BLENDING COTTON AND POLYESTER FIBERS--
EFFECTS OF PROCESSING METHODS ON FIBER
DISTRIBUTION AND YARN PROPERTIES
A THESIS
Presented to
The Faculty of the Graduate Division
by
Nelson Ping Ching Chao
In Partial Fulfillment
of the Requirements for the Degree
Master of Science in Textiles
Georgia Institute of Technology
September, 1963 3^ 12,^ ^
BLENDING COTTON AND POLYESTER FIBERS-
EFFECTS OF PROCESSING METHODS ON FIBER
DISTRIBUTION AND YARN PROPERTIES
Approved!
"—xy '—17 Date Approved by Chairman: ^^ysu^.^1^ ^h^ R^^ li
ACKNOWLEDGMENTS
The author wishes to express his sincere gratitude and apprecia tion to Dr. James L. Taylor, Director of the A. French Textile School,
£or granting him a graduate assistantship and a Celanese fellowship which made this study possible; to Professor R. K. Flege, his thesis advisor, and to Professor R. L. Hill, both of the A. French Textile
School, for their advice and recommendations; and to Dr. Joseph J.
Moder of the School of Industrial Engineering for his assistance with the statistical aspects of the experiment. He also extends his thanks to Mr. R. C. Freeman, technician of the A. French Textile School, for his kind assistance. iii
TABLE OF CONTENTS
Page
ACKNOWLEDGMENTS ii
LIST OF TABLES iv
LIST OF ILLUSTRATIONS vii
SUMMARY vill
Chapter
I. INTRODUCTION I
Some Aspects of Blending Fibers Stateioent of the Problem
II. INSTRUMENTATION AND EQUIPMENT 11
Raw Materials Used Processing Equipment Testing Equipment
III. PROCEDURE 13
Processing Blended Yarn Physical Tests Tests for Uniformity Tests for Breaking Strength and Elongation of Yarn Examination of Fiber Distribution Analyses of Data
IV. DISCUSSION OF RESULTS 24
V. CONCLUSIONS 44
VI. RECOMMENDATIONS 47
APPENDIX 48
BIBLIOGRAPHY 74 Iv
LIST OF TABLES
Table Page
la. Identification of Processes 15
lb. Organization of Weights and Drafts 16
2a. Analysis of Variance for Drawing Sliver Evenness 25
2b. Tukey Test for Significance of Drawing Sliver Evenness Differences Between Drawing Processes 25
3a. Analysis of Variance for Roving Evenness 28
3b. Tukey Test for Significance of Roving Evenness Differences Between Drawing Processes 28
4a. Analysis of Variance for Yam Evenness 31
4b. Tukey Test for Significance of Yarn Evenness Difference Between Drawing Processes 31
5. Sunmary of Per Cent Coefficient of Variation for Product Evenness 33
6a. Analysis of Variance for Yarn Breaking Strength 35
6b. Tukey Test for Significance of Yarn Strength Differences Between Drawing Processes 35
7. Analysis of Variance for Yarn Elongation 36
8. Sunmiary of Yarn Breaking Strength Test 38
9a. Analysis of Variance for Yarn Nep Count 39
9b. Tukey Test for Significance of Yarn Nep Count Differences Between Drawing Processes 39
10a. Analysis of Variance for Fiber Migration Index 41
10b. Tukey Test for Significance of Fiber Migration Index Differences Between Drawing Processes 41
11. Sunmary of Yarn Nep Count Test 42 Table Page
12. Summary of the Migration Index of Cotton Component 42
13. Operating Data for H & B Revolving Flat Card 49
14. Settings for H & B Revolving Flat Card 50
15. Operating Data for Saco-Lowell Roller Top Card 51
16. Settings for Saco-Lowell Roller Top Card 52
17. Operating Data for Saco-Lowell, 4 Over 5, DS-4 Drawing Frame 53
18. Operating Data for 10-1/2" Saco-Lowell Lap Winder 54
19. Operating Data for Saco-Lowell Model 57 Comber 54
20. Operating Data for Whitin Woonsocket Roving Frame 55
21. Operating Data for Saco-Lowell SS-2 Spinning Frame 56
22. Operating Data for Uster Evenness Tester 57
23. Operating Data for Uster Automatic Yarn Strength Tester . . 58
24. Fiber Fineness Test Using Sheffield Micronaire 59
25. Cotton Fiber Strength Test Using Pressley Tester 60
26. Fiber Length Test Using Servo-Fibrograph 61
27. Uniformity of Cotton Picker Lap 62
28. Uniformity of Dacron Picker Lap 62
29. Per Cent Coefficient of Variation for the Evenness of Slivers 63
30. Summary of Per Cent Coefficient of Variation for the Evennesses of Sliver, Roving and Yarn 64
31. Per Cent Coefficient of Variation for the Evenness of Blended Sliver 65
32. Per Cent Coefficient of Variation for the Evenness of Roving 67
33. Per Cent Coefficient of Variation for the Evenness of Yarn 69 vi
Table Page
34. Summary of Results from Yarn In^erfectlon Indicator .... 71
35. Results of Fiber Count for Fiber Migration Index 72
36. Summary of Results from Uster Automatic Yarn Strength Tester 73 vli
LIST OF ILLUSTRATIONS
Figure Page
1. Sequence of Operations for Producing Blend of Dacron/Combed Cotton 14
2. Effects of Drawing Process and Drawing Speed on the Evenness of Drawing Sliver 26
3. Effects of Drawing Process and Drawing Speed on Roving Evenness 29
4. Effects of Drawing Process and Drawing Speed on Yarn Evenness 32
5. Effects of Drawing Process and Drawing Speed on Yarn Breaking Strength and Elongation 37
6. Effects of Drawing Process and Drawing Speed on Fiber Migration Index 43 viti
SUMMARY
The blending of cotton and man-made fibers at the drawing frame has been a common practice In the textile Industry. In order to reduce the processing cost, the newer high speed drawing frames have been adopted to Increase the production, and the number of drawing processes has also been reduced, In most of the mills, from three to two processes.
This Investigation was conducted to statistically evaluate the effects of the speed of drawing frame and the number of drawing processes on the fiber distribution, In terms of fiber migration Index, and other physical properties of the blended yarns made from the silvers blended at the drawing frame.
The blend of 35 per cent combed cotton and 65 per cent polyester was made at the drawing frame where three different processes--one- process, two-process, and three-process drawlngs--and three levels of front roll speed--100, 200, and 300 feet per mlnute--were Introduced to yield nine lots of blended silver. These silvers were then processed
Into 30's yarn through roving and spinning operations.
The silvers, rovlngs, and yarns were tested for evenness. The yarns were tested for breaking strength, elongation, nep content, and fiber migration Index. All the data obtained were statistically analyzed to evaluate the results.
It was found that the number of drawing processes had a signifi cant effect. In a statistical sense, on the evenness of silvers, rovlngs, and yarns. An Increase In the number of drawing processes had Improved Ix
the evenness of the products. Speed of the dravlng frame was found to have but little effect on the product evenness. All evenness tests were performed on the Uster Tester.
The yarn breaking strength and elongation tests, made on the Uster
Automatic Yam Strength Tester, revealed that the number of drawing proc esses significantly affected the yarn strength, while the quadratic com ponent of the drawing frame speed significantly affected the yarn elonga tion. Both breaking strength and per cent elongation increased with each additional drawing process. The speed of 200 feet per minute was found to have yielded the strongest yarn with the highest per cent elongation.
The nep content in the yarns was determined by the Uster Imper fection Indicator. The number of drawing processes had a significant effect on the nep content but only at the 10 per cent level. Two- process drawing produced fewer neps in the yarns. Also, nep count was lower in the yarns produced at the slower speed.
Microscopic examination of yarn cross sections revealed that the cotton fibers had an outward migratory tendency, while the polyester fibers had an inward migratory tendency. The migration index was lower as the number of drawing processes increased. As the migration index decreases, uniformity of the fiber distribution increases. Three-process drawing yielded the yarn with the most uniform distribution of fibers.
Also, the yarn processed at the lowest drawing frame speed showed the most uniform distribution of fibers in the cross section. The effects of the number of drawing processes, and drawing fraxoe speed, were found to be significant only at the 10 per cent level. CHAPTER I
INTRODUCTION
Some Aspects of Blending Fibers
The blending or mixing of natural and/or man-made fibers has been practiced for many years, but only recently has it attracted great at tention from textile manufacturers. Reduction in number of processes required on modern machinery, differences in harvesting and ginning practices and increased usage of new man-made fibers have greatly in creased the importance and significance of blending processes and procedures.
Blending nay be defined as the mixing of two or more masses of fibers so that the resulting mixture has the characteristics of the average of the component items. Blending of cotton is done for at least three purposes (1):
(a) To reduce the variation in fiber characteristics so that a homogeneous sliver or roving is produced for the spinning frame. The fiber properties vary with the variety of the cotton, area of growth, cultural practices, weather conditions, time of harvest, harvesting methods and ginning treatments. The coefficient of variation of fiber fineness and strength within the bale has been estimated to be as much as 40 per cent. Thorough blending is, therefore, necessary to reduce the variation and yield more uniform yarn of controlled quality.
(b) To provide the mill aiachinery with a continuous supply of cotton of the same average quality. This is done to maintain a uniform stock from day to day, week to week or even longer periods of time.
(c) To take advantage of the price differentials in cotton between grades and fineness levels, etc. It may be more economical to blend cot tons of different price ranges than to use only one cotton with the same average properties.
In recent years, since the adoption of many man-made fibers by the textile industry, the blending of man-made fibers with each other or with natural fibers has become popular. Speakman (2) has given three main reasons for blending. The first is to produce a cheaper product. Blends of wool and cotton, and of wool and rayon are common practices used in the textile industry to reduce the cost without considerably affecting the quality. It should, however be eiiq>hasized that low cost is not necessarily a desirable end; cost in relation to performance is the basic criterion of merit. The objective is to give the best value for the money. The second reason is the correction of defects. Many fibers have some inherent undesirable characteristics which can be minimized by blending with some other fibers. The wear resistance of wool can be inq}roved by blending with nylon. Low water-absorption of polyester fiber fabrics can be improved by blending with cotton or rayon. The third and, perhaps, the most inq>ortant reason for blending is the crea tion of new and more desirable effects. Many fibers have specific properties which, if used properly, produce new and special effects.
