US2689813A

US2689813A - Method for making continuous twistless bonded yarn

Info

Publication number: US2689813A
Application number: US261049A
Authority: US
Inventors: Lawrence Beardsley
Original assignee: Fiberbond Laboratories Inc
Current assignee: Fiberbond Laboratories Inc
Priority date: 1951-12-11
Filing date: 1951-12-11
Publication date: 1954-09-21
Anticipated expiration: 1971-09-21

Description

Sept. 21, 1954 B, LAWRENCE 2,689,813

METHOD FOR MAKING CONTINUOUS TWISTLESS BONDEDXARN Filed Dec. 11 1951 v V I INVENTOR; M

METHOD 'FOR MAKING CONTINUOUS TWISTLESS BONDED YARN 2 Sheets-Sheet 2 Filed Dec. 11 I L95l INVENTOR.

Patented Sept. 21, 1954 UNITED sirA-res cram OFFICE METHOD FOR MAKING CONTINUOUS TWISTLESS BONDED YARN Beardsley Lawrence, Boston, Mass, assignor to Fiber-bond Laboratories Inc., Boston, Mass, a

corporation of Massachusetts Application December 11, 1951, Serial No. 261,049

11 Claims. 1

The novel yarn or strand of my invention ore-- sents-a marked departure from conventional con- "oepts of a yarn or strand. This factis indicated .im'tiallyby the absence of any word-adequate to describe my product. The terms yarn or strand are misleadin because theyconnote a twisted product, while the product of my invention-has no twist. The word filament might be used, but, in as :much as it connotes an individual fiber, it wouldlikewise be misleading. Therefore, for lack of better terms, the words yarn and strand will be employed interchangeably-herein and have been selected because they seem best in a functional sense to describe the productofmy invention, but whereintheyconnote a twisted product, it must be understood-that they do not apply to myinvention.

In the conventional twisted yarn or strand, tenisile strength-is a functionot-fiber strength, and

resistance to linear relative motionbetween fibers. For purposes of analysing the construction of the strand, fiber strength can be looked upon as a constant depending upon the rawmaterial. Revsistance to linear-relative -motion, however, depends uponthe surface 1 condition of the fibers, the armor contact between them 'and the pressure betweenwthem; and while surface condition in-conventional strands like fiber strength may be looked-upon as a constant depending upon the biped-strength of the fibers of which it is com- .posed for several reasons. :In the first place, the resistance 'to-linear-relative motion between fibers cannot be" maintained uniform throughout the strand because the pressure 'between the fibers near the outer 'e'dges f'of 'thestrand is considerably :lessrthan at the "center i of the strand; 1 Secondly,

Z twisting the strand subjects certain of the fibers to greater tension than others. And thirdly, the stretching characteristics of a twisted strand are not uniform throughout the strand. Of course the stretchin characteristics of the i d vidual fibers may be considered uniform, but there isan additiona1 component of stretch in a twisted strand due to'lateral motion of the outer fibers towards the center of the strand. This latter component of stretch varies from the edges to the center of the strand. Thus, when a conventional twisted strand is subjected to tension, parts of it reach th elastic limit ofthe fibers before others,

certain fibers not subjected to substantial pressure slide pasteach other shifting the load to the fibers held together under pressure, and certain ing conditions of twist. Attempts have been made i however, to impregnate conventional strands with an adhesive for the purpose of increasing the resistance .to linear relative motion between the individual fibers. These efforts have shown that impregnated twisted strands are stronger than similar conventional strands of the same fiber length and twist ratio. However, a complete and uniform impregnation of a conventional strand is extremely difiicult due to the matted thickness of the twisted fibers. And furthermore, due to the twisted construction, the fibers are still subjected to uneven tension, and the non-uniform component of stretch due to twist still is present, rendering progressive failure unavoidable.

