University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange
Masters Theses Graduate School
11-1963
An Experimental Study of Spinning Tension and Its Relation to Fiber Properties and End Breakage
Charles Busch Landstreet University of Tennessee - Knoxville
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Recommended Citation Landstreet, Charles Busch, "An Experimental Study of Spinning Tension and Its Relation to Fiber Properties and End Breakage. " Master's Thesis, University of Tennessee, 1963. https://trace.tennessee.edu/utk_gradthes/3132
This Thesis is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Masters Theses by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council:
I am submitting herewith a thesis written by Charles Busch Landstreet entitled "An Experimental Study of Spinning Tension and Its Relation to Fiber Properties and End Breakage." I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Master of Science, with a major in Polymer Engineering.
Anna Jean Treece, Major Professor
We have read this thesis and recommend its acceptance:
David Chambers, Lois E. Dickey
Accepted for the Council: Carolyn R. Hodges
Vice Provost and Dean of the Graduate School
(Original signatures are on file with official studentecor r ds.) November 11, 1963
To the Graduate Council:
I am submitting herewith a thesis written by Charles Busch Landstreet entitled "An Experimental Study of Spinning Tension and Its Relation to Fiber Properties and End Breakage". I recommend that it be accepted for nine quarter hours of credit in partial fulfillment of the requirements for the degree of Master of Science, with a major in Textiles. �adZ� or o aaor v
We have read this thesis and recommend its acceptance:
Accepted for the Council: AN EXPER IMENTAL STUDY OF SPINNING TENSION
AND ITS RELATION TO FIBER PROPERTIES
AND END BREAKAGE
A Thesis
Presented to
the Graduate Council of
The University or Tennessee
In Partial Fulfillment
or the Requirements for the Degree
Master of Science
by
Charles Busch Landstreet
December 1963 ACKNOWLEDGEMENT
The author acknowledges Catherine Landstreet, wife, whose capable help and encouragement contributed greatly toward the completion of this work; Miss Catherine Waggoner who assisted in all the experimentation and calculations, and Mr. Herbert Hutchens and the USDA Spinning Laboratory staff for the mechanical processing.
ii
�R4G61 TABLE OF CONTENTS
CHAPTER PAGE
I. INTRODUCTION ...... 1
Statement of the Problem ...... 1 Review of Present Methods ...... 3
Definition of Terms •••••••••• •••••••••••• , • • . 5
II. METHOD OF PROCEDURE • • • • • • • • • • • • • • • • • • • • • • • • • • . • 8
Theory of Spinning Tension •.•..••••••••...•·. • 8
Tension Meters ·· ··················�·········· 11
Effect of Tension on Yarn Properties:
Material and Methods ••••••••.••; • . • • • • . . • • • 14
Strain Gage Measurements ••••••••••••••••••..• 22
Accelerated End-Breakage Rate Test ••••. ••••.• 22 . Maximum Spinning Tension Study ...... 27
I II. DISCUSSION OF RESULTS • • • • • • . • • • . • • • • • • • • . • • . • • • 35 Effect of Tension on Yarn Strength and
Elongation • • • • • • . • • • • • • • • • • • . • • • • • • • • • . . • • • 35 Effect of Traveler Weight and Spindle
Speed ••••••••••••.••.••••••••••••• •••.•.••• 36
Accelerated End-Breakage Rate Test ••••••..••• 38
Effect of Fiber Properties on Maximum
Spinning Tension ••••••••.•••••• •••••••••.•• 38
IV. SUMMARY AND CONCLUSIONS •• •.. •••••••.•••••.•••.• 41
LITERATURE CITED ...... 44
iii LIST OF TABLES
TABLE PAGE
I. Test Conditions for Producing Given Spinning
Tension for Three Yarn Numbers ooo o ooooooooooo 16
II. Individual Skein Strengths for Run-1, 161s
Yarn at Five Values of Spinning Tension ••oooo 17
III. Individual Skein Strengths for Run-2, 16•s
Yarn at Five Values of Spinning Tension • • • o•• 18
IV. The Effect of Traveler Weight and Spindle Speed
on Spinning Tension for 22Vs Yarn o •••oooooo oo 25
V. Fiber Data and Average Maximum Spindle Speed
for the Paired Samples Used in the Accelerated
End Breakage Rate Test oooooo oooooo oo ooo oooooo 30 VI. Maximum Spindle Speeds for the Te,st Pair
Differing Only in Fiber Length oo o ooooo oooooo• 31 VII. Maximum Spindle Speeds for the Test Pair
Differing Only in Fiber Tenacity oo ooooooooooo 32
VIII. Maximum Spindle Speeds for the Test Pair
Differing Only in Fibe� Fineness oooo oooo ooo •• 33
iv LIST OF FIGURES
FIGURE PAGE
1. A Schematic Diagram of the Spinning Frame
Components for Twisting and Winding the Yarn:
A, an Elevation; Bg a Plan View ooo oooo oo ooo oooo 9
2. The Mechanical Tension Meter Mounted on the F2
Spinning Frame oo ooooooo ooooooooooo ooooooo oooooo 12
3. A Schematic Diagram of the Mechanical Tension
Meter o o • o o o o o o o o o o o o o � o • o o ••o o o o o.o o o o o • o o •••o o 13 4. Effect ot Spinning Tension on Yarn Skein Strength
and Elongation for 161s Yarn oo o oooo oooooooooo oo 19
5. Effect of Spinning Tension on Yarn Skein Strength
and Elongation for 22's Yarn ooooooooooooo oooo oo 20 6. Effect of Spinning Tension on Yarn Skein Strength
and Elongation for 50's Yarn ooo ooo oooooo oo oooo • 21
1. Effect of Traveler Weight on Spinning Tension
for 169s Yarn oo oooo ooooooooooo ooooooo ooooo ooo oo 23
B o Effect of Traveler Weight on Spinning Tension
for 32's Yarn ooooooooo ooooo oooooooooooo oooooooo � 9. Effect of Spindle Speed on Spinning Tension for
Four Traveler Numbers ooooo o ooooooo o oooooooo oooo 26
10. The Variable Speed Drive on the F2 Spinning
Frame oo o oo o o o o o o • o • o o o o • o o o o o o o o o o o • o o • o oo o o o· • o 28
v vi
FIGURE PAGE
11. Effect of Three Fiber Properties on Max�um
Spinning Tension. Maximum Spindle Speed is
in Thousands of rpm •• ••••• •••••• ••• •••••••••••• 34 CHAPTER I
