ASTM D332-87(1997)e1

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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e1
Designation: D 332 – 87 (Reapproved 1997)
Standard Test Method for
Relative Tinting Strength of White Pigments by Visual
Observation
This standard is issued under the fixed designation D 332; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
e NOTE—Editorial changes were made throughout in September 1997.
1. Scope are made until the lightness of the test pigment paste is
matched. The weight of the tinting pigment is used to calculate
1.1 This test method describes the procedure for determin-
relative tinting strength.
ing the relative tinting strength of white pigments by visual
assessment of blue tints.
4. Significance and Use
1.2 This test method is applicable only for comparing the
4.1 This test method is used as a referee method and for
test pigment with a reference standard of the same type and
quality control. The vehicle (oil) for preparing the dispersions
grade.
and the tinting pigment (ultramarine blue) are specified but
NOTE 1—ASTM Test Method D 2745 describes a procedure for instru-
other vehicles and tinting pigments can be used. Any such
mental evaluation of black tinted samples.
changes in the test method must be agreed upon between the
1.3 The values stated in inch-pound units are to be regarded
purchaser and the seller.
as the standard. The values given in parentheses are for
4.2 The results obtained with a muller do not necessarily
information only.
agree with an industrial situation where different dispersing
1.4 This standard does not purport to address all of the
conditions exist. However, dispersing with a muller is a fast
safety concerns, if any, associated with its use. It is the
and relatively inexpensive way of testing tinting strength for
responsibility of the user of this standard to establish appro-
routine quality control.
priate safety and health practices and determine the applica-
5. Apparatus
bility of regulatory limitations prior to use.
5.1 Balance, laboratory-type, sensitive to 0.1 mg, equipped
2. Referenced Documents
with a counter-balanced watch glass.
2.1 ASTM Standards:
5.2 Buret, 1-mL capacity, stopcock controlled, graduated in
D 262 Specification for Ultramarine Blue Pigment
0.1-mL divisions, or other suitable dispensing apparatus with a
D 2745 Test Method for Relative Tinting Strength of White
delivery accurate to 0.05 mL.
Pigments by Reflectance Measurements
5.3 Glass Hand Muller—A weighted glass hand muller with
beveled edge having a total weight of 15 lb (6.8 kg) and a
3. Summary of Test Method
grinding face of from 2 ⁄4 to 3 in. (70 to 75 mm) in diameter.
3.1 Specified amounts of white pigment and blue tinting
The face shall be free of blowholes and other imperfections and
pigment are dispersed together in oil using a glass hand muller
kept roughened by lightly grinding with No. 303 optical emery,
or an automatic muller. Both the test and standard pigments are
or its equivalent, and turpentine.
treated identically. The pastes are drawn-down together on a
5.4 Rubbing Surface—A ground glass plate, at least 14 by
panel and visually assessed for tinting strength. To obtain a
20 in. (355 by 510 mm), the surface of which is kept roughened
numerical rating of tinting strength, dispersions with the
by lightly grinding with No. 303 optical emery, or its equiva-
standard white pigment and more or less of the tinting pigment
lent, and turpentine.
5.5 Automatic Muller, automatic, equipped with a weight
that exerts a permanent 50-lbf (220-N) force and an additional
This test method is under the jurisdiction of ASTM Committee D-1 on Paint
and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.26 on Optical Properties. The sole source of supply of the muller known to the committee at this time is
Current edition approved Nov. 27, 1987. Published January 1988. Originally Hoover Color Corp., P. O. Box 218, Hiwassee, VA 24347. If you are aware of
published as D 332 – 31 T. Last previous edition D 332– 64 (1980). alternative suppliers, please provide this information to ASTM Headquarters. Your
Annual Book of ASTM Standards, Vol 06.03. comments will receive careful consideration at a meeting of the responsible
3 1
Annual Book of ASTM Standards, Vol 06.01. technical committee, which you may attend.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 332
weight exerting a 50-lbf making a total of 100-lbf (445-N). The 1 in. (25 mm) wide and 2 in. (50 mm) long. Use the scraper to
two glass plates shall be kept sharp by removing from the smooth the surface of the pastes (here called “draw-downs”) by
machine and grinding them face-to-face with No. 303 optical drawing the scraper lightly over the pastes to give a straight
emery or equivalent, and water. and even line of contact between them. Keep the drawn-downs
5.6 Spatula—A flexible spatula having a chromium-plated sufficiently thick to obscure the panel.
or plastic blade 3 to 6 in. (75 to 150 mm) long. 7.4 Immediately examine the draw-downs of the two pastes,
5.7 Panels of bright tin, glass, or white-lacquered card- on the top side only, for relative lightness of tint. If the sample
board. is lighter than the ref
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