Many man-made fibers have high tenacity and low water absorption; this may be an advantage in making easy-care fabrics which will dry quickly and do not need pressing. Also, the mixture of different fibers gives a
diversity to the appearance and handle of fabrics. Special effects may
be created by the use of cross-dyeing to introduce two different colors
into a fabric.
Due to large variations in the fiber properties of today's cotton,
large quantity preblending and storing of blended bales has been practiced by many cotton mills as a means for leveling out the variations. In
studies by Howe (4), four sources of cotton fiber variations were recog nized: (a) within each bale; (b) between bales within a mix; (c) between shipments; and (d) from crop to crop. When the final blend is made from preblended bales, taken across a reservoir of preblended lots, the resultant blend will represent a cross section of perhaps several hundred bales. This should provide uniform stock, and result in relative
ly constant processing performance and yarn quality week after week. The preblending operation is usually done by using blending feeders (eight to ten) and cleaning units (Axi-Flo Cleaners) to remove some of the trash
from cotton.
In a mill operated on the cotton system, the blending of natural and/or man-made fibers is usually done by any one, and frequently a com bination, of the following methods (5):
(a) Sandwich blending by hand. This involves spreading weighed quantities of the several fibers in their correct proportions in hori zontal layers in large capacity bins or on the floor. This method re quires a large storage area and a high labor cost. The degree of uniformity is largely dependent on the care taken in building the sandwich. (b) Use of blending feeders in the opening unit. An older method of blending at the opening unit used a single bale opener around which were placed a number of bales of fibers representing the proportion of the components in the blend. The stock was fed on to the lattice by hand at a controlled rate from each bale so that all bales would run out at the same time. Uniformity of the resulting blend depended almost entirely on the skill and care of the operator. A new and more effective method for blending makes use of blending feeders, each supplied with a single fiber component, and provided with a metering device to regulate the weight of fiber delivered to the proportions required in the blend. A controlled quantity of fibers from each blending feeder drops to the feed table to form a sandwich blend. The resulting blend is then conveyed to the next machine for further processing.
(c) Lap blending. In a two-process picking line, the laps pro duced by breaker pickers are placed on finisher picker for blending.
The proportion of blend can be regulated by the nundaer of laps of each con^onenc placed on finisher picker.
(d) Card blending. The card does not mix fibers completely at random, but it does break down fiber bunches very well, and blending can be done in a later process with good results (6).
(e) Blending at the drawing frame. Blending can be made at the first drawing process with six or eight ends up. The fibers which re quire different opening and carding treatments are normally blended at this stage.
Blending also can be done at the roving or spinning frame by using double creel for the rovlngs fed to the drafting element.
The appropriate stage for blending the different fibers is deter mined by the state of the component fibers as well as the quality level required in the final product. When conditions are such that the blended conqponents do not tend to regroup during the subsequent processing, the greatest dispersal is obtained by blending at the earliest possible stage in manufacture. This will give more doublings and result in uni form blends. When there is considerable difference in the degree of opening or in the amount of foreign matter present there should be a pre liminary opening before blending. As the man-made fiber is free from entanglement and impurities, opening is concerned only with separation of fibers in the tufts of baled staple. Excessive processing will damage the fibers. With cotton/man-made fiber blends, opening and clean ing of cotton must be carried out before blending with man-made fiber on a short opening unit.
Selection of blend components is determined by the end-use for the product. Determining factors are (3): (a) to define the cost of the blend by union of coiq>onent8 of different prices, (b) to in^rove manufacturing performance by addition of a small percentage of higher grade fibers, (c) to improve end-use performance, and (d) to stimulate consumer appeal by the introduction of end products with new character istics.
The ideal blend is one in which the individual fibers of the com ponents are mixed to give a uniform texture, appearance and handle. Also there shall not be any unwanted shade variation in the finish cloth. This is best effected when the components have approximately similar
characteristics.
Three types of irregular blending can be distinguished (7):
(a) Variation, along the yarn, in the proportion of the different
fibers in each cross section.
(b) Inadequate mixing of the different fibers in each cross
section.
(c) Variation, along the yarn, in the degree of mixing of the
different fibers at each cross section.
These irregularities will be influenced by the methods used to blend the fibers, but they will not all have the same effect on the appearance of the finished fabrics. The average degree of mixing of the different fibers in the cross section of the yarn, together with any tendency for one fiber to adopt preferential positions on the inside or outside of the yarn, will affect the appearance and character of the fabrics, but will not cause barring or streakiness. These faults are caused by variation In the composition o£ the yarn along its length, or by variation along the length of the yarn in the degree of mixing of the fiber in each cross section.
Lund (8) has pointed out that (a) finer yarns will appear less well blended than coarser yarns when the yarns are spun from similarly proportioned blends of similar fibers; (b) yarns of the same count spun from coarser fibers will appear more streaky; and (c) yarns of same counts spun from distinctly different fibers of the same size but in decidedly unbalanced blends, such as 90/10, will appear more streaky than yarns of the same fibers in a 50/50 blend. since a perfect blend is not realized In practice, the best that can be hoped for Is a random distribution of fibers In the yarns. Lund showed that this random distribution of fibers could be achieved by using a sufficient number of doublings in the processes. For a 50/50 blend, he suggested that the minimum number of doublings In the processes should be equal to the number of fibers In the cross section of the final yarn.
But Cox suggested (9) that the number of doublings should be five times the number of fibers In the cross section, and the number of doublings with unbalanced blends should be greater than the ratio quoted. It may be concluded that, based on the number of fibers In the cross section of yarn, the finer yarns will require less doubling than the coarser yarns when they are spun from the fibers of same fineness. For the yarns of same count, those spun from finer fibers will require more doubling than those from coarser fibers.
The migration In a transverse direction of component fibers In blended yarns Is a well-known possibility. The work done by Ford In this line shows the fiber migration depends on the following factors (10):
(a) Denier. Increasing the denier of a component causes that component to migrate towards the surface.
(b) Staple length. Increasing the length of a component causes that coiiq>onent to migrate towards the center.
(c) Chemical identity. This factor is believed to depend partly on the length characteristic of the component. Acetate and protein materials are known to undergo fiber breakage during processing and the migration of these two fibers toward the surface is partly due to this effect. (d) Extensibility. For a given chemical Identity of fiber, In
crease In extensibility causes that coiaponent to migrate towards the
surface. With differing chemical Identities, the extensibility alone
does not, however, determine the migration tendency.
(e) Swelling and shrinkage. Components having a greater swel
ling and shrinkage In liquid treatments subsequent to yarn spinning
migrate towards the yarn center.
Statement of the Problem
During recent years, processing blends of man-made fibers and
cotton on the cotton system has become very common In the textile In
dustry. Cotton's characteristics of pleasing hand, breathing capacity
and absorbency make It Ideal for blending with man-made fibers posses
sing high strength, abrasion resistance and wrinkle recovery properties.
This concept of blending cotton with man-made fibers has met with ex
cellent consumer acceptance. More than 320 million yards of polyester and cotton blend fabrics were produced in 1961 (11).
Because cotton and man-made fibers often require different opening and carding treatments, blending at th« drawing fraiae has become a common practice in many mills. Mill men have tried to in crease the production rate and reduce the number of drawing processes
In order to cut down the processing cost. Newer high speed drawing frames have made it possible to operate at 800 feet of sliver per minute which is about six times the speed of conventional drawing frames. The number of drawing processes, in most of the mills, has been reduced from three to two processes. The purpose o£ this study was to evaluate the effects of the speed
of drawing frame and the number of drawing processes on the fiber distri
bution and other physical properties of the blended yams made from the
slivers blended at drawing frame.
Limited work has been done along this line. The experiment con
ducted by Cancelliere II (12) concluded that the drawing speed had no
effect on the strength, elongation or uniformity of the resultant yarn.
The study made by Bogdan (13) showed that the increase in front roll
speed of an Ideal SP drawing frame did not affect the yarn strength of
16's carded yarn and 16's combed yarn. However, 13's carded yarn
showed a 7 per cent loss in strength when the speed was increased from
370 feet per minute to 770 feet per minute. In the comparison of 20*8
carded yarns produced with one, two and three drawing processes, Bogdan
pointed out that the yarn strength was increased slightly with additional
drawings. Both Cancelliere II and Bogdan used 100 per cent cotton in
their experiments; no literature has been found regarding the effect of
these process variables on blended yarns.
The blend of 35 per cent combed cotton and 65 per cent polyester
fiber was selected for this study because it is the most popular blend
for many Industrial products. Three levels of speed and three different
processes were employed in drawing operations to yield nine lots of
blended sliver. Various tests were made on each lot of slivers, rovings
and resultant yams to provide the data for statistical analysis and
comparison.
The drawing frame used in this experiment was a Saco-Lowell,
Model DS-4 machine. It was designed to operate at normal speed of 120 10
feet per minute. The highest speed that could be obtained was approxi mately 300 feet per minute. The three levels of speed were, therefore, chosen at 100, 200 and 300 feet per minute. One-process, two-process and three-process drawings were eoq>loyed in the experiment. The number of doublings in the drawing processes were 8, 16 and 24, respectively. 11
CHAPTER II
INSTRUMENTATION AND EQUIPMENT
Raw Materials Used
The raw materials used included American Upland cotton and poly
ester fiber.
The cotton was Good Middling grade, one-and-one-quarter inches
staple length. The data on fiber fineness, strength and length are
shown in Tables 24, 25 and 26 in the Appendix.
The polyester fiber was Dacron Type 54, one-and-one-half inches staple length, and one-and-one-half denier.
Processing Equipment
The following processing equipment was used in these experiments:
1. Cotton opening line including Saco-Lowell Hopper
Feeder 1925, Superior Cleaner 1948, Saco-Lowell
Opener 1940, and Condenser.
2. Saco-Lowell One-Process Picker and Picker Hopper, 1918.
3. Whitin One-Process Picker, Model T, 1949, with Automatic
Picker Feed and Blending Hopper, Model K-6, 1949.
4. H & B Revolving Flat Card, Flexible Wire Clothing.
5. Saco-Lowell Roller Top Card, Model 1, 1948.
6. Saco-Lowell Drawing Frame, Model DS-4, 1957.
7. Reeves Variable Transmission, Size 1, Class F,
No. 44oqQ. 12
a. Saco-Lowell 10-1/2" Lap Winder, Model 37, 1948.
9. Saco-Lowell Comber, Model 57, 1959.
10. Whitin 10 x 5 Woonsocket Roving Frame, Casablancas
Drafting System, 1939.