INTRODUCTION
Statement of the Problem
The last step in making a fibrous yarn is reducing the weight per unit length of material to a predetermined value and locking the fibers into a continuous strand by inserting twist. This is the principle of the modern spinning frame and also the ancient spinning wheelo
The reduction of weight per unit length, or draft ing, is accomplished by precision rollers and synthetic aprons. The t�ist is inserted by turning the yarn about its own axis with a spindle and ring arranged in a partic ular manner. The yarn is wound on the bobbin during the twisting operation. The twisting and winding during the spinning process cause tension in the yarn. The yarn at times cannot sup port the load due to tension and the fibers either break or slip apart and the yarn breaks. Mill terminology for this oecurence is "end down" or "end break "o The ends-down rate is usually expressed as the number of breaks per thousand spindle hours. This rate is an important factor in mill operation and in a general way is the most important indicator of mill e.ffieiency. . The ends-down rate in an average American mill ranges
1 2 from 10 to over 200 per thousand spindle hours. This im portant event is a relatively infrequent occurenceo If the ends-down rate were 50, this would be equivalent to one break every twenty miles of 22's yarn.
The end-breakage rate is a .function of many variables, some of which can be controlled and some of which cannoto
Spindle speed, ring diameter, yarn number, yarn twist, and
tiber properties are some of the controllable variableso
Ring wear, traveler wear, and yarn irregularity are variables that cannot be controlled.
Experiments conducted in a spinning laboratory can be carried out under test conditions that are impossible to duplicate in a textile mill. The disadvantage is that to get reproducible results long-term experiments are required i.f conventional test methods are used. The experiments be come expensive and time consuming. There is little recorded data relating fiber properties, yarn tension, and end-break age rates. The study of spinning tension as it affects yarn pro perties required the development of special instruments and techniques. Two devices were built and used. One was a mechanical tension meter attached directly to the spinning frame. The second was an adaptation of a strain gage, strain gage amplifier, and continuous strip-chart recorder.
The effects of spindle speed and traveler weight on 3 spinning tension were studied. Spinning frame adjustments were worked out to give desired tensions, and the effect of these tensions on yarn physical properties analyzed.
The specific objectives of this study were:
1. To develop an instrument which would measure spin
ning tension over a wide �angeo 2. To work out combinations of spindle speed, traveler
weight, and yarn number producing predetermined
yarn tension.
3. To develop an accelerated end-breakage rate test
for laboratory use.
4. To use the accelerated end-breakage rate test to
measure the effects of fiber length, tenacity,
and fineness on the ability of a yarn to support
a load while spinning. The present study was also to serve as a guide to further experiments involving fiber properties and end breakage rates.
Review of Present Methods The theoretical aspects of spinning tension were investigated by De Barr (l)o In his many publications, he developed equations for describing mathematically the shape of the balloon formed by the yarn during spinning, and for the forces acting on the traveler. 4 An attempt was made by Woo (2) to predict end-break- age rates from small lot spinning tests. The theo):-y was that if an end break were an infrequent occurence, the rate could be described by the Poisson distribution. Tables were worked out so that the end-bre akage rate could be predicted from a small number of observations.
A method for measuring the "spinnability" of cotton in terms of the end-breakage rate wa.s developed by Burley and Eddins { 3). For this test an 84-spindle frame, four yarn numbers, and a 1-hour running time for each yarn number were used. A 15-minute warm-up time was required. The yarn number versus end-breakage rate for each yarn number was plotted to determine the spinnable limit of a cotton. The yarn number that gave an end-breakage rate of 20 ends down per hour was considered the spinnable limit.
The problem of relating fiber properties to end breakage rate was described by Fiori, Louis, and Tallant (4).
They showed that because no rapid, reliable method existed for measuring end-breakage rates, only limited information was available.
The effect of yarn size on spinning end-breakage was investigated by Burley and Milliken {5). They tried to explain discrepancies in observed end-breakage rates in laboratory experiments in terms of small differences in the actual yarn number. No single correction could be 5 found for all levels of end-breakage rateso
A small-sample spinning test was developed by
Louis (6) at the Southern Regional Research Laboratoryo
This test measured the end-breakage rates and required
51-hours to perform. The test was based on the theory that too much or too little twist caused excessive end breakage in spinning. End breakage was caused by two variables--spindle speed and twist multiplier--which were allowed to vary simultaneouslyo Other factors, such as initial twist multiplier and front roller speed, varied from cotton to cotton and had to be arbitrarily choseno
Results based on the Louis testg reported in 1962 by Louis and Fiori (7) g agreed with those obtained at the
United States Department of Agriculture Laboratory at
Knoxville with the accelerated end-breakage rate test.
