Historic, archived document

Do not assume content reflects current
scientific knowledge, policies, or practices.

VN
\

ED STATES DEPARTMENT OF AGRICULTURE

2 *eweeeets
we

In Cooperation with
Clemson Agricultural College, South Carolina

DEPARTMENT BULLETIN No. 1488

Washington, D. C. April, 1927

MANUFACTURING TESTS OF COTTON OF THE WHITE GRADES OF THE
UNIVERSAL STANDARDS FOR AMERICAN COTTON

By Horace H. Wits, Cotton Technologist, Division of Cotton Marketing,
Bureau of Agricultural Economics !

CONTENTS
Page ; Page
IBUEMOSCLON LES tees ae Sees one ee ie elrresularitiy 10 fey arts eee. este een ent ieee 15
Mechanicall/conditionS- eases a sn eee 2 225 Warphyarnn(Gkein) se essia LL a ee 15
IMoistuneiconG@itlonss 22-2 eee ee 2 28s two-ply yarn (single strand) -..._._.._- 20
Percentages) Olewastes ssa ees es yee ee ee 4 |eVjariation Of thesizingse: 25) 2 eee 21
Waste and cotton per 500-pound bale__________ 6 | Difference in value between grades_-__________- 22
StreneihvolsyannSeee=s cen cedi se coed pre tet GAS crengCnuoOnclo tea seen eee ees eee 24
Method of presentation of strength data__..__ 7 | Manufacturing properties___-_-__.------_-_--_-- 25
DISUTAV WALD ViaAbna(GKelM)e ee Sai) binishin&, propertiesses == see eee 26
225 warp yarn. bleachedsandadyed: (Skein) ==) 12+ ‘Summarys eee oe ee ae 28
22s warp yarn (single strand) ________________ 13
28s two-ply yarn (single strand)___.-_._____-- 14

PURPOSE OF TEST

The spinning tests here described were conducted to determine
the relative intrinsic value of each of the nine white grades of Ameri-
can upland cotton as represented by the universal standards for
American cotton. ”

These standards, which became effective August 1, 1924, super-
seded the former official cotton standards of the United States, tests of
which are given in Department Bulletin 591, ‘Manufacturing Tests
of the Official Cotton Standards for Grade.” The results shown in

_ this bulletin are based on the new standards for white grades. A

thorough study of the manufacturing properties has been made,
including waste, working qualities, strength, and bleaching and dyeing
es of the yarn and of the cloth made from each of the nine
orades.

An effort has been made to correlate such factors as the price of the
raw cotton, value of waste, and value of yarn to make the results of
value to cotton growers, cotton factors, and manufacturers.

1 The writer acknowledges the cooperation of the several managers of finishing plants, manufacturers,
and cotton factors in these tests. The spinning tests were conducted under the general supervision of
Arthur W. Palmer, in charge of Division of Cotton Marketing, and under the direct supervision of Horace
H. Willis, cotton technologist, assisted by H. B. Richardson and C. E. Folk, assistant marketing economists;
E. S. Cummings, assistant in cotton testing; and Miss Etta Zeh, assistant scientific aid. :

? For a detailed description of the cotton standards, see Department Circular 278, ‘‘The Commercial
Classification of American Cotton,” by Arthur W. Palmer, and Service and Regulatory Announcements
No. 92 (Agricultural Economics), ‘‘Standards for Cotton Classification in the United States and Abroad,”
by Chester L. Finch.

33065°—27-——1

23 BULLETIN 1488, U. S. DEPARTMENT OF AGRICULTURE

The following nine grades of upland cotton seven-eighth to 1 inch
in length of staple grown east of the Mississippi River and similar lots
grown west of the Mississippi were tested:

Middling Warr. 2) 22st) 0. Beene ee Sen ice ee ee No. 1
StrictaAGood Middilrinig oe iets xii e ae vere ier ames Deere ey See eee No. 2
Good#Middling.2 2. 2275500008 Wi ist seks ity Fein eg fags OUR cirCieAe ae No. 3
strich Mid dinars.) - ihe tile ap gy Se Meier age Bee eee py ee No. 4
MPI ge Se oo eT a ee pe SB Oe a eee No. 5
Strict. Low Middling 3205s OS es) ate se Cine ee ee eee No. 6
Low, Middling. 222." Be 2 Se 2 ee Se ee ee No. 7
Strict-Good: Ordinary 22 vs. Jae ee ee No. 8
Good! Ordinary 22 55 ee See NS LA i co, ee gy em No. 9

The test lot of each of these grades of cotton consisted of a com-
posite sample of approximately 250 pounds taken in equal portions
from three different bales of that particular grade. The cotton for
the spinning test was selected from bales which were being used in
making up the types of working standards for grade. In order to
reduce other variables, cotton was selected which was deemed to be
as nearly as possible uniform in staple and character. The grade was
certified by a committee authorized to class cotton under the pro-
visions of the United States cotton futures act and of the United
States cotton standards act. The grade of the cotton will be desig-
nated by number throughout this report.

MECHANICAL CONDITIONS

To determine the comparative waste, these lots of cotton represent-
ing each of the nine white grades were run under similar mechanical
conditions, the drafts, speeds, and settings conforming to usual mill
practice. The net weight of cotton taken from the bale was recorded,
then the cotton was passed through the opener, and placed in a bin
and allowed to condition for 24 hours, during which time it either
gained or lost in weight, depending upon its character, the moisture
in it, and the weather conditions. This gain or loss was reflected in
the invisible waste from the pickers.

After 24 hours the cotton was taken from the bin, weighed, and
passed through the breaker and finisher pickers. The production
and waste at these machines were weighed and recorded. As soon
as convenient the production (called laps) from the pickers was
transferred to the card room, weighed, and passed through the cards.
The production and waste were again weighed. The cotton was then
passed through two processes of drawing frames, three processes of
roving frames, and then to the spinning department. Frequent
weighings of the laps, slivers, and roving were made to ascertain
whether proper size or weight was being delivered.

MOISTURE CONDITIONS

The relative humidity in the different rooms was kept as nearly
constant as possible. It has been found from experiments that a
relative humidity of 50 per cent in the picker room, 60 per cent in the
card room, and 70 per cent in the spinning and weaving rooms gives
satisfactory results. It is not always possible to maintain precisely
these moisture conditions, as the relative humidity is affected by the
weather. Table 1 gives the averages of the hourly readings of the
prevailing temperatures and relative humidities and the time required
to pass each grade through each machine, Only in extreme weather

MANUFACTURING TESTS OF COTTON 3

conditions did the relative humidity fluctuate more than 2.5 per cent
under or over the average as given in Table 1. Since the relative
humidity was observed and regulated every 15 minutes. the average
readings per hour were considered sufficient.

TABLE 1.—Average of hourly readings of room temperatures, average relative
humidity during processing, and time required by each type of machine for each
grade of cotton }

Eastern upland Western upland Time
Temperature run per
Machine and relative Grade Grade machine
humidity and
12a) PAS) GAZ Sho | t 2508 |e aaeaaleen a siinen| wsrade
Hours
anna Degrees F_____ 86! 86] 71| 81] 77| 69] 87] 82] 89] 87] 88] 73] 82] 78! 71! 79] 88] 80 3
ee Per cent______| 62] 57| 56] 58] 68] 54] 57] 57] 58] 61] 54| 51| 56] 70] 55] 62] 61| 57
Pinter Degrees F_____ 86| 86] 76] 73] 75] 67| 86] 80] 91| 89] 87| 78] 76] 77| 69] 78] 90] 72 4
Me SE ao Per cent______| 63] 57) 60] 54] 60] 52/ 58] 62] 55) 61] 54] 59] 54/ 59] 49] 67| 59] 53
Gace Degrees F_____ 84| 82] 74] 74] 74] 65] 84! 741 86] 83] 83! 77] 72] 72] 65] 75] 385] 74 12
PR STESES TS Per cent______| 62| 58] 61] 61] 59] 58] 62] 60] 61| 63] 61] 61] 59] 60] 58] 63] 62] 59
Dae Destees H uti 84| 83} 76] 73] 73] 65] 85] 66] 87| 81] 83) 81| 73] 74] 661 76] 86] 80 8
B----——- Per cent______| 62] 61] 62] 59] 60] 57| 62! 54] 61/ 62] 60] 61] 59] 61! 60] 59] 61] 61
Slubber Degrees F_____ 82| 83) 77] 73| 75] 67| 86] 68] 85| 81] 84! 83] 69] 76] 66] 76] 87] 78 3
See Per cent —-__- 60] 60) 60} 59] 59 ef pl 2 60 oI 6 6 69 60 a BI 64| 62
=: egrees F_____ 82} 84) 82! 70] 74 6] 6 1} 81 5 6] 87| 74
Intermediate___|{ p¢, cent.___..| 61/ 61) 61| 58] 61/ 60] 63| 59] 60| 62| 62| 58] 61) 62| 62| 63| 60! 60 5
Fine (pecres: E DRS 81| 84) 84| 76] 78] 68] 85] 67] 85| 84] 82| 84! 83] 80] 74] 77] 84] 67 5
SOIC ae Per cent______| 62| 61) 59] 60] 61] 63] 62] 60] 61) 64] 60] 56] 61! 63] 61] 61] 60] 59
ee Degrees F_____ 84| 85] 81| 80] 79] 75} 86] 74] 83] 84) 85! 81) 80] 79] 75] 79] 83] 75|\ 5
LE colgtaacaiene ial Per cent___-__| 69| 71] 71| 71] 70] 71] 72] 69] 71] 69; 71) 71] 71| 70| 71] 71) 71] 69|)

1 Temperatures expressed in degrees Fahrenheit and relative humidity in percentages.

Samples were collected for moisture tests at regular intervals
during the manufacturing processes. These samples do not neces-
sarily represent the average conditions of the entire lot of cotton of
the particular grade from which the samples were taken, but they
do show the amounts of moisture in the sample at the time taken.
The results of these tests are shown in Table 2.

