ASTM D2805-96a(2003)

Standard Test Method for Hiding Power of Paints by Reflectometry

SIGNIFICANCE AND USE
This is a precise instrumental method giving results having an absolute physical significance without reference to a comparison paint. It should be used when maximum precision and minimum subjectivity are required, as in testing specification coatings or evaluating the hiding efficiency of pigments.
Hiding power Test Method D 344 is visual instead of instrumental, and gives results that are relative to a material standard instead of absolute. It is less precise than Test Method D 2805 but more closely aligned with practical painting procedures.
SCOPE
1.1 This test method covers the determination, without reference to a material paint standard, of the hiding power of air dry coatings with Y tristimulus values greater than 15%. With appropriate modification, it can also be used to test baking finishes.
1.2  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.

General Information

• Status: Historical
• Publication Date: 09-May-2003
• ICS: 87.040 - Paints and varnishes
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.26 - Optical Properties

Relations

• Replaces: ASTM D2805-96a - Standard Test Method for Hiding Power of Paints by Reflectometry
• Effective Date: 10-May-2003
• Replaced By: ASTM D2805-11 - Standard Test Method for Hiding Power of Paints by Reflectometry
• Effective Date: 01-Jun-2011
• Referred By: ASTM D5146-10(2019) - Standard Guide to Testing Solvent-Borne Architectural Coatings
• Effective Date: 10-May-2003
• Referred By: ASTM D6762-18(2023) - Standard Test Method for Determining the Hiding Power of Paint by Visual Evaluation of Spray Applied Coatings
• Effective Date: 10-May-2003
• Referred By: ASTM D2205-20 - Standard Guide for Selection of Tests for Traffic Paints
• Effective Date: 10-May-2003
• Referred By: ASTM D5007-99(2017) - Standard Test Method for Wet-to-Dry Hiding Change
• Effective Date: 10-May-2003
• Referred By: ASTM D5324-16(2022) - Standard Guide for Testing Water-Borne Architectural Coatings
• Effective Date: 10-May-2003
• Referred By: ASTM D2243-20 - Standard Test Method for Freeze-Thaw Resistance of Water-Borne Coatings
• Effective Date: 10-May-2003
• Referred By: ASTM E284-22 - Standard Terminology of Appearance
• Effective Date: 10-May-2003
• Referred By: ASTM D6577-15(2019) - Standard Guide for Testing Industrial Protective Coatings
• Effective Date: 10-May-2003
• Referred By: ASTM D6763-16(2022) - Standard Guide for Testing Exterior Wood Stains and Clear Water Repellents
• Effective Date: 10-May-2003
• Referred By: ASTM D7394-18(2023) - Standard Practice for Rheological Characterization of Architectural Coatings using Three Rotational Bench Viscometers
• Effective Date: 10-May-2003
• Referred By: ASTM D6441-05(2016) - Standard Test Methods for Measuring the Hiding Power of Powder Coatings
• Effective Date: 10-May-2003
• Referred By: ASTM D3730-17(2022) - Standard Guide for Testing High-Performance Interior Architectural Wall Coatings
• Effective Date: 10-May-2003
• Referred By: ASTM D333-01(2021) - Standard Guide for Clear and Pigmented Lacquers
• Effective Date: 10-May-2003

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
Designation: D2805 – 96a (Reapproved 2003)
Standard Test Method for
1
Hiding Power of Paints by Reflectometry
This standard is issued under the fixed designation D2805; 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.
This standard has been approved for use by agencies of the Department of Defense.
INTRODUCTION
2
Using equations derived from Kubelka-Munk turbid media theory (1-4) (see Annex A1), the
reflectance of a coating can be predicted for any film thickness from measurements made at only one.
On this basis several rapid and accurate test methods (5, 6) have been developed for determining
hiding power. In the past such test methods have been considered difficult due to complexities,
apparent and actual, in the treatment of data. The present test method has been simplified in this
respect, primarily by adapting it fully for computer calculations.
Although the use of broad-band reflectometry makes this test method theoretically valid only for
nonchromatic(whiteorgray)colors,goodagreementhasbeenobtainedwithchromaticpaintsaswell.
Thisisundoubtedlybecausetheexperimentalmeasurementsaremadefairlyclosetothehidingpower
end point so that the Kubelka-Munk extrapolation and thus any associated error is relatively small.
This test method is therefore recommended without restriction as to color.
1. Scope D344 Test Method for Relative Hiding Power of Paints by
the Visual Evaluation of Brushouts
1.1 This test method covers the determination, without
D1475 Test Method For Density of Liquid Coatings, Inks,
reference to a material paint standard, of the hiding power of
and Related Products
air dry coatings with Y tristimulus values greater than 15 %.
D3924 Specification for Environment for Conditioning and
With appropriate modification, it can also be used to test
Testing Paint, Varnish, Lacquer, and Related Materials
baking finishes.
E284 Terminology of Appearance
1.2 This standard does not purport to address all of the
E1247 Practice for Detecting Fluorescence in Object-Color
safety concerns, if any, associated with its use. It is the
Specimens by Spectrophotometry
responsibility of the user of this standard to establish appro-
E1331 Test Method for Reflectance Factor and Color by
priate safety and health practices and determine the applica-
Spectrophotometry Using Hemispherical Geometry
bility of regulatory limitations prior to use.
E1347 Test Method for Color and Color-Difference Mea-
2. Referenced Documents
surement by Tristimulus Colorimetry
3
E1349 Test Method for Reflectance Factor and Color by
2.1 ASTM Standards:
Spectrophotometry Using Bidirectional (45°:0° or 0°:45°)
Geometry
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of
3. Terminology
Subcommittee D01.26 on Optical Properties.
3.1 Definitions—For definitions used in this test method,
Current edition approved May 10, 2003. Published June 2003. Originally
approved in 1969. Last previous edition approved in 1996 as D2805 – 96a. DOI:
see Terminology E284.
10.1520/D2805-96AR03.
3.2 Definitions of Terms Specific to This Standard:
2
The boldface numbers in parentheses refer to the list of references at the end of
3.2.1 contrast ratio—the ratio of the reflectance of a film on
this standard.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or a black substrate to that of an identical film on a white
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
substrate.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D2805 – 96a (2003)
3.2.1.1 C —the contrast ratio with a white substrate of and minimum subjectivity are required, as in testing specifica-
W
reflectance W. tion coatings or evaluating the hiding efficiency of pigments.
5.2 Hiding power Test Method D344 is visual instead of
Thus: C 5 R /R
W 0 W
instrumental, and gives results that are relative to a material
standard instead of absolute. It is less precise thanTest Method
3.2.1.2 C—the contrast ratio with a white substrate for
D2805 but more closely aligned with practical painting proce-
which W = 0.80.
dures.
Thus: C 5 R /R
0 0.80
6. Apparatus and Materials
3.2.2 reflectance—the daylight luminous diffuse reflectance 6.1 Substrates:
4
factor (specular reflection excluded). Also referred to in this 6.1.1 Black Glass Panels, minimum size 200 by 200 mm,
...