ASTM D6491-99(2003)

Standard Practice for Evaluation of Aging Resistance of Prestressed Prepainted Metal In a Dry Heat Test

ABSTRACT
This practice details the standard procedure for evaluating the resistance of prestressed prepainted metal panels to cracking, or loss of adhesion, or both, after accelerated heat aging by dry heat test. This test method requires the use of gravity or forced air laboratory oven, bench vise, bending dies or test shims, 10x magnifier, and adhesive tape.
SCOPE
1.1 This practice can be used to evaluate the resistance of a prestressed prepainted metal panel to cracking, or loss of adhesion, or both, after accelerated heat aging. Most coil coated products are formed and bent into specific shapes to produce a final product. These operations introduce stresses, which may be relieved by cracking of the coating after aging.
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 determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Nov-2003
• ICS: 87.020 - Paint coating processes
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.53 - Coil Coated Metal

Relations

• Replaces: ASTM D6491-99 - Standard Practice for Evaluation of Aging Resistance of Prestressed Prepainted Metal In a Dry Heat Test
• Effective Date: 01-Dec-2003
• Replaced By: ASTM D6491-09 - Standard Practice for Evaluation of Aging Resistance of Prestressed Prepainted Metal In a Dry Heat Test
• Effective Date: 01-Jun-2009
• Referred By: ASTM D3794-22 - Standard Guide for Testing Coil Coatings
• Effective Date: 01-Dec-2003

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D6491–99(Reapproved2003)
Standard Practice for
Evaluation of Aging Resistance of Prestressed Prepainted
Metal In a Dry Heat Test
This standard is issued under the fixed designation D 6491; 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 3.5 Adhesive Tape.
1.1 This practice can be used to evaluate the resistance of a
4. Test Specimens
prestressed prepainted metal panel to cracking, or loss of
4.1 Cut samples 75 mm (3 in.) wide (across the bend
adhesion, or both, after accelerated heat aging. Most coil
direction) by whatever length is necessary to make the appro-
coated products are formed and bent into specific shapes to
priate number of bends. The direction of the bend may be
produce a final product. These operations introduce stresses,
transverse or longitudinal to the “rolling direction” of the
which may be relieved by cracking of the coating after aging.
metal—or as agreed upon between customer and vendor.
1.2 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
5. Procedure
only.
5.1 Perform the fabrication at room temperature, 25 6 1°C
1.3 This standard does not purport to address all of the
(77 6 2°F). All test specimens should be equilibrated to the
safety concerns, if any, associated with its use. It is the
same temperature before fabricating.
responsibility of the user of this standard to establish appro-
5.2 Prepare three “T-bend” test specimens in accordance
priate safety and health practices and determine the applica-
with Test Method D 4145. The T-bend used should be agreed
bility of regulatory limitations prior to use.
upon between customer and vendor.
2. Referenced Documents 5.3 Examine the T-bend for cracking and tape pick-off in
2 accordance with Test Method D 4145 and record the results.
2.1 ASTM Standards:
5.4 Place the formed test specimens in the 60 6 3°C (140 6
D 4145 Test Method for Coating Flexibility of Prepainted
5°F) oven for 16 h. Different times and temperatures may be
Sheet
used if agreed upon between the customer and vendor.
3. Apparatus 5.5 Remove the test specimens and allow them to cool to
room temperature.
3.1 Gravity or Forced Air Laboratory Oven, capable of
5.6 Repeat the tape adhesion test.
maintaining a temperature of 60 6 3°C (140 6 5°F).
3.2 Bench Vise, with smooth jaws or inserts, 13 mm (5 in.)
6. Report
permanently mounted on a work tabl
...