Cotton, being highly hygroscopic, may either gain or lose in weight,
depending upon the amount of moisture in the cotton, the outside
weather conditions, and the temperature and relative humidity of
the room in which the test is conducted. The gains and losses are
indicated in Table 3.

TABLE 2.—Percentage of moisture regain in samples of the several grades at suc-
cessive stages in processing }

On

Eastern upland Western upland 3s

ics

"5 bb

Sample Grade Grade aa

loys) ~

3a

8

ESE EE TOM AD LG gi ISR BR coe ee tO a Ge

font

JE vl 2X HON EHO ENA 22 es ENON EON | 22(C4) EO eNO OI IZ eee ens EXO exo) ered Ved oe

Raw stock_._______- 6. 49/7. 18]5. 81/6. 55/7. 64/6. 60/7. 01/6. 84/7. 01/6. 55/6. 60}5. 93/6. 89)7. 1815. 26)/6. 38/6. 32/7. 58/6. 66

Breaker picker lap__/6. 15/6. 49/6. 38/5. 37/6. 72/6. 10/5. 48/6. 43/5. 59/6. 60/5. 76/6. 04/5. 42/6. 60/5. 15/6. 72/5. 70/5. 48/6. 01

Finisher picker lap__|6. 21/6. 32/5. 70/4. 77|6. 55/5. 70/5. 76/6. 26/5. 20/6. 10/5. 15/5. 54/5. 21/6. 26/5. 37|6. 72/5. 98/5. 15/5. 78

Lap back of card____/6. 43/5. 76/6. 15/5. 32/6. 75/5. 84/5. 82/6. 32/5. 59/5. 88/5. 5116. 21/5. 65/6. 26/5. 65/6. 43/5. 98/5. 4815. 95

Card sliver_________]6. 43/5. 90/6. 04/5. 64/6. 84/6. 18/5. 46/6. 38/5. 98/5. 98/5. 90/5. 8115. 70/6. 60/6. 04/6. 49/5. 90/5. 70/6. 05
Breaker drawing

Sikver ts wee sont 6. 32/6. 26/6. 55/5. 48/6. 89/5. 9915. 65/6. 21/6. 04/6. 72/6. 26/6. 32/5. 48/6. 66/5. 70/6. 10|6. 10/6. 26/6. 17
Finisher drawing

sliver spel UE ea iri 6. 49/6. 43/6. 84/5. 76/6. 49/6. 38/5. 59/5. 76/5. 54/6. 66/6. 32/6. 26/5. 71/6. 55/6. 21/6. 32/6. 38/5. 93/6. 20

Roving, fine frame__|6. 55/6. 32/5. 98/6. 60/6. 78/6. 32/6. 26|5. 98/5. 59/6. 43/6. 26/6. 10/5. 93/6. 55/6. 49/6. 66/6. 21/6. 10/6. 28
Roving, creel of

Splnning! 2. 2. 2 7. 99/7. 64/7. 41/7. 35/7. 01/8. 11]7. 01/7. 46/6. 32/7. 35/7. 87/7. 24/6. 95/6. 72|7. 35)7. 52/6. 49|7. 12/7. 27

RYGaTT ooeen eRe eh 9. 17/8. 16/8. 57/7. 87/7. 81/8. 99/7. 35/8. 75/6. 95/8. 69/8. 45/8. 22/7. 357. 24/8. 57/8. 22/7. 35/8. 51/8. 12

1 The amount of moisture that may be taken up by bone-dry cotton is called regain. The percentage of
ioe is a cneanedl by multiplying the amount of moisture taken up by 100 and dividing the result by the
ry weight,

4 BULLETIN 1488, U. S. DEPARTMENT OF AGRICULTURE

TaBLEe 3.—Percentage of the different kinds of waste removed by the pickers and
cards from each of the nine grades

Eastern upland

Machine and kind of waste Grade
1 2 3 4 5 6 ti 8 9
PICKERS !
Pck\ePs cts | (Pa ctj2P= cts |SBo cl Seat (PXcts | eh ck. |\'Paee
Opener breaker motes and fly___-_____- 0.:75°} 70! 80") - 0°80) | 1203.) 41. 18" | 42162) oe 735) oeAs | 2 eee
Binisher motesiand: flye = e=eees . 64 . 78 . 70 . 81 1.07 1.08 | 1.41 1 81:|.. 2548
Total visible waste____.._--_-_-____ 1.39] 1.58| 1.50] 1.84] 225| 270] 414] 426] 6.36
Invisibleswastes2. 22 ws) ees ee oe . 03 . 90 -09 | 1.63 Sel .82 | 1.50 “98 | 1870
CARDS 2
Flat strips#.2. 22.26 2 je eee tks AEP 1538. | 264 Pe t76 [9 e555)" 2.105] 32504 1-220 | oa30R 255
Cylinder and doffer strips______________ . 66 ait nae . 54 . 90 . 68 . 96 . 70 . 80
Motes and fit Oo: 0s _if2h ee ee 179s LST pe SESTa 2o0Sa 2.22 ||_ e2e4 alas eee Aes fi:
Sweepings- 4 500 Bee Ste ee ee Eee .10 . 07 -19 5733 . 24 .35 B25 lg . 26
Total visible waste__.._.-..-_------ 4.08} 4.29| 4.54] 435] 5.46] 5.52] 668| 7.45| 8.75
Invisible waste or gain..__._______- "3.47 | 3.68] 3.92| 3.56] 320| 3.46| 8.20] 0.00] .22
PICKERS AND CARDS !
Total visible waste:.<---- hetirneceiotetes 5. 41 5. 76 | 5. 97 6. 04 7.55 8.03 | 10.44 | 11.32 | 14.40
Totalinvisible waste or gain________ 3,14 24 3, 82 1. 09 . 58 .38 1.31 . 98 1. 90
| Western upland
Machine and kind of waste | Grade
i
| 1 2 3 4 5 6 7 8 9
PICKERS ! |
| Pet) P sche IP ch WEP ch AE Cla Paces te Gea eer Eee
Opener breaker motes and fiy__________ |} 0.73 | 0.69} 0.76 1.07} 1.50 1-699) 207 |eSal2 ) a30
Kinisher motes andshys 2. see | 63 . 60 -69 | .91] 1.00] 1.29) 162] 2.16] 2.64
Total vasibleswastes-- 28-94 == 22 | 1.36] 1.29 | 1. 45 | 1.98] 2.50] 2.98] 3.79| 5.28] 5.94
nyisibleswastess=- ee | 599) 13") bs: 46 HG GBs |e dele .80 | 1.33] 2.93
CARDS?
Inlat stripse se 2 LDA Fes Sie IBGE en Soo tea ee GeO SO) MPa al PAW A | BALTES seas:
Cylinder and doffer strips_____-________ . 64 . 64 . 74 . 64 . 86 . 68 . 94 FSi Tal?
Motes an ditliy. Sor ee es tee PRO 2.00 | 1.56 | 2:04:| 2.08} 2.12} 2:45] 3.387) 426] 4°86
DWCCpDINESE ei) eae eee eae .10 Ze 538 .18 Bally .16 = 22 aS “shi
Total: visible wastes 2255-220 4,29 4. 03 4. 72 4. 66 5. 14 5. 37 6. 79 7. 63 9. 36
Invisible waste or gain _________-_- 3.17| 3.43 | 3.56 | 3.56] 3,241 3,14| 329) .34] 3.08
PICKERS AND CARDS !
‘Rotal visibleswastese-- a est eee 5. 58 O22 6. 07 6. 48 7. 43 8.13 | 10.27 | 12.41 | 14.47
Totalinvisible waste.____-----__-__ we ¢ Aj) 030051), 292: fy d-40 .99 52 |° 1655] 2.36
| j

1 Percentages based on net weight fed to opener.
2 Percentages based on net weight fed to cards.
3 Invisible gain.

PERCENTAGES OF WASTE

Percentages of waste were determined from the net weight of
cotton fed to, delivered by, and discarded by each cleaning machine.
There are two kinds of waste in cleaning: (1) Visible, that which
may be gathered and weighed and put to some other use; (2) in-

MANUFACTURING TESTS OF COTTON 5

visible, that which results in a change in weight caused by loss or
gain in moisture, or by small particles passing off in the air. The
amount of this invisible waste is affected by the character of the
cotton in process, by outside weather conditions, and by the tem-
perature and relative humidity of the room in ‘which the test is
conducted.