Definition of Terms
Technical terms used in this thesis and not defined in the subsequent text are as follows:
Card - A textile machine used for converting a lap to sliver. The weight per unit length of the sliver 1� generally about 110 times less than that of the lapo
Ring - The part of a spinning frame on which the traveler rideso Rings are mounted on ring rails in such a way that the bobbins are perpendicular to the plane of 6 the rings and on their vertical centers.
Roving - A softly twisted strand of fibers, greater in weight per unit length than yarn but less than sliver.
The fibers have been drafted and twisted to give the roving strength.
Roving Frame - A textile machine for converting sliver into roving. The sliver is drafted, twisted and stored on bobbins for spinning.
Sliver - A long, continuous rope-like strand of fibers containing no twist.
Spinning Frame - A textile machine for making yarn by drafting either sliver or roving to the desired size, inserting twist, and storing the yarn on a bobbin.
Traveler - A small, almost circular wire clip.
The opening is pressed over the ring on the spinning frame and the ends of the traveler fit under the flanges on the ring. The yarn passes from the thread guide, under the traveler, and around the bobbin. A medium-sized traveler has about the same diameter as a common led peneilo Traveler number - An arbitrary number scale assign ed to travelers. Travelers numbered 1, 2, 3, etc. , get heavier as the number increases. Travelers numbered 1/o,
2/o, 3/o, etc., get lighter as the number increases.
Yarn - " A generic term for an assemblage of fiber.s or filaments, twisted together to form a eontinuous strand 7 which can be used for making a textile 11\aterial" (8).
Yarn Count - A number expressing the length per uni,t weight o� yarn. The length is in hanks of 840 yards and the weight in pounds.
Drawing Frame - A textile machine used for parallell ing the fibers in sliver by drawing them by each other with pairs of rollers. CHAPTER II
METHOD OF PROCEDURE
Theory of Spinning Tension
Spinning tension occurs in the yarn between the bite of the front rollers on a spinning frame and the bobbin on which the yarn is wound. Two schematic diagrams tor the s�ple analysts of spinning tension are shown in Figure 1.
The front rollers, thread guide, ring, traveler, and bobbin are shown in Figure lA. A plan view of the ring, traveler, and bobbin is shown in Figure lB.
There will be no motion in any component when the frame is at rest, and the tension T in the yarn will be zero. Each revolution of the bobbin would wind pi times the bobbin diameter length of yarn provided this much yarn was delivered by the front rollers, and the traveler re mained at rest on the ring. The tension buil�s very rapidly as the bobbin rotates because no yarn is being delivered. The component T1 of this tension acting on the traveler perpendicular to the ring r�pidly overcomes the traveler drag, and the traveler starts to move. How ever, when the traveler starts to move the component T1 diminishes, and yarn tension is reduced. If the component
T1 should become smaller than the drag, the traveler would stop. But when the traveler is stopped yarn tension builds
g rollers
-DnDnln
. yarn guide
B .
Figure 1. A schematic diagram of· the spinning frame components for ·twisting and winding the yarn: A, an elevation; B, a plan view.· "'
:.- 10
rapidly, and the process of stop and go of the traveler is
repeated. Actually when the bobbin is rotated with uniform
motion and no yarn is delivered by the front rollers, the traveler will rotate with a uniform speed equal to that of
the bobbin.
When the bobbin is run at a uniform speed and the front rollers deliver yarn at a constant rate, the traveler will run at a lower speed than before because of lower yarn tension. The traveler speed can be calculated when the delivery rate, spindle speed, and bobbin diameter are known,
as follows: (+ J.) Ts =s - · 1.
where Ts is the calculated traveler speed, S the spindle speed in rpm, R the delivery rate in inches per minute, and
d the bobbin diameter.
If the spindle speed were 10,000 rpm, the delivery rate 300 inches per minute, and the bobbin diameter 0.70
inches, the .calculated traveler speed would be 9864 rpm.
This difference in the speed of the bobbin and the speed
of the traveler is just eno-ugh to wind the yarn that is
delivered by the front rollers. The yarn would receive
9864 turns of twist in one minute or 32.8 turns per inch
of yarn. 11
Yarn tension is necessary and supplies the force to
move the traveler around the ring. There is evidence (9)
that the force is not constant but may increase and decrease
as the traveler makes one revolution. The brief description
of the spinning process has been greatly simplified, and
yarn contraction due to twist has not been considered.
Tension Meters
Two tension meters were developed. The first was
a mechanical device used for most of the exper�ental work.
·The second meter was a modi�ication or a Sanborn amplifier
and recorder and is referred to in this study as the strain
gage meter.
A photograph of the mechanical meter mounted on the
F2 spinning frame is shown in Figure 2. A schematic dia
gram for this meter is shown in Figure 3. The yarn segment
in which the tension was measured lies between points P1 and P2. The meter was mounted in such a way that wh en the
weight supporting ar.m �� Figure 3, was vertical, the roller
ar.m b was parallel to the yarn segme�t P1P2. P3 was then
on the perpendicular biseet·or of P1P2o When the meter was
in the operating position, the yarn segment was deflected
and formed the angles B1 and B2. The weight supporting
arm was also deflected and formed the angle Q with the
vertical...... Figure 2. The mechanical tension meter mounted on the F2 spinning frame. 1'\) p2.
