US2688160A - Direct spinning - Google Patents

Description

Sept. 7, 1954 A. K. cocKE EI'AL DIRECT SPINNING 2 Sheets-Sheet 1 Filed Aug. 4, 1948 INVENTORS ALBERT K. COGKE and BY RUDOLPH WOODELL ATTORNEY DIRECT SPINNING 2 Sheets-Sheet 2 Filed Aug. 4, 1948 FIG. 2.

efW T2 o w a v w, m L my 0,, f I $M 5.). 9 3 c3 b l IJO ANGLE 6 INVENTORS A TTORNE Y Patented Sept. 7, 1954 2 @88 l60 UNITED STATES PTENT OFFICE DIRECT SPINNING Albert K. Cooke and Rudolph Woodell, Richmond, Va., assignors to E. I. du Pont de Nemours & Company, Wilmington, Del.. a corporation of Delaware Application August 4, 1948, Serial No. 42,405

15 Claims. (01. Iii-41.41)

l 2 This invention relates to the manufacture of the front roll speed. Contact of the tow at the spun yarn directly from continuous filament tow. bend with the advancing surface is continuous An object of this invention is to avoid. the and non-intermittent. By such means as deobjectionable features of old processes and to scribed above, the tension on the tow is increased provide an improved method for converting a at least about before the tow reaches the continuous filament tow into spun yarn, which bend. That is, the increased tension is applied yarn will have improved strength and uniformchiefly within the breaking zone. While the ity. Another object of this invention is to conincrement will vary, for example, depending on trol the breaking point of the filaments in order the tow being processed, the value of 10% is to obtain a high proportion of long fibers and 10 operable over a large variety of conditions. The thus produce a finer and strong spun yarn from invention is not limited to an increment of 10% continuous synthetic filaments than could be in the tension and actually lower values or much produced heretofore. Still another object of this higher can be employed.

invention is to provide an improved process for One specific embodiment of apparatus for car- 1 converting continuous filament tow to yarn inrying out this process is diagrammatically illusvolving in combination improved break controltrated in Figure 1. In this specific arrangement, ling means which enable the operation of breakthe path of the travelling tow is sharply altered ing and drawing to be maintained over long at a point near the back rolls by the location of periods of time with the production of spun the belt or apron as shown. The angle of bend yarns of improved physical properties. Yet an made by the tow on contacting the belt is about other object of this invention is to provide suit- 82 (180 minus the included angle which is about able apparatus for carrying out the process. 98) and for convenience is marked 0 in Figure Other objects will be apparent from the discus- 1. Hereinafter the angle 0 or the angle of bend sion that follows. will be referred to rather than the central angle Figure 1 shows the apparatus of this invention or complement of this angle of bend. The disand the deflected path of the tow as compared tance the tow travels from the bite Z of the to the old, straight path; and back rolls 3 and 4 to the contact point 5 of the Figure 2 shows graphically the relationship belt 6 is about 4% inches, while the distance between snubbing angularity, tensions and coer'hfrom this contact point 5 to the bite l of the cients of friction. front rolls, 8 and 9, is about 11% inches. With The objects of this invention are accomplished this arrangement, and with the apron or belt by imposing sufficient frictional drag to the synspeed sufficiently great, it is possible to cause thetic filament tow at a point between the back breaking of the filaments to occur primarily and front sets of rolls as to cause most of the within the 1 inch distance between the last filaments to break at lengths substantially equal contact point ID with the last back roll 3 and to the distance between said back and front rolls. the apron contact point 5. As shown, the apron Breakage is made to occur as close to the back may be supported on and driven by rollers ll, rolls as is possible. For instance, with a 13 inch [2, l3 and M of which roller I4 is driven. A

ratch, breaking should occur within 6 inches guide rod I5 may be located just slightly beyond from the last point Of Contact ofthe tow with the belt and before the front rolls. Further, the a back roll. Actua ly, y the process and ppew back rolls can include a third roll it. From the ratus of this invention it is possible to control front rollers the tow is passed through any conbreaking within a much smaller distance than venient guide to a twister. Any of the conventhe representative 6 inches mentioned. The tional processes or apparatus may be used in frictional drag, which is constantl and substanthese subsequent'steps.

