1.0
:; ""I~
:::....
25
A.:.g
g~ IIIII~
.:
~i~
L:.
: :-
2.0
u
1111.1
I
111111.4 111111.6
MICROCOPY 11ESOl.UTlON
:; 1I1I1i£ IIIII~
2.2
fl.'
I.lJLU..
--
"
1.0
I~
L:.
111111.
25
.
I~ ~~I~
~
a.:;
1.1
--
11111
u.sr
CHART
NAUONAI IIUREAU Of STANIlAIW, 1%< A
L..
m~
••
Lll.Ol.o.
111111.25 111111.4
MICllOCOPY RESOLUTION
111111.6
n S1
CHAIli
NAII()NAI lillI/fAll (If SIANl),\I!l", 1%1 A
CLEANING MACHINE-STRIPPED COTTON FOR EFFICIENT GINNING AND MAXIMUM BALE "'1ALVES Technical Bulletin No. 1540
::;:-....
r.­
:>::
c.: ,.
-:;:)
':,t
,
,­
.-­
26
c-..:>
,,;
-
,.,
,.
"
~::i
~
)
{/)
=>
'"
-,
"
<~I
.....\
Agricultural Research Service UNITED STATES DEPARTMENT OF AGRICULTURE CONTENTS
Page A Dstract
1
Introduction ...................................................... .
Methodology ...................................................... .
Equip,lnent ................................................... .
Sampling, fiber testing, and analysis .......................... .
1969 Experiment ................................................. .
Design .. , ..................................................... .
Results ...................................................... .
1970 Experiments ........... . ................................... .
Design ....................................................... .
Results ...................................................... .
1971 Experiment ................................. , ............... .
Design ....................................................... .
Results ...................................................... .
1972 Experiment ................................................. .
Design ........................................................ .
Results ........................................' .............. .
Cleaning recommendations ........................................ .
Appendix ........................................................ .
1
2
2
3
3
3
3
7
7
7
10 10 11 13 13 13 16 18 ILLUSTRATION
Fig.
1. Recommended cleaning-machinery arrangement for machine­
stripped cotton ...............................................
16 TABLES
1. Range of foreign matter in machine-stripped cotton .......... .
2. Effects of seed-cotton cleaning on moisture and foreign-matter
contents, cleaning efficiencies, and ginning rates, 1969 ....... .
3. Effects of cleaning treatments on fiber properties, bale weights, and bale values, 1969 ........................................ .
4. Effects of lint cleaning on moisture contents and fiber and yarn properties, 1969 ....................................... .
5. Effects of seed-cotton cleaning on moisture contents, fiber prop­ erties, and foreign-matter contents of three cotton varieties, 1970 ............................................... '. ........ .
6. Effects of lint cleaning on moisture contents, fiber properties, waste removal, bale weights, and bale values of three cotton varieties, 1970 .............................................. .
7. Effects of lint cleaning on fiber lengths and nep contents of three cotton varieties, 1970 .................................. .
8. Effects of lint cleaning on yarn quality of 'Tamcot 788', 1970 ..
iii
2
.
"
5
6
7
8
8
9
Page
9. Effects of lint and seed-cotton cleaning on moisture and foreign­
matter contents, nonlint contents, and ginning rates, 1971 ......
10. Effects of cleaning treatments on moisture contents, bale
'weights, fiber and yarn properties, and bale values, 1971 ......
11. Cotton-cleaning machinery used in 1972 experiment ..........
12. Effects of seed-cotton cleaning on moisture and foreign-matter
contents, fiber properties, ginning rates, bale weights, and bale
values, 1972 .................................................
13. Effects of lint cleaning on moisture contents, bale weights, fiber
and yarn properties, and bale values, 1972 ....................
A-I. Principal features, operating speeds, settings, and adjustments
for equipment used in 1969-72 experiments ..................
A-2. Grade index values for various grades of cotton, 1969-72 .....
A-3. Results of statistical analysesfol' the 1970 experiments. . . . . . . .
10
11
13
14
15
18
18
19
The data in this publication were collected during 1969-72. The rec­
ommendations remain useful to ginners of machine-stripped cotton.
Wm;hington, D.C.
iv
Issued Jan uary 1977
CLEANING MACHINE-STRIPPED COTTON FOR EFFICIENT GINNING AND MAXIMUM BALE VALUES By
Roy V. BAKER, EUGENE P. COLUMBUS, and J. 'WELDON LAIRD, agriCltltu1"a1 enginlle1's, South Plains Ginning Re­
search Lab01'atory, Agr'icnltm'ul Resca1'ch Service, U.S. Dcpa1·tmcnt of Ag1'iculture, L1Lbbock, Tex.
ABSTRACT
Experiments were conducted over a 4-year period to determine the
amount of conventional seed-cotton cleaning machinery and number of
lint cleaners required for machine-stripped cotton to achieve acceptable
ginning performance, maximize producer returns, and insure satisfactory
end-use performance of lint. Seed cotton was processed through various
combinations of cleaning-machinery sequences and was subjected to one,
b\'o, and three stages of lint cleaning. The combined test data indicated
that machine-stripped cotton having a lint turnout of 22 percent (or
more) can be satisfactorily cleaned with two extractors, two inclined
cleaners, and an air-line cleaner. Cotton having a lint turnout of less
than 22 percent would benefit from an additional stage of extraction.
Two stages of lint cleaning were near optimum for bale value and fiber
quality and produced slightly higher bale values than one stage of clean­
ing. Lint cleaned by three stages of lint cleaning was generally worth
no more than that cleaned by two stages and often had lower fiber and
yarn properties. Lint that received no lint cleaning was heavily dis­
counted in price, and yarn made from this lint was low in appearance
and high in imperfections. These results indicated that gins processing
machine-stripped cotton should be equipped for two stages of lint cleaning.
INTRODUCTION
Approximately 30 percent of the U.S. cot­
ton crop is harvested by mechanical strippersJ
Cotton producers in the High Plains and Black­
lands of Texas use this method almost exclu­
sively. Other large stripper areas are located
in Oklahoma and eastern New Mexico.
Machine-stripped cotton requires rigorous
cleaning because of high foreign-matter con­
tent (table 1). The complete cotton boll and
1 Chat'ges for ginning cotton, ,:osts of selected serv­
ices incident to marketing, and related information,
sem;on 1972-73. U.S. Dep. Agric., Econ. Res. Servo
[Rep.]ERS-2, 1 p. 1973.
varying amounts of stems, branches, and leaf
material are harvested during the stripping
process. Large pieces of foreign matter inter­
fere with the operation of gin stands and have
to be removed from the seed cotton before gin­
ning. Smaller foreign-matter particles do not
interfere with ginning, hut they do lower the
quality of the ginned lint and reduce the unit
price of the cotton. Effective cleaning systems
must be employed to achieve economical gin­
ning performance and to provide acceptable
monetary returns to the producer.
A series of experiments was conducted at
the South Plains Cotton Ginning Research
Laboratory, Lubbock, Tex., to determine the
1
TABLE
I.-Range of fo-reign matte-r in machine­
st1-ipped cotton1
Type of
foreign matter
Range in pounds per bale 2
Low
Typical
High
Burs ..................
Sticks 3 •..••••.•.•••.•.
Fine trash ............
340 45 75 450
115
135
Total ...............
460 700
650 350 400
METHODOLOGY Equipment 1,400
Data based on South Plains Ginning Research Lab­
oratory records.
2 Based on a standard 480-pound bale of lint, net
weight.
3 Includes stems, branches, and limbs.
1
amount and arrangement of cleaning machin­
ery required to achieve acceptable ginning
performance, maximize producer returns, and
insure satisfactory end-use performance of lint.
These experiments were designed to evaluate
conventional cleaning machinery and to formu­
late recommendations for the ginning indus­
try in stripper harvesting areas.
Seed-cotton-cleaning and lint-cleaning ex­
periments 'were conducted from 1969 to 1972
at the laboratory's full-scale ginning plant. Six
experiments were conducted over the 4-year
period so that the combined results would be
representative of the range of growing, har­
vesting, and ginning conditions expected over
an extended period of time.
Early freezes occurred during the 1969 and
1970 cotton seasons, which lowered cotton
yields but had only minor effects on cotton
quality. Adverse growing conditions during
1971 resulted in one of the poorest cotton sea­
sons on record. However, the cotton used in
the 1971 experiments was above average for
that year and was equal .in quality to the cot­
tons used in 1969 and 1970. Cotton produced
during 1972 yielded well but was of lower
quality than cotton normally produced on the
Texas High Plains.