11. Saco-Lowell SS-2 Spinning Frame, Shaw Drafting System,
1948.
Testing Equipment
The following testing equipment was used in this work.
1. Saco-Lowell Lap Meter, Model 4, 1951.
2. Shadowgraph, Model 4104-A.
3. Sheffield Micronaire, Model D 80400.
4. Spinlab Servo-Fibrograph, Model 163.
5. Spinlab Fibrosampler, Model 192.
6. Pressley Fiber Strength Tester, No. 1127.
7. Uster Evenness Tester, Type GGP-B20.
8. Uster Evenness Recorder.
9. Uster Quadratic Integrator, Type ITG-Q7.
10. Uster Spectrograph, Type SPG-9.
11. Uster Spectrogram Recorder.
12. Uster Imperfection Indicator, Type IPI-3.
13. Uster Automatic Yarn Strength Tester With Automatic
Bobbin Attachment.
14. Microscope, American Optical Cotr?>any, lOX & 43X. 13
CHAPTER m
PROCEDURE
Processing Blended Yarn
The flow chart in Figure 1 shows the sequence of operations for producing the blend of Dacron polyester staple and combed cotton. Dacron
and cotton silvers were prepared separately from the raw stocks and blended at the drawing frame, where the number of processes and speed were varied to make nine lots of blended silver. These silvers were then processed Into yarn through roving and spinning operations. All processes were carried out at a temperature of 80^ F. and a relative humidity of 50 per cent. The Identification of processes and organiza tion of weights and drafts are shewn In Tables la and lb.
To prepare the cotton silver, four picker laps of 35 pounds each were made from raw cotton by conventional opening and picking processes.
Tests were made on the Saco-Lowell Lap Meter for yard to yard weight and uniformity of the laps. The data showed that the average weight was 13.5 ounces per yard and coefficient of variation was 1.68 percent
(Table 27). The results Indicated that the laps were fairly uniform.
In the carding process, the laps were run through an H & B flat top carding machine to make 16 cans of 55-graln card silver. The machine was operated at low speed (doffer speed six revolutions per minute) to assure the good quality of silver. 14
Cotton Dacron
Opening
Picking Picking
Carding Carding
Breaker Pre- Drawing Drawing
Lap Winder
Conibing
Pi P2 P3 1st Drawing Ist Drawing Ist Drawing Si S2 S3 Si S2 S3 Si S2 S3
' ' ' 1 2nd Drawing 2nd Drawing
' 1 1 3rd Drawing
1 ' 1 •' _; 1 1 1 ' RovjLn g
i J ' 1 1 ' 1 \ '1 Spinning
Figure 1. Sequepce o£ Operations for Producing Blend of Dacron/Combed Cotton 15
Table la. Identification of Processes
Lot Drawing Front Roll Speed NuiEber Process of Drawing Frame
PiPSI One-Process Drawing 100 Feet per Minute P1S2 One-Process Drawing 200 Feet per Minute
P1S3 One-Process Drawing 300 Feet per Minute
Vi Two-Process Drawing 100 Feet per Minute P2S2 Two-Process Drawing 200 Feet per Minute
P2S3 Two-Process Drawing 300 Feet per Minute
P3S1 Three-Process Drawing 100 Feet per Minute
P3S2 Three-Process Drawing 200 Feet per Minute
P3S3 Three-Process Drawing 300 Feet per Minute 16
Table lb. Organization of Weights and Drafts
Weight of Weight of Number Material Material of Actual Fed Delivered Doublings Draft
Picker (Cotton) 13.4 ozs/yd
Picker (Dacron) 13.0 ozs/yd
Carding (Cotton) 13.4 ozs/yd 55.0 grs/yd 1 107
Carding (Dacron) 13.0 ozs/yd 57.5 grs/yd 1 99
Breaker Drawing (Cotton) 55.0 grs/yd 47.0 grs/yd 8 9.37
Lap Winder 47.0 grs/yd 904 grs/yd 20 1.04
Comber 904 grs/yd 50.0 grs/yd 6 109
Predrawlng (Dacron) 57.5 grs/yd 56.0 grs/yd 8 8.21
1 Drawing (Blend): Pi (Ist Process) / 50.0 grs/yd ^ Cotton,3 Ends 1 \ / 56.0 grs/yd 50.0 grs/yd 8 8.6 ^ Dacron,5 Ends
P2 (2nd Process) 50.0 grs/yd 50.0 grs/yd 8 8.0
P3 (3rd Process) 50.0 grs/yd 50.0 grs/yd 8 8.0
Roving 50.0 grs/yd 1.5 Hank 1 8.98
Spinning 1.5 Hank 30's 1 20 17
The 16 cans of card silver were divided into two groups, each group
consisted of two cans produced from each lap. Two groups of sliver were
then processed on the drawing frame, using same delivery, to make 47-grain
drawing sliver. This was the breaker drawing process.
At the lap winder, 20 ends of drawing sliver were fed and 12 laps
of 55 yards each were made. The laps were randomly divided into two groups and processed on the comber. The percentage of noil was found to be 19.4 which indicated that a large amount of short fiber was being removed during
the combing operation. Six cans of 50-grain combed sliver were produced, ready for blending with Dacron.
To prepare the Dacron sliver, the raw stock was processed on a
synthetic fiber picker. Four picker laps were made and the tests made on
Saco-Lowell Lap Meter showed that the average weight approximated 13 ounces per yard. The coefficient of variation was 2.26 per cent (Table
28) which implied that the laps were not uniform.
These laps, about 25 pounds each, were processed on the roller top card and, in order to reduce the variation from the laps, the sliver weight was often checked and draft gear was changed accordingly when necessary. The mean weight of sliver was 57.5 grains per yard.
After carding, the sliver was processed on a drawing frame for a predrawing treatment. This was done to parallelize and orient the Dacron
fibers similar to the cotton fibers in the combed sliver. As a result, the tension variation between the Dacron and cotton slivers was mini mized on Che subsequent blend drawing. In addition, the predrawing would lixq>rove the uniformity of the card sliver. A total of 20 cans of 56-graln sliver were prepared for blendlne with cotton. 18
To obtain an accurate and reliable result, at least one replica- tion o£ entire experiment vas necessary. It vas, therefore, decided to repeat the whole experiment £rom blend drawing through spinning.
The combed cotton sliver and carded Dacron sliver, prepared for blending, were randomly divided into two groups. After the first group of slivers had been blended and processed into yarn, the same procedure was followed in processing the second group of slivers.
To blend the slivers at the drawing frame, three ends of cotton sliver and five ends of Dacron sliver were fed to make a 33 per cent cotton and 65 per cent Dacron blend. The slivers were arranged as fol lows: Dacron, cotton, Dacron, cotton, Dacron, cotton, Dacron, Dacron.
Nine lots of blended sliver were produced from the drawing operations by using three different numbers of processes and three different levels of front roll speed. The three different processes used were one- process, two-process and three-process drawings. Three levels of front roll speeds were 100 feet per minute, 200 feet per minute, and 300 feet per minute which was the maximum speed attainable. Three different speeds were obtained by manipulating the Reeves Variable Speed Trans mission which drove the drawing frame. The nine lots of blends were produced in random order, each lot was made up of five half-full cans.
There were 15 spindles available on the front row of the roving frame. A total of 45 cans of blended sliver were randomized and 15 cans at a time were assigned to the spindles. One 1.5 hank roving was made from each can so there were 45 rovlngs produced in three operations.
Five rovlngs were obtained for each lot. 19
On the spinning frame, there vere 24 spindles available. It was de
elded to use 23 spindles in the first operation and 22 spindles in the
second. All 45 rovlngs were randomized and processed into yarn in two
spinning operations. Two bobbins of yarn were produced from each roving
so the total production was 90 bobbins, 10 bobbins per lot. Single creel
ing was used in the spinning to eliminate the effect of doubling at this
stage on the final result of experiment.
Physical Tests
All of the tests were conducted under the standard atmospheric con
ditions of 70° F. temperature and 65 per cent relative humidity. The
samples were conditioned for at least three days before being tested.
Tests for Uniformity
Prior to blending, the cotton slivers resulting from carding, breaker drawing, and combing processes, and the Dacron slivers produced
from carding and predrawlng processes, were tested for their uniformi ties on the Uster Tester. Four test specimens, of 100 yards each, were
sampled at equal Intervals to represent the quality of the product.
After the Dacron and cotton slivers were blended, a 100-yard speci men of blended sliver was withdrawn from each can. There were five speci mens from each lot to be tested. One test was made from each of the five rovlngs in a lot. One bobbin of yarn produced from each roving was chosen and one test was made from each bobbin. A total of five tests were made for each lot of roving and yarn. Four readings were taken from each of the five tests. / 20
The Uster Tester included an evenness tester, evenness t-ecorder, quadratic integrator, spectrograph, spectrogram recorder/and imperfection indicator. All tests were carried out in accordance with the procedures described in the instruction book by the Uster Corporation. The operating data for the tests are shown in Table 22.
The tester was properly calibrated and the initial reading was taken one and one-half minutes after starting the test, and thereafter at 30- second intervals. A total of 20 readings was taken for each lot of sam ples. The result obtained from this integrator was the deviation of the product diameter from the average, expressed as per cent coefficient of variation. In conjunction with the evenness test, the yarn was also tested with the spectrograph and imperfection indicator for a period of five minutes. The spectrograph recorded the wave length for waves or irregularities that repeated in the material. The imperfection indicator registered an actual count of the neps, low places, and thick places in the yarn.
Tests for Breaking Strength and Elongation of Yarn
The Uster Automatic Yarn Strength Tester was used to test the breaking strength as well as the elongation of the yarn. This tester makes use of the inclined plane principle of loading in which the pull on the specimen under test increases proportionately with time. It can be set to give an automatic pretensioning of the sample before the load is applied. Forty breaks were made from each of the ten bobbins giving 400 breaks per lot of yarn. The operating data for this machine are given in Table 23. 21
The breaking strength and elongation for each individual test were
recorded on an autograph. Two counters, one for breaking strength and
one for elongation, recorded the cumulative sum of the data. At the com
pletion of the test, these readings were taken from counters to confute
the total, and average, strength and elongation for each lot of yarn.
The frequency distribution of the breaking strength was also ob
tained from the machine. At the end of each individual test a small ball was fed into the proper vertical slot in a plate corresponding to its breaking strength. At the end of a test series, the frequency distribu
tion diagram formed by these balls in their respective slots was trans
ferred to a ruled chart as a permanent record.
