US2702167A - Yarn package - Google Patents

Description

Feb. 15, 1955 w. A. BIGGS. JR.. ETAL 2,702,167

YARN PACKAGE Filed NOV. 3, 1951 Maw 17 1 f"---"zf f i. 1

, JNVEVTORS WILLIAM 4. mass, .m e.

WILL/4M ADAMJ A TI'ORNE VJ 2,702,167 Patented Feb. 15, 1955 2,7,167 YARN IACKAGE WIIIImLBMJmmdWIIIiIIIlS-Adnmlhrhfllh,

S.C.,assignorstoSonocoProductlCompuny,acor- 'pl'ationofSonthCaroIba Application November 3, 1951, Serial No. 254,762

' 3 Clflnll. (CL 242-161) Ibis invention relates to textile yarn carrie l color to a conical carrier having a specially adapted coating for handling multifilament yarns.

F r many years, mper .cones havin have been the standard carrier for syn tic textrles such as viscose, cupranunonium, acetate, V n on, nylon, etc. To obtain good holding ropertics for e yarn on this tapered cone surface an to assure good release properties on delivery, it has previously been proposed to invest the cone with a so-called velvet surface as d15- clnsed in Dunlap Patents 1,634,492 and 2,219,836, and good results have been obtained in handli ordinary yarns with cones surfaced in this manner. is velvet surface" is produced by high speed sanding of the paper cone surface with various grits of sandpaper to produce an irregular surface characterized by a nap of paper fibers lifted to a more or less erect position. fundamental holding mechanism on this surface is the single paper fiber, varying mainly in length by the choice of the abrasive grit plus an inherent roughness in the surglarcieldsproduecd by scratdaing, particularly on the coarser Now, with yarns of lower filament denier and/or twist, and garticularly the line multifilament synthetic yarns whi are characteristically formed of filaments from about to to 6 denier size, and which have been used increusinw by the textile industry to a marked extent in meat years, the performance of the ground velvet surface" has not always been consistent or satisfactory. These has been diiliwlty with this surface bom from the standpoint of holding the liner yarns without slippage when corned and of allowing uniform delivery at high weed without excessive tension increases when the last layers of yarn on the surface are pulled away.

A. mechanical analysis of the nature of the holding surface of a conical yarn carrier to illustrate the basic problem may be made in connection with the accompmying drawings in Fig. 1 is a schematic diagram illustrating the relation ride your winding on a enne'snrl'ace to a holding fiber;

winding tensions, 1. e., A gm./denier, this slipping force at 3 30' taper:

S is relatively small and theoretically only a slight re- 1 sistance in the holding surface would be required to hold it at the relatively low taper angle 4, However, in pracrice and particularly with reci rocating winding, considerably more is required for ety.

Now, when the mechanism restraining the yarn from slippage on the cone taper is a more or less erect, single, essentially round holding fiber, then the restraining force F is equal to 11' times the elastic stiffness of the holding fiber material, times the fourth power of the fiber diam eter d, divided by a constant times the radius of curve.- ture of bending C, times the fiber length l to the point of glication of the restraining force F (see Harold Dewitt ith, Textile Fibers, an Engineering Approach to 'Hzeir Properties and Utilization, Edgar Marburg Lectrue, 1944, ASTM', pp. 38-39), or,

where,

F=restraining (or bending) force =radius of bending I l=bending length Sy=elastic stifiness of the holding fiber material d=holding fiber diameter Since thewound fiber or yarn must be released on thlivery without excessive tension increase in order to avoid breakage or stretch beyond the elastic limit which may result in dye-resist spots, the conical holding surface of the yarn carrier must be a carefull balanced compromise between the resistance or restraining force F needed for satisfactory holding in the package and that for allowing proper delivery. The ideal case would be where the restraining force F equaled the slipping force S and correspmrded to the allowable tension on the wound fiber or yarn. This points up the shortcormng of the velvet surface" obtained by grinding a paper cone, because grinding does not essentially alter the paper fiber diameter, so that the only variable available for altering, surface properties, other than paper of dilfcrent fiber size, is fiber length; and a study of the mechanics involved will show that altering the length will not effect the deivery materially for a, given yarn WllhOllI eficcting the. holding at the same time. As to papers composed of fibers of different diameters, the range is very limited. In addition, the age, source, and treatment of the same paper fibers may alter their inherent stiffness in a manner that is practically unpredictable.