Therefore, the general object of my invention, turning attention for the moment particularly to the product thereof, is to provide a continuous strand having a tensile strength substantially equal to the combined tensile strength of the individual fibers which form its cross section. Another object is to provide a strand wherein progressive fiber failure is substantially eliminated and wherein the individual fibers uniformly bear the load. Further objects directed more specifically toward obviating progressive fiber failure are to provide a strand having characteristics of stretch substantially the same as the fibers of which it is composed, to provide a strand in which all of the fibers are substantially free from initial tension, and to provide a strand in which the resistance to linear relative motion between the fibers of which it is composed is not a function of pressure between the fibers.

In the accomplishment of these objects, I construct a continuous fibrous strand having substantially straight individual fibers disposed in substantially parallel relation, parallel to the axis of the strand, overlapping each other, being bonded together by an adhesive. The adhesive employed to bond the individual fibers is applied as a thin coating to the fibers uniformly through the strand, It is a feature of the product of my invention that the individual fibers are bonded over substantial portions of their by the adhesive. This feature is of importance because it means that an inexpensive and weak bonding material may be employed. Being bonded over a considerable area, the total longitudinal resistance of the adhesive exceeds the tensile strength of the fibers themselves although it would not, if bonded only over a small area. Thus the tensile strength of the product is sub stantially equal to that of the individual fibers forming its cross section. Furthermore, shorter fibers may be employed to achieve the same result so long as the area of bond is large enough to provide a longitudinal resistance as great as the tensile strength of the fibers.

It is a feature of the product of my invention that the adhesive coating of the fibers is very thin, and therefore, the displacement of the adhesive, when the strand is subjected to tension, is negligible. Thus the stretching characteristics of the strand are substantially the same as those characteristics of the individual fibers.

It is an additional feature of the product of my invention that all of the fibers in the strand are substantially free from initial tension either longitudinally or torsionally. This feature, combined with the fact that the stretching characteristics of the strand are substantially the same as the individual fibers throughout the strand, provides a substantially uniform fiber elongation, and a substantially simultaneous fiber failure.

Turning attention now to the objects and fear.

tures of the method of my invention, a brief discussion of the major difiiculties encountered in the production of the strand of my invention will best serve as an introduction. Uniform impregnation or saturation of a fiber mass with adhesive, and forming parallel fibers into a continuous strand without initial fiber tension constitute the most important obstacles. Uniform impregnation of thickly matted fibers with an adhesive is extremely difilcult. Highly penetra tive volatile liquid mediums for the adhesive have been employed with moderate success with thickly matted fibers, but the coating is not truly uniform and the cost of such liquids is prohibitive. Also, heat and pressure improve impregnation of thickly matted fibers, but still iall iar short of uniformity. On the other hand, uniform. impregnation is possible if the fibers are dispersed to airy thinness, but hitherto, it has been thought impossible to handle fibers in such a state or dispersion, much less to form them into a continuous untwisted strand.

Therefore, it is an important object of my in-- vention to provide a method for uniform coating of fibers and for forming them, after being coated, into a continuous untwisted strand. Other objects include the provision of a method for align ing the fibers in parallel relation in a strand without subjecting some of the fibers to initial tension, and the provision of a method for bonding the fibers to each other over substantial portions of their length.

In the method of my invention, I draw the fibers of a continuous roving into substantially parallel relation with a thickness of only several fibers. In this state, the fiber group is without coherence and easily falls apart. If the fiber group were suificiently compact to cohere without support during processing prior to saturation, thorough and uniform saturation could not thereafter be obtained. After drafting, I pass the fibers continuously between two opposed surfaces upon which an adhesive has been deposited. A controlled pressure is exerted upon the fibers while being saturated, in order to prevent excess adhesive from coagulating unevenly between them and to distribute the adhesive uniformly. Thereafter the fibers are formed into a composite strand by a reciprocal rubbing action which serves to gather the fibers near the edge of the fiber group toward the center, and to roll the fibers back and forth into a composite group. In this latter state, the fibers form a strand with substantially parallel fibers uniformly coated with an adhesive.

