ASTM D6290-05e1
(Test Method)Standard Test Method for Color Determination of Plastic Pellets
Standard Test Method for Color Determination of Plastic Pellets
SIGNIFICANCE AND USE
Before proceeding with this test method, reference should be made to the specification of the material being tested. Any test specimen preparation, conditioning, dimensions, or testing parameters, or a combination thereof, covered in the materials specification shall take precedence over those mentioned in this test method. If there are no material specifications, then default conditions apply.
Note 2—Some materials, such as polyamide (nylon), can be cooled very differently during the production of the pellets. This variation in the cooling of the pellets can result in different levels of crystallinity in the pellets only. More crystalline nylons will be more opaque than amorphous nylons. This will result in differences in pellet opacity. The pellet shape is independent of the crystallinity of the material. This variation in pellet appearance, due to varying levels of crystallinity, does not affect final properties.
Note 3—This test method should not be used for general material specifications.
This test method describes a technique useful for making color comparisons of resins in pellet form that is fast and convenient as it does not require preparation, such as molding or extruding specimens. The test method shall be used only to compare specimens of similar pellet shape, size, texture, and degree of translucency. For example, translucent disc-shaped pellets should be compared to translucent disc-shaped pellets, not with opaque, rectangular shaped pellets.
Exact measurements of resin pellet color may not be directly related to the color of the final cast, molded or extruded product due to the multitude of variables, such as producing variables, methods, and pellet shape and size. Color measurements can be useful for comparing resins in pellet form when all samples are similar in shape and size.
A three-number tristimulus system is necessary to quantify color completely and precisely. The general method used in this procedure measures color using the CI...
SCOPE
1.1 This test method is intended primarily for the instrumental measurement of the degree of yellowness (or change of degree of yellowness) under daylight illumination of homogeneous, nonfluorescent, nearly-colorless transparent or nearly-white translucent or opaque plastics. The measurement is made on pellets and based on tristimulus values obtained with a spectrophotometer or colorimeter.
1.2 This test method is applicable to the color analysis of plastic pellets. Each material may have unique characteristics that determine the color values.
1.3 This procedure outlines a method to determine color measurements, such as Yellowness Index, CIE X, Y, Z, and Hunter L, a, b, or CIE L*, a*, b*.
1.4 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.
Note 1—There is no equivalent ISO Standard.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
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Designation: D6290 − 05
StandardTest Method for
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Color Determination of Plastic Pellets
This standard is issued under the fixed designation D6290; 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.
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´ NOTE—Added research report information to Section 10 editorially in September 2010.
1. Scope* E308 PracticeforComputingtheColorsofObjectsbyUsing
the CIE System
1.1 This test method is intended primarily for the instru-
E313 Practice for Calculating Yellowness and Whiteness
mental measurement of the degree of yellowness (or change of
Indices from Instrumentally Measured Color Coordinates
degree of yellowness) under daylight illumination of
E691 Practice for Conducting an Interlaboratory Study to
homogeneous, nonfluorescent, nearly-colorless transparent or
Determine the Precision of a Test Method
nearly-white translucent or opaque plastics. The measurement
E1331 Test Method for Reflectance Factor and Color by
is made on pellets and based on tristimulus values obtained
Spectrophotometry Using Hemispherical Geometry
with a spectrophotometer or colorimeter.
E1347 Test Method for Color and Color-Difference Mea-
1.2 This test method is applicable to the color analysis of
surement by Tristimulus Colorimetry
plastic pellets. Each material may have unique characteristics
E1349 Test Method for Reflectance Factor and Color by
that determine the color values.
Spectrophotometry Using Bidirectional (45°:0° or 0°:45°)
1.3 This procedure outlines a method to determine color Geometry
measurements, such as Yellowness Index, CIE X, Y, Z, and
Hunter L, a, b, or CIE L*, a*, b*. 3. Terminology
1.4 This standard does not purport to address all of the
3.1 Definitions—RefertoTerminologiesD883andE284for
safety concerns, if any, associated with its use. It is the
definitions of terms used in this test method.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4. Significance and Use
bility of regulatory limitations prior to use.
4.1 Before proceeding with this test method, reference
NOTE 1—There is no equivalent ISO Standard.
shouldbemadetothespecificationofthematerialbeingtested.
Any test specimen preparation, conditioning, dimensions, or
2. Referenced Documents
testing parameters, or a combination thereof, covered in the
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2.1 ASTM Standards: materials specification shall take precedence over those men-
D883 Terminology Relating to Plastics tioned in this test method. If there are no material
D2244 Practice for Calculation of Color Tolerances and specifications, then default conditions apply.
Color Differences from Instrumentally Measured Color
NOTE 2—Some materials, such as polyamide (nylon), can be cooled
Coordinates
very differently during the production of the pellets. This variation in the
E179 Guide for Selection of Geometric Conditions for
cooling of the pellets can result in different levels of crystallinity in the
Measurement of Reflection and Transmission Properties
pellets only. More crystalline nylons will be more opaque than amorphous
nylons. This will result in differences in pellet opacity. The pellet shape is
of Materials
independent of the crystallinity of the material. This variation in pellet
E284 Terminology of Appearance
appearance, due to varying levels of crystallinity, does not affect final
properties.
NOTE 3—This test method should not be used for general material
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specifications.
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.40 on Optical Properties.
4.2 This test method describes a technique useful for mak-
Current edition approved April 1, 2005. Published June 2005. Originally
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ing color comparisons of resins in pellet form that is fast and
approved in 1998. Last previous edition approved in 1998 as D6290 - 98 . DOI:
10.1520/D6290-05E01.
convenient as it does not require preparation, such as molding
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
or extruding specimens. The test method shall be used only to
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
compare specimens of similar pellet shape, size, texture, and
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. degree of translucency. For example, translucent disc-shaped
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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