The varieties of cotton selected for these ex­
periments ranged in staple length from Hinch
to 111[ inches and in Micronaire reading from
2.8 to 4.2. The varieties selected were those
most popular with farmers, as \vell as those
having a range of fiber characteristics. The
varieties were 'Paymaster 111', 'Tamcot 788',
'Stripper 31', 'Lankart Lx571', and 'Paymaster
909'. During the period 1969-72, approximately
2
35 percent of the cotton land in stripper areas
was planted with these five varieties. All cot­
tons were produced within a 30-mile radius of
the laboratory and were harvested by conven­
tional brush strippers.
The laboratory's full-scale ginning plant,
which is equipped with modern high-capacity
machinery, was used for these experiments.
Special remote-control bypass valves, trash
collecting devices, weighing devices, measur­
ing instruments, and lint-sampling equipment
'were used to increase the flexibility of the gin­
ning system and to improve the accuracy of
the datu. Details on the machinery used in
these experiments are given in table A-I (ap­
pendix), including equipment types, sizes, op­
erating speeds, settings, and adjustments.
Processing rates through the ginning system
were controlled by a conventional automatic­
feed control and an ampere controller for the
gin-stand feeder. The selected processing rates
provided normal loadings for the sizes of equip­
ment used. Seed cotton was processed through
cleaning, extracting, and drying equipment at
rates of approximately 6 bales per hour. Gin­
ning rates varied because of experimental treat­
ments but were generally within the range of
3.5 to 4 bales per hour. All cotton was ginned
on one high-capacity gin stand containing 178
12-inch-diameter saws.
The cotton used in these experiments arrived
at the gin with lint-moisture contents within
the 5- to 7-percent range, which is generally
accepted as optimum for ginning. Because dry­
ing was not required to satisfactorily process
the cotton, unheated ambient air was used to
convey the cotton through the two tower driers.
DUJ"i~g these experiments, the relative humidity
of the outside ambient air ranged from 25 to 55
percent. Equilibrium moisture contents of lint
for this range of humidity vary from approxi­
mately 4 to 6.5 percent. Thus, in some cases
the ambient air used for conveying probably
dried the cotton a slight amount. However, this
small drying effect was approximately equal
for all treatments in D, given experiment and
was assumed to have no effect on the relative
ranking of the treatments.
Sampling, Fiber Testing, and Analysis
1969 EXPERIMENT
Seed-cotton samples were taken from the
wagon ~nd at the feeder apron for moisture
and foreigr:-matter determinations. These data
were used to ev~Llnate seed-cotton cleaning per­
formance. Moisture samples were ovendried by
using standard gravimetric procedures. 2 For­
eign-matter determinations were made by per­
forming conventional seed-cotton fractionation
tests.
Lint samples (200 grams) were taken be­
fore and after lint cleaning for selected fiber­
property measurements. Six-pound lint samples
"were taken after lint cleaning for conventional
small-scale spinning tests. Standard fiber­
property measurements and spinning-test re­
sults were obtained from the USDA's Cotton
Testing Laboratory at College Station, Tex.,
in 1969, 1970, and 1971. Texas Tech Univer­
sity's Textile Research Center at Lubbock per­
formed these tests in 1972. Smith-Doxey
classifications of ginned lint samples wer'e
made by the USDA's Cotton Classing Office
at Lubbock.
Samples of seed cotton and lint "were ran­
domly "withdrawn from the processing stream
at the desired stage of cleaning. Each test sam­
ple consisted of three spec;mens collected dur­
ing the processing of a test lot. Specimen
results were averaged for each lot before the
data were analyzed statistically by means of
analysis of variance. Signjfjcant differences
between treatment effects were identified by
Duncan's new mUltiple-range test.
Bale values "were calculated by using Com­
modity Credit Corporation loan rates and dis­
counts that were applicable during the year
each experiment was conducted. Bale weights
were computed by adjusting actual lot weights
to a common base. Input bur-cotton weight-­
was used as the base for these computations.
A selected base weight for each experiment al­
lowed the adjusted bale weights for the various
treatments to fall within the normal bale­
weight range of 450 to 550 pounds (gross
weight) .
Design
~ Shepherd, J. V. 1972. Standard procedures for for­
eign matter and moisture analytical tests used in cot­
ton ginning research. U.S. Dep. Agric. Handb. No.
422, 13 pp.
Experimental treatments were selected to (1)
determine if inclined cleaners were required
for cleaning machine-stripped seed cotton, (2)
measure the effectiveness of a seed-cotton
cleaning system using three stages of extrac­
tion, and (3) determine the effects of lint
cleaning on fiber and yarn quality. The follow­
ing four system combinations for seed-cotton
cleaning were selected:
1. ElCLbomte.- (28 cylinders and 3 extrac­
tors ) air-line cleaner, tower drier (no heat),
inclined cleaner, bur machine, tower drier (no
heat), inclined cleaner, stick machine, inclined
cleaner, inclined cleaner, stick machine, extrac­
tor feeder.
2. Tlfpical.- (16 cylinders and 2 extrac­
tors) air-line cleaner, tower drier (no heat),
inclined cleaner, bur machine, tower drier (no
heat), inclined cleaner, stick machine, extrac­
tor feeder.
3. Elabora.te-extmcting.-(3 extractors)
tower drier (no heat), bur machine, tower drier
(no heat), stick machine, stick machine, ex­
tractor feeder.
4. Modemte-extmcting.-(2 extractors)
tower drier (no heat), bur machine, tower drier
(no heat), stick machine, extractor feeder.
The elaborate system contained all the ma­
chinery normally used for stripped cotton plus
that normally used for machine-picked cotton.
The typical system contained only the machin­
ery normally used for stripped cotton. The
elaborate-extracting system contained the same
amount of extracting equipment as the elabo­
rate system but without inclined cleaners. The
moderate-extracting system differed from the
typical system in a like manner.
Each system for seed-cotton cleaning was
tested with no lint cleaning and in combination
with one, two, and three stages of lint cleaning.
The 16 cleaning combinations were randomly
processed within each of 3 replications. Forty­
eight bales of 'Paymaster 111' cotton were
ginned in one-bale lots.
Results
Bur cotton on the wagon averaged 32.4 per­
cent foreign matter and 8.2 percent moisture
3
TABLE
2.-Effects of seed-cotton cleeming on moisture and fo'reign-matter contents> cleaning
efficiencies, g,nd ginning rates, 19691
Seed-cotton cleaning treatment
Measurement
Moisture cuntent:
Bur cotton, wagon ...... pct ..
Seed cotton, feeder ...... pct ..
Bur content:
Bur cotton, wagon ...... pct ..
Seed cotton, feeder ...... pct..
Cleaning efficiency ..... pct..
Stick content:
Bur cotton, wagon ...... pct ..
Seed cotton, feeder ......pct ..
Cleaning efficiency ..... pct ..
Fine trash content:
Bur cotton, wagon ......pct ..
Seed cotton, feeder ...... pct ..
Cleaning efficiency ..... pct..
Total foreign matter:
Bur cotton, wagon ...... pct..
Seed cotton, feeder ...... pct ..
Average cleaning
efficiency •................. pct ..
Ginning rate ............. bales/h ..
Elaborate
Typical
Elaborateextracting
Moderateextracting
Average of
all levels
Level of
significance 2
8.6
7.6
7.9
7.4
8.4
7.5
7.8
7.5
8.2
7.5
NS
NS
18.3
0.6
97.8b
19.6
1.1
96.2a
19.2
0.5
98.1b
19.2
0.9
96.6a
19.1
0.8
97.1
NS
5.4
0.7
90.4b
5.1
1.1
84.9a
5.6
0.9
88.1ab
5.4
1.2
84.3a
5.4
1.0
86.9
NS
8.4
2.4
79.5c
7.6
2.9
73.2b
8.2
3.3
71.2b
7.7
3.8
64.8a
8.0
3.1
72.2
NS
32.1
3.7
32.3
5.0
32.9
4.8
32.4
5.9
32.4
4.9
91.9c
3.89b
88.9b
3.75a
89.8b
4.00b
86.9a
3.90b
89.4
3.89
.
..
..
NS
..
.
Means in a row followed by a common letter are not statistically different at the 0.05 level.
Asterisk indicates significant differences among seed-cotton cleaning treatments at the 0.05 level. NS indi­
cates no significant differences at the 0.05 level.
1
2
(table 2). The average bur, stick, and fine-trash
contents were 19.1, 5.4, and 8.0 percent, re­
spectively. There were no significant differ­
ences among treatments in initial moisture or
foreign-matter contents. The average fiber
strength of the test cotton was 86,200 pounds
per square inch, and the average micronaire
reading was 4.0.
