ASTM D3769-20
(Test Method)Standard Test Method for Microcellular Urethanes-High-Temperature Sag
Standard Test Method for Microcellular Urethanes-High-Temperature Sag
SIGNIFICANCE AND USE
4.1 This test method is used to indicate the potential tendency of microcellular materials to deform during paint application in an assembly plant operation. Since a standard specimen is used, do not assume heat sag measurements to be exactly those which will occur on a part during or after the paint application and baking operation of an assembly process.
4.2 Before proceeding with this test method, reference shall 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.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
Note 1: There is no known ISO equivalent to this standard.
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.
General Information
Relations
Frequently Asked Questions
ASTM D3769-20 is a standard published by ASTM International. Its full title is "Standard Test Method for Microcellular Urethanes-High-Temperature Sag". This standard covers: SIGNIFICANCE AND USE 4.1 This test method is used to indicate the potential tendency of microcellular materials to deform during paint application in an assembly plant operation. Since a standard specimen is used, do not assume heat sag measurements to be exactly those which will occur on a part during or after the paint application and baking operation of an assembly process. 4.2 Before proceeding with this test method, reference shall 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. 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Note 1: There is no known ISO equivalent to this standard. 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.
SIGNIFICANCE AND USE 4.1 This test method is used to indicate the potential tendency of microcellular materials to deform during paint application in an assembly plant operation. Since a standard specimen is used, do not assume heat sag measurements to be exactly those which will occur on a part during or after the paint application and baking operation of an assembly process. 4.2 Before proceeding with this test method, reference shall 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. 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Note 1: There is no known ISO equivalent to this standard. 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.
ASTM D3769-20 is classified under the following ICS (International Classification for Standards) categories: 83.100 - Cellular materials. The ICS classification helps identify the subject area and facilitates finding related standards.
ASTM D3769-20 has the following relationships with other standards: It is inter standard links to ASTM D883-24, ASTM D883-23, ASTM E456-13a(2022)e1, ASTM D883-20, ASTM D883-19c, ASTM D883-19a, ASTM E145-19, ASTM D883-19, ASTM D883-18a, ASTM D883-18, ASTM E2935-17, ASTM E456-13A(2017)e1, ASTM E456-13A(2017)e3, ASTM D883-17, ASTM E2935-16. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
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Standards Content (Sample)
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: D3769 − 20
Standard Test Method for
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* E2935Practice for Conducting Equivalence Testing in
Laboratory Applications
1.1 Thistestmethodcoverstheprocedureandapparatusfor
measuring high-temperature sag of microcellular urethane
3. Terminology
materials.
3.1 Terms used in this standard are defined in accordance
1.2 The values stated in SI units are to be regarded as
with Terminology D883, unless otherwise specified. For terms
standard.
relating to precision and bias and associated issues, the terms
1.3 This standard does not purport to address all of the
used in this standard are defined in accordance with Terminol-
safety concerns, if any, associated with its use. It is the
ogy E456.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4. Significance and Use
mine the applicability of regulatory limitations prior to use.
4.1 This test method is used to indicate the potential
NOTE 1—There is no known ISO equivalent to this standard.
tendency of microcellular materials to deform during paint
1.4 This international standard was developed in accor-
application in an assembly plant operation. Since a standard
dance with internationally recognized principles on standard-
specimen is used, do not assume heat sag measurements to be
ization established in the Decision on Principles for the
exactly those which will occur on a part during or after the
Development of International Standards, Guides and Recom-
paintapplicationandbakingoperationofanassemblyprocess.
mendations issued by the World Trade Organization Technical
4.2 Before proceeding with this test method, reference shall
Barriers to Trade (TBT) Committee.
be made to the specification of the material being tested. Any
test specimen preparation, conditioning, or dimensions, or
2. Referenced Documents
combination thereof, and testing parameters covered in the
2.1 ASTM Standards:
materials specification shall take precedence over those men-
D883Terminology Relating to Plastics
tioned in these test methods. If there are no material
D3040Practice for Preparing Precision Statements for Stan-
specifications, then the default conditions apply.
dards Related to Rubber and Rubber Testing (Withdrawn
1987) NOTE 2—This test method is applicable to solid urethanes.
E145Specification for Gravity-Convection and Forced-
5. Apparatus
Ventilation Ovens
E456Terminology Relating to Quality and Statistics
5.1 Test Fixture,capableofholdingthespecimensinafixed
E691Practice for Conducting an Interlaboratory Study to
cantileverpositionforthedurationoftheentiretestprocedure.
