirable. Further_ more, the webs A—l and A—2 act as barriers to 15 the scope thereof as de?ned by the language of the seepage of the thermoplastic binder used in web B. As thermoplastic binders must be neces sarily of low softening point, i. e. between about 140° F. and 160° F. when used in fabrics which the following claims. - . ‘ What is claimed is: 1. A composite fabric comprising an open texture web of heterogeneously distributed are designed to be ?exible, the binder under warm 20 strands saturated with and bonded together at the intersections thereof by a thermoplastic bind conditions, often stains or discolors articles com ing in contact with the fabrics. If the coating or ' er and another web of loosely arranged unspun ' long ?bers that are bonded together by a non saturant used on webs A—l, A—-2 is preferably non-thermoplastic and, preferably, non-come thermoplastic binder that is non-compatible with patible with the binder used in web B, this seepage 25 said thermoplastic binder, and that are bonded is eliminated. I > to the strands of said first web to form an in Su?icient binder material of the. appropriate tegral tough sheet, said strands of said ?rst web kind may be used either in webs A-l, A--2 or B r being of substantially greater tensile strength to make the fabric moisture proof or resistant to than the ?bers of said second web, and the ?bers gases and chemicals (depending upon the type of 30 of said second web being arranged in closer binder) or a lesser amount may be used to make texture than the strands of ‘said first Web and the fabric porous. preserving the structural integrity and strength Another modi?cation of this invention shown of said ?rst web, and said strands being of larger in Fig. 3 may be prepared with the apparatus of diameter than said ?bers. V Fig. 4 by substituting rolls bearing respectively 35 2. A composite fabric comprising an open webs B-—| and B—2 of the material of web B texture web of heterogeneously distributed for the rolls ‘I and 9, and by substituting a roll - ‘ strands saturated with and bonded together at bearing a web A—3 of the same-material as web ' the intersections thereof by a thermoplastic bind-e A for the roll 8. The resulting fabric M of Fig. 3 er and another web of loosely arranged unspun consists of a web A-3 sandwiched between the 40 long ?bers bonded to said strands by said binder . webs B—l, 3-2 of heterogeneously distributed and bonded together by a non-thermoplastic strands. The webs B-l, B—2 and A—3 as well binder that is incompatible with said thermo as the resulting fabric M may be treated in any plastic binder to form an integral tough sheet, of the ways previously described with respect to I said. strands of said ?rst web being of larger the webs A, B and the fabrics K and L. vdiameter, of greater length and of substantially The fabrics K, L oriM produced according to greater tensile strength than the ?bers of said this invention have great toughness and tear re second web, and the ?bers of said second web sistance as a result of the special coactions being arranged in closer texture than the strands of said ?rst web and preserving the structural wrap about and yieldably hold the strands of the 50 integrity and strength of said ‘?rst web. wherebythe ?bers of the weaker web or webs stronger web or webs providing a fabric which as a whole is yieldable without tearing. These fabrics are unlike so-called reinforced papers wherein the paper sheets‘ have short ?bers rein forced by adherent ?bers. In such paper, the ~ paper backing sheets are relatively; stiff, dense, _ 3. A composite fabric comprising'a web of un spun long ?bers and adherently bonded to the ?bers of said web a multiplicity of strands having greater tensile strength than the tensile strength of the ?bers of said web, said strands occurring in a condition of heterogeneous distribution, the said strands being saturated with a thermoplastic binder and the said ?bers being saturated with a non-thermoplastic binder that is non-compati brittle and unyieldable. The reinforced paper does not have the high degree of toughness of fabrics made according to this invention. The short ?bers of the paper do not wrap about the 60 ble with said thermoplastic binder. strands of the reinforcing ?ber. The strands on 4. A composite .fabric comprising a pair of reinforced paper, therefore, strip off easily. In ' webs each of uniform long fibers and adherently > contrast, the fabrics K, L and M have their bonded to the?bers of each of said pair of webs strands enwrapped by ?bers and hold together and between the latter a multiplicity of strands very well and, insofar as toughness is concerned, 65 having greater tensile strength, than the tensile manifest a resistance to sudden strains that is strength of the ?bers of said pair of webs, said much greater than the sum of the strengths of strands occurring in a condition of heterogeneous the individual webs of the fabrics. The enwrap distribution, the said strands being saturated ping of the strands by the ?bers appears to in with a thermoplastic binder and the said ?bers troduce a multiplying factor. In some fabrics 70 being saturated with a non-thermoplastic binder embodying the invention the strength of the fab ric has been found to be as much as twenty times the sum of the strengths of the individual webs. This is a very important attribute of fabrics of that is non=compatible with said'thermoplastic binder. _ . BEARDSLEY LAWRENCE. JR.