The four seed-cotton cleaning systems had
significantly different cleaning efficiencies and
produced a range of 3.7 to 5.9 percent foreign
matter after the feeder. The elaborate system
did the most cleaning, and the moderate-ex­
tracting system did the least. The typical
and elaborate-extracting systems had approxi­
mately equal cleaning efficiencies, which were
intermediate between the high and low levels.
The systems with inclined cleaners removed
more fine trash than the comparable systems
without inclined cleaners. Average cleaning ef­
ficiency for total foreign matter varied from
a low of 86.9 percent (moderate-extracting) to
a high of 91.9 percent (elaborate).
4
Bur content of seed cotton after the feeder
appeared to affect the rate of ginning. An in­
crease in bur content from 0.5 to 1.1 percent
was accompanied by a decrease in ginning rate
from 4 bales per hour (elaborate-extracting)
to 3.75 bales per hour (typical). The range in
stick and fine-trash contents did not affect gin­
ning rate.
N onlint contenta before and after two stages
of lint cleaning reflected the amount of seed­
cotton cleaning received (table 3). However,
after three stages of lint cleaning, differences
in nonlint contents were not significant. The
seed-cotton cleaning systems with inc1ined
cleaners produced cleaner lint than the com­
parable systems without inclined cleaners. The
typical system produced cleaner lint than the
elaborate-extracting system, indicating that an
additional stick machine was not equal to two
a Throughout this report, "nonlint content" refers to
total waste removed from lint by a Shirley analyzer.
TABLE
3.-Effects of cleaning treatments on fiber properties, bale weights,
and bale values, 1969 1
Lint or seed-cottoll
cleaning treatment
Nonlint
content
(pct)
Elaborate:
No lint cleaning ............
1 stage .....................
2 stages · ....... ............
3 stages ....................
Typical: No lint cleaning ............
1 stage .... ................
2 stages ....................
3 stages · ...................
Elaborate-extracting:
No lint cleaning ............
1 stage .....................
2 stages · ...... ............
3 stages ....................
Moderate-extracting:
No lint cleaning ............
1 stage .....................
2 stages ........ " ............
3 stages
~
~
~
•••••
••
w ••••••••••••
Grade
index 2
Staple
length
(32d inch)
Bale
weight 3
(lb)
Bale
value 4
7.5d
3.7ab
2.8a
2.8a
80a
9lb
95c
92bc
31.3a
31.9b
32.0b
31.8b
533d
5l5c
502b
499a
$79a
93cde
94e 8tlbcde 8.0d
3.8b
3.3a
3.2a
83a
92b
93c
~Ob
31.6a
3l.4a
3l:7ab
31.9b
540d
5l5c
504b
50la
84abc 93de 89bcde 9lbcde 9.lde
4.lc
3.5ab
3.la
8la
89b
9lb
94c
31.5a
32.lb
31.9b
32.0b
546e
5l7c
505b
500a
85abcd
9lbcde
92bcde
94de 9.7e
5.5c
3.7ab
3.la
79a
84b
89b
93c
31.5a
R2.1b
32.lb
32.lb
548e
517c
503b
498a
82ab
86abcde
90bcde
94de
) Means in the same column followed by a common letter are not statistically dif­
fel'ent at the 0.05 level.
2 Grade index values for various grades of cotton are given in table A-2 (appendix) .
3 Bale weights include 21 pounds of bagging and ties.
·1 Bale values based on 1969 Commodity Credit Corporation loan prices.
inclined cleaners in controlling the amount of
foreign matter in lint. The lowest nonlint con­
tent (2.8 percent) was obtained with the
elaborate system and three lint cleaners. The
moderate-extracting system with no lint clean­
ing produced the highest nonlint content (9.7
percent) .
Grade index varied directly with nonlint con­
tent and ranged from 79 (Low Middling Light
Spotted) to 95 (Strict Low Middling). The
elaborate and typical systems required two
stages of lint cleaning to produce maximum
grades. The elaborate-extracting and moderate­
extracting systems (those without inclined
cleaners) required three stages of lint clean­
ing to produce maximum grades. The third
stage of 1int cleaning did not improve grade
index for the elaborate and typical systems.
Bale weights were affected most by the first
and second stages of lint cleaning. Seed-cotton
cleaning affected bale weight before lint clean­
ing, but differences after lint cleaning were 3
pounds (or less) per bale. The first and second
stages of lint cleaning reduced bale \veights 18
to 31 pounds and 11 to 14 pounds, respectively.
The third stage of lint cleaning reduced bale
weights 3 to 5 pounds.
Bale values, .''lS a result of the 16 cleaning
treatments, ranged from $79 to $94. Bale values
approaching the $94 maximum were obtained
with all foul' seed-cotton cleaning systems.
However, more lint cleaning was required to
produce maximum bale values for the two sys­
tems without inclined cleaners than for the
systems with inclined cleaners. The typical
system required only one lint cleaner to pro­
duce maximum bale value. Two lint cleaners
produced maximum bale value for the elaborate
system. The elaborate-extracting and moderate­
extracting systems required three stages of lint
cleaning to produce maximum bale values.
Bypassing all inclined cleaners, and relying
solely on lint cleaners to remove fine trash,
resulted in higher nonlint content, lower grade
index, and lower bale value. One additional
stage of lint cleaning was required to compen­
5
TABLE
4.-Effects of lint cleaning on moist~lre contents and fiber and yarn
propert'ies, 19691
Measurement
0
Lint moisture content 3 .......... pct .. 6.1
Classer's staple length .. , .32d inch .. 31.5a
2.5-pct span length .......... inches .. 1.04b
Length '.miformity .............. pct ..
45
Reflectance ............... .......R d ••
69.3
Yellowness ·············· ....... +b ..
8.5
Picker and card waste .......... pet.. 10.9c
22s-yarn strength ................ lb ..
107
44s-yarn strength ................ lb ..
45
Average break factor unit ... ....... 2,168
Average yarn appearance index ...... 105b
22s-yarn imperfections ........... No.
20b
44s-yarn imperfections ····.· ..... No. 26bc
~
Stage of lint cleaning
1
2
3
6.2
31.9b
1.02a
44
71.0
8.8
7.4b
165
43
2,107
107b
17a
22ab
6.0
31.9b
1.03ab
44
71.7
8.8
6.5a
105
43
2,088
106b
17a
21a
6.2
32.0b
1.03ab
44
72.5
9.0
6.3a
105
43
:'!,098
102a
19b
24b
Level of
signifi­
can!!e 2
NS
>I<
>I<
NS
>I<
NS
NS
NS
>I<
>I<
>I<
1 Means in a row followed by a common letter are not statistically different at the
0.05 level.
2 Asterisk indicates significant differences among stages of lint cleaning at the 0.05
level. NS indicates no significant differences at the 0.05 level.
:I Moisture content determined from samples taken before lint cleaning.
sate for bypassing two or more inc]jned clean­
ers. Substituting a stick machine for two
inclined cleaners resulted in slightly higher
nonlint content, lower grade index, and lower
bale values.
Fiber- and yarn-quality measurements ,,,ere
made on lint samples taken after each cleaning
treatment. Seed-cotton cleaning had only minor
effects upon fiber and yarn properties. For
this reason, data for each level of lint cleaning
'were avoraged across all four seed-cotton clean­
ing levels (table 4) .
Fiber length, determined subjectively by the
classer and measured mechanically by the Dig­
ital fibrograph, showed no significant differ­
ences after one, two, and three stages of lint
cleaning. Classer's staple length was shorter be­
fore than after one stage of lint cleaning, but
2.5-percent span length averaged longer before
lint cleaning. This apparent discrepancy may
have been due to differences in appearance of
lint samples before and after lint cleaning. The
lint cleaners paralleled the fibers and produced
smoother samples than the uncleaned lint sam­
ples. It is possible that the uncleaned lint sam­
ples were penalized unduly because of their
rough appearance and because area classers
were not accustomed to classing lint that had
not been processed through at least one lint
cleaner.
6
Lint cleaning increased color reflectance and
yellowness vakes. With no lint cleaning, re­
flectance and yellowness values were 69.3 and
8.5, respectively. These values were 72.5 and
9.0 after three stages of lint cleaning.
Lint cleaning decreased picker and card
waste from 10.9 percent (no ]jnt cleaning) to
6.3 percent after three stages of lint cleaning.
Differences between two and three stages of
lint cleaning were not significant.
No significant differences were found in the
strength of 22s and 44s yarns or in average
break factor. Yarn strengths before lint clean­
ing were only 2 pounds higher than after any
stage of lint cleaning. The average break factor
before lint cleaning was 2,168, and after three
stages it was 2,098, a difference of only 70
units.
Average yarn appearance was significantly
affected by lint cleaning. Three stages of lint
cleaning produced the lowest appearance index
(l 02). One stage produced the highest appear­
ance index (107), but this value was not sig­
nificantly different from the index with no lint
cleaning (105) or the index after two stages
(106) .