Determine the Precision of a Test Method
The test fixture shall be constructed from a material such as
aluminum or steel that exhibits a low coefficient of linear
thermalexpansionandthereforeallowsthetestfixture’sheight
to be considered constant through the test. See Fig. 1.
ThistestmethodisunderthejurisdictionofASTMCommitteeD20onPlastics
5.2 Oven, conforming to the specifications for a Type IA
and is the direct responsibility of Subcommittee D20.22 on Cellular Materials -
Plastics and Elastomers. laboratory oven in accordance with Specification E145.
CurrenteditionapprovedJuly1,2020.PublishedJuly2020.Originallyapproved
5.3 Scaled Rule, accurate to 1 mm.
in 1979. Last previous edition approved in 2015 as D3769-15. DOI: 10.1520/
D3769-20.
5.4 Thickness Indicator, accurate to 0.03 mm.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
5.5 Base, a flat, smooth surface free of any surface irregu-
Standards volume information, refer to the standard’s Document Summary page on
larities that would affect the height measurements. The base
the ASTM website.
mustbeheat-resistanttothemaximumtemperaturethatthetest
The last approved version of this historical standard is referenced on
www.astm.org. fixtures will be exposed.
*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
D3769 − 20
8.4 Placetheclampedspecimeninanair-circulatingovenat
the test temperature of 120 6 1°C for 60 6 1 min.
8.5 After oven aging, remove the fixture with the specimen
from the oven.
8.6 After5min,repeatthemeasurementasin8.3forA and
o
call this distance A.
f
NOTE 4—Other combinations of test temperatures, test times, and
overhanglengthsarepermittedsubjecttoprioragreementbetweenthetest
requestorandthetestingfacility.Theseconditionsaretobeincludedinthe
test report.
9. Calculation
9.1 Sag= A
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3769 − 15 D3769 − 20
Standard Test Method for
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. 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*
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.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
NOTE 1—There is no known ISO equivalent to this standard.
NOTE 1—There is no known ISO equivalent to this standard.
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.
2. Referenced Documents
2.1 ASTM Standards:
D883 Terminology Relating to Plastics
D3040 Practice for Preparing Precision Statements for Standards Related to Rubber and Rubber Testing (Withdrawn 1987)
E145 Specification for Gravity-Convection and Forced-Ventilation Ovens
E456 Terminology Relating to Quality and Statistics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.22 on Cellular Materials - Plastics
and Elastomers.
Current edition approved Sept. 1, 2015July 1, 2020. Published September 2015July 2020. Originally approved in 1979. Last previous edition approved in 20102015 as
D3769 - 10.D3769 - 15. DOI: 10.1520/D3769-15.10.1520/D3769-20.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
*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
D3769 − 20
NOTE 1—Not to scale.
FIG. 1 Fixture for High-Temperature Sag
E2935 Practice for Conducting Equivalence Testing in Laboratory Applications
3. Terminology
3.1 Terms used in this standard are defined in accordance with Terminology D883, unless otherwise specified. For terms relating
to precision and bias and associated issues, the terms used in this standard are defined in accordance with Terminology E456.
4. Significance and Use
4.1 This test method is used to indicate the deformationpotential tendency of microcellular materials that may occur to deform
during paint application in an assembly plant operation. Since a standard specimen is used, do not assume heat sag measurements
to be exactly those which will occur on a part during or after the paint application and baking operation of an assembly process.
4.2 Before proceeding with this test method, reference shall 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.
5. Apparatus
5.1 Test Fixture, capable of holding the specimens in a fixed cantilever position for the duration of the entire test procedure. The
test fixture shall be constructed from a material such as aluminum or steel that exhibits a low coefficient of linear thermal expansion
and therefore allows the test fixture’s height to be considered constant through the test. See Fig. 1.
5.2 Oven, conforming to the specifications for a Type IA laboratory oven in accordance with Specification E145.
5.3 Scaled Rule, accurate to 1 mm.
5.4 Thickness Indicator, accurate to 0.03 mm.
5.5 Base, a flat, smooth surface free of any surface irregularities that would affect the height measurements. The base must be
heat-resistant to the maximum temperature that the test fixtures will be exposed.
6. Test Specimens
6.1 The test specimen shall have a minimum length of 125 mm, and be 25 6 1 mm in width by the nominal thickness of the
plaque or part. The recommended standard test specimen is 4 mm in thickness. The minimum specimen thickness shall be 3 mm.
D3769 − 20
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
ffs d s d s d g g
r 1 2 n
B
r = within-lab
...
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