The percentage of waste on each machine is based on the. net
weight fed to that machine. The net weight fed to the cards is less
than the weight fed to the pickers by the amount of waste reinoved
by the pickers. The percentage of total waste removed’ is not
obtained, therefore, by adding the waste percentages for pickers
and cards. For example, follow the computations for grade No.
3 (eastern cotton) in Table 3. For every 100 pounds o: raw cotton
fed to the pickers, 1.50 pounds (1.5 per cent) of_vis*ble waste were
removed and 98.41 pounds of cotton delivere’,1éaving 0.09 pound
(0.09 per cent) not accounted for and designated as invisible loss.
The total waste on the pickers is therefore 1.59 per cent.

The 98.41 pounds delivered from the pickers were fed to the cards
which removed 4.47 pounds (4.54 per cent) of waste and delivered
94.85 pounds of cotton, making a total of 99.32 pounds. This
latter figure exceeds the weight fed by 0.91 pound (0.92 per cent
of the quantity fed to the cards). This 0.92 per cent is called in-
visible gain.

Combining the pounds of visible waste (1.50+4.47), dividing it
by 100 (pounds fed to the opener), and multiplying this result by 100
gives the percentage of total visible waste removed. Total visible
waste removed by the pickers and cards is 5.97 per cent, an amount
slightly smaller than the sum of the visible wastes (6.04 per cent)
recorded in Table 3 as from pickers and cards.

The total invisible waste is figured in a manner similar to that
used for determining the total visible waste. Note that there was
a loss of 0.09 pound on the pickers and a gain of 0.91 pound on
the cards. Therefore, 0.91 pound gain on cards minus 0.09 pound
loss on pickers equals a net gain of 0.82 pound, which, based on
100 pounds fed to opener, is 0.82 per cent again. The oreater por-
tion of this gain on the card is due to the fact that approximately
60 per cent relative humidity is maintained in the card room,
whereas approximately 50 per cent relative humidity is maintained
in the picker room where the preceding process takes place.

The percentage of total visible waste from each grade of the east-
ern and western cottons is given in Table 4.

/

TaBLE 4.—Percentage of total visible waste from pickers and cards, by grades of
eastern and western cottons

¥v

Grade
Type of cotton
e 1 2 3 4 5 6 a 8 9
Per Per Per Per Per Per Per Per Per
cent cent cent cent cent cent cent cent cent
Brinnon aera ote ett 5. 41 5. 76 5. 97 6. 04 TOD 8.03 | 10.44] 11.32 14. 40
WUCSHOrIL es abo) ts fe ey x 5. 58 5. 22 6. 07 6. 48 7. 43 8. 13 | _ 2. 41 14. 47

14, 44

AV CTAB OS (2% 223556 12. 5. 50 5. 49 6. 02 6. 26 7.49 8. 08

xX

\

~%
‘

a. BULLETIN 1488, U. 8. DEPARTMENT OF AGRICULTURE

The average of the total visible waste from each grade of the
eastern and western cotton is shown graphically in Figure 1.- Data
\ised in this graph were taken from Table 4. The cross on each ver-
tial grade line indicates the total amount of visible waste removed
from that grade. These crosses have been connected by the dotted
liné for convenience in reading. The solid curve best represents the

waste data. The method of locating this curve is to draw it among
¥

PERCENTAGE
OF WASTE

14

GRADE NUMBERS

Fic. 1.—Average percentage of total visible waste from eastern and western cotton of each of
the nine grades. The crosses on the dash line indicate the actual waste removed in the test
while the solid-line curve is the best representative line

the points representing the waste percentages so that the sum of the
squares of the distances of the points above the curve is equal to the
sum of the squares of the distances below the curve.

WASTE AND COTTON PER 500-POUND BALE

e

The pounds of waste and of cotton per bale as found in this test
are given in Table 5.

The waste may be divided into two parts—spinnable and nonspin-
nable. To the first class belong the flat strips which are the highest
quality of waste removed from cotton used in manufacturing carded
yarns, These are usually spuninto coarseyarns, Tothesecond class

MANUFACTURING TESTS OF COTTON 7

belong the motes and fly from the pickers and the cards. This waste
is run through special machines which separate the trash from the
short fibers. These fibers are used for various purposes, such as
wadding and packing. In the case of low-grade cotton, however,
even the flat strips may be found nonspinnable, in which event they
are put to uses similar to those of motes and fly.

TaBLE 5.—Tare,! visible waste, and cotton removed from each 500-pound bale of the
several grades

Grade
Bale contents See Ve ata
1 2, 3 4 5 6 7 8 9

Pounds pou: Faunds Pounds | Pounds | Pounds | Pounds | Pounds Pounds
Wie teralek Se nite Berane ore ee er 26. 18 26. 1 28. 6 29. 80 35. 65 38. 46 49. 31 56. 45 8. 73
COtLOn eer eae) 449. 82 | 449. 2 447. a 446. 20 | 440.35 | 437. 54 | 426.69 | 419. 55 any. 27

1 Tare assumed to be 24 pounds in each case. Invisible waste disregarded.
STRENGTH OF YARNS

The cotton of each grade was manufactured into 22s warp yarn,
28s filling yarn, and 28s two-ply soft twist yarn, the latter for the
purpose of mercerization. The twist inserted in the 22s yarn was 19.9.
21.1, and 22.3 turns per inch. Twenty-four skeins were reeled and
tested from each twist of each grade, giving a total of 72 determina-
tions for each grade. Thirty-two determinations were made by the
single-strand method on the middle twist of each grade. These yarns
were conditioned and tested on standard-speed motor-driven machines
under an automatically controlled relative humidity of 65 per cent
at a temperature of 70° F.

METHOD OF PRESENTATION OF STRENGTH DATA

Space forbids the inclusion in numerical form of complete data
relating to each of the various strength tests, but in the case of 22s
eray warp yarn spun from No. 5 eastern and western cottons, respec-
tively, such complete data are given. (See sample Tables 6 and 7.)
These tables are included in order to show the thoroughness of the
tests. Data for all other strength tests were obtained in a similar
manner, are on file, and copies will be furnished on request. This
publication does include, however, graphic presentations of the
results of each strength test made, each graph being based on obser-
vations similar to those recorded in Tables 6 and 7.

In plotting the data a series of parallel vertical grade lines, num-
bered consecutively from 9 to 1 corresponding to the grades ‘of the
universal standards for American cotton, are drawn equal distances
apart. The observed strength in pounds or ounces, as the case may
be, is noted on the particular vertical grade line. These points have
been connected for convenience in following the results of any one of
the severai comparative tests.

8 BULLETIN 1488, U. S. DEPARTMENT OF AGRICULTURE
22s GRAY WARP YARN (SKEIN)

One of the chief requisites of warp yarn is strength. This property
is highly desirable because the yarn during weaving must withstand
high tension as well as chafing. Strength is also important in respect
to the wearing qualities of the cloth.

Examples of the strength data for 22s gray warp yarn spun from
gerade No. 5 eastern and western cottons are given in Tables 6 and 7,
respectively. The break per 22s is found by multiplying the average
strength by the average size and dividing by the specified number—
22 in this case. As an illustration, refer to columns under 19.9 turns,
Table 6. The 89.67 pounds (average strength) multiplied by 21.20
(average size) divided by 22 (specified number) equals 86.41 (break
per 22s). Similarly, other strengths per 22s were determined.