Yarn imperfections were highest with no
lint cleaning and after three stages of lint
cleaning and were lowest after one and two
TABLE
5.-Effects of seed-cotton cleaning on moisture contents, !'ibe1' p1·ope1·ties, and fore'ign­
matte?' contents of th1'ec cotton 'Va?-ieties, 1970
---,--,-------------_._-----------------------
Measurement
'Tamcot
788'
Foreign-matter content:
Bur cotton, wagon .. , ............................•........... pct ..
Seed cotton, feeder .......................................... pct ..
Moisture content:
Bur cotton, wagon .................... " ....... , ............ pct ..
Lint, before lint cleaning .................................... pct ..
Nonlint content, before lint cleaning ............................ pct ..
Pressley strength ..................................... 1,000 Ib/inch2 ..
Fiber array, before cleaning:
Upper-quartile length ................................... inches ..
Mean length ............... , ................................ inch ..
Coefficient of variation ..................................... pct..
Short fibeI's~ ., .............................................. pct ..
Fibrograph length, before lint cJeaning:
2.5-pct span length ...................................... inches ..
Length uniformity ......................................... pet ..
Neps, before lint cleaning .................. ' .No./100 inch 2 of web ..
Classification, before lint cleaning:
Grade index 2 .................................................... .
Staple length ........................................... 32d inch ..
1Ylicronaire reading .............................................. .
1
2
Test variety
'Paymaster
111'
'Stripper
31'
Average
of all
cottons
25.5
3.9
29.5
3.2
28.6
5.2
27.9
4.1
10.9
6.9
6.4
101
6.6
5.8
5.2
91
6.9
6.2
6.7
87
8.1
6.3
6.1
93
1.17
0.94
32.5
11.0
1.11
0.91
30.8
11.0
1.01
0.84
30.7
11.5
1.10
0.90
31.3
11.2
1.08
46
17
1.00
47
15
0.93
47
11
1.00
47
14
93
32.5
3.5
89
30.8
4.2
86
30.0
4.0
89
31.1
3.9
Percent of fibers shot·ter than 1/2 inch.
Grade index values for various grades of cotton are given in table A-2 (appendix).
stages. Imperfections in 22s yarn ranged f}'om
17 to 20 and in 44s yarn from 21 to 26.
These data indicate that yarn spun from .lint
receiving one or two stages of lint cleaning was
of slightly high!>.r quality than yarn spun from
lint receiving no lint cleaning or three stages.
No lint cleaning produced a higher waste per­
centage and more imperfections than one and
two stages. Three stages produced a lower ap­
pearance index and more imperfections than
one and two stages. Differences in yarn quality
between one and two stages were not signifi­
cant. The only signi:icant difference between
one and two stages was in picker and card
waste percentage. A slightly lower waste per­
centage was obtained with two lint cleaners.
1970 EXPERIMENTS
Design
Three experiments were conducted in 1970
to obtain additional and more detailed data
011 the effects of lint cleaning on fiber quality
and value. 'Tamcot 788', 'Paymaster 111', and
'Stripper 31' cotton varieties were subjected
to identical c.leaning and ginning arrange­
ments. Each experiment consisted of process­
ing one of these varieties through a typical
seed-cotton cleaning system and then subject­
ing the lint to one, two, and three stages of
lint cleaning. The gin machinery sequence con­
sisted of an air-line cleaner, inclined cleaner,
bur machine, inclined cleaner, stick machine,
and an extractor feeder. All cotton was con­
veyed through two tower driers using un­
heated ambient air. Six replications of each
experiment were conducted with each variety
of cotton. The lint cleaning treatments were
selected at random within each replication. Six
bales of each variety were ginned in one-third
bale lots.
In the 'Tamcot 788' experiment, 6-pound lint
samples were taken after lint cleaning Lor
small-scale spinning tests. Spinning tests were
not performed on 'Paymaster 111' or 'Stripper
31' cottons.
Results
The three experiments were individually
analyzed, and results of the analyses of vari­
7
6.-Effects of lint .cleaning on moisture contents, fiber properties,
waste removal, bale weights, and bale values of three cotton varie­
ties, 1970
TABLE
Test cotton and
stages of lint
cleaning
Measurement
Moisture Nonlint Waste
Bale
~rade
contenV content removal weight 2
index 3
(pct)
(lb)
(pc~)
Db)
'Tamcot 788·: 1 stage ..... ......
2 stages ..........
3 stages ..........
'Paymaster 111':
1 stage ...........
2 stages ..........
3 stages ..........
'Stripper 31':
1 stage ...........
2 stages ..........
3 stages ..........
Staple
Bale
length
value 4
(32d inch)
6;9
7.0
6.6
3.8
3.3
3.3
22
30
32
510
502
500
97
99
99
34.1
33.9
33.9
6.0
5.8
5.8
3.6
2.7
.2.5
16
23
25
509
502
500
98
99
99
31.2
31.5
31.5
9.5 98 98 6.2
6.2
6.2
3.1
2.9
3.1
20
28
31
511
503
500
96
98
99
30.1
30.0
30.0
89
88
90 Average, all cottons:
1 stage ....... 6.4
2 stages ...... 6.3
3 stages ...... 6.2
3.5
3.0
3.0
19
27
29
510
502
500
97
99
99
31.8
31.8
31.8
~
$114
116
115
99
101
101
Moisture content of lint samples taken before lint cleaning.
Bale weights include 21 pounds of bagging and ties. Bale weights of 'Tamcot 788',
'Paymaster 111', and 'Stripper 31' before lint cleaning .averaged 532, 525, and 531
pounds, respectively.
3 Grade index values for various grades of cotton are given in table A-2 (appendix).
4 Bale values before lint cleaning for 'Tamcot 788', 'Paymaster 111', and 'Stripper
31' were $101, $88, and $84 respectively. Bale values based on 1970 Commodity Credit
Corporation loan prices.
1
2
TABLE
7.-Effects of lint cleaning on fibe7' lengths andnep contents of three cotton varieties,
1970
Measurement
Test cotton and
stage of lint
cleaning
2.5-pct
Length
span length uniformity
(inch)
(pct)
'Tamcot 788':
1 stage ................
2 stages ...............
3 stages ...............
'Paymaster 111':
1 stag(' ...........•....
2 stages...............
3 stages,., ... ,. '......
'Stripper 31':
1 stage................
2 stages...............
3 stages...............
I
8
Mean
length
(inch)
Co­
efficient
of variation
(pet)
Short
fibers l
(pct)
Neps
(No. per 100
inch 2 of
.card web)
1.09
1.08
1.07
46
46
45
1.17
1.16
1.17
0.93
.93
.93
33.1
33.3
33.8
11.6
11.8
12.1
34
42
51
.99
.99
.99
47
47
46
1.11
1.11
1.10
.91
.91
.90
30.6
30.8
31.5
10.9
10.7
11.3
13
14
15
.94
.93
.93
47
47
47
1.02
1.01
1.01
.84
.82
.82
31.4
32:7
32.5
12.0
13.4
13.0
12
13
14
1.01
1.00
1.00
47
1.10
1.09
1.09
.89
.88
.88
31.7
32.3
32.6
11.5
12.0
12.1
20
23
27
--------
Average, all cottons:
1 stage ...........
2 stages ..........
3 stages ..........
Upper­
quartile
length
(inch)
Percent of fibers shorter than 1/2 inch.
.,.1"
ance are given in table A-3 (appendix). For
simplicity and ease of comparison, data from
all three experiments were combined for pres­
entation in tables 5-8.
Average foreign-matter contents of the three
test cottons at the wagon ranged from 25.5 to
29.5 percent (table 5), indicating that all test
cottons were cleaner than the 30 to 32 percent
foreign-matter content of normal stripped cot­
ton. Moisture contents of bur cotton -at the
wagon ra.nged from 6.6 to 10.9 percent. Dif­
ferences in the initial average moisture and
foreign-matter contents among test lots within
a particular cotton variety were not signifi­
cant.
Seed-cotton samples taken after the feeder
were analyzed for moisture and foreign-matter
contents. Lint samples taken before lint clean­
ing were tested for nonlint, moisture, strength,
length, neps, and classification. 'Tamcot 788'
fibers were longer, stronger, and finer than
those of 'Paymaster 111' or 'Stripper 31'. The
'Stripper 31' variety had the shortest and weak­
est fibers, and 'Paymaster 111' was intermedi­
ate in length and strength. 'Paymaster 111'
had the lowest nonlint content and thus was
the cleanest of the three cottons before lint
cleaning, and 'Stripper 31' contained the most
foreign matter. Grade indices before lint clean­
ing ranged from 86 (Low Middling) for 'Strip­
per 31' to 93 (Strict Low Middling) for
'Tamcot 788'. All cottons were within the pre­
mium Micronaire range of 3.5 to 4.9. 'Tamcot
788' was in the low end of this range with a
reading of 3.5. Micronaire readings for 'Pay­
master 111' and 'Stripper 31' were 4.2 and 4.0.
