ASTM D7856-21
(Specification)Standard Specification for Color and Appearance Retention of Solid and Variegated Color Plastic Siding Products using CIELab Color Space
Standard Specification for Color and Appearance Retention of Solid and Variegated Color Plastic Siding Products using CIELab Color Space
SCOPE
1.1 This specification establishes requirements and test methods for the color and appearance retention of solid and variegated colored plastic siding products.
1.2 Color retention testing provides a method for estimating the acceptability of color change in a plastic siding product over an extended period of service.
Note 1: The exposure locations and durations specified in this standard have been shown to provide a good estimation of the color change in vinyl and polypropylene siding products over an extended period of service (see 2.2). It is expected that materials designed for the exposure conditions typical of exterior siding will respond similarly, but the applicability of this standard to other types of plastic siding has not been empirically established.
1.3 This specification is a successor to Specifications D6864 and D7251, which cover solid colors and variegated colors, respectively. This specification combines coverage for both, and has the same scope as those standards.
1.4 Specifications D6864 and D7251 use Hunter Lab color space for measurement of colors and evaluation of color change. These standards require classification of colors into regions based on the L, a, and b coordinates of the color, and evaluation of color changes is done using an ellipsoid value equation having unique coefficients for each color region. This specification uses CIE 1976 L* a* b* color space for measurement and evaluation of color change. Using this method, the need for separate color regions and evaluation equations has been eliminated.
1.5 Provisions for sample selection and preparation, and weathering are the same in this specification as in Specifications D6864 and D7251.
1.6 Characterization of color and appearance for variegated colors is complicated by the presence of multiple colors in a random pattern. The procedure for measuring variegated colors in this specification is based on using a template to reference six spots for color measurement.
1.7 This standard specifies outdoor weathering in three specific climate zones for a single 24-month exposure, and the color retention performance requirements under these conditions are established to be indicative of acceptable performance over an extended period of service. However, nothing in this standard precludes the use of different or additional climate zones, or different exposure durations, so long as those conditions are clearly specified in any reports.
1.8 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.9 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
Note 2: There is no known ISO equivalent to this standard.
1.10 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.
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Standards Content (Sample)
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:D7856 −21
Standard Specification for
Color and Appearance Retention of Solid and Variegated
1
Color Plastic Siding Products using CIELab Color Space
This standard is issued under the fixed designation D7856; 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* in this specification is based on using a template to reference
six spots for color measurement.
1.1 This specification establishes requirements and test
methods for the color and appearance retention of solid and 1.7 This standard specifies outdoor weathering in three
specific climate zones for a single 24-month exposure, and the
variegated colored plastic siding products.
color retention performance requirements under these condi-
1.2 Color retention testing provides a method for estimating
tionsareestablishedtobeindicativeofacceptableperformance
the acceptability of color change in a plastic siding product
over an extended period of service. However, nothing in this
over an extended period of service.
standard precludes the use of different or additional climate
NOTE 1—The exposure locations and durations specified in this
zones, or different exposure durations, so long as those
standard have been shown to provide a good estimation of the color
conditions are clearly specified in any reports.
change in vinyl and polypropylene siding products over an extended
period of service (see 2.2). It is expected that materials designed for the 1.8 Units—The values stated in inch-pound units are to be
exposure conditions typical of exterior siding will respond similarly, but
regarded as standard. The values given in parentheses are
the applicability of this standard to other types of plastic siding has not
mathematical conversions to SI units that are provided for
been empirically established.
information only and are not considered standard.