t y uniformly app s brought about y The following illustrative examples describe m ns of n advancing surface ch as an pr various ways of practicing the invention and are belt or roller so located as to cause the tow to t, t b considered as limitative.

bend at least 15 from its normal line of travel,

said advancing surface moving in the same direc- EXAMPLE I tion as the tow and travelling at a surface speed A viscose rayon tow of 4,400 denier, 2 9 fi1a approximately at least 0.3 times the front roll ments, having a dry tenacity of about 4.0 grams surface speed. The precise value for this speed per denier and a dry breaking elongation of is a function of the particular angle, the roll 100% as converted into spun yarn of about speeds and friction coefficient involved, and, ac- 50/1 nt (cotton) on a direct spinner with the cordingly, may in some instances be less than arrangement of the angled apron shown in Figthe 0.3 value. Preferably the advancing surface ure 1. In all the tests conducted, the draft rais so located as to cause the tow to bend at least tio was about 42, the back roll speed being main- 25", is as close as practicable to the back rolls tained at 7.55 inches per minute, the front roll and is driven at a speed of not less than 0.6 times speed at 317 inches per minute, while the speed of the belt or apron was varied as indicated. For comparison the same tow was converted to spun yarn with a straight line run, the tow being supported between the back and front rolls by 4 EXAMPLE 111 Example II was repeated except the draft ratio used was 75. The front roll speed was 317 a straight, apron running t t peeds given inches per minute, the back rolls 4.17 inches per This straight line path is indicated in Figure 1 minute and the angled ap 26511101185 P m by dotted line H. ute. The spun yarn measured 86.5/1 count, had

Table I Apron y T s d, L T 4 E; W, Sample Apron g3? Count Con? Y j pep Tililrlnsl F. L.1 Min. cent sum. 49. 5 2,064 2. 20 5. 1 19. s 7 sm--. 60 4s. 2 1, 841 2.04 4. 9 20.5 7 St. 340 47. a 2,166 2. 27 5. 4 19.2 5 Aug. 5 a0 47. 7 1, 776 1. s2 4. 3 19. 5 0.5 Aug. 60 47. 5 1, ass 1. 5s 4. 9 19. 7 s. 5 Aug as 46. 7 2, 287 2. 20 5. 2 20.0 7. 75 Aug. 5 105 48.8 2, 515 2. 3a 5.8 18.2 9. 5 Aug. a 140 47. 6 2, 925 2. 41 6.8 22. a 11 Aug. 265 48. 0 2, 52a 2. 42 6. 5 22. 2 12 Ang. 340 48.3 2,800 2. 61 6. 2 21.0 12 Aug. 575 47. 0 2, 859 2. 57 5. 5 19.8 12

1 Lea count is the product of the yarn count and the breaking strength in pounds of an 80 revolution (120 yard) skein. It is a measure of uniform or minimum strength rather than maximum strength and a yarn of good uniformity with little spread between maximum and minimum strengths will show a relatively high lea count.

I F. L. fiber length in inches of 50% of the fibers. This value shows the minimum length of 50% of the fibers. In other words, at least 50% of the fibers in the processed tow have a length equal to or greater than the value shown. I T=tenacity; E=elongation; St.=straight', Ang.=angled.

It is to be noted in the above table that at low apron speeds, whether angled or straight, the spun yarn strengths are relatively low and the fiber length in the spun yarn noticeably shorter. Also, as compared with the straight apron, the high speed angled apron results are decidedly superior. Moreover, fabrics prepared from these several runs show a very considerable improvement in uniformity when made from yarn spun with the angled apron at high speeds.