One and two stages of lint cleaning reduced
nonlint content· in all test cottons (table 6).
However, the third stage of lint cleaning had
little effect on nonlint content. Bale weights
were reduced an average of 19, 27, and 29
pounds, respectively, by one, two, and three
stages of lint cleaning. Reductions in bale
weight (as a result of foreign-matter removal)
were accompanied by corresponding increases
in grade index. The largest increases in grade
index occurred after the first stage of lint
cleaning. These increases ranged from 4 units
for 'Tamcot 788' to 10 units for 'Stripper 31'.
These vast improvements in grade index indi­
cate that 50 to 100 percent of the cotton 'was
increased one full grade by the first stage of
lint cleaning. The second stage produced addi­
tional increases in grade index of 1 or 2 units,
which is equivalent to improving the grade of
approximately 10 to 20 percent of the bales.
The third stage of lint cleaning did not pro­
duce further improvements in grade index for
'Tamcot 788' and 'Paymaster 111' cottons, but
it did improve 'Stripper 31' by one unit.
Classer's staple length tended to average
longer after .lint cleaning than before. These
differences were similar to those obtained in
1969 and presumably were the result of varia­
tions in appearance between uncleaned and
lint-cleaned samples. Differences in staple
length after one, two, and three stages of lint
cleaning were not significant.
Bale values were improved $5 to $13 by the
first stage of Hnt cleaning. Bale-value differ­
en ces after one, two, and three stages of lint
cleaning ($1 to $3) were not statistically sig­
nificant.
Table 7 shows the effects of lint cleaning on
TABLE 8.-Effects of lint cleaning on yarn quality of 'Tamcot 788', 1970~
Measurement
Stage of lint cleaning
123
Picker and card waste ............. pct. .
5.9 22s-yarn strength ...................lb.. 127b 50s-yarn strength ................... lb.. 45b Average break factor unit .............. 2514b Average yarn appearance index ........ 100b 22s-yarn imperfections .............. No.
25 50s-yarn imperfections .............. No. 19a 5.4
5.4
125a
44a
2463a
98b
24
18a
125a
43a
2457a
92a
25
21b
Level of
significance~
NS
'"
'"
'"
'"
NS
*
1 Means in a row followed by a common letter are not statistically different at the
0.05 level.
~ Asterisk indicates significant differences among stages of lint cleaning at the 0.05
level. NS indicates no significant differences at the 0.05 level.
9
fiber length and nep content. Changes in fiber
length and length uniformity were similar for
all three cottons. Successive stages of lint
cleaning generally reduced 2.5-percent span
length, upper-quartile length, mean length, and
length uniformity and increased coefficient of
variation, short fibers, and neps. Reductions
in length were small (0.01 to 0.02 inch), and
increases in short fibers were generally less
than 2 percentage points. N eps in 'Tamcot 788'
samples increased from 17 before lint cleaning
to 51 after three stages of lint cleaning. Lint
cleaning did not increase neps in 'Paymaster
111' samples and produced only small nep in­
creases in 'Stripper 31' samples. These differ­
ences in nep formation among the test cottons
were likely the result of differences' in fineness
and maturity. Micronaire readings, which indi­
cate fineness and maturity, averaged 3.5 for
'Tamcot 788', 4.2 for 'Paymaster 111', and 4.0
for 'Stripper 31' (table 5).
Yarn quality of 'Tamcot 788' was deter­
mined by conventional small-scale spinning
(table 8). Successive stages of lint cleaning
decreased strength and appearance of 22s and
50s yarns. Average break factor after one,
two, and three stages of lint cleaning was
2,514, 2,463, and 2,457, respectively. The aver­
age yarn appearance index was highest (100)
after one stage of lint cleaning &lld was low­
est (92) after three stages. Imperfections in
22s and 50s yarns were lowest after two stages.
Differences in picker and card waste were not
significant. These results indicated that lint
receiving one stage of lint cleaning produced
slightly superior yarn.
1971 EXPERIMENT
Design
This experiment was designed to determine
the optimum amounts of lint cleaning for cot­
ton receiving two levels of seed-cotton clean­
ing. 'Lankart Lx571' cotton was subjected to
two levels of seed-cotton cleaning consisting
of a typical machinery sequence and a simple
sequence containing about half the machinery
typically used to clean stripped seed cotton.
The typical sequence contained an air-line
TABLE 9.-Effects of lint and seed-cotton cleaning
on moisture and
for'eign-matte't" con'tents, nonlint contents, and ginning rates, 1971
Measurement
Seed-cotton cleaning
Level of
treatment
. 'f'
1
-----".,-~- slgm Icance
Typical
Simple
Moisture content:
Bur cotton, wagon ......................... pct ..
Seed cotton, feeder ........................ pet ..
7.9
7.6
7.9
7.7
NS
NS
Foreign-matter content, wagon:
Burs ....................................... pet ..
Sticks ..................................... pct ..
Fine trash ................................. pet ..
19.5
3.8
6.7
19.4
3.6
7.0
NS
NS
NS
Total .................................... pct ..
30.0
30.0
NS
Foreign-matter content, feeder:
Burs ...................................... pct ..
Sticks ..................................... pct ..
Fine trash ................................. pct ..
2.3
1.1
3.3
4.6
1.5
3.6
*
*
*
6.7
9.7
*
7.4
3.6
2.7
2.5
3.66
9.1
3.9
3.1
2.9
3.60
Total .................................... pet ..
Nonlint content:
Before lint cleaning ....................... pet ..
After one lint cleaner ..................... pet ..
After two lint cleaners .................... pct ..
After three lint cleaners .................. pct ..
Ginning rate .............................. bales/h ..
*
NS
NS
NS
*
Asterisk indicates significant differences between seed-cotton cleaning treatments
at the 0.05 level. NS' indicates no significant differences at the 0.05 level.
1
10
cleaner, inclined cleaner, bur machine, inclined
cleaner, stick machine, and an extractor feed­
er. The simple sequence contained only an in­
clined cleaner, stick machine, and extractor
feeder. All cotton was processed through two
tower driers using unheated ambient air. Lint
from both seed-cotton cleaning treatments re­
ceived no lint cleaning and one, two, and three
stages of lint cleaning.
The eight cleaning combinations were repli­
cated four times. Processing order was ran­
domly selected for each replication. Eleven
bales of cotton were ginned in lis-bale test lots.
Results
There were no significant differences in ini­
tial moisture or foreig-n-matter contents of the
cotton, which contained 7.9 percent moisture
and 30 percent foreign matter (table 9). The
two seed-cotton cleaning treatments, typical
and simple, produced significant differences
in all components of foreign matter. The
foreign-matter content of cotton at the feeder
TABLE
apron averaged 6.7 percent (typical) and 9.7
percent (simple). Differences inforeign-mat­
ter content (as a result of these treatments)
produced significant differences in ginning
rate and nonlint content of lint before lint
cleaning. The ginning rate for the simple
treatment was slightly lower than for the typi­
cal treatment. Nonlint contents before lint
cleaning averaged 7.4 percent (typical) and
9.1 percent (simple). Lint cleaning reduced
differences in nonlint content (as a result of
seed-cotton cleaning treatments) to nonsignifi­
cant levels.
Both seed-cotton cleaning treatments and
each stage of lint cleaning produced signifi­
cant differences in bale weight (table 10). The
typical treatment and three stages of lint
cleaning produced the lowest bale weight (479
pounds), and the simple treatment with no
lint cleaning produced the highest bale weight
(524 pounds). For the typical and simple
treatments, one stage of lint cleaning reduced
bale weights 23 and 30 pounds; two stages
10.-Effects of cleaning treatments on moistu1'e contents, bal.e
propM·ties, and bctle values, 1971 1
Measurement
0
Bale weight ................. lb ..
Grade index4 . ...................
Staple length .......... 32d inch ..
Micronaire reading ..............
Bale loan value 5 . . . • . . . . • • . . . • • • .
2.5-pct span length ...... inches ..
Moisture content6 .......... pct ..
Length uniformity ......... pct ..
Stelometer strength ...... g/tex ..
Neps .... . No./100 inch 2 of web ..
Picker and card waste ..... pct ..
Characteristics of 22s yarn:
Yarn strength ..........lb ..
Imperfections ............ No.
Characteristics of 50s yarn:
Yarn strength .......... lb ..