TABLE 6.—Variation in skein break and size of 22s gray yarn spun from No. 5
eastern cotton

Turns per inch for 22s gray yarn

Observations 19.9 21.1 22.3
Break or a Break or . Break or :
strength | °!Z€ | strength | Si | strength | Size
Pounds Count Pounds Count Pounds Count
UY Ee i ee NS SEY Ee ee. Se 90. 5 ZiB25 88. 0 20. 75 89: 0 21. 25
QZ ENES ik ait MEMO ERIE Sia eG Le ae SSE Ret hal ae 92.3 TA AS 92. 0 20. 75 90. 0 21. 25
eee ENA PAPO A NE SPRAY — WRENS E OTR S 87.0 Mil 7S 88. 0 Pig 2s 90. 5 20. 75
A lecye ee! Wierd wR Ye Ee gue eure tas 83. 0 22. 00 90. 0 21. 00 90.5 20. 75
Hay alec ty Oa) (2 Sal Lorseargper Wee vei e eh rar oie Cae Boe 91.0 20. 75 96. 0 119, 75 92.0 20. 25
GOSPEL Ey PES See ET ee Pe ee WY a) 91.5 20. 75 89.5 D205 183.0 21. 25
[ESSER AN Ge eT PES Tt Aly SER TRE ET 90. 0 20: 75 94.5 20. 25 87.0 20. 75
Sigel Nahe Re OA OU ea ee Ces 90. 5 7Al. 2) 94. 0 20. 25 86. 5 122. 25
(OA tse Bb eae BIE a ea eee 94.0 20. 75 91.0 20. 25 94. 0 20. 5
Hf SE ares Re ed rd a RR AOR TS ced RIE 92.5 21. 50 81.5 22. 00 89. 5 20. 50
TA Ee JE tn ee NC hl et aR See 87.0 21. 50 94.5 20. 50 196.5 20. 50
1 RS eer een tae als eos i Se da ger dy gS 85. 5 PAE TAD 198. 5 20. 50 87.5 20. 50
1 os Ra A eee ee te eis es eg ae A ee ee 93. 0 20.25 92.0 21. 00 92.5 20. 25
Af Aa pee ee eee) ERS eee Uy te! eae BE 90. 5 20. 75 94. 0 21. 00 94.5 20. 25
Oud sehr wy peels See Pe oe eee ety) ots Ok 93. 0 21. 25 180.5 122. 25 95. 0 20. 50
TK ge oe Waal cei pe ee Ey Sem tha Ae Ee «Reka ee eo 88. 0 1 20. 25 86. 0 21. 25 94.0 1 20. 00
Ure ie Ct ae ki tae deat a Se Ua ed, Sg ee BR 89.0 21. 50 91.5 21. 00 95. 0 20. 50
1S a pe ee Oy Mh, Bl peal Et Selly Pal, 89.5 PAs 92. 0 20. 25 G5. 0 21. 00
TUG Jn ie ey Oh sted (Ors rk LIS pe er 197.0 20. 50 90. 5 20. 75 90. 0 22. 00
PASS Gn b SRE CO Beebe i oy ase) ASE Ce ales ce 86. 0 1 22. 25 81.0 21. 25 86. 0 20. 50
FALEIE MP SAW in pa ena ey 1 id ore ek COS RERW NN RRR y 182.0 Pals 7) 93.5 19. 75 92.0 20. 25
DRED ANAS Se PANES ROL ERR UN 85. 0 21250 85. 5 21 00 96. 5 20. 25
NE NOME) Grea hoes dr Ne LAE eee eet A eo 92.0 20. 75 93. 0 20. 75 92.0 20. 75
Do, gett Neal eer g ve: voli Ap oN =” BI EERE SAP Ee 92.0 21. 50 94.0 20. 50 91.5 20. 50
PUNO Ba gs ah aca dpe 1 ne a 2, 152. 0 508. 75 Pele) 499. 25 2, 190. 0 497. 25
WASVOTAG Cares Ne PONS BP raneh EV Bec Ee ap 89. 67 21. 20 90. 46 20. 80 91. 25 20. 72
Breaker Oost. Fae Se Oe al SGA4d, |e reese SH haha eee bees 85. 94) |oo elie
Per cent | Per cent | Per cent | Per cent | Per cent | Per cent
Average deviation ?_______________- 3. 22 2. 07 4. 06 210 3.13 1. 94

}ixtreme variation! 225 oss. 32 2a 16. 73 9. 43 19. 89 12. 02 14. 79 10. 86

1 ®xtremes.
+ See discussion of irregularity of yarns (p. 15) for method of calculation.

}
|
|

MANUFACTURING TESTS

TABLE 7.—Variation in skein bre

Observations

AASV CVO ese eh rag dE ee Ml oe
IB TECAKS CTE 2 2S eae aaa ak ye MUR eee apes

mAverave Meviablon tessa se ese me
Extreme variation ?_______.________-

1 Extremes.

2 See discussion of irregularity of yarns (p. 15) for method of calculation.

western

cotton

OF

COTTON

Turns per inch for 22s gray yarn

19.9
Break or .
strength Size
Pounds Count
83. 5 22525
89. 0 21. GO
91.0 21. 25
89.5 21. 00
90. 5 20. 75
89.5 21-75
90. 0 21. 50
91.0 yess)
82.5 1 22. 25
90. 0 21. 50
83. 0 22. 00
93.5 21. 25
93. 0 21.75
83.5 21. 50
88. 0 PIS
92.0 21. 50
94.5 20. 75
1105.0 1 20. 25
90. 5 20. 75
92.0 20. 75
181.5 22. 00
94.5 225
89. 0 21.5
84.0 21. 50
2, 150. 5 512. 50
89. 60 21. 35
SOSG5 eee ee
Per cent | Per cent
3. 97 1.85
26. 23 9. 37

9

ak and size of 22s gray yarn spun from No. &

21.1 22.3
Break or : Break or .
strength | 2 | strength | Size
Pounds Count Pounds Count
90. 5 21. 50 87.5 21. 25
87.5 21. 50 $0. 0 Diy
98. 0 21.00 98. 5 20. 50
90. 0 20. 50 98.0 Dileeie
82.0 22. 25 91.0 21. CO
89.5 21. 25 93. 0 20. 00
87.0 225ml O65) 20. 00
92.0 21. 00 91.0 20. 75
93. 0 21. 00 86. 0 1 22. 00
92.5 21. 00 102.0 20. 25
1 100.0 20. 75 94.0 20. 50
88. 0 21. 25 92.0 21. 00
95. 5 1 20. 25 92.0 20. 75
90. 5 20. 75 86. 0 22. 00
179.5 Diteiio 97.5 20. 25
81.5 21. 25 92.0 20. 75
87.0 1 22. 50 98. 5 1 20. 00
99.0 20. 75 92.0 21. 50
86. 5 22. 00 182.5 21. 75
85. 0 22. 25 89.0 7A 245
90. 0 21. 00 89. 0 20. 75
92.5 21. 50 93. 0 21. 50
93. 0 21. 00 90. 5 21. 00
98.0 20. 75 91.5 20. 75
2, 168. 0 510. 00 | 2, 223.0 502. 50
90. 33 21. 25 92. 63 20. 94
QTD cnet o bee SBI |e kee
Per cent | Per cent | Per cent | Per cent
4. 66 2. 06 4. 26 2. 39
22. 69 10. 59 25. 91 9. 55

The average strength of yarns of each twist of each grade is given
in Table 8, which was compiled for each grade from data similar
to those shown in Tables 6 and 7.

TaBLE 8.—Strength of yarn in pounds per skein of 120 yards (22s yarn spun from
eastern and western upland cotton)

Grade of cotton

s Turns
Kind of cotton per
inch 1 2 3 4 5
Lbs. Lbs. Lbs. Lbs. Lbs.
19.9 85. 2 86. 8 87.9 82. 9 86. 4
PAE 85. 3 88.0 88. 4 84. 4 85.5
Wasterines ee 22.3 84.1 87.4 88. 0 81.0 86.0
Averages 2 222i. 84.9 87.4 88. 1 82.8 86.0
19.9 | 102.6 96.0 82.8 92. 2 87.0
21.1 103. 7 97.2 83. 4 90. 4 87.3
Western. ____-_..__- 22.3 | 102.0 96.1 83.3 90. 2 88. 2
Average: 2 5|ioes 2! 102. 8 96. 4 83. 2 90. 9 87. 5

338065°—27——2

Lbs.
78. 4

Lbs.

10 BULLETIN 1488, U. S. DEPARTMENT OF AGRICULTURE

Figure 2 is a graphic presentation of the strength of 22s warp
yarn spun from each grade of eastern upland cotton. The. dash
line indicates the actual conditions, the point of intersection of the
dash line with the vertical grade line being the average strength of
the yarn produced from that particular grade. Strength does not
follow the grade in all cases, but there is a tendency in that direction.
Note that only grades No. 2 and No. 3 equaled or exceeded the new
Draper standard, the well-known commercial standard developed
as the result of much research at Hopedale, Mass. The solid line
is the best representative straight line through the data and indi-
cates that there is a tendency for the cotton to produce stronger
yarn as the grade becomes better.