EXAMPLE II Using the same arrangement shown in Figure 1 and the same continuous filament tow as used in Example I, 70/1 cotton count spun yarn was made at a draft ratio of 58. The front roll speed was maintained at 317 inches per minute, while the back rolls were driven at 5.47 inches per minute and the angled belt at 265 inches per minute. The spun yarn obtained measured a dry tenacity and elongation of 2.00 grams per denier and 4.8% respectively, a twist of 23.2 turns per inch and a lea count of 1522. Attempts to spin such yarn with conventional equipment were unsuccessful.

EXAMPLE IV Table II Dry E Twist Tow 13. A SW D. R Count Dry Per- Lea Turns; F. L.

In./ G /D. t Count I h I I. C8D 11C 42 48. 2 2. 04 4. 9 1, 841 20. 5 7 265 42 48. 0 2. 42 6. 5 2, 823 22. 2 12 60 84 49. 9 l. 74 3. 8 l, 287 18. 9 7 265 84 47. 7 2. 36 5. 6 2, 336 19. 0 12 60 119 45. 7 l. 57 4v 4 l, 062 19. 7 7 265 119 44. 5 l. 93 5. 3 2, 033 18. 8 12 1 Tow D.=tow denier; Ap.= apron; Ap. Sp.=apron speed; D. R.== Draft ratio.

67.1/1 count, had a dry tenacity in grams per denier of 2.27 with an elongation of 5.4%, a twist of 18 turns per inch and a lea count of 2143.

Attempts to spin such yarn with the straight apron were unsatisfactory and gave yarns the properties of which were decidedly inferior.

EXAMPLE V corded the pertinent data obtained.

accents Table .I V

Dry Dry L Twist, Apron Count Tenacity, Elong, ea Turns/ F. L.

. G./ Percent Count 'Inch Straight 46. 3 2. 88 I2. 3 3, 299 23. G 4 Angled" 47. 4 3. 96 13. 1 3,-981 23. 4 9

EXAMPLE VII A 17,600 denier tow of the same type viscose rayon filaments as set forth under Example I was converted directly into 35/1 cotton count spun yarn at a draft ratio of 116 using the angled apron arrangement shown in Figure 1. With an apron speed of 265 inches per minute, spun yarn of 32.? count having a dry tenacity of 2.15 g. p. d., a dry elongation of 6.0%, a lea count of 2529 a twist of 16.9 was obtained. In this'spun. yarn 50% of the fibers were at'least 10 inches in length. Attempts to convert this same tow at this same high draw ratio using a straight apron were unsuccessful at apron speeds of from 60 to 34.0 inches per minute.

EXAMPLE VIII A 4400 denier tow like that of Example. I was converted into 30/1 cotton count spun yarn at a draft ratio of using the angled apron set up in Figure 1 at an apron speed of 265 inches per minute. In this case the straight apron wa also operative but produced yarn of inferior properties as is apparent from the results given below in Using an arrangement similar to-that shown in Figure 1 but with the angle 0 or the angle of bend equal to 25 instead of 82, an apron speed of 340 LP. M. 'witha draft ratio of 4'2,-a 4400 denier Table III T D t A its? n R o 1: DryTDlgyE; 'r 'l L cw men p. oun erurns Count GJD cent Count Inch 4,400 4,400 Aug. 265 84' 100.2 2.46 3.2 2,155 21. 4 12 "Cannot be spun.

EXAMPLE VI viscose rayon tow of the type-given in Example I,

the following results were obtained:

The results are comparable to those of Sample 7 in Example I wherein angle 0 was 82.

EXAMPLE X The angled apron is dispensed with and a small roller (of 1 inch diameter) is mounted and driven in the location of the apron supporting roller II at the bend of the tow in Figure 1. This causes the tow like that used in Example I to bend the same amount, 1. e. 82 from its straight line of travel and by driving this roll at a peripheral speed of 265 inches per minute while the front roll i driven at 317 inches per minute and the back rolls at 7.55 inches per minute togive a draft ratio of about 42, a spun yarn-can be made with the following properties:

useful spun yarn.