Imperfections ............ No.
Average break factor ...........
Average appearance index ......
~veights,
Seed-cotton cleaning treatment
Typical 2
Simple2
1
1
2
3
0
2
fiber and yarn
3
Level of
signifi­
cance 3
51Of
80b
32.3ab
3.5
$75ab
1.05d
7.8
45
19.9
13a
9.7d
487d
92c
32.1ab
3.4
$83c
1.04c
7.5
45
19.6
14a
6.8b
481b
93c
31.5a
3.4
$80bc
1.03a
7.6
45
20.1
15ab
5.8a
479a
95c
31.7ab
3.5
$82c
1.02a
7.6
45
19.9
16b
5.8a
524g
75a
32.5b
3.4
$73a
1.05d
7.8
45
19.7
13a
12.6e
494e
92c
31.8ab
3.4
$82c
1.04c
7.6
44
19.9
14a
7.5c
488d
94c
31.7ab
3.4
$83c
1.03a
7.6
45
20.2
14a
6.2a
483c
92c 31.6a
3.4
$80bc 1.03a
7.7
44
20.4
17b
6.0a
101cd
40b
100cd
35ab
98b
32a
96a
32a
102c
39b
101cd
34ab
101cd
30a
98b
30a
*
*
35d
27b
1977c
108b
34c
26ab
1944bc
105b
33b
25ab
1906b
104ab
32a
26ab
1846a
100a
35d
24ab
1997c
106b
35d
24ab
1971c
108b
34c
21a
1958c
l06b
33b
23ab
1900b
l06b
*
*
*
*
*
*
NS *
*
NS NS NS
*
*
*
Means in a row followed by a common letter are not statistically different at the 0.05 level. Zero, 1, 2, and 3 indicate stages of lint cleaning. 3 Asterisk indicates significant differences at the 0.05 level. NS indicates no significant differences at the 0.05 level. 4 See footnote 2 to table 3. S Bale values based on 1971 Commodity Credit Corporation loan prices. 6 Based on seed-cotton samples taken at the feeder apron. 1.
2
11
reduced bale weights 29 and 36 pounds; and
three stages l'educed bale weights 31 and 41
pounds.
One stage of lint cleaning significantly im­
proved grade index of lint for both seed-cotton
cleaning treatments, but the second and third
stages produced no furt~er improvements in
grade. Average gr&.de indices before lint clean­
ing were 75 (Strict Good Ordinary) for the
simple treatment and 80 (Low Middling) for
the typical treatment. There wel'e no signifi­
cant differences in grade index after one, two,
and three stages of lint cleaning, and the aver­
age grade index ranged from 92 to 95 (Strict
Low Middling) .
There was some evidence that lint cleaning
reduced staple length. For the simple treat­
ment, the staple length before lint cleaning
was 32.5 thirty-seconds of an inch, and after
three lint cleaners, it was significantly lower
at 31.6 thirty-seconds of an inch. A similar
trend occulTed (though not statistically sig­
nificant) with lint from the ty'pical treatment.
There were no differences in staple length as
a result of seed-cotton cleaning treatment.
Micronaire reading was not affected by ex­
perimental treatments and averaged 3.4 or 3.5
for all test combinations.
Bale values were not affected by seed-cotton
cleaning treatments. One stage of lint cleaning
increased bale value $8 (typical) and $9 (sim­
pie). Bale values after two and three stages
of lint cleaning were not significantly different
from those produced by one stage.
Fiber quality, as determined by length,
strength, and nep content measurements, was
not affected by seed-cotton cleaning. Lint
cleaning reduced 2.5-percent span length but
had little effect on length uniformity. Before
lint cleaning, the 2.5-pel'cent span length of
lint was 1.05 inches, and each successive stage
of lint cleaning caused a reduction of about
0.01 inch.
Lint cleaning also increased the number of
neps per 100 square inches of card web. Be­
fore lint cleaning, the nep content of lint was
13 per 100 square inches. After three stages
of lint cleaning, nep contents were significant­
ly higher and averaged 16 and 17 per 100
square inches. Differences before lint cleaning
and after one and two stages of lint cleaning
were not statistically significant.
12
Picker and card waste was highest (12.6
percent) for the simple treatment with no lint
cleaning. With no lint cleaning, the typical
treatment produced a waste value of 9.7 per­
cent. The typical and simple treatments pro­
duced waste values of 6.8 and 7.5 percent after
one stage of lint cleaning. There were no sig­
nificant differences in picker and card waste
after two or three stages of lint cleaning.
As a l'esult of lint and seed-cotton treat­
ments, yarn quality measurements on 22s and
50s yarns showed some significant differences.
Increases in both seed-cotton cleaning and lint
cleaning reduced yarn strength. Maximum
strengths of 22s and 50s yarns were 102 and
35 pounds, the results of the simple treatment
with no lint cleaning. The typical treatment
with three lint cleaners produced yarns of
lowest strength, averages of 96 and 32 pounds
for 22s and 50s yarns. Both seed-cotton treat­
ment and lint cleaning reduced average break
factor. The simple seed-cotton treatment with
no lint cleaning produced the maximum break
factor (1997). Two stages of lint cleaning
were required to significantly reduce break
factor for lint from the typical treatment. Lint
from the simple treatment required three
stages of lint cleaning to significantly reduce
break factor.
Seed-cotton cleaning had little effect on yarn
imperfections. Two and three stages of lint
cleaning reduced imperfections in 22s yarn.
For 50s yarn, differences in imperfections as
a result of lint cleaning were not significant.
Each successive stage of lint cleaning re­
duced average appearance index of yarn from
the typical treatment, but three stages were
required to produce significant differences.
Appearance of yarn from the simple treat­
ment was not affected by level of lint cleaning.
The results of these data indicated that the
typical treatment with one stage of lint clean­
ing and the simple treatment with two stages
produced yarns of approximately equal quality.
The yarn quality produced by these two com­
binations was near maximum for this test.
The typical treatment with two stages of lint
cleanmg also produced yarn of satisfactory
quality, but yarn strength was slightly lower
than for yarn produced by the two optimum
combinations. Three stages of lint cleaning
produced ya; n of SUbstantially lower quality
TABLE 1l.-Cotton-clefJ,ning machVfLer'1j used in 1972 experiment1
Machinery sequence and
stage of lint cleaning
1
Machinery combination in treatment-­
2
3
4
5
6
--------------------------------------X
Air-line cleaner ........................ .
Inclined cleaner ........................ .
Stick machine .......................... .
Inclined cleaner ........................ .
Stick machine .......................... .
Inclined cleaner ........................ .
Stick machine .......................... .
Inclined cleaner .........................
Stick machine ................•..........
Extractor feeder and gin................
Stages of lint cleaning:
Two stages only ....................
0, 1, 2, and 3 stages ......•.........
1
x
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X indicates machine was a part of the cleaning sequence.
than that produced by other experimental
treatments.
1972 EXPERIMENT
Design
This experiment was designed to determine
the cleaning efficiency of an air-line cleaner
and to study the effects of various levels of
seed-cotton cleaning on ginning rate. Lint
cleaning effects were also studied to gain more
information on the lint cleaning requirements
of machine-stripped cotton. The experiment
consisted of processing seed cotton through six
machinery sequences, ranging from a mini­
mum of one extractor feeder to an elaborate
sequence containing four inclined cleaners,
four stick machines, and an extractor feeder.
No lint cleaning and one, two, and three stages
of lint cleaning were used with three of the
sequences, and bvo stages of lint cleaning were
used with the other sequences (table 11).
'Paymaster 909' cotton was subjected to
these treatments in three randomized ginning
replications. Data pertaining to seed-cotton
cleaning were analyzed as three replications
of six cleaning sequences. The lint-cleaning
data were analyzed as a factorial experimr-·,;t
consisting of three seed-cotton cleaning levels
and four lint cleaning levels.
Results
There were no significant differences in ini­
tial moisture or foreign-matter contents of the
test cotton (table 12). Moisture contents of
bur cotton at the wagon ranged from 9.3 to
9.6 percent, and total foreign-matter contents
ranged from 35.1 to 38.8 percent, a higher
than normal range for stripped cotton.
The six seed-cotton cleaning treatments pro­
duced significant differences in foreign-matter
content of seed cotton after the feeder. The
extractor feeder alone (treatment 1) produced
the highest foreign-matter content (21.6 per­
cent). Treatment 4 (three inclined cleaners,
three stick machines, and a feeder) produced
maximum cleaning and the lowest foreign­
matter content (6.2 percent). Treatment 5
(four inclined cleaners, four stick machines,
and a feeder) produced essentially the same
cleaning results as treatment 4. Treatment 3
(two inclined cleaners, two stick machines,
and a feeder) produced significantly higher
foreign-matter content than treatments 4 and
5. Treatment 6, which contained the amount
of machinery normally used to clean stripped
cotton (an air-line cleaner, two inclined clean­
ers, two stick machines, and a feeder), pro­
duced significantly hi g her foreign-matter
contents than treatments 4 and 5 but approxi­
mately equal to that of treatment 3. Treatment
2 (one inclined cleaner, one stick machine,
and a feeder) produced cleaning results that
were intermediate between treatments 1 and 3.
