ASTM D4217-02
(Test Method)Standard Test Method for Gel Time of Thermosetting Coating Powder
Standard Test Method for Gel Time of Thermosetting Coating Powder
SCOPE
1.1 This test method determines the length of time a thermosetting coating powder takes to gel on a polished metal surface at a specified temperature, such as 204°C (400°F). The determination of the gel time is a very simple method for the characterization and quality control of coating powders. However, the gel time determined by this method is not directly related to the time for the coating powder to cure in practical applications.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D4217–02
Standard Test Method for
1
Gel Time of Thermosetting Coating Powder
This standard is issued under the fixed designation D 4217; 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 * powder to a substrate and fused in a continuous film by the
application of heat or radiant energy.
1.1 This test method determines the length of time a
3.1.5 thermosetting, adj—describing a material that, when
thermosetting coating powder takes to gel on a polished metal
heated per a minimum recommended cure condition, under-
surface at a specified temperature, such as 204°C (400°F). The
goes a chemical reaction and a permanent change to a more
determination of the gel time is a very simple method for the
durable state capable of specific properties as designed for
characterization and quality control of coating powders. How-
substrate protection or decoration, or both.
ever, the gel time determined by this method is not directly
related to the time for the coating powder to cure in practical
4. Significance and Use
applications.
4.1 This test method is useful for selecting coating powders
1.2 This standard does not purport to address all of the
that gel in the desired time at the specified temperature. The
safety concerns, if any, associated with its use. It is the
method is not useful for determination of cure time.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
5. Apparatus
bility of regulatory limitations prior to use.
3
5.1 Hot Plate, having an electrically heated metal block
with a polished surface capable of being maintained at tem-
2. Referenced Documents
peratures between range 130-230°C (266-466°F) to within
2.1 ISO Standards:
62°C (64°F). The temperature should be controlled by means
ISO 8130–6:1992 Coating powders—Part 6: Determination
of a thermoregulator.
of gel time of thermosetting coating powders at a given
2
temperature
NOTE 1—There are expected differences in results between this method
and ISO 8130-6 which requires a heating block with small depressions.
3. Terminology
5.2 Stopwatch or Timer, accurate to at least 1 s.
3.1 Definitions:
5.3 Stirrer, of very low heat capacity and of suitable size.
3.1.1 coating powder, n—finely divided particles of resin,
Woodenstirrerswithdimensionsof2mmby6mmby130mm
either thermoplastic or thermosetting, generally incorporating
1 1
or ( ⁄16 in. by ⁄4 in. by 5 in.) have been found suitable.
pigments, fillers, and additives and remaining finely divided
5.4 Surface Contact Thermocouple, suitable for use at
during storage under suitable conditions, which, after fusing
150–250°C (300–480°F) and reading no greater than 1°C
and possibly curing, give a continuous film.
(2°F).
3.1.2 cure time of a coating powder—the time required for
1
5.5 Measuring Spoon, of 1.25 cc ( ⁄4 tsp) capacity.
a thermosetting coating powder to sufficiently chemically
5.6 Scraper, made of material softer than that of the heating
crosslink at a given temperature to provide the required coating
block, for removing the test material from the heating block
properties.
without scratching its surface.
3.1.3 gel time of a coating powder— the interval required at
a given temperature for a coating powder to be transformed 6. Selection of Specimens
from a dry solid to a gel-like state.
6.1 Obtain a representative sample of the coating powder.
3.1.4 powder coating, n—coatings which are protective or
6.2 Store the sample of coating powder in accordance with
decorative, or both, formed by the application of a coating
the manufacturer’s recommendations, after sampling and prior
to testing.
1
6.3 A specimen shall consist of approximately 1.25 ml ( ⁄4
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint
tsp) of coating powder.
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.51 on Powder Coatings.
Current edition approved July 10, 2002. Published September 2002. Originally
e1
published as D 4217 – 82. Last previous edition D 4217 – 91 (1995) .
2 3
Available from American National Standards Institute (ANSI), 25 W. 43rd St., Model SS-200 hot plate, available from Thermo-Electric Co., 455 Route 30,
4th Floor, New York, NY 10036. Imperial, PA 15126, or equivalent, has been found suitable.
*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
---------------------- Page: 1 ----------------------
D4217
7. Calibration 8.8 R
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.