Legend
Pl-P2 yarn segment B1 deflection angle B2 deflection angle \ PJ roller \ a weight arm P, \ b roller arm \..,.....Q w weight \ q deflected position \ of weight \ ) ..... , ,_,
Figure 3. schematic diagram of the mechanical tension meter. .... A \,..) 14
The tension in the deflected yarn segment can be calculated as follows:
Q a W tan 2 T = -- . b sin B1 + sin B2 where T is the calculated tension, W the weight on the arm,
� the length of the weight arm, and b the length of the roller arm.
Several factors such as friction and yarn rigidity caused the theoretical static calibration to be biased.
The final dial divisions were made using an experimental method. A series of accurate weights were attached to fine threads. These threads were mounted in the spinning frame in the same position that a yarn would have while spinning.
The deflection of the tension meter pointer for each of the calibration weights was carefully marked on the dial. A series of deflections were made for each weight, and the final dial mark was the average position.
A load detector for the Sanborn amplifier was made by cementing a strain gage element to a piece of beryllium copper. This unit was attached to a mounting bracket and occupied the same position on the spinning frame as did the mechanical meter.
Effect of Tension on Yarn Properties: Material and Methods
One cotton representing medium staple Upland was 15 selected. The cotton was processed on conventional machin
ery except that no picker was used, and the card laps were made by hand. The ha�d laps were carded on a Saeo Lowell card into 45 grain per yard sliver.
Two drawing processes were used with si x ends up at each process. The 45-grain finisher drawing was made into
1. 75, 2. 50 and 4.00 hank roving on a Whitin Superdraft roving frame. Three yarn numbers--16•s, 22's and 50's- were spun on the Whitin F2 spinning frame. The twist multipliers used were for maximum yarn strength (10).
The tension meter was installed on one spindle of the spinning frame, and the preselected tensions were ob- tained by varying both the spindle speed and traveler
weight as necessary. The test conditions for the 161s,
22's, and 50•s yarns are shown in Table I.
The yarn skein strength was measured on a model J 0 Scott tester under standard atmospheric conditions of 70 F and 65 per cent relative humidity. The yarn elongation was measured on a Scott IP-4 single-strand tester. The indi vidual skein strengths for five different spinning tensions for the 16•s yarn are shown in Table II and III. These data are representative, and no other individual readings
are shown. Graphs showing skein strength and yarn elonga
tion versus spinning tension for 161s, 221s, and 50's yarns
are shown in Figures 4, 5, and 6 respectively. 16
TABLE I TEST CONDITIONS FOR PRODUCING GIVEN SPINNING TENSIONS FOR THREE YARN NUMBERS
Traveler Traveler Spindle Yarn No. Tension (g.) No. Wt. (g.) Speed
161s 5. 1 o.o65 4440 161s 19. ii0 9 0.149 7250 161s 36.06 12 0.214 7250 16's 51. 11 17 0. 292 7250 16's 64. 40 20 0. 338 7445 22's 3. 90 3/ 0 0.049 4410 22's 18.13 8 0. 130 7460 22's 39.49 11 0.195 7 460 22ts 53.94 15 0.27 3 7460 22Js 66. 36 15 0. 27 3 9380 50's 2. 30 12/0 0.029 50's 4. 90 12/0 0.029 mg 50's 7.95 1 0.065 6800 50's 10. 30 3 . 0. 07 8 6800 50ts 14. 7 0 7 0.117 6800 17
TABLE II
INDIVIDUAL SKEI N ST RENGTHS FOR RUN-1, 16•s YARN AT FI VE VALUES OF SPINNING TENSION
Spinning Tension 5.44g. 19.8g. 36.1g. 51.1g. 64.4g.
Miniature Skein Strength in Pounds
94 101 102 104 101 93 100 100 106 106 81 100 98 107 101 94 100 97 104 93 92 96 99 102 107 94 103 99 97 102 97 94 102 107 103 91 106 107 102 107 76 101 102 99 105 94 96 104 111 103 91 98 101 99 104 86 101 98 103 10.5 8.5 94 98 108 102 8.5 100 100 102 107 88 107 100 110 106 82 101 101 104 97 93 100 104 100 105 86 96 102 100 103 83 9.5 100 100 97 87 97 103 105 108 73 87 107 99 102 87 98 102 107 101 86 94 101 104 109 8 ,90 97 101 10.5 6 86 100 98 103 104 86 97· 102 104 97 83 104 100 103 103 86 101 94 112 106 74 93 95 99 102 87 99 98 108 101
Mean 87.0 98.5 100.5 103.8 102.5 Std. Dev. 5.9 4.0 2.9 3.8 3.7 3 4 % c.v. 6.7 4.1 2.9 ).6 . Yarn number 15.7•s 15. 8•s 15.9's 15.9's 15.9's 18
TABLE III
INDIVIDUAL SKEIN STRENGTHS FOR RUN-2, 16•s YARN AT FIVE VALUES OF SPINNING TENSION
Spinning Tension 5.44g. 19.8g. 36.1g. 51.1g. 64.4g.
