ASTM D2967-96
(Test Method)Standard Test Method for Edge Coverage of Coating Powders
Standard Test Method for Edge Coverage of Coating Powders
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NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 2967 – 96
Standard Test Method for
Edge Coverage of Coating Powders
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 perpendicular to the surfaces.
1.1 This test method covers the determination of the ratio of
4. Significance and Use
edge thickness (see 3.1.3) to face thickness (see 3.1.4) of
4.1 This test method measures the degree to which different
powdered plastic coatings applied to a specific face thickness
powdered plastic coating materials cover sharp edges to
by dipping preheated square bars into aerated powder and
provide electrical insulation. Edge coverage is influenced by
curing the coating using predetermined conditions.
face thickness, thixotropy, melt viscosity, surface tension, cure
1.2 This standard does not purport to address all of the
rate, and temperature of application and curing.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5. Apparatus
priate safety and health practices and determine the applica-
5.1 Aerated Bed—Suitable for providing a uniformly sus-
bility of regulatory limitations prior to use. For a specific
pended dense phase of free–moving powder. Fig. 1 shows a
hazard statement, see Section 6.
schematic of an aerated bed used for suspending the powdered
2. Referenced Documents plastic. The equipment consists of an open top chamber which
has a porous plate for a false bottom. Air is introduced under
2.1 ASTM Standards:
the plate at a low pressure so that it filters through the porous
D 374 Test Methods for Thickness of Solid Electrical Insu-
2 plate and uniformly suspends the particles contained in the
lation
3 chamber.
D 1898 Practice for Sampling of Plastics
5.2 Micrometer Caliper—1 in. (25.4 mm), in accordance
3. Terminology with Method C of Test Methods D 374.
5.3 Oven, with forced convection capable of maintaining
3.1 Definitions of Terms Specific to This Standard:
the specified temperature within 63°C.
3.1.1 coating powder, n—a heat-fusible, finely divided,
5.4 Test Bars, four, measuring 13 by 13 by 100 mm ( ⁄2 by
solid, resinous material used to form electrical insulating
⁄2 by 4 in.) in accordance with Fig. 2.
coatings.
5.4.1 Use bars that are free of rust and dirt, and which have
3.1.1.1 Discussion—The coating powder may contain fill-
been washed with a clean solvent to remove any traces of oily
ers, colorants, curing agents, etc., consistent with producing the
substances. Bars may be reused if the coating used in a
desired coatings. The powder is applied by various methods
previous test has been completely removed without marring the
such as spraying, sprinkling, or dipping. Usually hot parts are
surfaces or corners of the bars. Appropriate methods of
used. Heat causes the powder to melt and flow into a dense
removal include the use of stripping solutions, heat, and careful
coating.
scraping with a sharp blade, or combinations thereof.
3.1.2 edge coverage, n—of coating powder, the ratio of the
edge thickness to the face thickness of the fused coating
6. Hazards
expressed in percent.
6.1 Warning—Provide adequate ventilation, avoid breath-
3.1.3 edge thickness, n—of powder coating, the average
ing the dust or fumes, and prevent contact with skin since many
thickness of the coating on sharp 90° edges of steel bars
of the reactive materials used in coating powders have been
measured at 45° to the flat surfaces.
reported to be toxic or cause irritation to sensitive skin.
3.1.4 face thickness, n—of powder coating, the average
thickness of the coating on flat surfaces of steel bars measured
7. Sampling
7.1 The powder sample shall be from one lot and be
This test method is under the jurisdiction of ASTM Committee D-1 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.
8. Test Specimens
Current edition approved Oct. 10, 1996. Published December 1996. Originally
e1
issued as D 2967 – 71. Last previous edition D 2967 – 91 (1995) .
8.1 The test specimens shall be the steel bars in accordance
Annual Book of ASTM Standards, Vol 10.01.
with 5.4, coated with powder to form a smooth, continuous
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.
D 2967
used for aeration must be less than 50 % relative humidity.)
Aerate powder at a rate providing a constant dense phase
behaving as a liquid with a minimum of geysering. Determine
the depth of aerated powder, then turn off air and de
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.