Figure 3 is a graphic presentation of the strength of the yarn spun
from the different grades of western upland cotton. Note that Nos.
1, 2, 4, 5, and 6 exceeded the new Draper standard strength for 22s

POUNDS
PER
SKEIN

a New Pieper SLT! a ==.
85
80
75
70

5
GRADE NUMBERS

Fic. 2.—Strength in pounds per skein of 22s gray warp yarn spun from eastern upland cotton. The
crosses on the dash line indicate the average strength obtained from 72 observations, while the
solid line ‘‘A’’ is the best representative line. Note the tendency for the strength to increase
as the grades vary from No.9 to No.1. (See Table 8.)

warp yarn. On an average, the western upland yarn was found to
be 7.2 per cent stronger than the eastern, which may be due in part
to adverse weather conditions which prevailed in the Southeast
during the harvesting season of 1924.

Length and character of staple may or may not be affected by
conditions which influence grade. Grade is largely dependent upon
climatic conditions, care exercised in picking or harvesting, and
methods of ginning, whereas length and character are varietal char-
acteristics. For instance, two bales of cotton may be of the same
grade, but the yarn spun from one may be much weaker than that
spun from the other, even though the manufacturing methods and
conditions remain unchanged. Thus, the strength variation from
the trend line (figs. 2, 3, and 4) may be attributed to these conditions.

Figure 4 is a graphic presentation of the average strength obtained
by combining the results of the 72 determinations of each grade of
eastern and western lots (figs. 2 and 3). Note that in this case only

MANUFACTURING TESTS OF COTTON 1h

the average of grades 1 and 2 exceeded the strength of the new
Draper standard for 22s carded warp yarn.
Figure 4 shows that there is less variation in average strength of the
several grades from the best representative line than is shown in
POUNDS

PER
SKEIN

90

Ww
or ae ¢
100 vier c) 4
ie

Va New Draper Standard Bs ot@=a =
1 '

GRADE NUMBERS

Fic. 3.—Strength in pounds per skein of 22s gray warp yarn spun from western upland cotton.
The crosses on the dash line indicate the average strength obtained from 72 observations, while
the solid line ‘“‘A”’ is the best representative line. Note the tendency for the strength to increase
as the grades vary from No. 9to No.1. (See Table 8.)

either Figure 2 or Figure 3. This greater uniformity or decreased
variation from the trend line is due mainly to the fact that a greater
number of bales was used. The result for each grade was obtained

POUNDS

90

i New Draper Standard
| |

80

GRADE NUMBERS

Fic. 4.—A verage strength in pounds per skein of 22s gray warp yarn spun from eastern and western
upland cotton (average of results shown in Figs. 2and 3). The variation of the plotted data
from the best representative line ‘‘A”’ is less than in either Figure 2 or Figure 3. The strength
has a tendency to increase from grade 9 to grade 1

from 144 observations, 72 eastern and 72 western. This is permissible
since the same number of bales was used in the case of the eastern as
in the western cotton. In commercial mills this greater uniformity is

.

12 BULLETIN 1488, U. S. DEPARTMENT OF AGRICULTURE

obtained by mixing from 15 to 30 bales of cotton in the opening room.
If the bales were taken one by one and were not mixed, the manufac-
tured product would probably show streaks of high and low quality
rather than an average uniformity.

22s WARP YARN, BLEACHED AND DYED (SKEIN)

A portion of the 22s gray yarn of each grade was bleached and a
portion bleached and dyed in acommercial mill. The effects of these
processes upon the strength and brightness of the yarn were studied.
All grades were treated at the same time, that the same conditions

STRENGTH

d and Dyed, Blue

80
x *
70 |} K *,
e e
IN sienched (Single)
Bleached (Double) | = ——|__ geen? ®t sles coese eeee
\ ateceeeeeennaner®
60 =
[ik oe oe ae |
50 = I Sea
9 8 7 6 5 4 3 2 1

GRADE NUMBERS

Fic. 5.—Skein strength of 22s gray and treated yarns spun from eastern cotton. (21.1 turns per
inch in yarn.) The gray yarn is stronger than the treated yarn of the same grade. The extent
re wee a double bleaching has decreased the strength of the yarn from that of the single
bleach is shown

might prevail in all cases. One lot was given a single bleach, a second
lot was given a double bleach, and a third lot was dyed on the single-
bleach base. The results of the strength tests on these lots are shown
eraphically in Figures 5 and 6.

Single bleach reduced the strength of the eastern yarns approxi-
mately 11 per cent. The double bleach reduced the strength of the
eastern yarns 23 per cent. The double-bleached yarn was 13 per
cent weaker than the single-bleached, indicating that double bleaching
has a marked detrimental effect on the strength of the yarn. The
dyed blue yarns were 6 per cent weaker than the gray yarns. The
above percentages are based on averages of the nine grades (fig. 5).

MANUFACTURING TESTS OF COTTON L3

The single-bleached western yarns were approximately 10 per cent
weaker than the gray, whereas the double-bleached yarns were 22 per
cent weaker than the gray. The double-bleached yarns were 13 per
cent weaker than the single-bleached. The dyed blue western yarns
were 5 per cent weaker than the gray. These percentages are based
on the averages of grades 1 to 9 (fig. 6).

STRENGTH

IN POUNDS
SKEIN TEST

100
30
Bleached and Dyed Blue
ad
we MOG © mums @ mace @ 4, “
80
70
60
GRADE NUMBERS
Fic. 6.—Skein strength of 22s gray and treated yarns spun from western cotton. (21.1 turns per

eon in yarn.) The gray yarn is stronger than the treated yarn. The decrease in strength of
grade 3 is probably due to the influence of weather or cultural conditions upon the strength and
character of the cotton. The extent to which double bleaching has decreased the strength of the
yarn from that of the single bleach is shown

A comparison of the results in Figures 5 and 6 and of the two
preceding paragraphs shows that the eastern and western cottons
were similarly affected when bleached and dyed by the same method.

22s WARP YARN (SINGLE STRAND)

The single-strand method is advocated by some manufacturers in
preference to the skein method on the supposition that it gives a truer
index of the quality of the yarn. Correction has been made for differ-
ences in the size of the yarn by multiplying the average machine
break of the single strand by the average size found in the skein break
of the corresponding yarn and dividing this result by 22. Figures 7
and 8 show graphically the results of the single-strand tests.

14 BULLETIN 1488, U. S. DEPARTMENT OF AGRICULTURE

There is a marked similarity between the results of the single-
strand tests and of the skein tests, although the results do not check
in every instance. It is possible that such differences may be due
to the fact that single-strand tests do not cover so large a quantity
of yarn as do the skein tests.

STRENGTH
IN OUNCES 42

SINGLE
STRAND TEST

1] —¢
?

!
’ Bleached and Dyed Blue

4

7?
g

RUE +1}
/

e
\ Bleached (Sing!
e

|
: Or ey
Seales,

GRADE NUMBERS

Fic. 7.—Strength in ounces per single strand of 22s gray and treated warp yarns spun from the
eastern upland cotton. (21.1 turns per inch in yarn.) The gray yarn is stronger than the
eee yarns. The double bleach has decreased the strength of the yarn from that of the single
bleac

28s TWO-PLY YARN (SINGLE STRAND)

The 28s two-ply yarn, mercerizing twist, spun from each grade of
cotton was bleached; bleached and mercerized; and bleached, mer-
cerized, and dyed. These yarns were broken by the single-strand
method, the results of which were corrected on the basis of the size
of gray yarn. The average strength of yarns finished by two plants
is shown graphically in Figures 9 and 10. oO

The results of single-strand tests of the two-ply yarn show a |
tendency for the yarns spun from the higher grades to have a greater
breaking strength than those spun from the lower grades,

MANUFACTURING TESTS OF COTTON 15

IRREGULARITY OF YARNS

The specifications for the purchase of yarns are usually based
upon the average strength and size. The average strength alone,
however, is not always a true index of the quality of the yarn. Two
yarns may have the same average strength but differ in uniformity.
There are several methods of determining the irregularity of yarns,
two of which are used herein: (1) Plotting the range of strength

STRENGTH ay
IN OUNCES

SINGLE
STRAND TEST

Bleached
and dyed

Bleached
( Single)

7 e,
oe”
we” “N\ Bleached

POH Pat a aa CL oa ae (Double)

GRADE NUMBERS

Fic. 8.—Strength in ounces per single strand of 22s gray and treated warp yarns spun from the
western upland cotton. (21.1 turns per inch in yarn.) The gray yarn is stronger than the
LS a yarns. The double bleach has decreased the strength of the yarn from that of the single

eac

from the corrected breaks, and (2) calculating the percentages of
average deviation and extreme variation of the breaks.