Further features of the method of my inven tion include subjecting the strand to a slight draft before the adhesive has been allowed to set, removing a substantial portion of volatile liquid or waterfrom the adhesive and thereafter compressing the strand. These features ensure absence of initial fiber tension, and the maximum bonding area.

These and other objects and features of my invention will be best understood and appreciated from a detailed description of a preferred embodiment thereof, selected for the purposes of illustration and shown in the accompanying drawings in which:

Fig. 1 is a diagrammatic sectional View in side elevation of the strand of my invention,

Fig. 2 is a diagrammatic sectional view in side elevation illustrating a normal bond between two individual fibers,

Fig. 3 is a diagrammatic View in end elevation of the strand of my invention,

Fig. 4 is a diagrammatic illustration of the process of my invention,

Fig. 5 is a diagrammatic illustration of a variation of the process of my invention, and

Fig. 6 is a diagrammatic plan view of the axially reciprocating forming roll.

The product In the product of my invention as shown in Fig. 1, I employ cotton fibers Ell, aligned in parallel relation, overlapping each other, and bonded together by an adhesive 22 (see Fig. 2). The fibers 2% are cotton in this preferred embodiment but it is to be noted that the invention is not limited to the use of cotton fibers. The fibers 2t may comprise other staples such as hemp, fiax, sisal, etc. or synthetic fibers such as rayon, nylon, fortisan, spun glass, etc. The adhesive 22 employed in this preferred embodiment, is conventional rubber latex, but here again it may readily comprise other bonding agents having suitable properties of viscosity and adhesiveness.

It will be seen from Fig. 1 that the fibers substantially overlap each other, and with reference to Fig. 2, the overlapping has the eifect of greatly augmenting the area contact of the bond. 1

In Fig. 3, furthermore, it will be seen that all the fibers other than those at the extreme peripheries of the strand will be largely surrounded by adhesive and that only ashort toverlapping will" l have-the efiect' of producing-a bonding area sub stantiallyrgreater than thexcross -seetional area-of the fibersa themselves. .1 Thus an inexp'ensive ad i hesive: maybe. employedchaving a per square inch bonding. 1' strength 9 :considerablyl less. than the it tensile strength oflthe ifibers, but'by: being bonded overrr a :large 2. area still 2. ensure that the fib'ers :will bear the load.-:.

'It isf'further toibe noted thatithereifis littleiair i910 space :between 1 the :fiberszwithim the :strand. :This- -a feature :is: concomitantawi-thrthe:fact thatr-f-ther fibersrarerbonded: together-aoverr substantial'apor tionsnrof their area; w

- The 1 adhesive: coating- 22- is -.extremelys.thirnands l 5 therefore itsadisplacement when: the strand is subjected to tension 1 Willi abe extremely smalL'. Thus, the stretchingproperties of thestrandrwill z be substantially the same asathoseseproperties:oft the fiberS ZO and-When.the'strandot my inven-c tion is -subjected -to. tension, all of the. fibers-will elongate :uniiormly and r rupture simultaneously when their elastic limitwisiireachedi Thus, ..=therupture? of .the strand! herein: shown .tismaccompanied' by a resounding .sn'ap,"awith the. fibers near 25 the break remaining: substantially qunt-rayedt.

. The strand' oflmyiin-ventionwill substantially; approach. the maximumi l strength: oft FthBmfibfiI'S which. compose. its cross section; andr-it ..'is*-tor oe noted that neither. expensive adhesives-nor. longer, staple fibers need be employed in the estranda herein shown rto achieveresultsrastlyrsuperior 'to conventional twisted 1 strands. Tests have shown 1 that-the strand of .my ainvention employing inexpensive adhesives and shorttstaplecotton.fibers; it achieves. :a tensile strength upwards of. 35,0000 lb./sq.. inaas compared to. 16,000. lhlsqesinn-intra twisteclstrand composed of the .same fibers.

