ASTM D1440-96

Standard Test Method for Length and Length Distribution of Cotton Fibers (Array Method)

SCOPE
1.1 This test method covers the determination of the fiber length and length distribution in loose cotton fibers.  
Note 1-For another method for measuring fiber length, see Test Method D 1447.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Nov-1996
• Technical Committee: D13 - Textiles
• Drafting Committee: D13.11 - Cotton Fibers

Relations

• Replaced By: ASTM D1440-96(2002) - Standard Test Method for Length and Length Distribution of Cotton Fibers (Array Method)
• Effective Date: 10-Nov-1996

Standards Content (Sample)

Designation: D 1440 – 96
Standard Test Method for
Length and Length Distribution of Cotton Fibers (Array
1
Method)
This standard is issued under the fixed designation D 1440; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope that length which is exceeded by 25 % of the fibers by weight
in the test specimen.
1.1 This test method covers the determination of the fiber
3.2 For definitions of other terms used in this test method,
length and length distribution in loose cotton fibers.
refer to Terminology D 123.
NOTE 1—For another method for measuring fiber length, see Test
Method D 1447.
4. Summary of Test Method
1.2 This standard does not purport to address all of the
4.1 A sorting apparatus consisting of two banks of parallel
safety concerns, if any, associated with its use. It is the
combs is used to straighten and align the fibers in a 75-mg test
responsibility of the user of this standard to establish appro-
specimen. The fibers are pulled from one bank of combs and
priate safety and health practices and determine the applica-
transferred to the other in such a manner that one end of each
bility of regulatory limitations prior to use.
fiber is aligned with the base comb. The transfer is repeated to
straighten the other ends of the fibers. As the fibers are
2. Referenced Documents
withdrawn from the combs for the third time, they are placed
2.1 ASTM Standards:
in order of length on velvet covered boards. The pulls are
2
D 123 Terminology Relating to Textiles
measured, and those that fall within each length interval are
2
D 1441 Practice for Sampling Cotton Fibers for Testing
collected and weighed. From these weight-length data, the
D 1447 Test Method for Length and Length Uniformity of
upper quartile length, mean length, and coefficient of length
2
Cotton Fibers by Fibrograph Measurement
variation are calculated.
2
D 1776 Practice for Conditioning Textiles for Testing
5. Significance and Use
3. Terminology
5.1 The array method provides objective measurements for
3.1 Definitions:
determining the fiber length and length distribution in a sample
3.1.1 coeffıcient of variation, CV, n—a measure of the
of cotton. The results can be plotted to show the length-weight
dispersion of observed values equal to the standard deviation
distribution of all the fibers in the sample. Data obtained from
for the values divided by the average of the values; may be
array tests are useful in fiber length research studies, for
expressed as a percentage of the average (CV %).
investigation of changes in fiber length distribution in ginning
3.1.2 length group, n—all fibers, or pulls, whose lengths fall
and mill processing, and for other research purposes.
within a given length interval.
5.2 Upper quartile length is correlated with, but usually
1
3.1.3 length interval, n—a class interval of ⁄8 in. (3 mm),
longer than, Fibrograph and 2.5 % span length as defined in
usually designated by its midpoint length in odd-numbered
Test Method D 1447. Judgment must be used in making
sixteenths of an inch.
comparisons between length measures from arrays and mea-
1 1
Example:the0to ⁄8-in. interval is designated as ⁄16.
sures obtained by other methods, which may be basically
3.1.4 mean length, n—in testing of cotton fibers, the average
different.
length of all fibers in the test specimen based on weight-length
5.3 The coefficient of length variation is a measure of length
data.
distribution, or nonuniformity of length. Because the fiber
3.1.5 pull, n—a group of fibers grasped by the forceps at
weight-length distribution is usually highly skewed, statistical
one time and drawn from the specimen in the combs.
judgments based on the assumption of normality are not
3.1.6 upper quartile length, n—in testing of cotton fibers,
justified.
5.4 The array method makes a physical separation of fibers
1
of different lengths. It therefore serves as a standard, or
This test method is under the jurisdiction of ASTM Committee D-13 on
Textiles, and is the direct responsibility of Subcommittee D13.11 on Cotton Fibers. benchmark, with which other methods may be compared and
Current edition approved Nov. 10, 1996. Published March 1997. Originally
by which their precision and accuracy may be judged.
published as D 1440 – 55. Last previous edition D 1440 – 90.
5.5 Test Method D 1440 for testing length and length
2
Annual Book of ASTM Standards, Vol 07.01.
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D 1440
a and c—Banks of combs.
b—Forceps, tips padded with hard leather, for transferring fibers from one set of combs to the other.
d—Depressor for placing fibers in combs.
f—Dissecting needle.
g—Fork for scooping up fiber groups off velvet su
...