ASTM D6961/D6961M-09(2021)

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: D6961/D6961M − 09 (Reapproved 2021)
Standard Test Method for
Color Measurement of Flax Fiber
This standard is issued under the fixed designation D6961/D6961M; 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 2.2 Other Standard:
AATCC Evaluation Procedure 6 Instrumental Color Mea-
1.1 This test method covers the instrumental color measure-
surement
ment of flax fiber.
3. Terminology
1.2 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in 3.1 For all terminology related to Flax see Terminology
each system are not necessarily exact equivalents; therefore, to D6798.
ensure conformance with the standard, each system shall be 3.1.1 The following terms are relevant to this standard:
dew-retting, enzyme-retting, and water-retting.
used independently of the other, and values from the two
systems shall not be combined.
3.2 For other textile terminology, see Terminology D123.
1.3 This standard does not purport to address all of the
4. Summary of Test Method
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 4.1 Samples of flax fiber are presented to a color spectro-
photometer. Color measurements are taken through a large
priate safety, health, and environmental practices and deter-
apertureport25.4mm[1 in.]diameter,inordertoaverageover
mine the applicability of regulatory limitations prior to use.
the natural color variation that occurs in flax fiber. The
1.4 This international standard was developed in accor-
instrumentapertureisfittedwithaquartzwindow.Thewindow
dance with internationally recognized principles on standard-
serves two functions, namely, to provide a base for compacting
ization established in the Decision on Principles for the
the sample during measurement, and to protect the instrument
Development of International Standards, Guides and Recom-
fromaccumulationofstrayfiberparticles.CIELABL*,a*,and
mendations issued by the World Trade Organization Technical
b* measurements are taken and are instrumentally calculated
Barriers to Trade (TBT) Committee.
from tristimulus X, Y, and Z data, observer function, and
illuminant data.
2. Referenced Documents
5. Significance and Use
2.1 ASTM Standards:
D123 Terminology Relating to Textiles
5.1 Few standards exist to objectively judge flax quality.
D1776/D1776M Practice for Conditioning and Testing Tex-
Color is an important factor in the quality of flax fiber. Natural
tiles
variations in raw flax fiber, various processing steps, fiber
D6798 Terminology Relating to Flax and Linen
blending, and a wide range of end uses contribute to the need
E284 Terminology of Appearance
for a standard method of objectively measuring the color of
E308 PracticeforComputingtheColorsofObjectsbyUsing
flax fiber. Spectrophotometic data provide an accurate, precise
the CIE System
determination of the color of flax fiber. Colorimetric data are
E1164 PracticeforObtainingSpectrometricDataforObject-
obtained through specimen measurement by combining speci-
Color Evaluation
men spectral data with data representing a CIE standard
observer and a CIE standard illuminant, as described in
Practice E308.
This test method is under the jurisdiction ofASTM Committee D13 on Textiles
5.2 If there are differences of practical significance between
and is the direct responsibility of Subcommittee D13.17 on Bast Fibers and Plants.
reported test results for two (or more) laboratories, compara-
Current edition approved July 1, 2021. Published July 2021. Originally approved
ɛ1 tive tests should be performed to determine if there is a
in 2003. Last previous edition approved in 2015 as D6961/D6961M–09(2015) .
DOI: 10.1520/D6961_D6961M-09R21.
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 Available from American Association of Textile Chemists and Colorists
Standards volume information, refer to the standard’s Document Summary page on (AATCC), P.O. Box 12215, Research Triangle Park, NC 27709-2215, http://
the ASTM website. www.aatcc.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6961/D6961M − 09 (2021)
statistical bias between them, using competent statistical assis- sites, care should be taken to avoid areas in which there are
tance. As a minimum, use the samples for such a comparative obvious changes in fiber orientation that could result in
test that are as homogeneous as possible, drawn from the same shadows that might contribute to error in measurement.
lot of material as the samples that resulted in disparate results
7.3.2 Users are advised that moisture may influence color of
during initial testing and randomly assigned in equal numbers
flax and linen. Samples should be conditioned prior to
to each laboratory. The results from the laboratories involved
measurement, as described in Practice D1776/D1776M.
should be compared using a statistical test for unpaired data, a
7.3.3 Bundles of flax fiber presented for measurement are
probability level chosen prior to the testing series. If a bias is
rather open-structured, capable of being easily compacted
found, either its cause must be found and corrected, or future
through pressure. Care should be taken in applying the same
test results for that fiber sample type must be adjusted in
pressure to samples during measurement, because the density
consideration of the known bias.
of the sample may influence readings. The sample should be
compressed firmly against the glass-covered aperture to assure
6. Apparatus
that the entire aperture is covered by fiber. Consistency in
6.1 A visible range spectrophotometer (minimum of 20- pressure can be achieved through the use of a fiber compres-
point) is recommended. Such an instrument provides greater sion cell that consists of a cup fiber specimen holder and clamp
accuracy than colorimeters, spectro-colorimeters, or 10-point that is pressed against the specimen through application of
color spectrophotometers. compressed air.Air pressure of 206 843 Pa [30 psi] or 275 790
6.1.1 Instrument Configuratio
...