In the preliminary analysis,, outlinedt-above of it thelimitationofa twisted. strand, tensile strength-r 40 oftindividualzfibers. was. regarded.asi.a..consta11t regardless of.-.fiber-leng-th. wHoweventiin actual practice ..the :-long.er.-cottoni. fibers, .besides being better forreasons of. promoting *fIlGtiGIlySlSO have greater. individual tensile. strength... Thus the; strandof. my. invention twhenaconstructed with inexpensive short staple. cotton .fibers, .rtvill :have.

a tensile strength substantially:greaterithani that of. a twisted strand composed-of.expensive-long staplefibers, butif longstaplefibers are employed t in my strand, the resultant tensile strengthtwill. bevastly superior to that=of. the. expensive twisted strand.

Inadditionto being .arranged insubstantially, parallel relation, and .bonded. over..-largeiportions of. their .area, substantially. all. .of ...the..individual fibers .areiree frominitial tensions. on torsions... Acertain small. amount of..random...s1ight .mis-.. alignmentas indicated at 24 cannotbeleliminated in. actual practice, but. it.will...be seen..that..no. initial. tensions or torsions. such asT..exist...in..the. conventional strand areipresent in thestrandof' my invention. Furthermore, stretchingwthestrand of my inventionwill.not..cause greater pressure tube. exertednupon .somefibersiand not 55; on others, either through. variance of stretchingcharaoteristics within: the i strand r501. through variations. in alignmentas l in. 1 a atwisteds strand.-. Therefore, the maximumefiber strength=is sub-- stantially obtained;

While no twist .isnormally .employed in. :the strand of my invention,.it may-bev desirable to-.im-. pose a twist upon the strandLfonthev purpose of giving itmanmadditionalr factor of. stretch. This may be. desirable. in reinforcing... rubber -.where i 7 5.

strands having' varying properties or: stretch-tare." required. 5 It wilhbe noted in this connection. that; although: twisting the strand. of my. invention may. slightly reduce. its-strength; conventionalstrands: 1 cannot be given varyingdegrees of twist without:

drastically altering..theiratensile strength.

The method The characteristics of the strand of myinven- 1 tion are: highly dependent. upon .the method not constructing the strand. Thusit mighttbe sup.-, poseduthat .a twistedstrand could be -un-ravelled and bonded to produce the strand of my :invention. Suchan assumption, however, wouldbe false. because in that case thesindividual fibers" would be subjected .to initial tensions and torsions inherentiin the original strand andca'used by the untwisting process.

The preferred method .ofconstructing --.the strand.of=myinvention.isiillustrated in FigA andincludes a first. step ,of .drawingthe. fibers. into..

substantially. parallel relationship atJBO, conveying them as-an extremely thin ribbon incapable... of sustaining its. own -weight at 3 l,.-saturating them under pressure-between. surfaceswith ant adhesiveat 32,:forming them .into...a composite strandiat 34:by a reciprocal rubbing action across thesurface upon which the fibers are saturated,.\

subjecting the compositestrand. to a slightdraft at 36, substantially drying the. strand at 38, subjecting. the strand. to a. secondiorming. step at. 40, subjecting it to pressure at. 42,.and a third form-.

ing step .at 44.

The raw material. employed in. one.- example. of

the method of. .my. invention .herein shown is a.

No; 4 Americanupland cotton rovingwith. a staple length. of. 11%", conditionedin. the conventional; mannerforv drawingand straightening.- In; drawingithe fibers! into. parallel relationship. at. 30,11 subject them. to.-an.8.to. 1 draft and. form them. into. an .extremely. thin ribbon being only several. fibers. thickness.- In this. state. the. fiberemass is.

soeweaknthat it cannotsupport. its own weight acrossa gapduringprocessing .and. for this. rea-- son it .is guidedto the saturating rollsby a chute.