Examinations of Fiber Distribution
It has been generally recognized that the blending of dissimilar
fibers in spun yarns may lead, not to a uniform distribution of these
fibers throughout the yarn cross section, but to one in which particular fiber components congregate either towards the surface or to the core of the yarn. This Is a direct result of fiber migration effects at cer tain process stages during yarn manufacture. As previously pointed out in the Chapter I, these effects depend on the fiber length, denier, and other properties.
Microscopic techniques were used in this study to examine the distribution of cotton and Dacron fibers throughout the yarn cross sec tion. For purposes of identification, the test yarns were dyed with direct dye (3 per cent Direct Blue 1 CI-24410). The cotton was dyed to blue color, the Dacron remained white, so that they could be easily 22
distinguished under the microscope. For each lot of yarn, ten specimens,
« each about four inches long, were sampled randomly and embedded in paraf fin wax. The sections were cut from the embedded sauries by using Schwarz microtome.
The method used in this microscopical examination was developed by
Hamilton (14). The fiber distribution was measured and represented by a single numerical parameter, termed the Migration Index. This migration index was based on zoned fiber counts taken from yarn cross-section and expressed the actual migration of the component fiber in terms of the maximum possible which could have occurred in the given yarn. Thus, a migration index of + 100 per cent represented complete separation of the component in question from the other fibers. The positive and negative signs denote outward and inward migration, respectively. A migration index of zero might be taken to represent uniform distribution of the component throughout the yarn cross-section. In the case of this two-component blend, the migration indexes of both components were equal in value but opposite in sign.
To examine the fiber distribution, the cross-section of yarn was mounted on slide and placed under the microscope. A micrometer carrying a fine ruled scale was placed on the diaphragm in the eyepiece. By slowly rotating the eyepiece, the divisions on the scale divided the image of yarn cross-section into five concentric zones with equal incre ments in radius. Numbers of cotton fibers and Dacron fibers in each zone were counted and recorded. Ten specimens from each lot of yarn were examined and grand totals of zoned fiber counts on the ten yarn cross- sections were used to compute the migration index of the yarn. 23
Analyses of Data
For each lot of sliver, roving and yarn, the average per cent co efficient of variation was computed from the data taken during the even ness test. The frequency distribution diagrams and autographs obtained
from the yarn breaking strength test were analyzed and the average breaking strength, average per cent elongation and their per cent coefficients of variation were computed for each lot of yarn. The migration index for each lot of yarn was also calculated by using the method developed by
Hamilton (14).
A con^lete analysis of variance was performed on all the data relating to the evenness, breaking strength, elongation, nep count and fiber migration of the products. The sources of variation included nun^er of drawing processes (P), speed of drawing (S), their interaction
(PxS) and replication (R). Since the speed of drawing (S) was a quantita tive factor and its three levels were at equal intervals, a further analysis was made to determine the effects of its linear and quadratic coQ^onents. The interactions of linear S and quadratic S with process
(P) were also determined. If the effect of process (P) was found to be significant at ten, five or one per cent levels, the Tukey method (13) was used to determine the significance of the differences among the three processes. 24
CHAPTER IV
DISCUSSION OF RESULTS
The results o£ evenness tests for the cotton and Dacron slivers
produced at each stage prior to the blend drawing (Table 29) showed
that the silvers were average even as compared to the Uster standard values for evenness.
Table 2a gives the analysis of variance for blended drawing
sliver. It was found that the drawing process (P) was main source of variation. The variance ratio of 162.92 indicated that the effect of
the drawing process (P) on the sliver evenness was significant at the
1 per cent level. The effect of the quadratic component of the drawing
speed was also found to be significant, but only at the 10 per cent
level.
In Table 2b, the Tukey test was made for the significance of dif
ferences between the drawing processes. The results showed that none of the confidence Intervals of differences between two process means
Included zero; they were all greater than zero. Therefore, the differ ences between processes were all significant at the 5 per cent level.
In Figure 2, it can be seen clearly that the per cent coefficient of variation for one-process drawing (Pj^) was much higher than that for two-process drawing (P2) and three-process drawing (P3). The mean per cent coefficients of variation, as shown in Table 2b, were 3.38 for P]^,
2.47 for ?2 and 2.26 for P3. The uniformity of drawing sliver was 25
Table 2a. Analysis of Variance for Drawing Sliver Evenness (Per Cent C. V.)
Sum Degrees Probability Points of Source of of Mean Variance Variance Ratio of Variation Squares Freedom Square Ratio 10% 5% 1%
4.235 2.118 162.92 3.ir 4.46 8.65 Linear S 0.001 1 0.001 0.07 3.46 5.32 11.3 Quadratic S 0.051 1 0.051 3.92 3.46* 5.32 11.3 Total S 0.052 2 0.026 2.00 3.11 4.46 8.65
P withj Linear S 0.064 2 0.032 2.46 3.11 4.46 8.65 Quadratic S 0.042 2 0.021 1.62 3.11 4.46 8.65 Total P X S 0.106 4 0.027 2.08 2.81 3.84 7.01
Replication 0.038 1 0.038 2.92 3.46 5.32 11.3
Remainder 0.104 _8 0.013
Total 4.535 17
* Indicating the effect is significant.
Table 2b. Tukey Test for Significance of Drawing Sliver Evenness Differences Between Drawing Processes
Drawing Mean Confidence Interval of Difference Process Difference (5% Level) Between Means
3.38 Pi - ?2 0-91 ± 0-05 > 0 Significant
2.47 P2 - P3 0.21 + 0.05 > 0 Significant
2.26 Pi - Po 1.12 + 0.05 > 0 Significant
Average 2.70 26
A = P. X = P3
• = P, fl = Average
4.00-
3.50-
o 3.00- •Cu
« 2.50- C9 V C > M
2.00- CO
1.50-
100 200 300 Drawing Speed (Feet/Minutes)
Figure 2, The Effects of Drawing Process and Drawing Speed on the Evenness of Drawing Sliver 11
improv.ed by each additional drawing process. The curve of average value
in Figure 2 indicated that the slivers produced at the drawing speeds of
100 feet per minute (S,) and 300 feet per minute (S3) had essentially the
same per cent coefficient of variation. The per cent coefficient of vari
ation was slightly lower in the sliver produced at 200 feet per minute
(S2).
The analysis of variance for roving evenness is given in Table 3a.
The indication was that the drawing process (P) and linear coiiq>onent of
drawing speed (S) were the major sources of variation. The effect of^the
drawing process (P) was significant at the 1 per cent level. The linear
component of the drawing speed (S) had a variance ratio of 5.53 and was
significant at the 5 per cent level.
The Tukey test given in Table 3b reveals that the differences between drawing processes were all significant at 5 per cent level. The mean per cent coefficients of variation were 5.84 for one-process drawing
(Pj^), 5.29 for two-process drawing (P2) and 5.12 for three-process drawing
(P3). These differences can also be seen in Figure 3.
Figure 3 also reveals that the increase in the drawing speed (S) resulted in a higher per cent coefficient of variation for roving even ness. However, as pointed out previously, only the linear component of the effect of drawing speed (S) was significant.
The analysis of variance for yarn evenness is given in Table 4a.
It was found that the drawing process (P) was the only source of varia
tion, and was significant at the 1 per cent level. The Tukey test given in Table 4b shows that the difference between one-process drawing (P^^) 28
Table 3a. Analysis of Variance for Roving Evenness (Per Cent C.V.)
Sum Degrees Probability Points of Source of of Mean Variance Variance Ratio of Variation Squares Freedom Square Ratio 10% 5% 1%
1.694 0.847 56.47 3.01 4.26 8.02
Linear S 0.083 1 0.083 5.53 3.36 5.12'" 10.6 Quadratic S 0.007 1 0.007 0.47 3.36 5.12 10.6 Total S 0.090 2 0.045 3.00 3.01 4.26 8.02
P with: Linear S 0.024 2 0.012 0.80 3.01 4.26 8.02 Quadratic S 0.021 2 0.011 0.73 3.01 4.26 8.02 Total P X S 0.045 4 0.023 1.53 2.69 3.63 6.42
Replication 0.001 1 0.001 0.015 ) Remainder 0.136 _8 Total 1.966 17
* Indicating the effect is significant.
Table 3b. Tukey Test for Significance of Roving Evenness Differences Between Drawing Processes
Drawing Mean Confidence Interval of Difference Process (% C.V.) Difference (5% Level) Between Means
5.84 Significant ^1 ?l - ?2 0.55 + 0.06 > 0 P2 5.29 P2 - P3 0.17 + 0.06 > 0 Significant
P3 5.12 ?^ - P3 0.72 + 0.06 > 0 Significant Average 5.42 29
6.50-1 *^ = Pi X = P.
• » Average
6.00-
5.50-
a « o ou 5.00- (0 «CO a c «
00 4.50- c •H > o PH
4.00—
S3 «j 100 200 300
Drawing Speed (Feet/Minute)
Figure 3. The Effects of Drawing Process and Drawing Speed on Roving Evenness 30
and thxee-process drawing (P-,), and the difference between one-process
drawing (Pj^) and two-process drawing (P2) were still significant at the
5 per cent level.
The most Inqportant source of variation, which had significant effects on the evennesses of sliver, roving and yarn, appeared to be the
drawing process (P). The drawing speed (S) had some significant effects but only at drawing and roving stages. It was found that the variance ratios of both drawing process (P) and drawing speed (S) were continually
decreasing from drawing stage to yarn stage. This indicated that the ef fects of the drawing process (P) and the drawing speed (S) became less significant at the latter stage of processing.
The effect of the drawing process (P) on the evenness of sliver, roving or yarn was that the per cent coefficient of variation decreased as the number of drawing processes was increased. The increase in the nuniber of doublings by each additional drawing process improved the uniformity of the sliver produced.
Th« summary of the per cent coefficient of variation for sliver, roving and yarn is given In Table 5.
Table 6a gives the analysis of variance for yam breaking strength.
The drawing process (P) was found to be significant at the 3 per cent level. The Tukey test given in Table 6b reveals that only the difference between one-process drawing (P.) and three-process drawing (P^) was sig nificant at the 5 per cent level.
It was found that the yarn produced with three-process drawing
(P3) gave the highest breakiipg strength of 285.71 grams. The breaking 31
Table 4a. Analysis of Variance for Yarn Evenness (Per Cent C.V.)