With multifilamcnt yarn-s of very low twist (0-2.5 turns) the problem is greatly complicated further because, at such twists, the yarn tends to behave not as a compact solidmass, but rather as a number of independent filaments flattening out more or less under tension against the holding surface. Under these conditions the tendency to slip may be less, due to greater contact area, but from a release standpoint the yarns are much more sen sitivc, since the filament diameters are very small as compared to the diameter of the. yarn twisted from them.

Confronted with this problem, we have found that conical yarn carriers may be provided with a flock coating wherein the holding fibers on the cone surface are more or less erect, and which may be specially adapted for use with multifilament yarns on the basis of a dellmite relation for good delivery between the size and stillness of the fiber holding and the size and twist of the yarn or fiber b held. Thus we have found that:

(1) The. allowa c holding fiber denier for good do at a given angle of held yarn twist varies as the square root of the held yarn denier.

(2) The allowable holding fiber denier for good dehvery for a given held yarn of a given denier varies as the. square of the sins of the angle of held yarn twist up to a twist angle of approximately l0,, above which the allowable holding fiber denier becomes essentially consteal.

(3) The allowable stiffness of the holding fiber for good delivery of a given held yarn varies as the square of he bolding fiber denier times the inherent dynamic stiffness of the holding fiber: material: at a given delivwy and which stiffness may be expressed in grams per mer.

By good delivery" it is meant that the held yarn may be elivered directly from the fiock coated cone surface at substantially the same tension at which it will deliver over itself from a wound package, or, in other words, that the inner windings of a yarn package supported on the flock coated cone surface will deliver without substantial variation from the tension employed to deliver the remaining or outer yarn windings from the yarn package.

The foregoing relations are demonstrated by the re sults outlined below of mm made to measure the elfect of holding fibers of different diameters and stiffness on the delivery of yarns of difierent diameters and twist.

Flock surfaces were produced on smooth-finished aper cones in a variety of textures by application of floc cut from filaments of the following deniers:

These flocks were cut in a Sprout-Waldron revolving blade cutter taking the fraction passing a 60 mesh screen, or that which would yield fibers of varied length up to about 1 to 2 mm. in length. Application to the cone was made by spraying an aqueous flock adhesive on the cone followed by spraying on the flock from a De V1lb1ss type flock gun. In each case the entire outer surface of the cone was heavily flocked except for an area one inch back from the nose which was left smooth.

In order to study delivery tensions, a typical creelmg set-up was constructed with a wrapper and suitable instrumentation to obtain the tensions of delivery with precision. The creel was arranged for a single "end," and a simulated warp beam was provided by a carefully balanced 36-inch pulley equipped with a variable speed drive. The complete set-up is shown schematically in Fig. 2 of the drawings.

In Fig. 2, a 3' 3 cone is mdicated at carrying yarn windings that are being delivered as when the cone 10 is in position on the creel (not shown). At a more or less conventional type of tensioning arrangement is indicated comprising a porcelain guide 21, a light tension disc 22 floating on the yarn and free to turn under friction and subject to added weight for tension control, and a molded plastic pulley 23 free to turn on a ball-bearing and resting on and turning against a felt washer for snubbing action, and to which weight might also be added for tension control, the yarn being looped completely around this pulley 23.

A tensiometer is indicated at for giving dial readings of the tension, the yarn being looped around jewel bearing rollers 31 and 32 with the arm of roller 31 arranged to swing back and forth as the tension varies; and at a phototensometer is represented comprising jewelled bearing rollers 41 and 42 and a sensing element 43, with the yarn threaded behind the rollers 41 and 42 and in front of the sensing element 43. This sensing element 43 reflects tension changes by oscillating slightly against a light helical spring 45, and the oscillation of sensing element 43 is picked up by a small mirror 44 arranged to swing or rock in accordance with the oscillation. A light beam from a lamp 46 is focused on the mirror 44 and is thereby angled to track on a light-sensitive film 47 travelling in front of it. Hence, any variation in yarn tension is recorded very sensitively by exposure of the film 47 and by varying the speed of the film travel very detailed recordings may be made of the delivery from one end of the cone traverse to the other.

Beyond the phototensometer a further porcelain guide 50 is arranged from which the yarn is taken onto the warp beam 60.