Miniature Skein Strength in Pounds
95 99 102 100 98 85 104 100 103 109 88 105 105 103 102 88 96 102 101 106 93 96 99 106 10� 93 97 106 99 10 103 98 106 100 100 88 96 100 95 96 95 95 105 101 98 92 95 107 107 106 91 96 100 105 107 85 104 94 103 99 83 99 104 1�� 99 89 100 105 104 91 97 100 104 103 93 99 106 103 103 83 99 103 102 105 95 102 105 106 103 90 98 105 106 109 87 95 104 102 100 81 105 105 104 102 89 102 96 105 107 96 98 104 101 103 89 97 97 109 104 94 96 105 106 101 89 92 101 108 105 88 93 99 101 102 95 96 106 106 96 90 97 105 102 98 96 98 104 102 102
Mea n 90.5 98.1 102.7 103.4 102.6 Std. Dev. 4.3 3.4 3.3 '3.7 3.6 % c.v. 4.7 3.5 3 .2 2.6 3.5 Yarn number 15.61s 15.81s 15.8•s 15.9's 15.9's 10!5 - 10
• - • .. 100 • .a . 9 ,I - - z 0 % ...... - (!) 95 c 8 ·- z (!) 11:1 z a:: 0 - ...... J (I) 90 11:1 7 z � i&.i � en 85 A s L B
0 0
0 10 20 30 40 50 80 70 0 10 20 30 40 50 60 70 SPINNING TENSION (grams) SPINNING TENSION (Qrams)
-Figure 4. Effect of spinning tension on yarn skein strength and elongation for 16' s yarn. !:0 70,_
•• 8
88 - .i - % 67 z7 t; 0 i= z c � 68 C!) � z ., 0 � w· � 85 .,.6 ¥ Cl)
64
63 L 4 A 5 8 ( 0 II 0 �--�--�--�--�--�--�--� 0 10 20 30 40 50 60 70 0 10 20 30 40 50 60 70
SPINNING TENSION ( eramt) SPif.. ING TENSION (Qrama)
N Figure 5. Erfect of spinning tension on yarn_skein strength and elongation . 0 for 22's yarn. 21
z 6 0 i= c (!) z � 0 ..J L&J � 4 8
0 0 2 4 6 a· 10 12 14 16 S�INNING TENSION (grams)
27
26
- • .G - 25 % t- (!) z L&J 24 a: t- 1/) z 23
�iij 1/) 22.
0 0 2 4 6 8 10 12 14 16 SPINNING TENSION (trame)
Figure 6. Effect of spinning tension 0n yarn skein strength and elongation for 50's yarn. 22 Strain Gage Measurements The strain gage meter did not give the same level of results as the mechanical meter. Because of the basic dif ferences between the two instruments, no attempt was made to correlate the readings. The strain gage was so sensitive and difficult to damp in operation that the trace on the strip-chart consisted of a band approximately !-inch wide, made by the rapid pen deflections. The chart reading fo r a given test was taken as the center of the band over a relatively long running time. Two experiments were performed with the strain gage meter. Two yarn numbers--161s and 32's-- were spun with a series of traveler weights and the graphs are shown in Figures 7 and 8. The second experiment was performed using 22's yarn only. The spinning tension was measured using seven spindle speeds and four traveler weights. The results are summarized in Table IV and Figure 9.
Accelerated End-Breakage Rate Test The accelerated and-breakage rate test was developed because both tension meters were slow and difficult to cali brate and use. Studies with the tension meters showed that if the proper values for the yarn number, ring diameter, and traveler weight were chosen, yarn made from cottons having any combination of fiber properties could be made to spin or 30 •
-25 • E • �.,-.-· .. �20 z 0 �15 ... � G :•o z
8; 5
0 0.1 o.z 0.3 0.4 TRAVELER WEIGHT (oramt)
Figure 7. Effect of traveler weight on spinning tension for 16•s yarn. 1\.) VJ 30
- 25 • E D !!� 20 z . �....-----· 0 m z 15 I&J .- /�· (!) � ./ z z B; 5 .. -----�
0 0 0. 1 0.2 0.3 0.4 TRAVELER WEIGHT (oroms)
F-igure 8. Effect.of traveler weight on spinning tension for 32's yarn.
� TABLE IV
THE EFFECT OF TRAVELER WEIGHT AND SPINDLE SPEED ON SPINNING TENSION FOR 22's YARN
Spindle S innin Tension in Grams Speed (rpm) p g
8/0 Travel�r No.1 Traveler No.5 Traveler No.8 Traveler
5000 5.0 7.5 9.2 11.5 6000 5.5 9.2 12.3 17.2 7000 9.5 11.2 15.0 21.8 8000 12.0 14.0 18.6 25.9 9000 14.8 17.5 22.6 32.3 10,000 16.6 21.0 27.5 38.4 11,000 20.5 26.0 35.0 46.5
{\) C1l �0
N0.8 4�
40
- 3� • e a �30 - z 0 NO.I � 2S Ill � � 20 8/0 z z iL {/) 1 5
10
s •
0 0 2 3 4 � 6 7 8 · 9 10 II 12 SPINDLE SPEED 1\) 0' Figure 9. Effect of spindle speed on spinning tension for .four traveler numbers. 21 could be stressed by varying only the spindle speed until it broke. The Whitin F2 spinning frame was equipped with a variable-speed drive and remote controlso The spindle speed could be inereased9 decreased, or held constant by these controls while the frame was running. A photograph of the device is shown in Figure 10. The spinning frame constants for the accelerated end-breakage rate test were: (1) a 1.5 inch diameter ring,
(2) a number nine traveler, and (3) a 601s yarn. A stro botac was used to measure spindle speed. The test was performed by first processing the test cotton into a 3.00 hank roving and then double creeling at the. spinning frame to give a 1.50 hank roving. The spindle speed was set at a low value, and the frame started. The spindle speed was then increased continuously until the end broke. The spindle speed at the break-point was measured with the strobotac and recorded. The process was then repeated until the desired number of observations were obtained.
