ASTM D2968-22

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D2968 − 22
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 4. Summary of Test Method
1.1 This test method covers the determination by micropro- 4.1 Themagnifiedimagesofaspecimenoftheanimalfibers
jection of the percentage of medullated fibers (med and kemp are examined. All medullated fibers are measured and classed
fibers)inwoolorotheranimalfiberssuchasmohair,cashmere, as either med fibers or kemp fibers. The observed numbers of
alpaca, or camel’s hair in their various forms. med and kemp fibers are expressed as percentages of the total
number of fiber images examined.
1.2 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5. Significance and Use
responsibility of the user of this standard to establish appro-
5.1 Test Method D2968 for the determination of med and
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. kempfibersbymicroprojectionmaybeusedfortheacceptance
testing of commercial shipments of wool and other animal
1.3 This international standard was developed in accor-
dance with internationally recognized principles on standard- fibers, but caution is advised since only a few types of animal
fibers have been subjected to interlaboratory tests to ascertain
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- the precision of tests for med and kemp fibers by this test
method. Comparative tests as directed in 5.1.1 may be advis-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. able.
5.1.1 In case of a dispute arising from differences in
2. Referenced Documents
reported test results when using Test Method D2968 for
2.1 ASTM Standards: acceptance testing of commercial shipments, the purchaser and
D123 Terminology Relating to Textiles the supplier should conduct comparative tests to determine if
D2130 Test Method for Diameter ofWool and OtherAnimal there is a statistical bias between their laboratories. Competent
Fibers by Microprojection (Withdrawn 2022) statistical assistance is recommended for the investigation of
D4845 Terminology Relating to Wool bias.As a minimum, the two parties should take a group of test
specimens which are as homogeneous as possible and which
3. Terminology
are from a lot of material of the type in question. The test
3.1 For all terminology related to D13.13, Wool and Felt,
specimens should then be randomly assigned in equal numbers
see Terminology D4845. to each laboratory for testing.The average results from the two
3.1.1 The following terms are relevant to this standard:
laboratories should be compared using Student’s t-test for
kemp fiber; med fiber; medulla, in mammalian hair fibers; unpaireddataandanacceptableprobabilitylevelchosenbythe
medullated fiber; wool. two parties before testing is begun. If a bias is found, either its
cause must be found and corrected, or the purchaser and the
3.2 FordefinitionsofallothertextiletermsseeTerminology
suppliermustagreetointerpretfuturetestresultsinviewofthe
D123.
known bias.
1 5.2 Knowledge of the incidence of med fibers and kemp
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.
fibers in wool and other animal fibers is of importance to
CurrenteditionapprovedJune1,2022.PublishedJuly2022.Originallyapproved
manufacturers of woven or knitted fabrics because of the
in 1971. Last previous edition approved in 2013 as D2968 – 13 which was
apparent dye resistance and light reflectance qualities of these
withdrawn in January 2022 and reinstated in June 2022. DOI: 10.1520/D2968-22.
fibers. This is not to imply that all kemp fibers will resist dye
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
and all med fibers will accept dye normally. In practice, a
Standards volume information, refer to the standard’s Document Summary page on
proportion of kemp fibers will appear normal after dyeing and
the ASTM website.
3 a proportion of med fibers will appear chalky white after
The last approved version of this historical standard is referenced on
www.astm.org. dyeing. From the perspective of visual and aesthetic problems,
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2968 − 22
medullated fibers having an abnormally large diameter and a kemp fibers,% 5 100 k/n (2)
high degree of medullation are probably the worst kind.
where:
6. Apparatus and Material m = number of med fibers observed,
k = number of kemp fibers observed, and
6.1 The apparatus and material required in this test method
n = total number of animal fibers observed.
are identical to those specified in Test Method D2130.
10. Report
7. Sampling
10.1 State that the specimens were tested as directed in Test
7.1 Adequate sampling procedures for loose fibers (grease,
Method D2968. Describe the material or product sampled and
pulled, and scoured), sliver, top, yarn, and fabric are described
the method used.
in Test Method D2130.
10.2 Report the following information:
8. Procedure
10.2.1 The med fibers content,
10.2.2 The kemp fibers content, and
8.1 Prepare the test specimens, calibrate the microprojector,
10.2.3 The total number of animal fibers observed.
condition the specimens, and prepare the slides by use of the
heavy-duty cross-section device as directed in Test Method
11. Precision and Bias
D2130. Have two operators independently prepare at least one
11.1 Interlaboratory Test Data —An interlaboratory test
slide for each test specimen.
wasconductedin1970inwhichthreerandomlydrawnsamples
8.2 Have each of the two operators make observations using
from one lot of mohair top were tested in each of five
theprocedurespecifiedinTestMethodD2130,exceptthatonly
laboratories. Two operators in each laboratory each examined
medullated fibers need be measured. For such fibers, measure
500 fibers per sample. The test results for med fibers and kemp
the diameter of both the medulla and the fiber, calculate their
fibers were found to be free of bias due to sampling o
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