ASTM D3769-05

Standard Test Method for Microcellular Urethanes--High Temperature Sag

SIGNIFICANCE AND USE
This test method is used to indicate the deformation tendency of microcellular materials that may occur during paint application in an assembly plant operation. Since a standard specimen is used, heat sag measurements cannot be assumed to be exactly those which will occur on a part during or after the paint application and baking operation of an assembly process.
Before proceeding with this test method, reference should be made to the specification of the material being tested. Any test specimen preparation, conditioning, or dimensions, or combination thereof, and testing parameters covered in the materials specification shall take precedence over those mentioned in these test methods. If there are no material specifications, then the default conditions apply.
Note 2—This test method is applicable to solid urethanes.
SCOPE
1.1 This test method covers the procedure and apparatus for measuring high-temperature sag of microcellular urethane materials.
1.2 The values stated in SI units are to be regarded as standard.
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. Note 1
There is no similar or equivalent ISO standard to this test method.

General Information

• Status: Historical
• Publication Date: 31-Oct-2005
• ICS: 83.100 - Cellular materials
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.22 - Cellular Materials - Plastics and Elastomers

Relations

• Replaces: ASTM D3769-96(2000) - Standard Test Method for Microcellular Urethanes--High Temperature Sag
• Effective Date: 01-Nov-2005
• Replaced By: ASTM D3769-10 - Standard Test Method for Microcellular Urethanes--High Temperature Sag
• Effective Date: 01-Aug-2010
• Referred By: ASTM D3489-23 - Standard Test Methods for Microcellular Urethane Materials
• Effective Date: 01-Nov-2005

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D3769–05
Standard Test Method for
1
Microcellular Urethanes—High-Temperature Sag
This standard is issued under the fixed designation D3769; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 Thistestmethodcoverstheprocedureandapparatusfor
measuring high-temperature sag of microcellular urethane
materials.
1.2 The values stated in SI units are to be regarded as
standard.
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 appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
NOTE 1—There is no similar or equivalent ISO standard to this test
method.
2. Referenced Documents
2
2.1 ASTM Standards:
D3040 PracticeforPreparingPrecisionStatementsforStan-
3
dards Related to Rubber and Rubber Testing
E145 Specification for Gravity-Convection and Forced-
Ventilation Ovens
E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
3. Significance and Use
3.1 This test method is used to indicate the deformation
NOTE 1—Not to scale.
FIG. 1 Fixture for High-Temperature Sag
tendency of microcellular materials that may occur during
paint application in an assembly plant operation. Since a
standard specimen is used, heat sag measurements cannot be
combination thereof, and testing parameters covered in the
assumed to be exactly those which will occur on a part during
materials specification shall take precedence over those men-
or after the paint application and baking operation of an
tioned in these test methods. If there are no material specifi-
assembly process.
cations, then the default conditions apply.
3.2 Before proceeding with this test method, reference
NOTE 2—This test method is applicable to solid urethanes.
shouldbemadetothespecificationofthematerialbeingtested.
Anytestspecimenpreparation,conditioning,ordimensions,or
4. Apparatus
4.1 Test Fixture,capableofholdingthespecimensinafixed
1
cantilever position for the duration of the entire test procedure.
ThistestmethodisunderthejurisdictionofASTMCommitteeD20onPlastics
and is the direct responsibility of Subcommittee D20.22 on Cellular Materials -
The test fixture shall be constructed from a material such as
Plastics and Elastomers.
aluminum or steel that exhibits a low coefficient of linear
Current edition approved Nov. 1, 2005. Published November 2005. Originally
thermalexpansionandthereforeallowsthetestfixture’sheight
approved in 1979. Last previous edition approved in 2000 as D3769-96(2000).
to be considered constant through the test. See Fig. 1.
DOI: 10.1520/D3769-05.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4.2 Oven, conforming to the specifications for a Type IA
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
laboratory oven in accordance with Specification E145.
Standards volume information, refer to the standard’s Document Summary page on
4.3 Scaled Rule, accurate to 1 mm.
the ASTM website.
3
Withdrawn 4.4 Thickness Indicator, accurate to 0.03 mm.
*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.
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D3769–05
TABLE 1 Precision for Heat Sag Test
Flexural Modulus Values expressed in unit of mm (in.)
Material
A B
MPa (psi) Average S r
r
Urethane A 700 (100 000) 7.06 (0.278) 1.55 (0.061) 4.34 (0.171)
Urethane B 350 (50 000) 0.43 (0.017) 0.66 (0.026) 1.85 (0.073)
Urethane C 175 (25 000) 3.40 (0.134) 3.53 (0.139) 9.88 (0.389)
A
S = within-laboratory standard deviation for the indicated material. It is obtained by pooling the within-laboratory standard deviations of the test results from all of the
r
participating laboratories:
2 2 2 ½.
S 5 [@~s ! 1 ~s !··· 1 ~s ! #/n#
r 1 2 n
B
r = within-laboratory critical interval between two test results = 2.8 3 S.
r
4.5 Base, a flat, smooth surface free of any surface irregu- 9.1.2 Conditioning procedures before testing,
larities that would affect the height measurements. The base
9.1.3 Time and temperature of the test,
mustbeheat-resistanttothemaximumtemperaturethatthetest
9.1.4 Initial value at 23°C, average of three,
fixtures will be exposed.
9.1.5 Final sag value at test temperature, average of three,
5. Test Specimens
and
5.1 The test specimen shall have a minimum length of 125
9.1.6 Specimen thickness.
mm, and be 25 6 1 mm in width by the nom
...