Maximum Spinning Tension Study The cottons for this experiment were selected so that only one major fiber property at a ti me was allowed to vary. This was possible only by selecting paired samples from the United States Department of Agriculture Spinning
Laboratory's cotton library at Knoxvilleg Tennessee. Figure 10. The variable speed drive on the F2 spinning frame. f\) 0'> 29
The most difficult combination of properties to obtain was long length. medium fineness, and low fiber tenacity. Only
one paired sample was available from the 1100 in the cotton
library. Three pairs were found that varied only in fiber
tenacity, and two pairs that varied only in fiber fineness.
Fiber data for all samples are shown in Table v.
The cottons were processed into 3.00 hank roving and double creeled for spinning. The spinning frame draft gearing was adjusted to give 60's yarn, and the twist gears
were selected to twist each yarn for maximum skein strength.
Ten observations were made on a particular sampleo It was then replaced with another, and ten observations made on the new one. The samples were rotated in this way until the desired number of observations were made. The order of
testing was random, and at least two groups of ten obser vations each were made on each cotton. Ten specimens from each of 10 bobbins were measured for yarn elongation for
each sample. Individual representative observations of max
imum spindle speeds for three paired samples are listed in _ Tables VI, VII and VIII. The maximum spindle speeds and elongation data for all samples are summarized in Figure ll. 30
TABLE V
FIBER DATA AN D AVERAGE MAXIMUM SPINDLE SPEED FOR THE PAIRED SAMPLES USED IN THE AC CELERATED EN D BREAKAGE RATE TEST
Sample UHM Fiber Fiber Spindle Identification Length Tenacity Fineness Speed
Rl-53-lc 0.99 21. 7 493 10.67 Ex-55-7t 1.00 15.8 490 8.71
Cs-54-19t 1.08 22.2 430 10. 01 M-54-11t 1. 06 17.5 431 8.81
Br-55-13t 1.08 23.7 457 10.42 S-55-8t 1.07 18.5 468 9.17 Sh-57-o1d pima 1.48 24.6 519 10.44 Ss-52-3c 1.03 24.6 508 5.69
Cs-55-18t 1.02 18. 2 555 8.74 Cs-55-19t 1.03 17.8 473 8.67
Cs-55-3t 0.86 17.0 582 8.70 M-55-3t 0.99 18.1 . 392 8.22
UHM Length - inches Fiber Tenacity - gr�ms/tex Fiber Fineness - mm /mm3 Spindle Speed - thousands of rpm TABLE VI
MAXIMUM SPINDLE SPEEDS FOR THE TEST PAIR DIFFERING ONLY IN FIBER LENGTH
Spindle Speed in Thousands of Revolution per minute
Rep-1 Rep-2 Rep-3 Rep-4 Rep-1 Rep-2 Rep-3 Rep-4
Sh-Old Pima Ss-52-30
10.86 9.41 10.15 9.70 5.65 5.50 6.24 5.90 10.44 10.80 9.99 9.65 5.61 5.81 6.66 6.01 9.31 9.76 12.14 9.38 6.22 5.95 6.75 5.10 10.17 10.45 10.20 9.85 6.45 5.39 5.69 5.95 9.70 9.75 11.75 11.07 5.57 5.96 6.43 5.11 11.00 10.05 10.65 12.05 5.30 6.03 5.56 5.39 10.59 11.40 11.10 10.01 5.89 6.00 6.41 5.10 10.14 9.80 11.24 11.06 5.90 6.27 6.55 5.25 10.19 10.16 11.36 11.05 6.20 5.67 6.04 5.50 9.96 10.29 10.50 9.90 5.65 6.54 5.69 5.00
Mean 10o24 10.19 10.91 10.37 5.84 5.91 6.20 5.43 SD 0.49 0.56 0.69 0.83 0.34 0.33 0.41 0.37 %cv 4.76 5.45 6.31 7.95 5.80 5.51 6.20 6.81
� ...... TABLE VII
MAXIMUM SPINDLE SPEEDS FOR A TEST PAIR DIFFERING ONLY IN FIBER TENACITY
Spindle Speed in Thousands of Revolutions Per Minute
Rep-1 Rep-2 Rep-3 Rep-1 Rep-2 Rep-3
-
Br-55-13t S-55-St
9.45 11.10 9.10 7.81 9.86 7.95 8o83 11.00 10o05 8.80 7.86 10.00 8o91 12.10 8.16 9.18 9.51 llol9 10.94 11.40 10.11 9.50 9o20 9.98 llol5 10.60 10.44 8.50 9.06 8.96 10.30 10.44 10o45 9o54 8o00 7.50 9.60 9o50 10.52 10.68 7o85 9.75 llo06 8.98 10o98 10.95 9ol2 7.45 10.20 9o80 10ol5 8.78 9.38 10.25 llol9 8o50 10o35 9.73 8o31 8.56
Mean 10.16 10.34 10o03 9.35 8o82 9.16 SD 0.87 lo08 0.77 0.91 0.74 1.21 %cv 8.59 10.39 7.71 9.74 7. 99 13.73
(ll l\) TABLE VIII
MAXIMUM SPINDLE SPEEDS FOR A PAIR DIFFERING ONLY IN FIBER FINENESS
Spindle Speed in Thousands of Revolution Per Minute
Rep-1 Rep-2 Rep-3 Rep-4 Rep-1· Rep-2 Rep-3 Rep-4
Cs-55-19t Cs-55-18t
9.20 8.90 9.70 7.94 8.89 9.30 9.10 7.96 8.86 8 . 44 9.94 8.45 9.18 9.65 8.44 8.54 8.60 8.40 9.15 7.60 9.49 8.94 7.94 8.20 8.59 8.50 8 . 94 8.74 9.55 8.50 8.85 8.60 8.86 8.70 9.44 8.76 9.55 7.64 8.85 8.15 8.35 8.24 8.84 8.75 8.50 9.04 9.66 8.30 8.80 8 . 44 8 . 94 9.,30 9.10 9.00 8.64 7.44 8.75 8.85 8.54 7.75 9.09 8.00 8.30 8.40 8e36 9.10 8.70 7.70 9.20 8.20 9.34 8.60 8.15 8 ..50 8. 95 8.10 8.80 8.15 9.15 8.14
Mean 8.,65 8o61 9ol1 8.,31 9.14 8.72 8.83 8.23 SD 0.2 9 0.26 0.43 0.54 0.33 0.5'7 O e 49 0.33 %av 3.37 2.99 4.66 6.55 3.56 6.54 5.54 4 . 06
� � I I t I I I
10 10 � 10
0 0 4 0 9 LIJ 9 9 LIJ LaJ LIJ le LaJ 0. fJ) 2 0. en fJ) � 8 I LIJ 8 LIJ 8 "' � s � � 0 0 0 z z z cr ·i: fJ) U) 7 7 7 . Bs x )( � c � 2 2 6' 6 :1 6
A 8 c ·s s �
o· 0 0 0 1.0 1.2 1.4 . 1.6 0 16 18 20 22' 24 0 400 !500 600 . U.H.M. LENGTH (in.) �NACITY (e/tex) FINENESS (mm�/mm�)
F�gure 11. Effect of three fiber properties on maximum spinning tension. Maximum spindle speed _is in thousands or rpm. .