These results indicated that three inclined
cleaners, three stick machines, and a feeder
(treatment 4) were optimum for cleaning the
test cotton. The use of more machinery did
not improve seed-cotton cleanliness, and using
less machinery resulted in significantly more
13
foreign matter, especially burs and sticks. A
comparison of treatments 3 and 6 shows the
effect of using an air-line cleaner. The results
of this comparison indicates that the air-line
cleaner did not improve the cleaning perform­
ance of the seed-cotton cleaning system.
Ginning rates varied from a low of 2.95 bales
per hour (after treatment 1) to a high of 4.12
bales per hOlli' (after treatment 4). This range
in ginning rate corresponded to the range in
foreign-matt~r contents of seed cotton after
the feeder. Ginning rate was correlated to bur
and stick content of seed cotton by means of
regression analysis. The resultir.g equation was
y=4.56-0.02B-0.22S, 1,2=0.99,
where
and
y=ginning rate (bales per hour) I
B=bur content (percent),
S=stick content (percent),
2
1· =coefficient of determinaton.
This equation shows the vast reduction in
ginning rate that resulted from the sticks and
burs that were not removed before ginning..
The equation also indicated that sticks had'
about 10 times the effect of burs on ginning i
rate. The effect of bur content was small, but '
each percentage-point mCl'ease in stick content
resulted in a 4.82-percent reduction in ginning
rate.
Grade indices of samples from treatments
4 and 5 were approximately equal and were
significantlJT higher than those from the other
treatments (table 12). Differences in grade
indices among treatments 1, 2, 3, and 6 were
not significant. All of these samples were re­ duced one grade because of excessive bark, but only 45 percent of the samples from treat­ ments 4 and 5 'were reduced in grade because
of bark content. These data indicated that the
12.-Effects of seed-cotton cleaning on 1nOistu1'e and f01'eign-1natter
contents, fiber propel·ties, ginning nLies, bale weights, and bale values,
TADLE
1972 1
Measurement
I
Seed-cotton cleaning treatment
2
~
4
5
G
:\Ioisture content:
Bur cotton, wagon .. pet..
Lint, press ..........pet..
9.3a
6.5c
9.3a
6.3bc
9.3a
6.0ab
9.3a
5.8a
9.6a
6.lab
9.5a
6.lab
Foreign-matter content
at wagon:
Burs .......... ' .... pet..
Sticks .......... . ... pet..
Fine trash .......... pet ..
22.0a
9.1a
G.Oa
23.8a
8.5a
5.7a
23.9a
8.8a
5.8a
22.6a
8.8a
5.3a
2l.2a
8.4a
5.5a
25.2a
8.4a
5.2a
Total ............. pet..
Foreign-matter content
after feeder:
Burs ................ pet..
Sticks ............... pct..
Fine trash ....... .. pet. .
Total ............. pet..
Ginning' rate ..... " bales/h,.
Grade index:!
... ........
Barky samples ......... pct..
Staple length .... .32d inch..
l\ficronaire reading ..
Bale weight ............ lb..
Bale value3
••••• '" . . .. ••••
----~.-----------------------
37.1a
38.0a
38.5a
36.7a
35.la
38.8a n.5d
6.2c
4.0
4.8c
4.4b
3.2a
3.2ab
3.Gb
2.8a
l.Ga
l.9a
2.7a
1.8ab
2.4a
2.5a
3.4bc
3.8b
2.9a
------~~---.-----'"--------
2l.Gd
2.95a
82a lOOb
3l.8a
2.8a
483b $61a
l2.3c
3.55b
84a
100b
31.7a
2.9a
483b
$G4ab
9.5b
3.G3b
84a
lOOb
31.7a
2.9a
462ab
$6la
G.2a 4.l2c
9lb
45a
31.7a
2.8a
465ab
$68b
6.7a
3.99c
9lb
45a 31.8a
2.9a
444a
$65ab
10.Obc
3.67b
83a
100b
3l.8a
2.8a
475ah
$63ab
1 !\leans in a row followed by a common letter are not statistically different at the
0.05 level.
~ Grad.e index values for various grades of cotton are given in table A-2 (appendix).
'Bale values based on 1972 Commodity Credit Corporation loan prices.
stick content of the seed cotton entering the
gin influenced the bark content of the ginned
lint. Staple length was not affected by seed­
cotton cleaning and averaged 31.7 to 31.8
thirty-seconds of an inch for all treatments.
Micronaire readings, which were low because
of fiber immaturity, were not affected by the
treatments and ranged from 2.8 to 2.9. Pressley
strength averaged 74,000 pounds per square
inch, and Stelometer strength averaged 22
grams per tex.
Bale weights varied from 444 pounds (treat­
ment 5) to 483 pounds (treatments 1 and 2)
and generally reflected the amount of seed­
cotton cleaning received. High weights -were
associated with lower levels of cleaning.
Bale values after two stages of lint cleaning
for the six seed-cotton treatments ranged from
a low of $61 for treatments 1 and 3 to a high
TABLE
of $68 for treatment 4. Bale values for treat­ ments 2, 5, and 6 were intermediate. These data showed that three inclined clean­
ers, three stick machines, and a feeder (treat­ ment 4) were optimum for foreign-matter removal, ginning rate, and bale vabe. Less seed-cotton cleaning reduced these factors, and more cleaning failed to significantly improve them. Table 13 gives the average moisture con­
tents, bale weights, bale values, and fiber and
yarn properties for treatments 2, 4, and 6 at
four levels of lint cleaning. Each successive
stage of lint cleaning increased grade index.
Staple length and Micronaire reading were not
affected by lint cleaning. Bale weights ranged
from a high of 541 pounds with no lint clean­
ing to a low of 463 pounds after three stages
of lint cleaning. Lint cleaning had little effect
on bale values, which ranged from a low of
13.-Effects of lint Glenning on rnoisture contents, bale 'Weights,
fiber and yarn prope?-ties, and bale values, 1972 1
Stage of lint cleaning
2
Measurement
-0-~-~--1-
Grade index2 ••••••••• , ••• , ••••••••••• , ••••••••••••
73a
Staple length ........................... 32d inch .. 31.6a
2.9a
Micronaire reading ... -............... , ........... .
Bale weight .................................... lb .. 541d
Bale value ............................•............ $64a
Lint moisture content3 . . . . . . . . . . . . . . . . . . . . . . . pet ..
6.3b
.98a
2.5-pct span length .......................... inch ..
Length uniformity . . _. _..................... pct ..
46h
Nonlint content .............................. pct .. 12.2c
Reflectance . -... , ..............•........ , .... . R d • , 76.9a
YelJownes& ....................... , ........... b .•
8.7a
Picker and card waste . -...................... pct.. 14.4b
Neps .......... _.
. ... No'!100 incb 2 of web.
62a
Yarn strength:
22s yarn.· ............................... Ib ..
96a
28& yarn"' , ...... -.........................1b ..
70a
A \'erage break factor ...............•.......•..... 201[\a
Uster nonuniformity: 22s yarn ........... · .................... pct ..
20a
285 yarn ................................ pct. ,
22a
Average yarn appearance index ...... ' ........... . 81ab
+
3
83b
31.8a
2.8a
491c
$65a
6.1a
.97a
46b
4.4b
77.9ab
8.8ab
12.5a
59a
86c
31.7a
2.8a
474b
$65a
6.1a
.98a
45a
3.8ab
78.7b
8.9ab
12.5a
59a
88c 31.7a 2.8a 463a $65a 6.0a .97a 45a 3.3a 78.6b 9.0b 12.5a 59a 96a
69.u
2017a
96a
69a
1995a
94a 67a 1979a 20a
22a
83b
20a
22a
84b
20a 22a 77a I Averages of seed-cotton cleaning treatments 2, 4, and 6, and of 3 replications.
Means in a row followed by a common letter are not statistically different at the
0.05 level.
2 See footnote 2 to table 3.
:1 Lint moisture content of samples taken at the press.
·1 Yarn strength was I;ignificantly different among levels of seed-cotton cleaning
with treatments 2, 4, and G producing yarn strengths averaging 70, 67. and 69 pounds, respecti vely. 15
$64 with no lint cleaning to a high of $65 after
one, two, or three stages of lint cleaning. These
differences were not statistically significant.