V Fiber Dry Dry I m Twist, Length Count Tenacity, Elong, Count Turns/ in Inches G./D. Percent Inch of 50% of Fibers If desired, this modification may be further modified by using a supporting belt or tube or trumpet following the small roller to improve the distribution and bundling of the broken fibers but this is not necessary for the production of To break the filaments effectively, it is not only necessary to have the advancing surface in between the front and back rolls operating at a speed of approximately 0.3 times the front roll speed, but to have sufiicient snubbing angularity as near the back rolls as is practicable to build up the tension to the breaking point in the desired breaking location. The amount of snubbing angularity needed is dependent upon the coefficient of friction between the tow l and material of the contacting surface (apron, belt or roll) as well as on the angle of bend. The coefficient of friction will vary with the finish composition applied to the tow, the kind of filament comprising the tow and the material of the contacting surface. For most textiles and with leather aprons or leather covered rollers the coefficient of friction will generally be in the range of from 0.15 to 0.50 and for practical purposes an assumed value of 0.25 may be used in calculations with good results. A few degrees bend, i. e. 10, should theoretically add enough additional tension if the tow is completely uniform, althougha snubbing angularity of 25 increases the tension on the back roll side only about 10%. This theoretical value was calculated from the well-known belt formula T1/T2=e where in the present application T1 is the tension in some unit of force on the back roll side of the snubbing point and T2 the tension in the same unit on the front roll side of the snubbing point, e the base of natural logarithm, f the coefiicient of friction, and. w the angle of bend around the snubbing point in radians. The value of w is of course equal to the angle divided by 57.3 the approximate number of degrees in one radian. Other values of T1/T2 with various coefficient of friction values and snubbing angles are shown in the plotFigure 2.

Practically the bend in the tow or angle 0 can be as small as 25 without noticeably changing the localization of filament breakage or the distribution of fiber lengths obtained when angle 0 is 82. Obviously, this angle of bend (0) may be much greater than shown, such as 120 or 130, or more, with very satisfactory results. Obviously, the angle can be much less when the coefiicient of friction is high and when the coefiicient of friction value is low it is best to use a relatively large angle of bend.

At the first contact point between the tow and the apron or its equivalent, that is point 5, the bend in the apron should preferably be sharp, i. e., the roller at this point should be of small diameter such as an inch or even inch or thereabout. Nevertheless, a general improvement over prior art arrangements can be secured even with a roll of quite large diameter, for example, several inches as 4 or 5 inches. Obviously, a large diameter roll cannot be located as close to the back roll and the effective distance in which breaking occurs becomes greater and the fibers will vary more in length and the average length is shorter. Of course longer fibers can be obtained in the process and with the apparatus of this invention with the front and back rolls spaced farther apart. With a long ratch, the roller diameter at the point of bending is less critical.

If an apron or belt is used it need not be supported by four rolls as shown in Figure 1 but may have 3 or even 2 supporting rolls. If but 2 supporting rolls are used, they may be somewhat larger in diameter than those shown without sacrificing control of the breaking point, providing they are centered at the optimum points. If desired, the apron may be arched as by means of a curved support underneath in its run toward the front rolls. described above and shown in Figure 1 may be modified in any way with an equivalent part.

The apron material has not been found critical so long as the coefficient of friction is sufiicient when combined with angularity to provide the needed frictional drag. Any material of sufiicient flexibility and strength to withstand the strain and wear over long periods of time will be found reasonably suitable. Leather, artificial leather, synthetic rubber, canvas, and other heavy duty fabrics, and preferably those with a relatively high coefiicient of friction for the synthetic filaments, may be used with good results.

The many filaments comprising the tow can most effectively be broken and drawn out into a uniform spun yarn if they are presented to the advancing surface as a wide flat ribbon. Flattening of the tow to a ribbon form may be accomplished in many ways for instance by means of an electrical or mechanical vibrator, an air blast or The elements in the apparatus by means of two smooth rods arranged side by side, parallel to each other, and at right angles to the path of travel of the tow between which the tow passes. Means for spreading the tow is most effectively located near the entrance side of the back rolls.

