Standard Test Method for Inclined Plate Flow for Thermosetting Coating Powders

SIGNIFICANCE AND USE
5.1 This test method is useful for selecting coating powders of similar characteristics of melt flow under minimal shear. It is not recommended as an absolute measurement, but rather as a comparative measurement of samples on the same panel measured at the same time.
SCOPE
1.1 This test method specifies a method for determining the flow characteristics of a fused thermosetting coating powder down a plane inclined at a set angle to the horizontal. The test gives an indication of the degree of melt flow that may occur during the curing of the coating powder. This characteristic contributes to the coherence of the coating, to its surface appearance and to the degree of coverage over sharp edges (see Test Method D2967), however, it should not be used as the sole factor for judgment. The test acts as a useful method for checking for batch to batch variation in the behavior of a given coating powder. Correlation between the results from coating powders of differing composition is not to be expected. This method is unlikely to yield meaningful results with coating powders which have gel times of less than one minute at the test temperature (see Test Method D4217). Oven drafts, angle of inclination and pellet variations significantly affect results making inter-lab reproducibility somewhat difficult to correlate.  
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.3 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 to determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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ASTM D4242-07(2017) - Standard Test Method for Inclined Plate Flow for Thermosetting Coating Powders
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This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4242 − 07 (Reapproved 2017)
Standard Test Method for
Inclined Plate Flow for Thermosetting Coating Powders
This standard is issued under the fixed designation D4242; 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.
1. Scope 2. Referenced Documents
1.1 This test method specifies a method for determining the
2.1 ASTM Standards:
flow characteristics of a fused thermosetting coating powder D792 Test Methods for Density and Specific Gravity (Rela-
down a plane inclined at a set angle to the horizontal. The test
tive Density) of Plastics by Displacement
gives an indication of the degree of melt flow that may occur
D2967 Test Method for Corner Coverage of Powder Coat-
during the curing of the coating powder. This characteristic
ings
contributes to the coherence of the coating, to its surface
D4217 Test Method for Gel Time of Thermosetting Coating
appearanceandtothedegreeofcoverageoversharpedges(see
Powder
TestMethodD2967),however,itshouldnotbeusedasthesole
D5965 Test Methods for Specific Gravity of Coating Pow-
factor for judgment. The test acts as a useful method for
ders
checking for batch to batch variation in the behavior of a given
2.2 Other Documents:
coating powder. Correlation between the results from coating
ISO 8130-2 Coating powders—Part 2: Determination of
powders of differing composition is not to be expected. This
density by gas comparison pyknometer
method is unlikely to yield meaningful results with coating
ISO 8130-3 Coating powders—Part 3: Determination of
powders which have gel times of less than one minute at the
density by liquid displacement pyknometer
test temperature (see Test Method D4217). Oven drafts, angle
ISO 8130–11:1997 Coating powders—Part 11: Inclined-
of inclination and pellet variations significantly affect results
plane flow test
making inter-lab reproducibility somewhat difficult to corre-
late.
3. Terminology
1.2 The values stated in SI units are to be regarded as the
3.1 Definitions:
standard. The values given in parentheses are for information
3.1.1 coating powder, n—finely divided particles of resin,
only.
either thermoplastic or thermosetting, generally incorporating
1.3 This standard does not purport to address all of the
pigments, fillers, and additives and remaining finely divided
safety concerns, if any, associated with its use. It is the
during storage under suitable conditions, which after fusing
responsibility of the user of this standard to establish appro-
and possibly curing, give a continuous film.
priate safety and health practices and to determine the
3.1.2 powder coating, n—coatings which are protective or
applicability of regulatory limitations prior to use.
decorative, or both, formed by the application of a coating
1.4 This international standard was developed in accor-
powder to a substrate and fused in a continuous film by the
dance with internationally recognized principles on standard-
application of heat or radiant energy.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 3.1.3 gel time of a coating powder, n—the interval required
mendations issued by the World Trade Organization Technical at a given temperature for a coating powder to be transformed
Barriers to Trade (TBT) Committee. from a dry solid to a gel-like state.
1 2
This test method is under the jurisdiction of ASTM Committee D01 on Paint For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and Related Coatings, Materials, andApplications and is the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee D01.51 on Powder Coatings. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved June 1, 2017. Published June 2017. Originally the ASTM website.
approved in 1983. Last previous edition approved in 2013 as D4242 – 07 (2013). Available from International Organization for Standardization (ISO), 1 rue de
DOI: 10.1520/D4242-07R17. Varembé, Case postale 56, CH-1211, Geneva 20, Switzerland, http://www.iso.ch.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4242 − 07 (2017)
3.1.4 cure time of a coating powder, n—thetimerequiredfor 8.2 Weigh on the balance to an accuracy of 10 mg a mass of
a thermosetting coating powder to sufficiently chemically the product under test equivalent in grams to half of the density
crosslinkatagiventemperaturetoprovidetherequiredcoating (specific gravity) of the coating powder in accordance with
properties. Test Methods D792, D5965, ISO 8130-2, or ISO 8130-3. By
means of the pellet press, compact the coating powder into a
3.1.5 thermosetting, adj—describing a material that, when
pellet 12.5 6 0.05 mm (0.5 6 0.002 in.) in diameter and 6.5 6
heated per a minimum recommended cure condition, under-
0.2 mm (0.25 6 0.008 in.) thick and push the pellet out of the
goes a chemical reaction and a permanent change to a more
presswiththeknockoutrod.Weighthepellettoconfirmthatits
durable state capable of specific properties as designed for
mass is correct to 10 mg. If there is a delay between the
substrate protection or decoration, or both.
commencement of the test and the preparation of the pellet,
protect it against moisture absorption by storage in a desiccator
4. Summary of Test Method
or a sealed container.
4.1 The thermosetting coating powder is pressed into a
pellet of standard size which is allowed to melt and flow down
8.3 Unless otherwise agreed, the temperature of the test
a heated inclined plate. The extent of flow is measured.
shall be the recommended curing temperature. In the absence
of this information, a temperature shall be used that provides
5. Significance and Use
an adequate pill flow for measurement.
5.1 This test method is useful for selecting coating powders
8.4 If a plate assembly is to be used, place the plate(s) in the
of similar characteristics of melt flow under minimal shear. It
plate assembly in a horizontal position. Place the plate assem-
is not recommended as an absolute measurement, but rather as
bly and plate(s) into the oven set at the test temperature and
a comparative measurement of
...

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