22s WARP YARN (SKEIN)

Figures 11 and 12 show graphically the irregularity of the skein
break of the 22s single yarn spun from the eastern and western cottons
respectively (method 1). This irregularity is indicated by the angle
the curve makes with the horizontal—the greater the angle of the
curve, the more irregular the yarn, the smaller the angle, the more
uniform the yarn. The percentage of extreme variation of the cor-
rected breaks, represented by any one of the curves on Figure 11 or

16 BULLETIN 1488, U. S. DEPARTMENT OF AGRICULTURE

Figure 12, may be obtained by dividing the difference between the
maximum and minimum strength by the average strength, and multi-

plying this result by 100. As an illustration, take curve No. 8 in ©

Figure 11: 79 pounds (maximum strength on curve) minus 68.5
pounds (minimum strength on curve) equals 10.5 pounds (difference).
Dividing 10.5 by 73.7 (the strength found on the 50 per cent vertical
line) and multiplying this result by 100 gives 14.25 (per cent extreme
variation for this particular grade). This method is applicable to
any grade.

STRENGTH
IN OUNCES

SINGLE
STRAND TEST

21

20

no Bleached

(Single)

GRADE NUMBERS

Fic. 9.—Strength in ounces per single strand as determined by 32 observations of each grade of
28s two-ply yarn spun from eastern upland cotton. (21.1 turns per inch in yarn.) The mercer-
ized yarns were stronger than the gray and the gray yarns were stronger than the bleached

_ The percentage of breaks below a specified magnitude or standard
may be read from these curves. As an illustration, take Figure 12
and read on horizontal 100-pound line to the intersection of No. 1
curve and down on a vertical line through this point, which shows
that 21 per cent of this grade broke below the given magnitude,
100 pounds. Similarly, other percentages of breaks may be read.
In judging the relative values of yarns it is important to know the
percentage of these low breaks as well as their distribution.

The average deviation is determined by averaging the differences
between each item and the average (disregarding plus and minus

MANUFACTURING TESTS OF COTTON 17

signs), dividing this result by the average break and then multiplying
by 100 (method 2). The percentage of extreme variation is deter-
mined by subtracting the minimum from the maximum and dividing
by the average break and then multiplying by 100 (method 2).
Similarly, the irregularity of the size or number of the yarn may be
determined. (See Tables 6 and 7 for data.) Method 1 has some
advantage over method 2, for the reason that the results may be
more readily grasped from a graph than from a table of figures.

STRENGTH
IN OUNCES
SINGLE
STRAND TEST
: Rye eee

21 ip Oe =
Seems,” ae
20 a

3 2 |

GRADE NUMBERS

Fic. 10.—Strength in ounces per single strand as determined by 32 observations of each grade of
28s two-ply yarn spun from western upland cotton. (21.1 turns perinch in yarn.) The mercer-
ized yarns were stronger than the gray and the gray yarns were stronger than the bleached
except on grade No.

The results of these calculations indicate that there is no definite
relation between the grade and the uniformity of the 22s yarn.
Averaging the nine grades together (method 2) gave the results
shown in Tables 9 and 10. These figures indicate that this par-
ticular double bleach caused the yarn to become more irregular,

18 BULLETIN 1488, U. S. DEPARTMENT OF AGRICULTURE

POUNDS PER SKEIN
OF 120 YDS.

S2

86

84

82

80

78

76

74

72

70

68
6) 10 20 30 40 50 60

70 80 90 100

PER CENT OF CUMULATIVE BREAKS
Fic. 11.—Range of strength of 22s warp yarn spun from eastern upland cotton. The range of

strength of the yarn is represented by a curve according to grade.
curve makes with the horizontal, the more irregular the yarn

The greater the angle the

r %,

————$—$—

MANUFACTURING TESTS OF COTTON

POUNDS PER SKEIN
OF 120 YDS.

ify)

100

98

96

94

92

90

88

86

84

82

80

78

76

74

0 10 20 30 40 50 60 70 80
PER CENT OF CUMULATIVE BREAKS

Fic. 12—Range of strength of 22s warp yarn spun from western upland cotton. The range of

strength of the yarn is represented by a curve numbered according to grade.
the angle the curve makes with the horizontal, the more irregular the yarn

The greater

20 BULLETIN 1488, U. S. DEPARTMENT OF AGRICULTURE

TABLE 9.— Average irregularity of the nine grades of eastern and western yarns }

Average deviation

|
Kind of yarn Eastern Western
Strength Size Strength Size

Per cent | Per cent | Per cent | Per cent

Gra Yeo he Fe a Ln page Set tA teh Diba ae pine ae 3. 61 1. 85 3. 94 74, 18°
iBleached=(Sin gle) a1 Ae OMe Lara eee Bee a foe IE, ENE gies cote eee 3. 79 2. 06 3. 65 1. 76
iBleached*(double) 2. ae aoe ea as tee eo See 4.60 2. 46 4.49 Qu55
Dyed oe Sei Se RoE eee ote oe es ee BR ee ee ee 3. 39 1. 97 3. 50 1. 88

Average extreme variation

Grayeo2 2 Ei AS oe et ce oe Pad 5 ae bee 18. 20 9. 99 20. 56 10. 40
‘Bleached: (single) We | a Bie Sees Ey Sa Oe: een ee 18. 43 10. 60 18. 16 8. 64
‘Bleached *(double)2 se =o a eee eee 20. 58 11. 73 QT 11. 43

9. 57

DV Od Be 2s aie ene ian Be 2D, cane ae a eee ep eed ea 16. 55 10. 29 17. 22

1 Obtained by 24 observations made on 22s yarn with 21.1 turns per inch (skein test),

TABLE 10.—Average irregularity of the strength of the nine grades of eastern and
western 22s yarns }

Average extreme

Average deviation Seen ANT GO);

of strength

strength
Kind of yarn .
2 Eastern | Western | Eastern | Western
Per cent | Per cent | Per cent | Per cent
RT oe at res I SPL a 1 ee eg = a 8. 65 8. 63 44, 72 40. 85
IBlEaCHEd AGI GC yee ee a ae as 2 8. 38 7. 72 46. 39 42.70
iBleicheds(Goulble) =z wet > Les ee ee Ne Mines eee 10. 51 10. 40 52. 73 55. 54
DD Ved sR AR Me fF eS ot Een SS Bae eb ee ae 8. 96 9. 49 45. 88 48. 10

1 Obtained by the single-strand method from 32 observations of each grade.

The results shown in Tables 9 and 10 were obtained from the same
yarn, the only difference being in the method of testing. Table 9
gives the results of the skein tests, whereas Table 10 gives the results
of the single strand tests. The latter method checked the skein tests
in respect to the relative uniformity of the single bleach and double
bleach.

28s TWO-PLY YARN (SINGLE STRAND)

The irregularity of the strength of the 28s two-ply yarn (single-
strand test) finished by different mills is given in Table 11. Note
that the percentages are less than those on the single yarns.(See
Table 10.) This conforms to the general belief that ply yarns are
more uniform than single yarns,

oO)

MANUFACTURING TESTS OF COTTON Doll

TasBLeE 11.—Irregularity of strength of 28s two-ply yarn (single-strand test)

Boies Average extreme
Averace deviation Sarmiion iat

of strength t h
Mill and kind of yarn strengt

Fastern | Western | Eastern | Western

eS Per cent | Per cent | Per cent | Per cent

GT is ak ak OE ee 6. 25 7. 34 32. 42 43. 29

Ipleaeneda(Gin Ole) es ee Te a eee See ae eee 6. 01 6. 14 33. 50 35. 68

iBleacheds(double) tee se a Oe es ae 6. 81 Bi 35. 70 27. 93

IMIG ROAD Lert aS ea aa ee ie eee eee oad OL Oe eel Se a en ee 7. 48 7. 81 39. 51 39. 53

Ve eteenenms toes SRT Ce) AS Le a eS See I 7.10 7. 45 35. 53 39. 32
MILL H

Gry ee ee ee Rae Pe OTe, 2 Seen a eA SAE SS 6. 25 7. 34 32. 42 43. 29

Bleached (Gin gle) eek oe 26 eee SS ee ee eR et eg a oy 6. 90 6. 81 34. 47 37. 85

Bleached (COU) ie ects re eae sek a PM ere Ra te ede | 6. 24 8. 20 33. 84 41.14

INIGINES HVAT Lae bas et 6 Ee ey ee ESS Oe ee ee eee 6. 67 7. 03 37. 95 38. 34

DD TCE be ees es SORE FO eS Regt eae geen ee ae en ee ae 7.18 7. 01 39. 21 35. 38

1 Average of grades Nos. 7, 8, and 9 only.
VARIATION OF THE SIZINGS?

The question has frequently arisen as to what variation in the size
or weighings of the stock at different manufacturing processes may
be expected. During this test weighings were made as follows:

Breaker picker lap, 2-yard lengths, weighings from each Jap.
Finisher picker lap, 2-yard lengths, weighings from each lap.
Card sliver, l-yard lengths, 24 weighings.