The speed of the front rolls is pretty much governed by the speed of the twister spindle and the amount of twist required to obtain good spinning performance. However, higher speeds may be used than set forth in the examples with other conditions suitably balanced. For instance, optimum twist depends on fiber length. With the very long length fibers obtained by this invention, the twist can advantageously be lowered by simply running the front rolls at higher than normal speeds. Also, higher draft ratios may be used and draft ratios of the order of 125, 150 and more are feasible and operable. With this invention, it is possible to break, draft and spin directly in a single step a relatively large tow of continuous filament into very fine yarns, not only yarns of /1 to 100/1 cotton count but even finer.

The tow size which may be used in the process of this invention may vary widely, for instance, from 4,000 denier or less to 20,000 denier or more, depending, of course, on the size of the spun yarn, draft ratio, etc. Various filament sizes may also be used. One and one-half denier per filament is common, but finer filaments such as 1 denier per filament, or even denier per filament, or coarser filaments such as 2, 3, 4, 5, 10 or even 20 or more denier per filaments may be used for many productions. Naturally, if fine yarns are to be spun, say 70/1 cotton count, which is about denier, a coarse filament tow cannot be used if good uniform spun yarn is to be made. Obviously, with 5 denier per filament stock, there would be only 15 fibers in any given cross section and, if but 1 fiber were out of place the adding of one here or the subtracting of one there would cause the uniformity to become poor. For fine high quality spun yarn, it is, therefore, essential to use relatively fine filaments. However, this invention, while of greatest importance in connection with the production of fine yarns, is not so limited and is useful and applicable to the spinning of coarser yarns than heretofore mentioned as, for example, 30/1, 20/1 or even 12/1 cotton count yarn or coarser.

Although the invention has been illustrated primarily with rayon tow, any other synthetic filament tow may be used advantageously as, for example, nylon and other filament-forming condensation polymers; cellulose acetate or other cellulose organic ester or ether or mixed esters, ether esters and the like; polyvinyl compounds as polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, polyacrylonitrile, interpolymers of these or mixed polymers, glass, silicones, etc.

Spun yarns can be produced in accordance with this invention that have a strength of at least 65% of the strength of the continuous filament tow from which it is made. The retention of such a high proportion of the original filament strength is thought due to the more desirable fiber distribution obtained, i. e., the much higher proportion of long fibers, which long fibers in many cases amount to more than 60% of the total weight and their length being upwards of 12 inches. Further, there is noticeably less fly which, of course, contributes nothing but waste. The yarn uniformity is exceptionally good, and this, too, contributes to the good strength by the 9. elimination of thin and weak'-spots-.along the yarn. When itis considered thattthese results are achieved in a singlestep process going from continuous filament tow tofine high quality spun yarn, it is indeed an outstanding advance in the art.

The substantial freedom from fiy is in itself a remarkable achievement, for in the past, very large poundages of Wastein theform of fly resulted. It is not only a complete loss of starting material, but in the form of fly it gets on everything in the room and; requires extra. cleaning, causes undesirable working conditions, contaminates-oils and greases, and even contaminates the spun yarn product.

Important, too, for the continuity of; operation is therelatively better performance obtainable by this invention. In. tests made, the records of breaks per spindle hour have been most. gratifying, being of the order of one-fifth the number of breaks resulting from the use of the straight apron on fine counts.

Asdescribed in U. S; 2,419,320, a tensioned sliver is passed through a pairof breaker rollers which are intermeshing fluted rolls and which intermittently deflect the sliver out of its path of travel. By sodoing, the filaments in the sliver are broken at the points of deflection under the momentarily increased tension. The apparatus and process of the presentinvention described herein afford advantages over such devices as that described in: U, S. 2,419,320 in that there is less. fly, and in that greater uniformity and longer filaments are obtained. Breakage occurs inthis invention chiefly at some point between the back rolls and the point of deflection rather than at: the point of deflection. Further, the apparatus and theprocess of this invention provide substantially constant and uniformfrictional drag as opposed to the momentary impulses of previous devices.