UJ � CHAPTER III
DISCUSSION OF RESULTS
Both tension meters were difficult to use, and
neither would be satisfactory for textile mill applications.
The main source of trouble was machine vibration that could
not be damped out because of severe loss of instrument sen
sitivity. The mechanical meter was affected less by vibra
tion than the strain gage instrument. The experimental calibration worked very well with
both devices although the tension levels were different.
Many experiments using the mechanical meter, but not re
ported here (11), gave a good foundation for subsequent
research on spinning tension and led to the development
of the accelerated end-breakage rate test.
Effect of Tension on Yarn Strength and Elongation
Yarn strength increased as the spinning tension increased. The relation, as shown in Figures 5A, page 20,
6A, page 21, and 7A, page 23, was not linear. The change in strength was rapid at first but became almost zero at the higher values of spinning tension. Experiments have
shown that yarn strength as well as fiber strength increases
as the gage length of the specimen decreases (12). The
increased tension could possible have caused a shortening
35 36 of the break-zone or gage length in the yarn resulting in increased yarn strength. The higher tensions for the 16•s,
22•s, and 50•s yarns approached the level where the ends would not stay up. The highest tension values used were just below the point where the yarns would not spin. 'The max�um spinning tensions were: 14.5 gr,ams for the 50•s,
55 grams for the 221s, and 65 grams for the 16•s yarn.
For practical spinning there is no need to approach these values, since acceptable yarn strengths occurred at about one-half the maximum tension.
The yarn elongation decreased without excepti on as the spinning tension increased. The relation was linear as shown in Figures 5B, page 20, 6B, page 21, and 7B, page 23• The lines were fitted by the method of least squares. A fibr ous yarn resembles a spring with the fibers at some helical angle. The higher this angle and the loftier the yarn the higher will be the elongation.
Low tension spinning produced lo£ty yarns, and the high tension yarns were hard. Part of total yarn elongation is the elongation of the fibers themselves. High tension spinning removed some of this elongation contributing to a decrease in the final yarn elongati on.
Effects of Traveler Weight and Spindle Speed Spinning frame travelers are designed to ride on 37 the ring at very high speeds and produce a uniform tension in the yarn. The selection of travelers is usually made by a trial and error method. The effect of traveler weight on yarn tension for two yarns is shown in Figures 8, page 24, and 9, page 26. There is little difference in the yarn ten sion for a given traveler weight between the 161s and 32's yarn even though the 161s has twice the weight per unit length as the 32's. The actual yarn weight has a secondary effect, compared to traveler weight, in producing yarn ten sion. In fact the yarn weight can be neglected for prac tical purposes. Certain travelers are so light that they cannot produce sufficient tension to cause a yarn to spin.
All traveler weights shown in Figures 8, page 24, and 9, page 26, provided sufficient spinning tension. Spinning tension increased as the traveler weight and spindle speed increased. The family of curves in Figure 10, page 28, shows the relation for 22's yarn. The ring diameter was 1.5 inches for this experiment. Larger rings produce higher tension when all other variables are. held constant. This family of curves could be used to estimate tension when the ring diameter is 1.5 inches and the traveler weight and spindle speed are known. The esti mates would be fairly accurate for yarn numbers other than 22's. The mo st significant aspect of the data in Figure 10, page 28, is the uniform increase in spinning tension with 38 an increase in traveler weight and spindle speed. There is a common belief that at some value, not necessarily the lowest value, of spindle speed a traveler will ride the ring in such a way as to produce minimum spinning tension.
This condition is attributed to the geometry of the ring and traveler. No such value occurred in the curves shown in Figure 10, page 28.
Accelerated End-Breakage Rate Test Many exper�ents in addition to those described here were performed with the accelerated end-breakage rate test
(13). No changes were needed in the or iginal spinning or ganization, and no cottons were found that were beyond the spinning limits of the test. The average coefficient of variation within samples of 10 observations was 6.56 per cent. The time required for 10 observations after the roving was made and in the spinning frame wa s about 1-hour.