Sum Degrees Probability Points of Source of of Mean Variance Variance Ratio of Variation Squares Freedom Square Ratio 10% 5% 1% 8.386 4.193 25.11 3.01* 4.26* 8.02*
Linear S 0.270 1 0.270 1.62 3.36 5.12 10,6 Quadratic S 0.002 1 0.002 0.01 3.36 5.12 10.6 Total S 0.272 2 0 136 0 81 3 01 4.26 8.02
P with: Linear S 0.357 2 0.179 1.07 3.01 4.26 8.02 Quadratic S 0.638 2 0.319 1.91 3.01 4.26 8.02 Total P X S 0.995 4 0.249 1.49 2.69 3.63 6.42
Replication 0.001 0.001 0.167 Remainder 1.506 ;)
Total 11.160 17
* Indicating the effect is significant.
Table 4b. Tukey Test for Significance of Yarn Evenness Differences Between Drawing Processes
Drawing Mean Confidence Interval of Difference Process q C.V.) Difference (5X Level) Between Means
19.60 1.14 + 0.61 > 0 Significant
18.46 P2 - P3 0.50 + 0.61 Include 0 Not Significant
17.96 Pj^ - P3 1.64 + 0.61 > 0 Significant
Average 18.67 32
X = P3
20.0— • = Average
19.0-
•6u 9 O «U P4 18.0—
tno «
> M 17.0- M 0) JH
100 200 300 Drawing Speed (Feet/Minute)
Figure 4. The Effects of Drawing Process and Drawing Speed on Yarn Evenness 33
Table 5, Sunmary of Per Cent Coefficient of Variation for Product Evenness
Drawing Spe:e d Drawing Process Si S2 S3 Average
Drawing Sliver:
Pi 3.56 3.21 3.37 3.38
^2 2.42 2.44 2.55 2.47
^3 2.21 2.24 2.33 2.26 "k Average 2.73 2.63 2.75 2.70
Roving:
P, 5.74 5.78 6.01 5.84
5.23 5.24 5.42 5.29
5.08 5.16 5.13 5.12
Average 5.35 5.39 5.52 5.42
Yam:
P, 19.72 19.26 19.82 19.60
18.42 18.55 18.43 18.46
17.42 18.27 18.21 17.96
Average 18.52 18.69 18.82 18.67*
* Over-all average. 34
strength of one-process drawing (P,) and two-process drawing (P2) were
273.99 grams and 281.21 grams, respectively.
The analysis of variance for yarn elongation (Table 7) shows that the drawing speed (S) becomes the main source of variation. The quadxjapic coiiq>onent of drawing speed (S) was significant at the 5 per cent level.
Since the effect of drawing process (P) on yarn elongation was not significant, no Tukey test was performed here.
Figure 5 reveals that the drawing speed of 200 feet per minute (Sj) seemed to yield the strongest yarn with the highest per cent elongation while the drawing speed of 300 feet per minute (S^) gave the weakest yarn and the lowest per cent elongation.
A sunraary of yarn breaking strength test is given in Table 8. It may be pointed out here that, from the analyses of frequency distribution diagrams for yarn breaking strength, three-process drawing (P^) also had the lowest per cent coefficient of variation for the breaking strength.
The mean per cent coefficient of variation decreased from 16.45 to 14.92 as the nund^er of drawing processes increased from one to three.
The analysis of variance for yarn nep content is given in Table
9a. The drawing process (P) appeared to be the main source of variation but was significant only at 10 per cent level. The average numbers of neps per 2,500 yards yarn were 42.33 for one-process drawing (P^), 14.50 for two-process drawing (P2) and 26.17 for three-process drawing (P3).
Only the difference between one-process drawing (P.) and two-process drawing (P2) was found to be significant at the 5 per cent level as 35
Table 6a. Analysis of Variance for Yarn Breaking Strength (Grains)
Degrees Probab ility Po ints of Source Sum of of Mean Variance Variance Ratio of Variation Squares Freedom Square Ratio 10% 5% 1%
P 419.880 2 209.94 7.12 3.11* 4.46* 8.^5
Linear S 51.830 1 51.83 1.76 3.46 5.32 11.3 Quadratic S 50.790 1 50.79 1.78 3.46 5.32 11.3 Total S 102,620 2 51.31 1.74 3.11 4.46 8.65
P with: Linear S 4.790 2 2.40 0.08 3.11 4.46 8.65 Quadratic S 25.370 2 12.69 0.43 3.11 4.46 8.65 Total S 30.160 4 7.54 0.26 2.81 3.84 7.01
Replication 46.561 1 46.56 1.58 3.46 5.32 11.3
Remainder 235.908 _8 29.49
Total 835.129 17
* Indicating the effect is significant.
Table 6b. Tukey Test for Significance of Yarn Strength Differences Between Drawing Processes
Drawing Confidence Interval of Difference Process Mean (Grams) Difference (5% Level) Between Means 273.99 ^1 ' ^2 7.22+8.15 Include 0 Not Significant
^2 281.21 P2 - P3 4.50 + 8.15 Include 0 Not Significant P3 285.71 Pj^ - P3 11.72 + 8.15 > 0 Significant Average 280.30 36
Table 7. Analysis of Variance for Yarn Elongation (Per Cent)
Sum Degrees Probability Points Source of of Mean Variance of Variance Ratio of Variation Squares Freedom Square Ratio 10% 5% 1%
P 0.403 2 0.202 2.46 3.01 4.26 8.02
Linear S 0.168 1 0.168 2.05 3.36 5.12 10.6 Quadratic S 0.449 1 0.449 5.48 3.36* 5.12* 10.6 Total S 0.617 2 0.309 3.77 3.01* 4.26 8.02
P With: Linear S 0.094 2 0.047 0.57 3.01 4.26 8.02 Quadratic S 0.222 2 0.111 1.35 3.01 4.26 8.02 Total P X S 0.316 4 0.079 0.96 2.69 3.63 6.42
Replication 0.049 0.049 '} 0.082 Remainder 0.690 -1 ^ Total 2.075 17
* Indicating the effect is significant.
shown in the Tukey test (Table 9b) . A summary of nep content is given in Table 11.
Table 10a shovs the analysis of variance for fiber migration in dex. The indication was that the drawing process (P) and the linear component of drawing speed (S) were the major sources of variation.
However, their effects were significant only at the 10 per cent level.
The Tukey test given in Table 10b Indicated that there was no significant difference between the drawing processes. The average migration indexes were 10.65 per cent for three-process drawing (P3), 13.19 per cent for two-process drawing (P2) and'15.73 per cent for one-process drawing 37
Breaking Strength = Pi X = P- Elongation = Po • = Average
290-
285-
280-
275-
icj M « o 270- o u « 00 (U S 265- 6 u o T-l u « CO 00 to 6 •H -16.0 (d o (0 t-t u c Vi c S JH -15.5
15.0
100 200 300 Drawing Speed (Feet/Minutes)
Figure 5. The Effects of Drawing Process and Drawing Speed on Yam Breaking Strength and Elongation 38
•Jc * tr, r-t CM vO 1-1 ON vO 00 CO 00 rH in o \o
00 CM 00 CM r>. r^ CM 00 -d- r^ vO 00 r^ CO 00 vO \o o 00 rH rH CO vO vO CM o CM m CJ> > 00 m «n «* CM «n m •4- vo ox in vO > 00 m vO 00 r*» r^ o in in a\ CM CM CM CM in CM CM CM CM CO o o r^ r>- 00 iH r^ o\ r-l in r^ i-» '^r >* g CO CO vO rH in m 00 00 00 rmH* iH iH fmH CM CM CM CM 9 00 CO U ^-N > 4J « C « rH o tH u 1 PLo4 9u s^ 00 00 CM CO fit c rH CM CO (« fU fu u tu 04 tu •oH 9u * 4J 69 > 5 00 < a o » 39 Table 9a. Analysis of Variance for Yarn Nep Count (Number of Neps per 2,500 Yards) Degrees Probability Points of Source Sum of of Mean Variance Variance Ratio of Variation Squares Freedom Square Ratio 10% 5% 1% •k P 2344.333 2 1172.167 3.55 3.01 4.26 8.02 Linear S 602.083 1 602.083 1.82 3.36 5.12 10.6 Quadratic S 20.250 1 20.250 0.06 3.36 5.12 10.6 Total S 622.333 2 311.167 0.94 3.01 4.26 8.02 P with: Linear S 236.170 2 118.090 0.36 3.01 4.26 8.02 Quadratic S 17.164 2 8.580 0.03 3.01 4.26 8.02 Total S 253.334 4 63.334 0.19 2.69 3.63 6.42 Replication 200.000 200.000 330.000 Remainder 2770.000 i) Total 6190.000 17 * Indicating the effect is significant. Table 9b. Tukey Test for Significance of Yarn Nep Count Differences Between Drawing Processes Draving Confidence Interval of Difference Process Mean Difference (5% Level) Between Means 42.33 - ?2 27.83 + 27.16 > 0 Significant ^2 14.50 - P3 11.67 + 27.16 Include 0 Not Significant 26.17 - P3 16.16 + 27.16 Include 0 Not Significant ^3 Average 27.67 40 (Pj^). This result revealed the fact that the fiber distribution in the * blended yarn became more uniform as the number of drawing processes vas increased. The increase in drawing speed (S) would tend to cause a highjiar migration index. This was indicated by an upward trend in Figure 6. A summary of migration index is given in Table 12. Since in two-component blended yarn, the migration indexes of both components are equal in value and opposite in sign, only the data of one conq>onent were presented in Tables 10a, 10b and 12. The testing results showed that the migration index for cotton was positive while for Dacron was negative. This