Drawing sliver, l-yard lengths, 24 weighings.

Roving, 12-yard lengths, 24 weighings.

Spinning, 120-yard lengths, 24 weighings.

From these weighings the percentages of average deviation and
extreme variation were determined. Table 12 gives the average of
the nine grades.

TABLE 12.—Percentages of average deviation and extreme variation in the sizings of
stock at the different manufacturing processes

boner Average extreme
Average deviation SATO
Stock

Eastern | Western | Eastern | Western

Per cent | Per cent | Per cent | Per cent
PO ARE Rep O MAD Oe eon eee BON eS RSI oe 3 3. 94 4.07 12. 56 13. 74
LOTTIES TS SON 10 Cn ie a i es Sf 2 ee re ee 1. 28 A Re 3. 92 3. 62
pEdssiivic tee wee Poe ES ee Sessa Na ee 4, 94 6. 10 20. 88 24. 69
HS SOTA WANONS TVET eos Ue i ee Ak ERE 2. 33 2. 10 10. 08 9. 62
MCCOMMEGh AWN GIS Vee. wu re le eS . 95 “thy 5 inal 4. 73
SSEPCEREO UAH Cp reerp eke OS 880 ONS SE Ad RPT ESE eae 1B y 1.05 5. 48 5. 19
VerInediaperOvin ia. <- i252 5.6 200 Ui eek! Adee 8 1. 37 1. 27 | 6. 16 5. 73
IBMMGSIrATMES TO MEIE oe pee ot 2 2 8 Oe een mE ea ee ae 2. 40 2.27 12. 25 10. 30
Martin (69s Seg riis eens tks Pee ee a Peet ole bey 1. 85 2. 13 | 9. 99 | 10. 40

3 Sizing, or size, (trade names) as used throughout this bulletin refers to the hank or the number of the
yarn.

pips BULLETIN 1488, U. S.. DEPARTMENT OF AGRICULTURE

DIFFERENCE IN VALUE BETWEEN GRADES

In judging the advantages of one grade of cotton over another
gerade several factors should be considered: Cost of the raw stock,
storage and handling charges, quantity of waste discarded, value of
waste, number of machine hours required to handle the cotton, and
selling price of yarn.

To illustrate the relative importance of these factors, the writer
has derived a formula based on estimated average conditions. The
following discussion of these factors may aid in the interpretation of
the formula.

The differential in price of raw stock, both of the low grades and
of the high grades on the basis of Middling cotton, fluctuates with
supply and demand. However, the five-year average prices in cents
per pound for grades 1 to 9, respectively, based on the average of the
10 designated spot cotton markets as of the first day of each month,
September 1, 1920, to August 31, 1925, inclusive, are as follows: 24.83;
24.46; 24.06; 23.60; 23.02; 22.05; 20.73:19.59: 18.47.

Except in special cases the total storage and handling charges are
greater for low-grade cotton than for high-grade cotton when the
same given quantity of finished yarn is desired.

The lower the grade, the higher the waste percentage. Table
No. 4 shows the waste percentage to range from 5.50 on grade No. 1
to 14.44 on grade No. 9. The value of this waste depends upon
supply and demand. The estimated prices or relative values at the
time of these tests, however, were found to range from one-fourth
cent per pound for picker motes from grade No. 9 to 17 cents per
pound for card strips from grade No. 1. At this time grade No.1
cotton was quoted around 25 cents per pound. (See Figure 13 for
approximate relative values of waste and average prices of cotton
as above given.)

The cost for picking and carding in this formula is figured on the
machine-hour basis rather than on pounds delivered. The cost of
operating the card per hour on low-grade cotton is as much as, and
in some cases more than, the machine-hour cost for high-grade
cotton. This cost per hour prevails whether the card is producing
or being ground. More frequent grinding of the card is required
when low grades are being run. As an example, most cards need
grinding after 1,200 to 1,500 pounds of low-grade cotton have been
fed, whereas 1,600 to 2,200 pounds of high-grade cotton may be run
before grinding is required. ‘Therefore the number of hours lost in
grinding is greater when low grades are carded.

The price of yarn fluctuates as well as the differential in price
between yarns from different grades of cotton. Therefore this
price factor can be determined only at the time when the problem
arises, using the prices as of that period.

The gross weight of cotton required to produce a given quantity
of yarn from any grade of cotton may be determined by dividing the
pounds of finished yarn by 1 minus the percentage of total waste
expressed decimally.

This formula is not to be interpreted as a system of cost account-
ing, but values obtained by the usual cost systems may be substi-
tuted in the formula for the purpose of obtaining the practical
difference between the grades under consideration.

Cr)

MANUFACTURING TESTS OF COTTON 23

There are certain factors which can not be included in any formula
for determining the value of grade. For example, a mill may have
built up a trade on converters’ goods, in which bleaching and finishing
qualities are chief requisites. In such cases the use of low grades
may be inadvisable, even though the prices are materially lower than
those for high grades. But if the product is for other uses where

Cotton
(5-year average) N

20

Card strips et
15

Card motes and fly

GRADE NUMBERS

Fic. 13—Average price of cotton by grade and estimated prices of waste from cotton of the several
grades. Relative values of grades are based on five-year averages as of the first day of each
month, September, 1920, to August, 1925. The relative values of waste are based on estimates
as of August, 1925, obtained by personal interviews with waste dealers and cotton manufacturers

bleaching is not a chief requisite, the low grades might be used more
advantageously in case the spread in prices between grades was
great.

The formula will show the immediate monetary difference between
the grades, but the choice of the grade must rest upon the discretion
of the management of the mill.*

4 Valuable suggestions regarding this formula have been received from R. E. Loper, specialist in textile
cost service and William Smith, principal, New Bedford Textile School.

24 BULLETIN 1488, U. S. DEPARTMENT OF AGRICULTURE

If M= Market price of yarn of grade under consideration
Then (M3— Y3) —(M,— Ys) = Advantage of grade 3 over grade 9.
The value of Y may be determined as follows:

(osxay+(Pxa@)+(G*) omp+a—wo[ (57) + (257) #] cate— vw
Liab ECR Oe Cs os aie ee

Where Y=cost of varn per pound,

CS=cost per pound for storing and handling, : ‘ae
G=gross weight of cotton, y
P=price of cotton (grade under consideration),

T=tare (bagging and ties),
F=amount fed to machine per hour,
p=pickers (used as subnotation),
CM=cost per machine hour (labor and overhead),

W=percentage of waste removed expressed decimally,
c=cards (used as subnoitation),

N=number of pounds fed between grindings of card,
H=number of hours required for each grinding of card,

Vw=value of waste and tare from G pounds of cotton,

S=cost per pound subsequent to cards through spinning,
s=processes subsequent to cards (subnotation for front waste).

The value of the waste (Vw) is the sum of the values of the com-
ponent parts—tare, picker motes, card motes and fly, card strips,
and front or reusable waste.

STRENGTH OF CLOTH

Each grade of cotton was spun into 28s filling yarn and woven into
a five-harness filling-effect sateen, using a high grade 40s two-ply
untreated warp yarn. Portions of this cloth were bleached; portions
were bleached and mercerized; and other portions were bleached, mer-
cerized and dyed by different finishing plants. The cloth was tested

POUNDS

65

60

55

50

GRADE NUMBERS QO
ia. 14.—Effect of bleaching on the strength of the eastern cloth. Bleaching tends to weaken the cloth

fillingwise, using a l-inch strip with the jaws of the machine set 3
inches apart. Five observations were made of each finish—gray,
bleached, dyed, and mercerized. The resultant average of the five
observations of each treatment is denoted by the intersection of the
slope line with the vertical line representing the grade of cotton (figs.
14, 15, 16, and 17.) |

MANUFACTURING TESTS OF COTTON 745°

The cloth was finished in two different mills. The results of the
average strength tests of the cloth are shown graphically by Figures
14, 15, 16, and 17.

POUNDS

o%
of Bleached and
Po Mer cerized
a %.

65 a =

60

55

50

GRADE NUMBERS

Fic. 15.—Effect of mercerizing on the strength of the eastern cloth. Mercerizing tends to
strengthen the clot

The main fact brought out by the cloth tests was the effect of
the different finishings on the strength of the cloth. Bleaching
reduced the strength of the cloth approximately 7 per cent, mer-

5
GRADE NUMBERS
Fic. 16.—Effect of bleaching on the strength of ene western cloth. Bleaching tends to weaken
the clot

i)

_cerizing increased the strength approximately 1.5 per cent, and
dyeing on a bleached base reduced the strength approximately 5.5
per cent.