Seed-cotton cleaning treatments did not pro­
duce significant differences in any of the fiber
and yarn properties except for strength of 28s
yarn, which ranged from a high of 70 pounds
to a 10\'- of 67 pounds. Decreases in yarn
strength were associated with increases in
seed-cotton cleaning. Level of lint cleaning
had no significant effect on 2.5-percent span
length, but two and three stages of lint clean­
ing slightly reduced length uniformity. N onlint
contents ranged from a high of 12.2 percent
with no lint cleaning to a low of 3.3 percent
after three stages of lint cleaning. Reflectance
and yellowness of lint increased with one and
two stages of lint cleaning, but the third stage
produced no further changes in these proper­
ties. Picker and card waste was highest (14.4
percent) for lint with no lint cleaning and
averaged 12.5 percent after one, two, and three
stages of lint cleaning. Nep contents ranged'
from 59 to 62 per 100 square inches of card
web but were not affected by levels of lint·
cleaning. Yarn strength for 22s and 28s yarns
was not affected by levels of lint cleaning.
Uster nonuniformity was approximately equal
for all levels of lint cleaning. The average yarn
appearance index increased slightly with one
and two stages of lint cleaning but decreased .
significantly after three stages. Generally,
these data indicated that one and two stages
of lint cleaning produced fiber and yarn that
"'ere slightly superior to that receiving no lint
cleaning or three stages of lint cleaning.
CLEANING RECOMMENDATIONS Two stages of extraction ahead of the feeder
were required to satisfactorily clean cotton
SEPARATOR
---....
\
1
TOWER
DRIER
1
1
r
1
r
1
\.. l
~ """.
r
FEED
CONTRtiL
TowER
1
1
DRIER
L
\..
SEPARATOR
f
DISTRIBUTOR
r
)
,
I
STICK
I
MACfHNE
I
,
l
I
:
I
,
: (optional}
... _.,..
•
~
'- ,
FrGl;RE
16
I
... ,
,
J J
)
LINT
I.INT
Cl.EANER
CLEANER
I
~
TO PRESS
1.-Hecommended cleaning-machinery arrangement for machine-stripped coaon.
i
containing 25 to 30 percent fOl'eign matter.
Three stages of extraction were required fOl'
optimum cleaning and ginning of cotton con­
taining over 32 percent foreign matter, which
is in the high range for machine-stripped cot­
ton, Therefore, two stages of extraction would
be the illllllmum requirement. For most
stripped cotton, this arrangement would pro­
duce near maximum processing rates and bale
values. However, cotton with high foreign­
matter contents would require an additional
stage of extraction for maximum processing
rates and bale values. The addition of another
stage of extraction is an option available to
the ginner and would be a wise choice if the
foreign-matter contents of cotton produced in
his area frequently exceed normal levels, As
a guideline in making this decision, ginners
can use the rule of thumb that cotton having
a lint turnout of less than 22 percent (a typical
turnout for cotton containing 30 to 32 percent
foreign matter) would benefit from additional
extraction.
In addition to extractors, a minimum of 16
cylinders of cleaning is also required to satis­
factorily clean machine-stril1ped cotton for
maximum bale values. In our tests, this amount
of cleaning was obtained by using a 4-cylinder
air-line cleaner and two 6-cylinder inclined
cleaners. Another inclined cleaner can be used
instead of the air-line cleaner in production
areas where the sand content of seed cotton
is low.
Two stages of lint cleaning were found to
be near optimum for bale value and fiber qual­
ity, Lint which was not cleaned was heavily
discounted in price, causing a loss to the pro­
ducer, and yarn made from this lint was low
in appearance and high in number of impel'­
fections. Lint cleaned by three stages of lint
cleaning was general1y worth no more than
that cleaned by two stagc q and was often
found to have lower fiber and yarn qualities.
The difference between one and two stages of
lint cleaning was not large. However, over a
period of time two stages of lint cleaning
would generally produce slightly higher bale
values. Differences in lint and yarn qualities
between one and two stages of lint cleaning
were generally not significant. Therefore, it is
recommended that gins processing machine­
stripped cotton be equipped for two stages of
lint cleaning.
The recommended amounts of lint and
seeel-cotton cleaning machinery for machine­
stripped cotton are summarized in figure 1.
17
APPENDIX TABLE
A-l.-Principal teatu'res, ope'rating speeds, settings, and adjustments t07' equipment used
in 1969-72 experiments
Equipment
Size
(inch)
Type Operating speed
(r/min)
Setting and adjustment Air-line cleaner "" .4-cylinder ..........72 (width)
540 ............... %-inch grid bars
spaced % inch apart.
Inclined cleaner .....6-cylinder ..........72 (width) 420 · .............. % -inch grid bars
spaced % inch apart.
Bur machine ......... Rotating­
168 (length),
115 (saw),
5/16-inch clearance
stripper.
30 (dia) saw.
445 (stripper).
between saw and
stripper.
Stick machine ....... Gravity-fed, 96 (width),
310 · ..............Three %.-inch grid bars
3 saws.
17 (dia) top saw.
2 inches apart; %-inch
clearance to saw.
Do ................ do .... ·· .. · ..... 7 (dia) middle
700 .............. .Three lh-inch grid bars,
saw.
% inch apart; *-inch
clearance to saw.
Do ................ do .. · .... ·.· .... 7 (dia) bottom
360 · , .............Six 7/16-inch grid bars,
saw.
% inch apart; I-inch
clearance to saw.
Tower drier ......... 24-shelf ............50 (width) ........ . ....... . . . .. . .. 9 % -inch shelf spacing.
Extractor fpeder .... Sling-off,
17 (dia) saw ...... 355 . •............. Four %-inch grid bars
2 cleaning
spaced 1% inches apart;
cylinders.
lh-inch clearance to saw.
Lint cleaner ........Saw-type ...........13lA (dia) saw ....1,090 .. .............17:1 combing ratio;
0.06- to 0.09-inch clearance
between feed bar and saw.
TABLE
A-2.-Gmde index values t07' various grades at cotton, 1969-721
Grade index fo1'Grade
White
Good Middling ................ 105 Strict Middling .............. 104 Middling Plus ................ 102 Middling ...................... 100 Strict. Low Middling Plus..... 97
Strict Low Middling .......... 94
Low Middling Plus ........... 90
Low Middling .... ,........... 85
Strict Good Ordinary Plus '" 81
Strict Good Ordinary ......... 76
Good Ordinary Plus ..•....... 73
Good Ordinary ................ 70
Below grade .................. 60
Light
Spotted
Spotted
Tinged
Light
Gray
Gray
103
102
101
99
94
91
99
98
93
91
97
93
82
92
84
89
83
75
85
75
80
75
68
1 Summary of cotton fiber and processing test results, crop of 1972. U.S. Dep. Agric.,
Agric. Mark. Serv., Cotton Div., May 1973.
18
TABLE A-3.-Results of st(~tistical (malyses for the 1970 eXpM-1.ments
Significance of differences
among factors 1
Seed-cotton
Lint
cleaning!!
cleaning!!
P
p
T
S
T
Measurement
Bur-cotton moisture content ..... ..... NS
Lint moisture content ................... NS
Foreign-matter content:
At wagon ..... .......................... NS
After feeder .................. , ..... Before lint cleaning .. , ., , ......... NS
After lint cleaning ................... NS
Grade index .............................. NS
Staple length. . . . .... ................ NS
Bale value ............... ,. ..... ........ NS
Nep content· ......... , ............. , .... NS
Upper quartile length . ................... NS
Mean length .. ...................... .... NS
Coefficient of variation ... ... . . ....... NS
Short fiber content ...................... NS
2.5-pct span length ... ' ................... NS
Uniformity 7.·atio ........................ NS
Picker and card waste .................. NS
22s-yarn strength . , ........ ............ ,. . NS
50s-yarn strength ... " ............... ". NS Average break factor ................... NS
Average appearance index ............. NS
22s-yarn imperfections . .. . ..... ........ NS
50s-yarn impel'iections . ................ NS
~
~
..
~
.
~
~
~
~
~
~
~
~
~
S
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
1'1'8
NS
NS
NS
NS NS
NS
NS
..
..
.
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
..
NS
NS NS NS
NS *
*
..
NS
NS
NS
NS
NS NS
NS NS
NS
NS
NS
NS
NS
.
..
.
..
NS
.
.
*
NS
NS
NS ..* *
*
NS '" 1 Asterisk indicates significant differences at the 0.05 level. NS indicates no sig­
nificant differences at the 0.05 level.
:: T, 'Tamcot 788'. P, 'Paymaster 111'. S. 'Stripper 31'.
19
t
"
:
,.'
.'