implied that the cotton fibers had a tendency to migrate towards the surface of the blended yarn while the Dacron fibers migrated towards the axis of the blended yarn. 41 Table 10a. Analysis of Variance for Fiber Migration Index (Per Cent) Degrees Probability Points of Source Sum of of Mean Variance Variance Ratio of Variation Squares Freedom Square Ratio 10% 5% 1% P 79.595 2 39.798 3.39 3.01 4.26 8.02 Linear S 59.586 1 59.586 5.07 3.36* 5.12 10.6 Quadratic S 4.000 1 4.000 0.34 3.36 5.12 10.6 Total S 63.586 2 31.793 2.71 3.01 4.26 8.02 P with: Linear S 26.903 2 13.452 1.15 3.01 4.26 8.02 Quadratic S 1.506 2 0.753 0.06 3.01 4.26 8.02 Total S 28.409 4 7.102 0.61 2.69 3.63 6.42 Replication 1.663 1.663 11.746 Remainder 104.055 ;» Total 277.308 17 * Indicating the effect is significant. Table 10b, Tukey Test for Significance of Fiber Migration Index Differences Between Drawing Processes Drawing Confidence Interval of Difference Process Mean Difference (5% Level) Between Means Pi 15.73 Pi - ?2 1.82 + 5.14 Include 0 Not Significant P2 13.91 P2 - P3 3.26+5.14 Include 0 Not Significant P3 10.65 Pj^ - P3 5.08 + 5.14 Include 0 Not Significant Average 13.43 42 Table 11. Summary of Yarn Nep Count Test (Number of Neps per 2,500 Yards) Dralvlng Drawing Spe ed Process Si S2 S3 Average 30.0 40.5 56.5 ''i 42.33 13.0 11.5 19.0 ^1 14.50 31.0 P3 21.0 26.5 26.17 Average 21.3 26.2 25.5 ic * Over--all average. Table 12. Summary of the Migration Index of Cotton Component* Drawing Drawing Speed Process Si S2 S3 Average pi 12.49 14.49 20.22 15.73 I"2 11.53 13.52 16.68 13.91 P3 10.59 10.28 11.08 10.65 Average 11.53 12.76 15.99 13.43** * The migration index of Dacron component is equal in value but opposite in sign to the migration index of cotton conq)onent. ** Over-all average. 43 = Pi X = P. 25.0- = Average 20.0- 4J (3 0) o u 9 (U 15.0- X 4) •0O § •H •U 4 10.0- M 60 100 200 300 Drawing Speed (Feet/Minute) Figure 6. The Effects of Drawing Process and Drawing Speed on Fiber Migration Index 44 CHAPTER V CONCLUSIONS From the statistical analysis and interpretation of the data obtained from this experiment, the following conclusions have been reached: 1. The drawing process (P) had a highly significant effect, in the statistical sense, on the evenness of the blended sliver. The sliver became more uniform as the number of drawing processes in creased. Differences between drawing processes covered were signifi cant at the 5 per cent level. Drawing speed (S) had little effect on the sliver evenness, only its quadratic coo^onent was found to be significant at the 10 per cent level. 2. At the roving stage, the effect of the drawing process (P) on roving evenness was highly significant. The differences between drawing processes were also significant. The effect of the linear com ponent of drawing speed (S) was found to be significant at the 5 per cent level. The roving was more uniform when processed at slower drawing speeds. 3. The drawing process (P) was the only source of variation which significantly affected the yarn evenness. The differences between drawing processes were still significant at the 5 per cent level with the exception of the difference between two-process drawing (P2) and three-process drawing (P3) which was not significant at the yarn stage. 45 4. The effect of either drawing process (P) or drawing speed (S) 4 on the product evenness became less significant as the manufacturing operation was prqgressing from drawing through spinning. An increase in the number of drawing processes improved the evenness of the sliver, roving and yarn. 5. Only the drawing process (P) was found to have a significant effect at 5 per cent level on the breaking strength of yarn. The major source of variation which affected the yarn elongation was the quadratic component of the drawing speed (significant at the 5 per cent level). 6. The breaking strength and per cent elongation of the yarn increased with each additional drawing process. The differences in yarn strength between the drawing processes were not significant except for the difference between one-process drawing (P^^) and three-process drawing (P^). Also there was no significant difference in yarn elonga tion between the drawing processes. 7. The drawing speed of 200 feet per minute (S2) was found to have produced the strongest yarn and the highest per cent elongation. 8. The drawing process (P) was the main source of variation which affected the nep content of the yarn. However, it was signifi cant at the 10 per cent level only. The difference in nep content be tween one-process drawing (Pj^) and two-process drawing (P^) was significant at the 5 per cent level. 9. The drawing process (P) and the linear coiiq)onent of the drawing speed had only a slight effect on the migration index of the fibers in the blended yarn. They were significant at the 10 per cent level. 46 10. The migration index of the fibers decreased as the number of drawing processes increased. Three-process drawing (P-) produced yarn with the most uniform distribution of fibers. Also, the yarn produced at slo^wer drawing speed showed more uniform distribution in the cross section examined. 11. In this 35/65 cotton and Dacron blended yarn, the cotton fibers were found to have outward migratory tendencies while the Dacron fibers had inward migratory tendencies. 12. The replication of experiment (R) and the interaction of drawing process with drawing speed (P x S) had no significant effect on the product properties which had been investigated. 47 CHAPTER VI RECOMMENDATIONS It is recommended that similar studies be made using various com binations and different types of fibers in blends. The blending should be done on various types of drawing frames and cover a wider range of drawing speeds. The sample size for microscopic examination should be larger than 50 in order to represent the true picture of the fiber distribution in the blended yarn. 48 APPENDIX 49 Table 13. Operating Data for H & B Revolving Flat Card Diameter Type Clothing R.P.M. Cylinder 50" Flexible Wire 160 Doffer 27" Flexible Wire 6 Lickerin 9" Metallic 440 Draft Constant 1672 Production Constant (Pounds per Hour) 0.0065 Draft Change Gear 17 T Production Change Gear 22 T 50 Table 14. Settings for H 6e B Revolving Flat Card Point of Setting Distance in 0.001" .... • I ' '•' • •• 11 ... I i I -1, •• .1 I. I. II > . 1,1 Feed Plate to Lickerin 12 Lickerin to Cylinder 7 Lickerin Screen (Blank Part) 29 Lickerin Screen (Bars) 12 Lickerin Screen (Nose) 187.5 Mote Knives from Lickerin (Bottom) 17 Mote Knives from Lickerin (Top) 22 Angle of Mote Knife to Lickerin 18° Doffer to Cylinder 7 Comb to Doffer 22 Cylinder Screen to Cylinder (Front) 187.5 Cylinder Screen to Cylinder (Middle) 58 Cylinder Screen to Cylinder (Back) 29 Lower Edge Back Plate 29 Upper Edge Back Plate 29 Flat to Cylinder (Back) 10 Flat to Cylinder (Intermediate) 10 Flat to Cylinder (Front) 10 Upper Edge of Front Knife Plate 22 Lower Edge of Front Knife Plate 29 Flat Stripping Comb 15 51 Table 15. Operating Data for Saco- Lowell Roller Top Card Diameter Type Clothing RiP.M. Cylinder 50" Flexible Wire 170 Doffer 27" Flexible Wire 9.5 Lickerin 9" Metallic 210 Worker Roll 7" Metallic 9 Stripper Roll 3.5" Metallic 310 Draft Constant 1581 Draft Change Gear 14 T to 16 T Production Constant (Pounds per Hour) 0.0104 Production Change Gear 22 T 52 Table 16. Settings for Saco-Lowell Roller Top Card Point of Setting Distance in 0.001' Feed Plate to Lickerin 12 Lickerin to Cylinder 7 Lickerin Screen (Front of Blank Part) 29 Lickerin Screen (Rear of Blank Part) 12 Mote Knives from Lickerin (Top) 22 Mote Knivds from Lickerin (Bottom) 17 Angle of Mote Knife to Lickerin 18° Doffer to Cylinder 7 Doffer Comb to Doffer 17 Cylinder Screen to Cylinder (Front) 187.5 Cylinder Screen to Cylinder (Middle) 58 Cylinder Screen to