ASTM D2968-95(2008)
(Test Method)Standard Test Method for Med and Kemp Fibers in Wool and Other Animal Fibers by Microprojection
Standard Test Method for Med and Kemp Fibers in Wool and Other Animal Fibers by Microprojection
SIGNIFICANCE AND USE
Test Method D 2968 for the determination of med and kemp fibers by microprojection may be used for the acceptance testing of commercial shipments of wool and other animal fibers, but caution is advised since only a few types of animal fibers have been subjected to interlaboratory tests to ascertain the precision of tests for med and kemp fibers by this test method. Comparative tests as directed in 5.1.1 may be advisable.
In case of a dispute arising from differences in reported test results when using Test Method D 2968 for acceptance testing of commercial shipments, the purchaser and the supplier should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens which are as homogeneous as possible and which are from a lot of material of the type in question. The test specimens should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using Student's t-test for unpaired data and an acceptable probability level chosen by the two parties before testing is begun. If a bias is found, either its cause must be found and corrected, or the purchaser and the supplier must agree to interpret future test results in view of the known bias.
Knowledge of the incidence of med fibers and kemp fibers in wool and other animal fibers is of importance to manufacturers of woven or knitted fabrics because of the apparent dye resistance and light reflectance qualities of these fibers. This is not to imply that all kemp fibers will resist dye and all med fibers will accept dye normally. In practice, a proportion of kemp fibers will appear normal after dyeing and a proportion of med fibers will appear chalky white after dyeing. From the perspective of visual and aesthetic problems, medullated fibers having an abnorma...
SCOPE
1.1 This test method covers the determination by microprojection of the percentage of medullated fibers (med and kemp fibers) in wool or other animal fibers such as mohair, cashmere, alpaca, or camel's hair in their various forms.
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.
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Standards Content (Sample)
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Designation: D2968 − 95(Reapproved 2008)
Standard Test Method for
Med and Kemp Fibers in Wool and Other Animal Fibers by
Microprojection
This standard is issued under the fixed designation D2968; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2.5 wool, n—the fibrous covering of the sheep, ovis
species.
1.1 This test method covers the determination by micropro-
jection of the percentage of medullated fibers (med and kemp
4. Summary of Test Method
fibers)inwoolorotheranimalfiberssuchasmohair,cashmere,
4.1 Themagnifiedimagesofaspecimenoftheanimalfibers
alpaca, or camel’s hair in their various forms.
are examined. All medullated fibers are measured and classed
1.2 This standard does not purport to address all of the
as either med fibers or kemp fibers. The observed numbers of
safety concerns, if any, associated with its use. It is the
med and kemp fibers are expressed as percentages of the total
responsibility of the user of this standard to establish appro-
number of fiber images examined.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
5. Significance and Use
2. Referenced Documents
5.1 Test Method D2968 for the determination of med and
kempfibersbymicroprojectionmaybeusedfortheacceptance
2.1 ASTM Standards:
testing of commercial shipments of wool and other animal
D123 Terminology Relating to Textiles
fibers, but caution is advised since only a few types of animal
D2130 Test Method for Diameter ofWool and OtherAnimal
fibers have been subjected to interlaboratory tests to ascertain
Fibers by Microprojection
the precision of tests for med and kemp fibers by this test
3. Terminology
method. Comparative tests as directed in 5.1.1 may be advis-
able.
3.1 Definitions—For definitions of other textile terms used
5.1.1 In case of a dispute arising from differences in
in this test method, refer to Terminology D123.
reported test results when using Test Method D2968 for
3.2 Definitions of Terms Specific to This Standard:
acceptance testing of commercial shipments, the purchaser and
3.2.1 kemp fiber, n—a medullated animal fiber in which the
the supplier should conduct comparative tests to determine if
diameterofthemedullais60 %,ormore,ofthediameterofthe
there is a statistical bias between their laboratories. Competent
fiber.
statistical assistance is recommended for the investigation of
3.2.2 med fiber, n—a medullated animal fiber in which the
bias.As a minimum, the two parties should take a group of test
diameter of the medulla is less than 60% of the diameter of the
specimens which are as homogeneous as possible and which
fiber. are from a lot of material of the type in question. The test
specimens should then be randomly assigned in equal numbers
3.2.3 medulla, n—in mammalian hair fibers, the more or
to each laboratory for testing.The average results from the two
less continuous cellular marrow inside the cortical layer in
laboratories should be compared using Student’s t-test for
most medium and coarse fibers.
unpaireddataandanacceptableprobabilitylevelchosenbythe
3.2.4 medullated fiber, n—an animal fiber that in its original
two parties before testing is begun. If a bias is found, either its
state includes a medulla.
cause must be found and corrected, or the purchaser and the
suppliermustagreetointerpretfuturetestresultsinviewofthe
known bias.
This test method is under the jurisdiction ofASTM Committee D13 on Textiles
and is the direct responsibility of Subcommittee D13.13 on Wool and Felt.
5.2 Knowledge of the incidence of med fibers and kemp
Current edition approved Aug. 1, 2008. Published October 2008. Originally
fibers in wool and other animal fibers is of importance to
approved in 1971. Last previous edition approved in 2001 as D2968 – 95 (2001).
DOI: 10.1520/D2968-95R08.
manufacturers of woven or knitted fabrics because of the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
apparent dye resistance and light reflectance qualities of these
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
fibers. This is not to imply that all kemp fibers will resist dye
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. and all med fibers will accept dye normally. In practice, a
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2968 − 95 (2008)
proportion of kemp fibers will appear normal after dyeing and 9. Calculation
a proportion of med fibers will appear chalky white after
9.1 Calculate, to the nearest 0.1 %, the med and kemp fibers
dyeing. From the perspective of visual and aesthetic problems,
content using (Eq 1) and (Eq 2):
medullated fibers having an abnormally large diameter and a
med fibers,% 5 100 m/n (1)
high degree of medullation are probably the worst kind.
kemp fibers,% 5 100 k/n (2)
6. Apparatus and Material
where:
6.1 The apparatus and material required in this test method
m = number of med fibers observed,
are identical to those specified in Test Method D2130.
k = number of kemp fibers observed, and
n = total number of animal fibers observed.
7. Sampling
10. Report
7.1 Adequate sampling procedures for loose fibers (grease,
pulled, and scoured), sliver, top, yarn, and fabric are described 10.1 State that the specimens were tested as directed in Test
Method D2968. Describe the material or product sampled and
in Test Method D2130.
the method used.
8. Procedure
10.2 Report the following information:
8.1 Prepare the test specimens, calibrate the microprojector, 10.2.1 The med fibers content,
10.2.2 The kemp fibers content, and
condition the specimens, and prepare the slides by use of the
heavy-duty cross-section device as directed in Test Method 10.2.3 The total number of animal fibers observed.
D2130. Have two operators independently prepare at least one
11. Precision and Bias
slide for each test specimen.
11.1 Interlaboratory Test Data —An interlaboratory test
8.2 Have each of the two operators make observations using
wasconductedin1970inwhichthreerandomlydrawnsamples
theprocedurespecifiedinTestMethodD2130,exceptthatonly
from one lot of mohair top were tested in each of five
medullated fibers need be measured. For such fibers, measure
laboratories. Two operators in each laboratory each examined
the diameter of both the medulla and the fiber, calculate their
500 fibers per sample. The test results for med fibers and kemp
ratio, an
...
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