52 or beltt i and more or less deposited thereon. On the otherhand'the thinness of dispersion of the fiberspermits thorough saturation, and by subjecting the ribbon. topressure? between rolls during saturation, substantial uniformity: of. sat

uration may beattained. After saturation, how-. ever, it is extremely difficultto handle the fibers. and practically impossible to withdraw them. di'-.

rectlyfrom the saturating aparatus. Therefore I gather them together by areciprocal rubbing action at 34. The reciprocal rubbing maydisrupt the true parallel alignment or the fibers slightly. by giving them a .mildiundulation from one side to the other,..and therefore, I preferably. subject the strand so iormedto aflslight draft at 36 while the. adhesive is stillwet, and will permit. the fibers to slide one past fthe other. The. resulting yarn. is equivalent to a 32 yarn.

Increferring to theextreme thinness of the.

fiber group or ribbon after drafting, I have stated that it is of. onlyseveral fibers thickness andoannotsupport its weight across a gapiduring. processing. It. will. be. understood, .however,

that these termsmustbe. readinthe light of the: context as a whole andthatthe conditions of.

processing must be taken-into. consideration. .The

fiber. ribbon of the specific example idGSCli'bGd abovelemployedsin producing: a 32 yarn is tsoilight. after :drafting thatdt will. only support its weightfon-a .few inchesxwhen held vertically-under 'idealt conditions. Of course, processing conditions are of necessity more rigorous than a simple lifting test, and in my preferred embodiment the ribbon is substantially continuously supported throughout its passage from the drafting element to the saturating roll, and is not permitted to pass a horizontal gap at any point. An additional factor to be considered, of course, is the fiber length. Extremely long staple length fibers would prob ably support their weight over a longer gap. Also under processing conditions the gap might not be so great as to cause a complete rupture in the ribbon but yet disrupt it unevenly and render the resulting yarn non-uniform. As a further illustration of the thinness of the ribbon employed herein prior to saturation, it is significant to note that under actual production conditions, I have been obliged to put an air screen alongside the ribbon between the drafting element and the saturating element in order to prevent casual air drafts from disrupting the fiber group.

It will be noted that the surface of the saturating rolls is slightly roughened. This factor is of importance in eventually disengaging the formed yarn from the saturating roll. If the surface of the saturating roll is absolutely smooth, forming becomes difiicult and apparently the surface tension of the roll is increased thereby rendering it more diflicuit to withdraw the yarn from the roll.

The adhesive employed in this example of the process of my invention is a curable neoprene latex and contains roughly 100 parts by weight of water and All parts by weight of soiid matter. Therefore, it will be seen that when the strand dries, there will be substantial space between the fibers and the illustration of the strand of my invention in Fig. 1 would be inaccurate. To compensate for this, I dry the strand as indicated at 36 to substantially eliminate the water, being careful, however, to leave the adhesive in a slightly tacky state. Thereafter, for the purpose of consolidating the strand and creating a uniform bond, I subject the strand to an additional forming action indicated at to, press it at if. and again form it by a reciprocal rubbing action at M. It will be seen that other proportions of water or volatiles may be employed and the ensuing steps varied to suit the difference.

It is to be noted that the composite strand formed at 315 is the basic product of my invention Its fibers are substantially parallel and are bonded together well enough to produce a strand comparable in strength to the conventional cotton strands. The steps 36 through is are merely for the purpose of perfecting the strand to approach the theoretical maximum, but it is not intended to limit the invention to them.

The fibers of the strand formed. at 3d are substantially free from initial tensions or torsions, and it will be seen that if thermo-plastic resins not containing substantial percentages of volatiles are employed, the steps 36 to it, although they doubtless would add strength, may be eliminated and the strand produced at 34 will have satisfactory properties of bond. The mild undulation in such a strand will not substantially reduce its strength nor cause progressive fiber failure, and may even be beneficial making the strand slightly more resilient.