1.3 ThisspecificationisasuccessortoSpecificationsD6864
1.9 This standard does not purport to address all of the
and D7251, which cover solid colors and variegated colors,
safety concerns, if any, associated with its use. It is the
respectively. This specification combines coverage for both,
responsibility of the user of this standard to establish appro-
and has the same scope as those standards.
priate safety, health, and environmental practices and deter-
1.4 Specifications D6864 and D7251 use Hunter Lab color
mine the applicability of regulatory limitations prior to use.
space for measurement of colors and evaluation of color
NOTE 2—There is no known ISO equivalent to this standard.
change. These standards require classification of colors into
1.10 This international standard was developed in accor-
regions based on the L, a, and b coordinates of the color, and
dance with internationally recognized principles on standard-
evaluation of color changes is done using an ellipsoid value
ization established in the Decision on Principles for the
equation having unique coefficients for each color region. This
Development of International Standards, Guides and Recom-
specification uses CIE 1976 L* a* b* color space for measure-
mendations issued by the World Trade Organization Technical
ment and evaluation of color change. Using this method, the
Barriers to Trade (TBT) Committee.
need for separate color regions and evaluation equations has
been eliminated.
2. Referenced Documents
2
1.5 Provisions for sample selection and preparation, and
2.1 ASTM Standards:
weathering are the same in this specification as in Specifica-
D660 Test Method for Evaluating Degree of Checking of
tions D6864 and D7251.
Exterior Paints
D661 Test Method for Evaluating Degree of Cracking of
1.6 Characterization of color and appearance for variegated
Exterior Paints
colors is complicated by the presence of multiple colors in a
D662 Test Method for Evaluating Degree of Erosion of
randompattern.Theprocedureformeasuringvariegatedcolors
Exterior Paints
D714 Test Method for Evaluating Degree of Blistering of
Paints
1
This test method is under the jurisdiction ofASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.24 on Plastic Building
2
Products. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 1, 2021. Published July 2021. Originally approved contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
in 2014. Last previous edition approved in 2015 as D7856 – 15a. DOI:10.1520/ Standards volume info
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM 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.
Designation: D7856 − 15a D7856 − 21
Standard Specification for
Color and Appearance Retention of Solid and Variegated
1
Color Plastic Siding Products using CIELab Color Space
This standard is issued under the fixed designation D7856; 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*
1.1 This specification establishes requirements and test methods for the color and appearance retention of solid and variegated
colored plastic siding products.
1.2 Color retention testing provides a method for estimating the acceptability of color change in a plastic siding product over an
extended period of service.
NOTE 1—The exposure locations and durations specified in this standard have been shown to provide a good estimation of the color change in vinyl and
polypropylene siding products over an extended period of service (see 2.2). It is expected that materials designed for the exposure conditions typical of
exterior siding will respond similarly, but the applicability of this standard to other types of plastic siding has not been empirically established.
1.3 This specification is a successor to Specifications D6864 and D7251, which cover solid colors and variegated colors,
respectively. This specification combines coverage for both, and has the same scope as those standards.
1.4 Specifications D6864 and D7251 use Hunter Lab color space for measurement of colors and evaluation of color change. These
standards require classification of colors into regions based on the L, a, and b coordinates of the color, and evaluation of color
changes is done using an ellipsoid value equation having unique coefficients for each color region. This specification uses CIE 1976
L* a* b* color space for measurement and evaluation of color change. Using this method, the need for separate color regions and
evaluation equations has been eliminated.
1.5 Provisions for sample selection and preparation, and weathering are the same in this specification as in Specifications D6864
and D7251.
1.6 Characterization of color and appearance for variegated colors is complicated by the presence of multiple colors in a random
pattern. The procedure for measuring variegated colors in this specification is based on using a template to reference six spots for
color measurement.
1.7 This standard specifies outdoor weathering in three specific climate zones for a single 24-month exposure, and the color
retention performance requirements under these conditions are established to be indicative of acceptable performance over an
extended period of service. However, nothing in this standard precludes the use of different or additional climate zones, or different
exposure durations, so long as those conditions are clearly specified in any reports.
1
This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.24 on Plastic Building Products.
Current edition approved Dec. 1, 2015July 1, 2021. Published December 2015July 2021. Originally approved in 2014. Last previous edition approved in 2015 as
D7856 – 15.D7856 – 15a. DOI:10.1520/D7856-15A.DOI:10.1520/D7856-21.
*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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D7856 − 21
1.8 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.9 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
NOTE 2—There is no known ISO equivalent to this standard.
1.10 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.
2. Reference
...
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