No other end-breakage rate test with equal reliability has been devised that could be performed in the same time.
Effect of Fiber Properties on Maximum Spinning Tension The maximum tensions for this experiment were meas ured in terms of maximum spindle speeds. The mathmatical relation between ·spindle speed and spinning tension is extremely complicated. Empirical curves are shown in
Figure 9, page 26. Because these curves did not have 39 extreme deviations from straight lines over the range of spindle speeds tram 4000 to 11, 000 revolutions per minute, no conversions to tension were made.
The observations were made in groups of 10, and the mean, standard deviation, and coefficient of variation are shown in Tables VI, page 31, VII, page 32, and VIII, page 33.
Graphs of average values only are shown in Figure 11, page 34.
The relation between maximum spindle speed and fiber length is shown in Figure llA, page 34. A unit change in length gave about 2 unit changes in the maximum spindle speed. Few cottons are grown that exceed the range in length shown in Figure llA, page 34. The longer the cotton the higher the spindle speed at which it can be spun.
Higher spindle speeds mean higher mill efficiency and lower processing costs.
The relation between fiber tenacit y and max�um spindle speed is shown in the three curves in Figure llB, page 34. One unit change in tenacity gave 0.53 unit changes in maximum spindle speed. These results were rather star tling as it was believed that few if any fibers were broken when an end came down during spinning. These data show · that strong cotton can be spun at higher speeds than weak cotton.
The relation between fiber fineness and maximum 40 spindle speed is shown by the two curves in Figure llC, page 34. The fineness had little effect even over the wide range from 400 to 600 mm2jmm 3. The samples Cs-55- 18t and
Cs-55- 19t, Table V, page 30, were not significantly di f fer ent at the 0.05 level. The samples Cs-55- 3t and M-55- 3t were significantly different at this level but the differ ence of 480 revolutions per minute is of no practical value.
Again these results were surprising since it was believed that fineness had almost as much effect on maximum spindle speed as did length. CHAPTER IV
SUMMARY AND CONCLUSIONS
The two tension meters that were developed worked well in the laboratory. They would be difficult to cal ibrate and stabilize for mill applications. The meters were able to measure spinning tension over a wide range far beyond that found in normal spinning frame operation.
Data acquired with the tension meters were used to develop
an accelerated end-breakage rate test.
The effect of spinning tension on yarn strength and elongation was investigated. Yarn skein strength increased
and elongation decreased as spinning tension increased.
The increase in yarn strength was attributed to the short ening of the break-zone in the yarn due to tighter packing of the fibers. The decrease in elongation was due to the
removal of part of the elongation during spinning.
Studies using different traveler weights showed a steady increase in tension as the spindle speed increased.
The accelerated end-breakage rate test was used to measure the independent effects of fiber length, tenacity,
and fineness on the ability of a yarn to support a load
during the spinning process. Maximum spindle speed rather
than spinning tension was measured because of the ease with
which the value could be obtained. The relation between
41 42 spindle speed and spinning tension was not linear, but the departure from a straight line was not of the degree to . necessitate converting maximum spindle speed to tension.
Fiber length had more effect on maximum spindle speed than either fiber tenacity or fineness. Fiber tenacity was next, and fineness had little or no effect even over a �ide range in fineness.
A new tension meter could be designed based on infor mation obtained with the mechanical and strain gage devices. The meter could be made portable and would not be fastened per.manently to the spinning frame. It could be aligned by special guide bars and held against the frame by permanent magnets. A device of th is type would find wide use in help ing solve many mill engineering problems.
The accelerated end-breakage rate test has been used in numerous experiments. An extensive study of the effects of bacterial damage on fiber quality was made by the United
States Department of Agriculture Spinning Laboratory at Knoxville, and the accelerated end-breakage rate test was . one of the tools used (13). The University of Tennessee physics shop has built prototype devices for installation on spinning frames to stress the yarn to the breaking point without varying the spindle speed. These devices have been only partially successful.
In the near future both a portable tension meter and 43 a practical way for performing the accelerated end-breakage
rate test should be perfected. LITERATURE CITED LITERATURE CITED
1. DeBarr, A.E. � Journal of the Textile Ins titute, 49 , T58-T88 (195� ).
2. Woo , K. C., Textile Research Journal , 612 (1958 ).
3. Burley, S. T. , and Eddins , F. , AMS Series 229 , (1958 ).
4. Fiori, A. , Louis , G.L., and Tallant , J.D. , Textile Bulletin , 88 , 86 (1962) .
5. Burley , S.T. , and Milliken , R. A ., Textile Bulletin, 88 , 63 (196 2 ).
6. Louis , Gain L., Textile Indus tries , 125, 76-80 (1961) .
Louis , Gain L. , and Fiori, L.A., Textile Bulletin, 88 , 31 (196 2) .
8. Linton, G. , The Modern Textile Dic tionary , Duell, Sloan, and Pearce, Little , Brown, and Company , New York; 1954.
9. DeBarr, Journal of the Textile Institute, 50, T284-T293 (1959) .
10 . Landstree t , C.B. , Ewald , P.R., Hertel , K.L. , and Craven, C.J. , Textile World, 104, 106 -107 (1954) .
11. Unpublished Report , U.S.D.A. Spinning Laboratory , Knoxville, Tennessee, (1959) .
12 . Peirce, F.T., Journal of the Textile Institute , 18 , T47 5-T489 (1927) .
13. Unpublished Reports , U. S.D.A. Spinning Laboratory , Knoxville , Tennes see (1957-1960 ).