The reciprocal rubbing action employed in the method of my invention herein shown is performed by a composition cork and neoprene surfaced roll 46 adapted to rotate in unison with a saturating roll 48 having a slightly roughened surface. The cork surfaced roll 46 is further adapted to reciprocate axially, bearing lightly against the saturating roll it. Actually the method herein shown is not dependent upon any specific surface of the rolls 56 and 48 because the strand may be thus gathered by rubbing ones finger back and forth over it while it is disposed in a thin ribbon-like condition on the saturating surface so long as the saturating surface is not slippery. The essential factor with respect to the surfaces of the rolls it and dB is that they must be capable of traction against a freshly saturated fiber mass. Furthermore, it is important not to apply too much pressure in rubbing the ribbon into a strand because excessive pressure causes the ribbon to shred into many small strands. While it may be theoretically possible to perform the reciprocal rubbing by hand, in practice, the production of a uniform and continuous strand is only feasible with a roll such as the roll 46.

Conveying the thin ribbon to the saturator may be accomplished by a chute 52 or a conveyor belt 5% (see Fig. 5) as desired.

Saturation is accomplished by opposed saturating rolls MI and 48 with the adhesive held between them by dams 56, or by saturating rolls 58 and so (see Fig. 5) wherein the roll 663 is partially immersed in adhesive in a pan E52. Pressure is applied between these rolls to ensure uniformity of saturation and to prevent local coagulation of adhesive.

Consolidation may be accomplished by pressing the strand in a mold, by rolling it between two hard surfaces, by passing it through a continuous press, or by passing it between rolls adapted to force the strand into a narrow groove, the latter method being illustrated diagrammatically at 42.

Drying and heating may be accomplished by carrying the strand along an endless belt 64 within a heated chamber 65. The slight draw step indicated at 36 may be accomplished by holding the strand lightly over a wide arc of a first roll 63 by means of an endless belt it driven by two rolls l2 and H5 disposed adjacent to the roll 68 but separated by a wide arc around the said roll 68; and drawing the strand between two draw rolls l6 closely associated to the former holding rolls 68, E2 and 74, but rotating at a slightly greater speed. In this embodiment I only subject the strand to a supplemental draft of approximately 6%.

The forming steps indicated at All and 44 may be accomplished by axially counter-reciprocating rolls it, or even by rubbing the strand between two relatively hard surfaces.

The process of my invention may be varied as desired to meet the characteristics of various resins or bonding agents employed. For instance thermal setting resins may be employed in which case provision for application of heat is made concurrent with the steps indicated at 32-44. Furthermore, the strand may be passed through a trumpet or grooved rolls for the purpose of altering its cross sectional shape.

While these and other variations will be evident to those skilled in the art, it is not intended to limit the invention to the precise form of the preferred embodiments herein shown but rather to measure it in terms of the appended claims.

Having thus disclosed and described an illustrative embodiment of my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. The method of making a continuous twistless strand from staple fibers comprising the fol- 9 lowing steps: aligning the fibers in straight parallel relationshipoverlapping each other in an extremely thin ribbon of only several fibers thickness said fibers being so extremely dispersed in said ribbon that said ribbon cannot sustain its it has been gathered together by the rubbing action.

3. The process of making a twistless staple length fiber strand comprising the following steps: aligning a multiplicity of straight fibers in parallel relation in a thin ribbon in which said fibers are so loosely dispersed that said ribbon cannot sustain its weight across a substantial gap during processing, thoroughly saturating the fibers with an adhesive while in said extremely dispersed condition by applying said ribbon to a surface having a coating of said adhesive thereon and then subjecting the ribbon to pressure, and I then gathering the fibers under pressure into a strand by a transverse motion reciprocated so as not to impart a twist to the strand.

4. The method of making a continuous twistless strand comprising the following steps: drafting a roving into a flat ribbon of only several fibers thickness wherein the individual fibers are so loosely dispersed that said ribbon cannot sustain its own weight across a substantial horizontal gap during processing, said fibers being straight and lying substantially in parallel relationship overlapping each other, passing the fibers continuously between two opposed surfaces upon which a liquid adhesive has been deposited, exerting a light pressure upon the said fibers between the two said surfaces, and thereafter gathering the fibers into a composite strand by a reciprocal rubbing in which the lateral fibers are gathered towards the central fibers.

