ASTM D2967-02
(Test Method)Standard Test Method for Edge Coverage of Powder Coatings
Standard Test Method for Edge Coverage of Powder Coatings
SCOPE
1.1 This test method covers the determination of the ratio of edge thickness (see 3.1.3) to face thickness (see 3.1.4) of powdered plastic coatings applied to a specific face thickness by dipping preheated square bars into aerated powder and curing the coating using predetermined conditions.
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
Relations
Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 2967 – 02
Standard Test Method for
1
Edge Coverage of Powder Coatings
This standard is issued under the fixed designation D 2967; 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.
1. Scope 3.1.4 face thickness, n—of powder coating, the average
thickness of the coating on flat surfaces of steel bars measured
1.1 This test method covers the determination of the ratio of
perpendicular to the surfaces.
edge thickness (see 3.1.3) to face thickness (see 3.1.4) of
3.1.5 powder coatings, n—coatings which are protective or
powdered plastic coatings applied to a specific face thickness
decorative, or both, formed by the application of a coating
by dipping preheated square bars into aerated powder and
powder to a substrate and fused in a continuous film by the
curing the coating using predetermined conditions.
application of heat or radiant energy.
1.2 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Significance and Use
responsibility of the user of this standard to establish appro-
4.1 This test method measures the degree to which different
priate safety and health practices and determine the applica-
coating powder materials cover sharp edges. Edge coverage is
bility of regulatory limitations prior to use.
influenced by face thickness, thixotropy, melt viscosity, surface
2. Referenced Documents tension, cure rate, and temperature of application and curing.
2.1 ASTM Standards:
5. Apparatus
D 374 Test Methods for Thickness of Solid Electrical Insu-
2 5.1 Aerated Bed—Suitable for providing a uniformly sus-
lation
3 pended dense phase of free–moving powder. Fig. 1 shows a
D 1898 Practice for Sampling of Plastics
schematic of an aerated bed used for suspending the coating
3. Terminology powder. The equipment consists of an open top chamber which
has a porous plate for a false bottom. Air is introduced under
3.1 Definitions of Terms Specific to This Standard:
the plate at a low pressure so that it filters through the porous
3.1.1 coating powders, n— finely divided particles of resin,
plate and uniformly suspends the particles contained in the
either thermoplastic or thermosetting, generally incorporating
chamber.
pigments, fillers, and additives and remaining finely divided
5.2 Micrometer Caliper—1 in. (25.4 mm), in accordance
during storage under suitable conditions, which, after fusing
with Method C of Test Methods D 374.
and possibly curing, give a continuous film.
5.3 Oven, with forced convection capable of maintaining
3.1.1.1 Discussion—The coating powder may contain fill-
the specified temperature within 63°C.
ers, colorants, curing agents, etc., consistent with producing the
1 1
5.4 Test Bars, four, measuring 13 by 13 by 100 mm ( ⁄2by ⁄2
desired coatings. The powder is applied by various methods
by 4 in.) in accordance with Fig. 2.
such as spraying, sprinkling, or dipping. Usually hot parts are
5.4.1 Use bars that are free of rust and dirt, and which have
used. Heat causes the powder to melt and flow into a dense
been washed with a clean solvent to remove any traces of oily
coating.
substances. Bars may be reused if the coating used in a
3.1.2 edge coverage, n—of powder coating, the ratio of the
previous test has been completely removed without marring the
edge thickness to the face thickness of the fused coating
surfaces or corners of the bars. Appropriate methods of
expressed in percent.
removal include the use of stripping solutions, heat, and careful
3.1.3 edge thickness, n—of powder coating, the average
scraping with a sharp blade, or combinations thereof.
thickness of the coating on sharp 90° edges of steel bars
measured at 45° to the flat surfaces.
6. Sampling
6.1 The powder sample shall be from one lot and be
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint representative of the lot using Method A of Practice D 1898.
and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.51 on Powder Coatings.
Current edition approved Jan. 10, 2002. Published March 2002. Originally issued
as D 2967 – 71. Last previous edition D 2967 – 96.
2
Annual Book of ASTM Standards, Vol 10.01.
3
Annual Book of ASTM Standards, Vol 08.01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
---------------------- Page: 1 ----------------------
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D2967–02
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.