It is possible through the use of this invention to produce fine quality yarns of high strength in one "operation whichhave been heretofore unobtainable except? through the useo'f multiple step processes represented by the cotton, worsted, flak and spun silk systems or modifications of these systems. These spun yarns of thisinvention have an unprecedented high proportionof long fibers. The process and apparatus of this invention afford? for the first time means for causing most of the filaments in the tow to break at lengths substantially equal to the ratch distance rather than the normal, disadvantageous lengths averaging approximately: one-half the latch distance.

Any departure from the above description .which conforms to'the present invention is intended to be included within the scope of the claims.

We claim:

1. A process for converting a continuous filament tow into spun yarn of uniform length on a direct spinner comprising a set of back rolls advancing said tow slowly and a set of front rolls advancing said tow rapidly which process comprises bending said tow as it leaves said back rolls at least out of its straight line path of travel from said back rolls to said front rolls, the bending being accomplished by passing the said tow over a rotating device that contacts only one side of the said tow, the bend being near said back rolls; imposing a substantial, continuous and uniform frictional drag on said tow as itpasses from said back rolls through the bending to said front rolls, said bending and said drag being sufficient to break substantially all of said filaments as 10 they pass from said back rolls to said bendand beforetl iey pass from said bend to said front rolls.

2 process for. converting a continuous filament tow into spun: yarn of uniform length on a direct spinner comprising a setwof back. rolls ad vancing saidtow slowly and a set of front rolls advancing said to'wrapi which process. com prises defiecti ngsaid tow as it leaves said back rolls from its straight l-ine path and imparting a substantial, continuous and uniform dragon said tow by frictionally contacting said tow on one side only, saiddeflection andsaid drag being sufficient to cause breakage of said'filamentsias they pass from: the point of. last contact with. said back rolls to the first point of deflection.

process-tor converting a. continuous filae merit tow into spuniy'arn ofuniform length ona direct spinner comprising asset of back rolls ad-e vancing said tow slowly and a: set. of. front rolls advancing said towrapid ly which process COmrI prises: deflecting said tow asit leaves said back rolls from its straight line path to said front rolls and imparting a substantial, continuous and uniform drag on said tow by frictionally contacting said tow on one side only with; an advancingdevice, said deflection and said drag being suificient to cause breakageof said-filaments as. they pass from thepoint of last. contact with, said back rolls to the first point of deflection, said frictionalcone: tact being made'fwith said: advancing devicemow ing at a speed approximately at: least 0.3 that.- of said front rolls,

4. A- process for converting. a continuous file-r ment tow into spun yarn= of uniform lengthzon a direct spinner comprising a set of back rolls advancing said tow slowly and a. set of front rolls advancing said tow rapidly. which process come prises deflecting said tow as it leaves. said "back rolls? from its straighthile. path. to said front rolls by passing it to an advancing device within 6 inches from the last. point. of. contact with said back rolls, said advancing device: continuously supporting said tow at the point of deflection, contacting only one sideof said tow-and-xbeihg. driven to impart a uniform drag on said tow sufficient to cause br'eakageof. said filaments as they pass from thezpointof last contact with. said back. rolls to the first point-of contact with: the

said-advancing. device, said advancing device running. at a speed. of. approximately 0.3 that of said front roll.

5. A process for converting a continuous: fila ment tow into spumy'arnof un-iformalengthonaa direct spinner comprising a setofback=ro1ls= ad'-: vancing said tow slowly and a set of front rolls advancing said towv rapidly which process comprises passing the said tow] from the. said back rolls to an advancing device which deflects said a tow out of its normal straight line path, which contacts only one side of said tow and which moves at a speed of approximately at least 0.3 that of said front rolls and which imparts at least 10% additional tension to said tow with said advancing device, thereby creating a drawing and breaking zone between said back rolls and said first point of contact of said advancing device and uniformly confining breakage of said filaments within said zone.