5. The method of making a twistless yarn comprising the following steps: drafting the fibers into substantially straight and parallel relationship overlapping each other, disposing the fibers in an extremely thin fiat ribbon of not more than a few fibers thickness said fibers being so extremely dispersed in said ribbon that said ribbon cannot sustain its own weight across a substantial gap under processing conditions, uniformly, coating the fibers with a liquid adhesive while the said fibers are disposed in the thin ribbon, subjecting the ribbon to uniform pressure to distribute the adhesive uniformly among the fibers thereof, and thereafter gathering the fibers into a composite strand by reciprocal rubbing, again drafting the fibers, and subjecting them thereafter to substantial pressure, whereby the individual fibers will be bonded togetherover substantial portions of their length and will be subjected to a substantially uniform initial tension.

6. The method of making a continuous strand defined in claim 5 further characterized by sublb stantially drying the strand after the second drafting stage but before the compression stage whereby the major portion of volatiles present in the adhesive will be eliminated prior to consolidation.

7. The method of making a continuous twistless strand comprising the following steps: drawing fibers into straight and parallel relationship substantially overlap-ping each other, forming them into an extremely thin flat ribbon of only a few fibers thickness said fibers being so extremely dispersed in said. ribbon that said ribbon cannot sustain its own weight across a substantial gap under processing conditions, uniformly coating the fibers with an adhesive while the fibers are in the said thin state by applying said ribbon to a surface having a coating of said adhesive thereon and then subjecting the ribbon to pressure, thereafter gathering the fibers into a strand by reciprocal rubbing action, further consolidating the fibers by a reciprocal rolling between two opposed surfaces, and subjecting thestrand to pressure whereby the individual fibers are securely bonded over substantial portions of their area.

8. The method of making a continuous twistless strand described in claim 7 further characterized by subjecting the strand to a. second rolling stage after the final compression stage.

.9. The method of making a continuous twistless strand comprising the following steps: aligning a plurality of fibers in straight and parallel relationship substantially overlapping each other, arranging the fibers in anextremely thin ribbon of only several fibers thickness said fibers being so extremely dispersed in said ribbon that said ribbon cannot sustain its own weight across a substantial. gap. under processing conditions, uniformly coating the fibers with an adhesive while the fibers are in the said arrangement by applying said ribbon to a slightly roughened surface having a coating of said adhesive thereon and then subjecting the ribbon to pressure thereafter gathering the fibers into a composite strand by a reciprocal rubbing action, subjecting the strand so formed to a minor draft under light pressure, and. applying radial pressure thereto. v

10. The method of making a continuous twistless strand defined in claim 9 further characterized by subjecting the strand to heat concurrently with the said radial compression.

11. The method of making a continuous twistless strand defined in claim 10 further-characterized by substantially drying the strand after the said minor draft and before applying the said radial compression whereby substantially all of the volatiles in the adhesive will be eliminated prior to the compression step.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES The New Fibers, Sherman and Sherman, D. Van Nostrand 00.

T. S. 154055, pages 325-332.

Received November 5, 1947, v

Claims

1. THE METHOD OF MAKING A CONTINUOUS TWISTLESS STRAND FROM STAPLE FIBERS COMPRISING THE FOLLOWING STEPS: ALIGNING THE FIBERS IN STRAIGHT PARALLEL RELATIONSHIP OVERLAPPING EACH OTHER IN AN EXTREMELY THIN RIBBON OF ONLY SEVERAL FIBERS'' THICKNESS SAID FIBERS BEING SO EXTREMELY DISPSESED IN SAID RIBBON THAT SAID RIBBON CANNOT SUSTAIN ITS OWN WEIGHT ACROSS A SUBSTANTIALL GAP UNDER PROCESSING CONDITIONS, PLACING THE RIBBON UPON A SUR-