ASTM D7251-09
(Specification)Standard Specification for Color and Appearance Retention of Variegated Color Plastic Siding Products
Standard Specification for Color and Appearance Retention of Variegated Color Plastic Siding Products
ABSTRACT
This specification establishes requirements and test methods for the color and appearance retention of variegated color plastic siding products. Color retention testing provides a method for estimating the acceptability of color change in a siding product over a period of years of service. Characterization of color and appearance for variegated colors is complicated by the presence of multiple colors in a random pattern. The procedure is based on using a template to reference 6 spots for color measurement. The color region for a color is determined by measuring the Hunter L, a, b color values for a sample population and calculating the average Hunter L, a, b color value. Ellipsoid Value Equations are used to determine the ellipsoid value representing the change in color due to weathering. Samples shall be exposed at three test sites: Temperate Northern represented by a site located in Louisville, KY or Cleveland, OH; hot, humid represented by a site located in Miami, FL, and hot, dry represented by a site located in Phoenix, Arizona. Materials shall be tested and the individual grades shall conform to specified values of ellipsoid value, color retention, and variegation change.
SCOPE
1.1 This specification establishes requirements and test methods for the color and appearance retention of variegated color plastic siding products.
1.2 Color retention testing provides a method for estimating the acceptability of color change in a siding product over a period of years of service.
1.3 Characterization of color and appearance for variegated colors is complicated by the presence of multiple colors in a random pattern. The procedure is based on using a template to reference 6 spots for color measurement.
1.4 Methods of indicating compliance with this specification are provided.
1.5 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 known ISO equivalent to this standard.
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An American National Standard
Designation: D7251 – 09
Standard Specification for
Color and Appearance Retention of Variegated Color Plastic
1
Siding Products
This standard is issued under the fixed designation D7251; 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* G147 Practice for Conditioning and Handling of Nonmetal-
lic Materials for Natural and Artificial Weathering Tests
1.1 This specification establishes requirements and test
methods for the color and appearance retention of variegated
3. Terminology
color plastic siding products.
3.1 Definitions—Definitions are in accordance with termi-
1.2 Color retention testing provides a method for estimating
nologies in Terminologies D883 and D1600 unless otherwise
the acceptability of color change in a siding product over a
noted.
period of years of service.
3.2 Definitions of Terms Specific to This Standard:
1.3 Characterization of color and appearance for variegated
3.2.1 color region—parameters that define the color space
colors is complicated by the presence of multiple colors in a
for a siding sample. Color is measured with Hunter Units,
random pattern. The procedure is based on using a template to
sphere geometry (di:8), Illuminant C, 2° Observer, specular
reference 6 spots for color measurement.
component included.
1.4 Methods of indicating compliance with this specifica-
3.2.1.1 Discussion—Thecolorvaluesusedtoclassifycolors
tion are provided.
by region were established by measuring the Hunter L, a, b
1.5 This standard does not purport to address all of the
color values from the sample population, calculating the
safety concerns, if any, associated with its use. It is the
average for Hunter L, a, b, and then choosing the integer from
responsibility of the user of this standard to establish appro-
the corresponding L, a, b average values (that is, by truncating
priate safety and health practices and determine the applica-
any fractional result) to be used to classify colors by region.
bility of regulatory limitations prior to use.
Thus, average values greater than zero are truncated down to
NOTE 1—There is no known ISO equivalent to this standard.
the next lowest integer, and average values less than zero are
truncated up to the next highest integer.All values greater than
2. Referenced Documents
-1 and less than +1 truncate to 0.
2
2.1 ASTM Standards:
3.2.2 color retention standards—predictive color regions
D883 Terminology Relating to Plastics
described by a three dimensional model which constitute
D1435 Practice for Outdoor Weathering of Plastics
acceptable color retention levels resulting from weathering of
D1600 Terminology for Abbreviated Terms Relating to
a specific product type and color.
Plastics
3.2.2.1 Discussion—Color retention standards are defined
D2244 Practice for Calculation of Color Tolerances and
by equations that describe the three dimensional ellipsoid
Color Differences from Instrumentally Measured Color
value.
Coordinates
3.2.3 ellipsoid value—a mathematical calculation derived
E805 Practice for Identification of Instrumental Methods of
by inserting the measured DL, Da, and Db values of a
Color or Color-Difference Measurement of Materials
weathered specimen into an ellipsoid equation.