Cylinder (Back) 29 Lower Edge Back Plate 29 Upper Edge Back Plate 29 Worker Roll to Cylinder 10 Worker Roll to Stripper Roll 17 Stripper Roll to Cylinder 10 Upper Edge of Front Knife Plate 22 Lower Edge of Front Knife Plate 29 53 Table 17. Operating Data for Saco-Lowell 4 Over 5, DS-4 Drawing Frame Bottom Rolls Top Rolls Diameter Type Diameter Type First' 125" Fluted 1.125" Ctjishion Second 750" Fine Fluted 2.000" Cushion Third 375" Fluted Fourth 375" Fluted 1.500" Cushion Back 1.375" Fluted 1.500" Cushion Cotton Dacron Breaker Pre- Blend Roll Settings: Drawing Drawing Drawing First to Third 2.563" 2.656" 2.656" Second to Third (Fixed) 1.500" 1.500" 1.500" Third to Fourth 1.625" 1.625" 1.625" Fourth to Back 1.875" 1.875" 1.875" Breaker Pre- Bl end Drawing Drawing Drawing p^- li h Back Draft Constant 0.059 0.059 0.059 0.059 0.059 Back Draft Gear 23 21 21 21 21 Back Draft 1.350 1.235 1.235 1.235 1.235 Mid. Draft Constant 90 90 90 90 90 Mid. Draft Gear 52 50 50 50 50 Mid. Draft 1.73 1.8 1.8 1.8 1.8 Front Draft Constant 175 175 175 175 175 Front Draft Gear 44 48 46 49 49 Front Draft 3.98 3.65 3.81 3.57 3.57 Total Roll Draft 9.32 8.11 8.47 7.94 7.94 Tension Gear 73 71 73 72 72 Cotton Dacron Breaker Pre- Blend Drawing Drawing Drawing Si S2 S3 Front Roll Speed (Feet/Minute) 145 100 100 200 300 54 Table 18. Operating Data for 10-1/2" Saco-Lowell Lap Winder Draft 1.04 Number of End Fed 20 Weight of Lap Delivered 904 Grains per Yard Table 19. Operating Data for Saco-Lowell Model 57 Comber Bottom Rolls Top Rolls Diameter Type Diameter Type First 1.25" Fluted 1.438" Cushion 0.75" Fine Fluted Second 2.000" Cushion Third 1.25" Fluted Fourth 1.50" Fluted 1.438" Cushion Back 1.50" Fluted 1.438" Cushion Roll Settings: First to Third 2.688" Second to Third 1.500" Third to Fourth 1.625" Fourth to Back 1.938" Feed Ratchet 15 T Front Roll Change Gear 26 T Front Roll Change Gear Constant 0.23 Noil Percentage 19.4 Drav Box Draft 11.95 Draft Change Gear 52 T 55 Table 20. Operating Data for Whitin Woonsocket Roving Frame (Casablancas Drafting System) Type Diameter Top Rolls: Front Cushion 1.219" Middle Apron 1.000" (Knurled Roll) Back Cushion 1.219" Bottom Rolls: Front Fluted 1.125" Middle Apron 1.000" (Knurled Roll) Back Fluted 1.000" Rloo Settings: Front to Middle 1.906" Middle to Back 2.063" Draft Constant 264 Draft 8.98 Draft Change Gear 29 T Twist Constant 50 Twist Multiplier 0.9 Twist Per Inch 1.27 Hank Size 1.5 Twist Change Gear 39 T Lay Gear 20 T Tension Gear 22 T Spindle Speed 740 RPM Front Roll Speed 170 RPM (50 Ft./Min.) 56 Table 21. Operating Data for Saco-Lowell SS-2 Spinning Frame (Shaw Drafting System) Type Diameter Top Rolls: Front Cushion 1.016" Middle Cushion 1.219" Back Cushion 1.016" Bottom Rolls: Front Fluted 1.000" Middle Apron 1.000" (Knurled Roll) Back Fluted 0.875" Roll Settings: Front to Middle 2.188" Middle to Back 1.750" Draft Constant 655 Actual Draft 20 Mechanical Draft 20.81 Draft Change Gear 32 T Twist Constant 784 Twist Multiplier 4.5 Yarn Number 30's TiiMist per Inch (Actual) 24.7 Tvist per Inch (On Roll) 23.7 T'-*iet Change Gear 33 T Spindle Speed 8600 RPM Frort Roll Speed 120 RPM Traveler No. 4/0 57 Table 22. Operating Data for Uster Evenness Tester Card & Comber Drawing Sliver Sliver Roving Yarn Material Speed (Yards/Minute) 8 8 100 loo Recorder Chart Speed (Inches/Minute) 4 4 10 10 Measuring Slot Number 3 3 5 7 Sensitivity Range 12.57. 12.5 % 257, 100% Number of Readings per Test 5 5 4 4 Number of Readings per Lot of Sample 20 20 20 20 Interval Between Readings (Seconds) 30 30 30 30 Spectrograph Evaluating Time (Minutes) 5 AiEplification 17-19 Iaq>erfection Indicator Evaluati2:ig Time (Minutes) 5 Sensitivity Position: Low Place 50% Thick Place #2 Neps #2 58 Table 23. Operating Data for Uster Automatic Yarn Strength Tester Bobbin Attachment; Number of Bobbins in Creel 10 Number of Breaks per Bobbin 40 Number of Breaks per Lot of Yarn 400 Knotter Number 1 Automatic Tester: Pretension Disc Setting #5 Length of Jaw Span 20" Setting for Rate of Loading #6 Loading Time to Break (Seconds) 9 i: 1.5 Complete Cycle Time (Seconds) 20tl.5 Range of Breaking Load 600 Grams Range of Elongation 40% K Value (Breaking Strength) 2.1 e Value (Elongation 0.4 L Value 0.707 59 Table 24. Fiber Fineness Test Using Sheffield Micronaire Micronaire Reading Test Number (MicroRrams per Inch^ 1 3.75 2 3.75 3 3.90 4 3.73 5 3.95 6 3.80 7 3.65 8 3.60 9 3.80 10 4.10 11 3.90 12 3.80 13 3.80 14 3.75 15 3.90 16 3.78 17 3.70 18 3.95 19 3.80 20 4.00 Average 3.82 3.82 Micrograms per inch is equal to 1.352 denier. 60 Table 25. Cotton Fiber Strength Test Using . 4 Pressley Tester (1/8" Gauge) Breaking Tensile* Test Strength Weight Pressley Strength "Nuniber (Lbs) (mgs) Ratio Index (1000 Ibs/i'n^) 1 17.80 6.10 2.918 91.47 76.83 2 13.02 3.35 3.887 121.85 102.35 3 17.95 5.00 3.590 112.54 94.53 4 16.51 4.40 3.752 117.62 98.80 5 17.41 4.58 3.801 119.15 100.08 6 14.91 4.00 3.728 116.87 98.17 7 17.21 4.60 3.741 117.27 98.51 8 19.25 5.15 3.738 117.18 98.43 9 13.46 3.40 3.959 124.11 104.25 10 13.20 3.60 3.667 114.95 96.56 11 13.73 3.55 3.868 121.25 101.85 12 19.11 5.25 3.640 114.11 95.85 13 13.43 2.90 4.631 145.17 121.94 14 11.38 2.55 4.463 139.91 117.52 15 16.65 4.00 4.163 130.50 109.62 16 14.25 3.34 4.266 133.73 112.33 17 15.10 3.70 4.081 127.93 107.46 18 13.59 3.60 3.775 118.34 99.41 19 14.05 3.60 3.903 122.35 102.77 20 17.20 5.00 3.440 107.84 90.59 Average 3.850 120.69 101.38 * Using new methods of calculation adopted by U.S.D.A. ^ , Pressley Ratio „ m^ Index = -—f— X 100 3.19 Tensile Strength (1000 lbs/in^) = Index X 84 100 Where 3.19 and 84 are the average Pressley ratio and Tensile strength of the 1954 U. S. crop. 61 Table 26. Fiber Length Test Using Se rvo-Fibrograph . i Test Mean Length Uppe r Half Mear. Uniformity Number ("Inches) Leugt h (Inc hes) Ratio (%) i 0.875 1.094 79.98 2 0.656 1.047 62.66 3 0.875 1.125 77.78 4 0.844 1.094 77.15 5 0.906 1.156 78.37 6 0.813 1.125 72.27 7 0.906 1.125 80.53 8 0.750 1.109 67.63 9 0.844 1.125 75.02 10 0.875 1.109 78.90 11 0.813 1.109 73.31 12 0.859 1.094 78.52 13 0.875 1.109 78.90 14 0.875 1.125 77.78 15 0.875 1.172 74.66 16 0.906 1.156 78.37 17 0.891 1.109 80.34 18 0.859 1.125 76.36 19 0.875 1.141 76.69 20 0.844 1.109 76.10 Average 0.861 1.118 77.01 62 Table 27. Uniformity of Cotton Picker Lap Weight Frequency (Ozs/Yd) Distribution 14.0 1 13.8 1 13.6 6 Standard Deviation: 0.226 oz, 13.4 8 % C.V,: 1.68% 13.2 3 Average Weight: 13.46 Ozs/Yd 13.0 1 Total 20 Table 28. Uniformity of Dacron Picker Lap Weight Frequency (Ozs/Yd) Distribution 13.6 1 13.4 1 13.2 2 Standard Deviation: 0.292 oz 13.0 7 7, C.V.: 2.261 12.8 4 Average Weight: 12.92 Ozs/Yd 12.6 4 12.4 1 Total 20 63 Table 29. Per Cent Coefficient of Variation for the Evenness of Slivers Cotton Cotton Cotton Dacron Dacron Sa.mple Test Card Drawing Comb Card Predrawing Number Number Sliver Sliver Sliver Sliver Sliver 1 1 5.77 5.40 6.50 3.60 3.26 2 5.56 5.55 6.10 3.70 3.42 3 5.46 5.55 5.90 3.60 3.57 4 5.25 5.50 5.60 3.65 3.38 5 5.40 5.35 6.10 4.15 3.29 2 1 5.40 5.50 5.85 4.40 3.23 2 5.25 5.55 6.10 4.40 3.23 3 5.30 5.61 5.80 4.40 3.86 4 5.30 5.50 5.70 4.35 3.38 5 5.25 5.40 5.45 5.00 3.71 3 1 5.35 5.40 5.45 5.63 3.84 2 5.97 5.35 5.05 5.38 3.36 3 5.90 5.20 5.80 5.57 4.03 4 5.66 5.30 5.60 5.38 3.68 5 5.56 5.46 6.00 5.09 3.49 4 1 5.80 5.20 6.10 5.15 3.30 2 5.66 5.46 6.00 4.90 3.33 3 5.55 5.35 5.60 4.94 3.24 4 5.50 5.20 6.20 5.20 3.20 5 5.51 5.20 6.50 5.66 3.20 Average 5.52 5.40 5.87 4.71 3.45 64 CO CO CO CO CM CO r-l ro CO CO CO O CM i-i CO o CM CM CM 00 O CM r'. r-l >4 CM CM CM m o CM CM CN4 CM «n iTi :- 00 00 00 r-l r-l r-l r-l 00 m CJ\ CM CM C>l CM CM o CO -d* CO OO CM CM CM >t m m r>» p^ r* eg A4 O CO •H >^ •M cd 'O 00 CM m CO o CM «* CM CO CO m \r\ in -t «* 00 04 fi «4-l -H O > o O 00 -d- CO >4- in CO CO Csl CO -M pe: r*4 in m CO a CM CM CN 00 00 0) •> PL< •»^ M o « ^ > *M f-l vO 00 CM in CO r< v£> CM «*-l f-i CO CO Csl CM m •^ « CO CO o CM CM CM CM «n 00 00 00 O «w ru o •M C « CO CM ON CM CM 4) • CO CO CO r-l 00 o CM 00 O • CO « CO CO CO vO m vO o CTx C7\ M « CM O C M-« > o u m O 00 00 CO VO ^^ « CM <0 9 « •>H CO o o m vO \0 CM CM vO O vO vD rH vO O »n CM CO ^ 00 CO CO CM O O ON ON vX3 r^ r>. CM r^ 1^ 00 'd' CO 00 CO CM r>« i-i i-i r- 00 CM CO CO ON 00 ON CO CM VO UO rH in 1-4 r^ CM 00 • M •n -^ ON o r-l r-( VO r-l O m r>. fo o m St CO CO r* m »o o r-l f-l CO St 00 o CO CO •—1 C>i «d- CM »-• CO CO vO CM CM r-4 CM CM r-l CM CO CO t-l O «-« r-l o\ Q \r\ H« r- rH r-« r-l r-l ^ "Q 0) ^ r-l CM CO »* rH CM CO « « V4 00 fH O CO a I-l « pci i-i CM CO in CO 55 5 66 C0| St iTl 0\ >d- ON '^ r^ lO r^ m St CM o «n ON CO ON to iTi O m o o o O •H CM CM CM 00 ON O CJN OT r-4 CO CM CO CO CM CM CM CTN ON O O O r-« CM CNI CO CO St CM O (l4 CM CM CM CM CM CM CM CM CM CM CM CM i-l rH CM CM CM CM CM CM ^ o o St »n NO O U^ ON CO -4- r^ CO 00 r-« ON r>. St St «n r^ St St CM rH CO O ON >i" 0> '-» •H ON CM CO CM CM CM to PH fH CM CM CO CM CM CM CM CM CM CM CM CM CM rH CM I-l CM CM i-< CM CM CM CM CM •o « c CO ON St •n o rH 00 m 00 NO ON u *J 0) 4J « O 00 u 18 V4 a i-i « piS (d p CM CO lO CO ?5 5 67 ' ro o o o m «n o o uo o o o o o o *o o »* ^f O CM »n o o o o o o o m in tr> o o o o o in o »n o iH ^f in vo o CO CO 1-4 «n 00 • CO m o o r-« ox «^ O CM o m m «r» O ^ "^o r^ O NO NO O CO 00 rH CO 00 in r*« r^ ON CO ON O CO ON i-« fH CO CO CO m vO ON •Nh a 1>I o u V «"s rHCMCOst rHCMCO>* fHCMCOvd- rHCMCO<;J- rH CM CO '4' V P H ja o 9 U btt rH « 00 O. u « pes i-i 0) to 7 CM CO m CO Z 68 o m m o m o 00 vo o o o m r- CM o o m o 'O m CM 00 ON o «s CO ir> vo vo r*- 00 o o CM CO -d" fO fO CM CM Ncf ^ m o «n r* o o in m o CM CM m ON «* in m ON m CM NO CM r-i ir> m r*- OS a« 00 00 ^ CO ^ m m o m O CM r* O CM u 1-4 r-l O rH m o »n o O o m r^ o m in m o NO ON CO CM m m o m o «M O O CO CO O i-H O -* ON O O r-t vO NO NO vO /—s in in vo NO m in m m in m m in U3 vO CM 00 CO o m o m o o m CM m m o rH O NO rH O CO r*"- 00 ON ON H^ r^ r^ ON H vO 00 r^ O m ON rH CO »H rH CO NO m m m NO m m m m m m NO u •M O to ^ *• iHCMcO /r% U-v O «0 O o o o o in in o m r* CM o r*- o m o o o tn m o o in o CO in «*>• fo o r^ CO pi 00 O O r^ vO CN O 00 n 00 r«. r^ 00 r^ 00 (jx 00 00 00 OvJ o o o o o o in o CM CM O m m vo o m o in o o CM leo O 00 O O O m o O m in in in m o o m O O O m in in NO CM vO r-i m in CO CO fO in vo m in vO i-H vo 00 m m r>. CO so 1^ rx. r^ vo r^ r*. r^ vO r^ vO NO r»<. 00 00 00 vo f^ r>- r^ CO »n o O O m in o in o m o m o o o o vO O O iH 'd- CO i-i -^ CO r- 00 o CO o m o 00 o CO m in fiH ^ . r«» r- o NO CO CM 00 00 00 00 r^^ r^ 00 00 f^ 00 ON OO 00 ON 00 00 r~-. r*. ON ON g M •H il3^ 00 U fQ fd •H O o m >d- i-i vO o O m vo >^ o m m m rH rH o O in u NO r-l r^ ON vO CO CO r^ 0} f^ O O CO CM CO rH CM m CM o o m O rH TH 00 m m o O r-l rH O 00 |CO ft ir\ ir\ tr\ CO r-4 vO NO sO >* r~. r^ in o m o cn lO NO r>«. in «r> O JQ « O O O Sf o r-i r-l O O O o o o m o o O O O H 1^ O r^ CM CO O O CO in CM ^O O k4 4J 0) CO A r-l rHCMCOsd- rHCMCO o O «r» «n O O u-i O OO 00 r-l O O »o «o «n CM in O «i o «n r» 00 m CM vo CM O r-< \0 o ico CO O r-l CM 00 CO r-l CO r>^ 1^ r^ r^ r^ 00 f^ r^ r>. r^ O rH m lO CM CO O ir» 00 i-t o o r-< 00 00 00 in o ON O -N tri \0 I-. CO vD »4- O vo CM CM 00 m r-t in CM CO CM >t ^ 00 ICO o CO r^ r^ 00 . r- 00 r>. r^ rv r>N 00 00 r^ r^ 04 oi 00 in o •n »n 00 00 CM O in m m o o m O 00 m O ON 1^ CM o in v£) C^4 O CM CO i-l «n vO rH vO 00 vO vO O vO .-1 CO 00 si- CO t^ 00 00 r-«. r- r-^ r~« 00 yO f^ r^ r^ r>. vD r^ r^ r--- r>* r>. r^ A4 u m o 00 o in m o O o O r-l O o o m o O O O O CM CO 00 0\ CO O r- m CM CM CM O O vO O CM NO CO O O m o CM m (4-1 P*« 00 ON ON r-. 00 000 0 00 00 OO 00 00 00 00 r^ 00 O O ON 00 •-4 r-l r-4 r-4 i-i f-t i-i t-H rH CM CM r-l a r-l r-l r^ rH fH iH f-l rH rH O /-s to 1-4 -O « P X m-sfoo oooo ooom ommo ooooo CO •H fl CM r^r-iooo mmrwin OONOCO or-ir-ico OONOO U -H Pico 00 Cd 4J CM i*-.ooooo\ a\ a\ o^ ococMCM dor-io OOOO oomo omoo ON (d OrHONNO o»*r^r-* OOONO o M 4j 4) 8B ^ c»i « H r-l CM CO St r-4 CM CO •* r-l CM CO -;f r- bO fH 0) (d u o a Cd p V CO 2 CM CO m ptS i 71 (T) »r» o W • • cn OJ CO r>. 00 o o CO CO 1-1 in oO CM in o r^ o 00 00 ON o 00 (N m m m CO O m ON 00 CO •o o td so «n O m vO CO O m 00 O m A C^^ xs o m 4J 00 a\ lO m r^ ON CO m m 00 CM m vO 00 CO o CM o CO CM «n m CM 00 CO vO v£> <* oCM OoN ON o CTi es o «M o (0 H 6 OB •O «0 c (d « « M 00 «> 00 00 O «.* (0 u « 01 « >^ OS »4 «M M o O r-l • o « < r-l CM > 04 r-l CM > CM r-l (x; < P!S OS < M PC Pti 04 (m ^ o ? o •i o ^•H p l-J H z: 72 cr» ON ON a\ C«< CM n CO CM CM 00 00 ON ON 00 00 00 00 CM CM m m m m vO \0 »r» in CM CM O O 0a , /-« •H B^ r^ c C< O Table 36. Summary of Result!9 from Uster . i Automatic Yarn Strength Tester Breaking Strength El Dngation Reading Reading Lot from Mean from Mean No. Replication Counter (Grams) % C.V. Counter (%]) ?• C V. PlSi Rl 1759 279 12 17 .18 555 14 94 20 88 R2 1677 267 26 16 .46 556 15 39 24 43 Average 273 19 16 .82 15 17 22 66 P1S2 Ri 1793 284 94 16 02 582 15 76 22 84 R2 1702 270 95 15 70 580 15 52 24 16 Average 277 95 15 .86 15 64 23 50 P1S3 Rl 1674 266 51 16 76 538 14 41 23,4 6 R2 1730 275 13 16 60 578 15 32 21 08 Average 270 82 16 68 14 87 22 27 P2S1 Ri 1788 283 38 15 22 576 15 57 22 86 R2 1789 284. 01 15 67 576 15 57 22 92 Average 283. 70 15 45 15 57 22 89 P2S2 Rl 1804 283. 18 14 15 573 15 51 22 05 R2 1757 279 35 15 37 576 15 31 22 99 Average 281. 27 14 76 15 41 22 52 P2S3 Ri 1749 277. 20 15 87 556 15 02 25 63 R2 1764 280 16 15 56 578 15 29 22 11 Average 278. 68 15. 72 15 16 23 87 P3S1 Ri 1844 292 17 15 85 570 15 35 22 93 R2 1775 281. 22 15 25 577 15 60 22 56 Average 286. 70 15.5 5 15,4 8 22, 75 P3S2 Rl 1815 287. 82 14 30 589 15.8 3 21 23 R2 1827 289. 83 15, 17 594 15. 79 21 66 Average 288. 83 14, 74 15 81 21 45 P3S3 Rl 1783 282. 88 14,0 2 582 15. 71 22 34 R2 1766 280. 34 14 92 582 15, 25 22 23 Average 281 61 14,4 8 15.4 8 22 29 74 BIBLIOGRAPHY 75 LITERATURE CITED 1. W. C. Harris, "Some Aspects of Preblending Cotton," Cotton Research Clinic, 1962. 2. J. B. Speakman, "Fiber Blends," Testile In8t:itute Journal. 49, P. 580 3. S. A. G. Caldwell, "Modern Fiber Blending Practice," Man-Made Tex tile, June, 1961, p. 51. 4. D. E. Howe, "Massive Blending as a Means of Leveling Out Cotton's Variables," Textile Bulletin, 85, July, 1959. 5. Caldwell, p. 52. 6. G. V. Lund, "Tips on Blending Fibers," Textile World, 104, April, 1954, p. 87. 7. A. E. DeBarr & P. G. Walker, "A Measure of Fiber Distribution in Blend Yarns and Its Application to the Determination of the Degree of Mixing Achieved in Different Processes," Textile Institute Jour nal, 48, T 405, 1957. 8. G. V. Lund, "Fiber Blending," Textile Research Journal, 24, August, 1954, p. 764. 9. D. R. Cox, "Some Statistical Aspects of Mixing and Blending," Textile Institute Journal, 45, 1954, T 113. 10. J. E. Ford, "Segregation of Component Fibers in Blended Yarns," Textile Institute Journal, 49, 1958, T 608. 11. G. S. Kates, "Some Technique Tips on Processing Blends of Dacron and Cotton on the Cotton System," Textile Bulletin, 88, April, 1962. 12. F. P. Cancelliere II, A Study of the Effects of High Speed Drawing on the Properties of Yarn, M. S. Thesis, Georgia Institute of Tech nology, 1955. 13. J F. Bogdan, "An Exploration of Roller Drafting," Cotton Research Clinic, 1962. 14. J. B. Hamilton, "The Radial Distribution of Fibers in Blended Yarns," Textile Institute Journal, 49, September, 1958, T 411. 76 15. A. H^ Bowker & G. J. Lieberman, Engineering Statistics. Prentice Hall Inc., p. 295. . OOOOOOOO 00 0) CO fU r-ICMrHr-l r-4r-li-4r-4 ,Hr-lr^i-l r-lrHr^r-l r-lrHr-li-4 •H JM u •H «H tM O voooo OOOO mooo moomo mooo CM tM CO iHmvom cMr^oo ooooom COONCOO vocMsfvo CM « « iKO. OOOOOON ONONOO r^r^ONON ONONONO ONONOOOO o «a CMr-lrHf-< r-4r-ICMCM r-