MANUFACTURING PROPERTIES

A considerable quantity of dust and fly was given off while the
the lower grades (Nos. 7, 8, and 9) were being machined. Con-
siderable pin trash continued to adhere to the fibers after they had

26 BULLETIN 1488, U. S. DEPARTMENT OF AGRICULTURE

been passed through the pickers and cards. Some of this trash
dropped from the fibers as the cotton passed through the rolls of
the fly frames and spinning frames, but small particles of trash
were noticeable in the gray yarn of the lower grades. These factors
should be given consideration when the use of low grades is con-
templated.

A record of the broken ends occurring while the yarns were be-
ing spun was kept. This record indicated but a small difference
in the end breakage except in the case of western grade No. 3. Ex-
cess difference there may be due to the general drop in strength of
this grade (fig. 3). 7

FINISHING PROPERTIES
In the bleached and dyed yarns there was a noticeable difference

in the brightness of the grades. This difference was less notice-
able in the mercerized yarns.

[Bleach ed and
A Mercerized
ee* |"e

GRADE NUMBERS

Fic. 17.—Effect of mercerizing on the strength of the western cloth. Mercerizing tends to
strengthen the cloth

Filling spun from each grade of cotton was used in a five-harness
filling-effect sateen with a constant warp of good quality of 40s
two-ply yarn. Portions of this cloth were bleached; portions were
bleached and mercerized; and portions were bleached, mercerized,
and dyed. Results of the strength tests on this cloth have been
described (figs. 14, 15, 16, and 17). Results of the tests of the
bleached and mercerized cloth for brightness are shown graphically
in Figure 18.°

In the case of the bleached cloth of this test it was found that
in most instances an increase of brightness was accompanied by a
decrease in strength or vice versa.

The brightness of the gray cloth woven from grades 6, 7, 8, and 9
was increased by the removal of the foreign matter from these grades.
The increase in brightness of the bleached cloth over the mercerized

5 Method recommended by E. E. Chandler, formerly of the Bureau of Agricultural Economies, con-
sisting of placing the cloth on blocks of wood in a dodecahedron and measuring the reflection ot light by
the use of a photometer.

Oo.

MANUFACTURING TESTS OF COTTON

VALUE eee
oo” 7. eache:
e ~S, | i | ees ee Ty TING
190 ee ee Date
ay,
e
“s
180 pia
Ch e
x ce
A rceri:
Ho Bleached and Mercerized \
e
170 ‘

16

27

(eo) (2)
iv}
e

15

14

13

12

(@) (oe) (2)

: al cen
100

Gray Cloth

90
IN

Cotton (Working Standards )
80
70

50 ee a 2 = SE

60
cS) 8 7 6 yrs 4 3 2
GRADE NUMBERS

Fic. 18—Comparative brightness of cotton and cloth as determined by photometric readings.
The brightness of the gray cloth of grades 6, 7, 8, and 9 is considerably improved over the
brightness of the corresponding grades of cotton. The bleached cloth is brighter than the
mercerized. Grade No. 5, valued as 100, is the base for all photometric readings. Grade No. 1
(A) is taken from a box of the working standards, whereas grade No. 1 (B) is from a special
sample of grade No. 1

l

28 BULLETIN 1488,.U. S. DEPARTMENT OF AGRICULTURE

cloth is probably due to the fact that fibers are transparent after
mercerization, hence some of the light is absorbed instead of being
reflected (fig. 18).

The strength of the gray cloth fillingwise tends to follow the
strength of the gray yarns. The strength of the latter is greater
because more twist was inserted in the warp yarn and more threads
were tested in each instance (fig. 19).

STRENGTH
IN POUNDS

70

eS 8 7 6 5 4 3 2
GRADE NUMBERS

Fic. 19.—Strength of gray cloth compared with gray warp yarns spun from the same grades.
(Average of eastern and western.) The strength of the gray cloth fillingwise tends to follow
the strength of the gray warp yarn from the same grade

SUMMARY

These spinning tests were conducted te determine the relative
intrinsic value of each of the nine white grades of American upland
cotton.

For comparative purposes all grades were run under similar
mechanical and moisture conditions.

The average percentages of visible waste from the nine grades of
cotton representing the universal cotton standards, when run under
these conditions ranged from 5.50 per cent on grade No. 1 to 14.44
per cent on grade No. 9. (See Table 4.)

The strength of the yarn did not always follow the grade of the
cotton, but there was a tendency for the higher grades to produce
stronger yarns. Bleached yarns of all the grades were weaker than
the corresponding gray yarns, whereas the mercerized yarns were
stronger. The strength of these finished yarns followed closely the
strength of the gray yarns.

The irregularity of the sizings of the stock in process and of the
strength and sizings of the yarns was independent of the grade of the
cotton. Double-bleached yarns were more irregular than single-
bleached. No marked difference was noted in the regularity of gray,
single-bleached, and dyed yarns. -

A formula has been suggested for estimating the difference in the
relative values of the grades.

0.)

MANUFACTURING TESTS OF COTTON 29

The different grades of cotton were spun into 22s warp yarn satis-
factorily. A considerable quantity of dust and fly was given off
when running grades 7, 8, and 9.

The finishing properties of the lower grades for bleaching and
dyeing were not so satisfactory as those of the higher grades. The
lower grades produced less bright yarns than did the higher grades.
Brightness of the lower grades may be obtained by bleaching, but
this is usually done at a sacrifice of strength.

The strength of the finished 22s warp yarns and the 28s two-ply
soft twisted yarns followed generally the strength of the gray yarns.
The effect of the finishing was practically the same for eastern and
western yarns.

The strength of the gray cloth followed closely the strength of the
eray yarns.

The strength and regularity of the finished yarns and cloth varied
with the finishing plants and the methods used.

ORGANIZATION OF THE
UNITED STATES DEPARTMENT OF AGRICULTURE

March 24, 1927

NEETCLOTY Of A OTUCUUEULT C2. ame a rate = eam Ane W. M. JARDINE.
SSUSUGTEL ISCCTCLET Ye eo rates ate ey ed ae R. W. DuN.uap.
Director ofuscrentifre Works 12 eae eee A. F. Woops.
Director of Regulatory Work = os. 2s 2 as WALTER G. CAMPBELL.
Director Of, PreLenStone WW Opies 22. aan sen nee C. W. WARBURTON.
Dincetar Of hp fOTrmaltoneee = ah eee eee eee NELSON ANTRIM CRAWFORD.
Director of Personnel and Business Adminis-

EGR TT Oost pages a ey Se SDN aay Seta A W. W. STocKBERGER.
ISOUL CREO T: Cmca ve yay Ce ns: NaN ica a kay ey ec RO R. W. WILuIaMs.
Wicathersh urea sae) < sate PIs ee ee Cuarues F. Marvin, Chief.
Bureau of Agricultural Economics__-___-_-__- Luoyp 8. Trnny, Chief.
BUrcai Of ANUNOL LNdUstTye =. 2 ee ee JoHN R. Mouter, Chief.
EURO Of AE LOATL IG ASUT Ufa es = a eee WiuiiaAmM A. Taytor, Chief.
TOR CST US CU COM Veer oid et yA alae eLearn W. B. GREELEY, Chief.
Bureau OpuCRemistry ois. see. Lae ees C. A. Browne, Chief.
TSURECALSOF SOULS tw see Lami fans Del cepa eae Mitton WHITNEY, Chief.
Bauecan. Ojplmtomologys i. 2 Fe a ee L. O. Howarp, Chief.
Bureau of Biological Survey. —- 22 2 ee EK. W. NE son, Chief.
bureanop Public hoadsi2-. - 3. ayes Tuomas H. MacDona.p, Chief.
BUReGi Of OMe HEOnOMmiCs. o. Saws eee LovIseE STANLEY, Chief.
BURL op Dari LnadUstry = =. ae eae C. W. Larson, Chief.
Ojieeroy Hc periment stations + 2 Fe E. W. ALuEn, Chief.
Office of Cooperative Extension Work___----- C. B. Smitu, Chief.
LEAD HET aR aE ee AEN RE iy SE a BRS, CLARIBEL R. BARNETT, Librarian.
Kederal Horticultural Board.2 _- 2 ae ee C. L. Maruatt, Chairman.
Insecticide and Fungicide Board_______--__- J. K. Haywoop, Chairman.
Packers and Stockyards Administration _____ Joun T. Carne III, in Charge.
Grain Futures Administration.____________- J. W. T. DuvEL, in Charge.

This bulletin is a contribution from

Bureau of Agricultural Economics___------- Lioyp 8. Trenny, Chief.
Division of Cotton Marketing..____---_- ArtHUR W. PautMgEr, Chief Market-
ing Specialist, in Charge.

30

ADDITIONAL COPIES

OF THIS PUBLICATION MAY BE PROCURED FROM
THE SUPERINTENDENT OF DOCUMENTS
GOVERNMENT PRINTING OFFICE
WASHINGTON, D. C.

AT

10 CENTS PER COPY