6. In a direct spinner for the conversion of a continuous filament tow into spun yarn which spinner comprises a set of back rolls advancing said tow slowly and a set of front rolls advancing said tow rapidly, an improvement for producing uniform lengths of spun yarn which comprises, located near the said back rolls, an advancing means for bending said tow out of its straight line path from said back rolls to said front rolls and for contacting only one side of said tow and for providing means for imposing continuous and uniform frictional drag on said tow at a point near the said back rolls and for causing thereby breakage of said filaments between said back rolls and said point of application of said drag so that the lengths of the broken filaments approximate the distance between said back and front rolls.

7. In a direct spinner for the conversion of a continuous filament tow into spun yarn which spinner comprises a set of back rolls advancing said tow slowly and a set of front rolls advancing said tow rapidly, an improvement for producing uniform lengths which comprises an advancing device located between said back and said front rolls to contact only one side of said tow and to bend said tow out of its straight line path from said back rolls to said front rolls and driven to impart substantial, uniform frictional drag to said tow, said advancing device also being a continuous support for said tow at the bend.

8. In a direct spinner for the conversion of a continuous filament tow into spun yarn which spinner comprises a set of back rolls advancing said tow slowly and a set of front rolls advancing said tow rapidly, an improvement for producing uniform lengths which comprises an advancing device located between said back rolls and said front rolls to contact only one side of said tow and to bend said tow out of its straight line path from said back rolls to said front rolls, said device supporting said tow at the bend and being driven to impart substantial, uniform frictional drag on said tow thereby confining breakage of said filaments to a relatively short space from the point of last contact with said back rolls.

9. In a direct spinner for the conversion of a continuous filament tow into spun yarn which spinner comprises a set of back rolls advancing said tow slowly and a set of front rolls advancing said tow rapidly, an improvement for producing uniform lengths which comprises an advancing device located between said back rolls and said front rolls which provides a contact for only one side of said tow and which provides means for bending said tow out of its straight line path from said back rolls to said front rolls and for continuously supporting and advancing said tow at the bend and means for imparting substantial, uniform frictional drag on said tow substantially at the bend.

10. Apparatus in accordance with claim 9 wherein said advancing device comprises a belt traveling at a speed less than that of said front rollers and located between said back and said front rolls to bend said tow at least 15 out of its normal path from said back to said front rolls.

11. Apparatus in accordance with claim 10 wherein said belt travels at a speed of at least 0.3 of that of said front rollers.

12. Apparatus in accordance with claim 10 wherein said belt supports said tow to a point near said front rollers.

13. Apparatus in accordance with claim 6 wherein said advancing means comprises a roller traveling at a speed of at least 0.3 that of said front rollers and bends said tow 15 to out of its straight line path from said back rollers to said front rollers.

14. A process for converting a continuous filament tow into spun yarn of uniform length on a direct spinner comprising a set of feed rolls and a set of stretch rolls which process comprises passing said tow as it leaves said feed rolls over a rotating member so that said tow deviates at least 15 out of the straight line path of travel from said feed rolls to said stretch rolls, the said rotating member contacting said tow on one side only and the bend being near the said feed rolls; and applying to said tow at the bend a tension sufficient to break the filaments in said tow as they pass from said feed rolls to said bend.

15. In a direct spinner for the conversion of a continuous filament tow into spun yarn which spinner comprises a set of feed rolls and a set of stretch rolls, an improvement for producing uniform lengths of spun yarn which comprises a rotating member located to pass the said tow at least 15 out of its straight line path of travel from said feed rolls to said stretch rolls, the said rotating member being near the said feed rolls, contacting the said tow on one side only and causing the breakage of the filaments in said tow at lengths approximating the distance between said feed and said stretch rolls.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,545,803 Vanni July 14, 1925 2,067,062 Oswald Jan. 5, 1937 2,074,556 Pilz Mar. 23, 1937 2,127,283 Van Beck Aug. 16, 1938 2,419,320 Lohrke Apr. 22, 1947 2,432,355 Truitt Dec. 9, 1947 2,497,511 Neisler Feb. 14, 1950 FOREIGN PATENTS Number Country Date 560,902 Great Britain Apr. 26, 1944

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