In operating this equipment, the following constant conditions were established.

and the following commercially available multifilament yarns were selected for test purposes:

TABLE 2 Type mum Denier Fllamantl g a so 20 s s so 2.1 z 75 so 4 75 30 10 15 so 1s 15 so so 15 so as 75 30 49 too to at s 1(1) 60 2.3 8 so a 100 so 10 100 B0 18 so a s a 1m to 2. s s 40 5 X50 40 11 150 so 1. s a too so 4 no so 9. s 150 90 21 250 60 2. 3 8 300 so 2. 5 B 300 50 4 30') 50 10 300 12) 2. 5 B 300 120 10 450 72 2. 5 mo 14:. 2.5

All yarns tested were coned on a #50 Universal Winder used exclusively for this purpose, and all work was done at 65% relative humidity and 70 F., so that the operating conditions substantially isolated the two important variables of holding flock denier and held yarn denler to be studied against each other at various twists with varying filament numbers and finishes.

In making the tests approximately 300 yards of each yarn was wound on a test cone, leaving several yards of pigtail. Before delivery the pigtail was removed from the cone base so that it could be delivered as a free end and thereby avoid any masking of the effect of the cone surface at the critical point of the run-out.

As a criterion for surface evaluation, the standard good" was chosen for the maximum holding flock denier from which a given held yarn could be delivered without essential increase in tension variation at the final runout over the variation existing with the yarn running over itself; the next highest holding flock denier from which the held yarn could not be delivered under these conditions was taken as bad. Due to the gaps between the denier of flock available for stud points of maximum tolerance could not be finely established, so that a range for good delivery and "bad" delivery is reported in each case. The test results are presented in Table 3 under the heading "Flock denier (FD)" with observed values for good and "bad":

TABLE 3 The eflect of twist and denier of held yam ondelivery from various denier of flock surfaced 3 30' canes Flock Denier (FD) Viscose Yarn Twist Good Bad 5 1. s s 2. 1 0. us 1 4 1. a 3 10 s 12 15 s is so a is as s 12 49 s 1: 2. s 1. s s 2. 3 1. 5 8 s a s. s s. s s 1s 1s 5 1s a 4 1. s I a s s s. s a as 12 1s 11 1s 15 as 12 u responds TABLE 3--Oontinued thallium-( 'D) viscose! Twist cm. Bed

1" i t. 9.5 12 16 s. a t a as s is,

12 15 1B 50 3s a u 1a is Sad l2 u is :0

Enaminatlon of these data up the obvious tact that increasing the twist in a g 11 held yarn increases its resistance to sagging and consequently its tolerance finstifler holding rs or lock very markedly, although at higher twists improvement in tolerance levels off. Also, the tolerance for stitier holding fibers increases with the denier of the heldyarn beln delivered, and held yarns made p of more and smaller aments at low twist have less tolerance than an equivalent denieryarn composed of larger filaments.

Analysis of these data further reveal that if the allowable holding flock denier for 75/30 yarn, for example, is plotted against the twist angle, or its tangent calculated in accordance with Milton M. Platt, "Mechanics of elastic performance of textile materials, Textile Research Journal, 20, 3 (January 1950)., for each twist number, then a farrl smooth 8 type curve is obtained which corost exactly with a sin curve plotted for the twist angle 6, and from which correspondence. the followingrelationcan be derived:

FD1s= l0 sin (500 tan 6) where F-Drs is the allowable holding flock dealer for good delivery of 75 denier held yarn; and tan 9 is equal to or less than 0.18, since there is 0 further improvement in delivery above the twist e 9 (approximately 10') at which tan 6 becomes 0.18.

Using this relation, the theoretical allowable holding flock deniers were calculated and recorded against the observed values for a typical group of the 75/30 yarns under consideration, and the results are shown in Table 4 It will be noted that the two sets of values check quite well as to range especially when it is realized that the calculated value is greatly dependent on precision measurement of the yarn diameter which necessarily depended upon the assumption that a microscopically examined sample was representative of several hundred yards of yarn. The impressive thing to consider from these re sults is the great dependence-of the In behavior on the twist angle 6, which not only ects the twist in terms per inch but the yarn diameter as well.

To translate this twist angle-holding flock denier relation into a general one covering different dealers of held yarn, the above equation for allowable holding flock denier with 75 denier held yarn was stated in general form, i. es:

FD=K sin (500 tan 9) and was solved for K by insertin the experimental data for the yarns tested as tabulate below (Table 5), the

6 meanFDvnuetoreachrmbeingmmwlthemhs to: each yarn denier eing averaged:

TABLES in m w I;

s .n s.

a: i2 i3 ii? iii u me use no a: i s:- s Isss c 12s a a a" is i iii "1 is s. a:

4 1 .ss a at a; as .441 no at saw as .40 10,0 as 4 .727 nu 1&0 as 10 1.0 no sea 1: is" *a a;

as .010 as tits ass Bxaminationottheabovedatashows litobe roughly asthe square roctoftheh ltat'ndenier which relation can beexpressed as:

where k is a constant dependent on the basic ho (1 hack material and the conditions of delivery, so the: r t: general mention for allowable holding flock denier FD then becomes:

wwwifiaecsoo tan 9) New, although this relationship is missed erally in terms of the holding flock deniefil), it. infi l:- vaons. that the. basic. dgtierence tn the holding flock fibers o1 diflsrent dear r which influences deli petibrmancc f a s d yarn is the difierence in title dynamic sttfiness; that re, the fiber sttfiness at high loading rates, such as at the withdrawal or creeling speed of 300 yards per minute used in this investigation. That various types of fibers have different inherent stillness properties that form an important factor in their rformance as textile materials rs well known, so that it was recognized that this factor should be accounted for too.

For this purpose, the relation (from Smith, above) of the stiffness of a cylindrical fiber as varying with the fourth power of the fiber diameter, or the square of its geflrer, may be employed by stating this relation as o ows:

FS= .Si0i =.S'il='D where FS is the holding flock stifiness; and Si is the instantaneous or dynamic elastic stifiness of the flock in grams per denier.

This relation may then be stated as:

and since FD=k 'Y D sin 500 tan a) then =Nfi Bin (500m 0 and FS=SUNYD sin (500 tan 0)] problem coating, the d of discrete fibers having an individual dynamic stiifness being considered and the particular conditions of delivery, such as delivery speed, winding speed, carrier shape. etc., but otherwise they are fundamental in re ard to the holding flock surface and state relations w ich allow the special adaption of flock coated arn carriers for particularly efl'ecuve and eflicient handling of multifllament yarns.

In addition, it should be noted that the relation derived above for holding flock stillness FS states a bash;

s o a relation that may be applied in handlin all type yarn on any sha of end delivery ca er. sub ect to suitable modiflca on of the constant k for the particular case involved. A practical roblem of holding and delivery exists even with paral el tube carriers for there is always a tendemgr of the yarn package to shift under impact, and the elivery problem is in fact more acute when a parallel tube core is, used because there is no taper to facilitate the release at run out when the yarn windings are being withdrawn directly from the carrier surface. As the angle of carrier taper increases, the hoidin problem likewise increases an the delivery ecreases; while with a decreasing an e of taper. it is the delivery problem that increases, al ough the holding problem decreases. In any case, however, the fundamental relative behavior of the holding flock surface with various yarns remains essentially unaltered as established by the present invention.

The resent invention has been described in detail above or purposes of illustration only and is notintended to be limited by this description or otherwise exce a as ldatitgned in the appended claims.

l. A textile yarn package comprising yarn wound in ackage form on a supporting core having a winding surace retaining the inner windin of said yarn package against slippalgle thereon while owing said inner windings to be de vered continuously and completely therefrom without essential increase it delivery tension over that existing when the yarn windings are delivering over themselves from the packs said windi surface bein covered for this urpose th an adhesive y secured lio forming said coating being com determined by the following relation:

fiber material and conditions 0 delivery; YD is where FS is the dock stiflness; Si is the instantaneous or dynamic elastic stillness of the flock fiber in grams per denier; k is a constant for the articular deliveretrlll yairn e elivered yarn denier; and a is the twist angle of the delivlered yarn up to the angle at which tan 0 becomes 2. A textile yarn package as defined in claim 1 and further characterized in that said package comprises continuous filament yarn wound in package form.

3. A textile yarn package comprising yarn wound in package form on a supporting core having a winding surface retaining the inner win ings of said am package against slippa e thereon while allowing sai inner windings to be de vered continuously and completely therefrom without essential increase tn delivery tension over that existing when the yarn windings are delivering over themselves from the packs said winding surface bei covered for this purpose with an adhesively secured floc coating, the doc forming said coating bein composed of discrete fibers having an inherent unit sti ness of the order of that of viscose fibers, and said flock fibers having an individual denier determined by the following relation:

where FDis the individual flock denier; K is a constant for the gsarticular delivered yarn fiber material and conditions 0 delivery; YD is the delivered yarn denier; and I is the twist an e of the delivered yarn up to the angle at which tan 0 ecomes 0.18.

References Cited in the file of this patent UNITED STATES PATENTS 2,076,451 Fallsheer Apr 6, 1937 2,219,836 Dunlap Oct. 29, 1940 2,430,710 Dunlap NOV. 11, 1947 FOREIGN PATENTS 885 Great Britain Mar. 5, 1879

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