3.2.4 temperate northern climate—in weathering testing,a
North American metropolitan area testing site located within
1
This specification is under the jurisdiction of ASTM Committee D20 on
73 to 100°W longitude and 37 to 45°N latitude.
Plastics and is the direct responsibility of Subcommittee D20.24 on Plastic Building
3.2.5 variegated plastic siding—siding having discrete
Products.
markings of different colors.
Current edition approved Nov. 1, 2009. Published December 2009. Originally
approved in 2006. Last previous edition approved in 2006 as D7251 - 06. DOI:
4. Classification
10.1520/D7251-09.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4.1 Definitions—Definitions are in accordance with termi-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
nology in Terminologies D883 and D1600 unless otherwise
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. noted.
*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.
1
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D7251 – 09
4.2 Color Regions—The color region for a color is deter- 4.2.13 Region 13—Dark Gray
mined by measuring the Hunter L, a, b color values at six
L
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
An American National Standard
´1
Designation:D7251–06 Designation: D7251 – 09
Standard Specification for
Color and Appearance Retention of Variegated Color Plastic
1
Siding Products
This standard is issued under the fixed designation D7251; 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
´ NOTE—Fig. 1 was editorially revised in September 2006.
1. Scope*
1.1 This specification establishes requirements and test methods for the color and appearance retention of variegated color
plastic siding products.
1.2 Color retention testing provides a method for estimating the acceptability of color change in a siding product over a period
of years of service.
1.3 Characterizationofcolorandappearanceforvariegatedcolorsiscomplicatedbythepresenceofmultiplecolorsinarandom
pattern. The procedure is based on using a template to reference 6 spots for color measurement.
1.4 Methods of indicating compliance with this specification are provided.
1.5 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 known ISO equivalent to this standard.
2. Referenced Documents
2
2.1 ASTM Standards:
D883 Terminology Relating to Plastics
D1435 Practice for Outdoor Weathering of Plastics
D1600 Terminology for Abbreviated Terms Relating to Plastics
D2244 Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates
E805 Practice for Identification of Instrumental Methods of Color or Color-Difference Measurement of Materials
G147 Practice for Conditioning and Handling of Nonmetallic Materials for Natural and Artificial Weathering Tests
3. Terminology
3.1 Definitions—Definitions are in accordance with terminologies in Terminologies D883 and D1600 unless otherwise noted.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 color region—parameters that define the color space for a siding sample. Color is measured with Hunter Units, sphere
geometry (di:8), Illuminant C, 2° Observer, specular component included.
3.2.1.1 Discussion—ThecolorvaluesusedtoclassifycolorsbyregionwillbeestablishedbymeasuringtheHunterL,a,bcolor
valuesfromthesamplepopulation,calculatingtheaverageforHunterL,a,b,andthenchoosingtheintegerfromthecorresponding
L, a, b average values (that is, no rounding up or down) to be used to classify colors by region. —The color values used to classify
colorsbyregionwereestablishedbymeasuringtheHunterL,a,bcolorvaluesfromthesamplepopulation,calculatingtheaverage
forHunterL,a,b,andthenchoosingtheintegerfromthecorrespondingL,a,baveragevalues(thatis,bytruncatinganyfractional
result) to be used to classify colors by region.Thus, average values greater than zero are truncated down to the next lowest integer,
and average values less than zero are truncated up to the next highest integer.All values greater than -1 and less than +1 truncate
to 0.
3.2.2 color retention standards—predictive color regions described by a three dimensional model which constitute acceptable
color retention levels resulting from weathering of a specific product type and color.
1
This specification is under the jurisdiction ofASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.24 on Plastic Building Products.
Current edition approved April 1, 2006. Published April 2006. DOI: 10.1520/D7251-06E01.
Current edition approved Nov. 1, 2009. Published December 2009. Originally approved in 2006. Last previous edition approved in 2006 as D7251 - 06. DOI:
10.1520/D7251-09.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*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.
1
---------------------- Page: 1 ----------------------
D7251 – 09
3.2.2.1 Discussion—Color retention standards are defined by equations that describe the three dimensional ellipsoid value.
3.2.3 el
...
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