ASTM D3769-96

Standard Test Method for Microcellular Urethanes--High Temperature Sag

SCOPE
1.1 This 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 the 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 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-Dec-1999
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.22 - Cellular Materials - Plastics and Elastomers

Relations

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

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 3769 – 96
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Microcellular Urethanes—High-Temperature Sag
This standard is issued under the fixed designation D 3769; 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 Any test specimen preparation, conditioning, or dimensions, or
combination thereof, and testing parameters covered in the
1.1 This test method covers the procedure and apparatus for
materials specification shall take precedence over those men-
measuring high-temperature sag of microcellular urethane
tioned in these test methods. If there are no material specifi-
materials.
cations, then the default conditions apply.
1.2 The values stated in SI units are to be regarded as the
standard.
NOTE 2—This test method may be applied to solid urethanes.
1.3 This standard does not purport to address all of the
4. Apparatus
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4.1 Test Fixture, capable of holding the specimens in a fixed
priate safety and health practices and determine the applica-
cantilever position for the duration of the entire test procedure.
bility of regulatory limitations prior to use.
The test fixture shall be constructed from a material such as
aluminum or steel that exhibits a low coefficient of linear
NOTE 1—There is no similar or equivalent ISO standard to this test
thermal expansion and therefore allows the test fixture’s height
method.
to be considered constant through the test. See Fig. 1.
2. Referenced Documents
4.2 Oven, conforming to the specifications for a Type I
laboratory oven in accordance with Specification E 145.
2.1 ASTM Standards:
4.3 Scaled Rule, accurate to 1.0 mm.
D 3040 Practice for Preparing Precision Statements for
4.4 Thickness Indicator, accurate to 0.25 mm.
Standards Related to Rubber and Rubber Testing
E 145 Specification for Gravity-Convection and Forced-
5. Test Specimens
Ventilation Ovens
5.1 The test specimen shall have a minimum length of 125
E 691 Practice for Conducting and Interlaboratory Study to
mm, and be 25 mm in width by the nominal thickness of the
Determine the Precision of a Test Method
plaque or part. The recommended standard test specimen is 4
3. Significance and Use
mm in thickness. Thinner specimens may be used, but shall not
be less than 3 mm.
3.1 This test method is used to indicate the deformation
5.2 Three specimens to each material shall be tested.
tendency of microcellular materials that may occur during
paint application in an assembly plant operation. Since a
NOTE 3—If test specimens are cut from parts, the specimens must be
standard specimen is used, heat sag measurements cannot be
cut from areas that are of constant thickness; that is, no ribs, bosses, holes,
assumed to be exactly those which will occur on a part during or other section changes are allowed.
or after the paint application and baking operation of an
6. Conditioning
assembly process.
6.1 Unless otherwise specified, condition the specimens and
3.2 Before proceeding with this test method, reference
should be made to the specification of the material being tested. fixture a minimum of1hat23 6 2°C and 50 6 5 % relative
humidity before testing.
This test method is under the jurisdiction of ASTM Committee D-20 on Plastics
7. Procedure
and is the direct responsibility of Subcommittee D20.22 on Cellular Materials—
Plastics and Elastomers. 7.1 Measure the thickness in the clamping area of the test
Current edition approved August 10, 1996. Published February 1997. Originally
specimen to the nearest 0.25 mm.
published as D 3769 – 79. Last previous edition D 3769 – 85 (1990).
7.2 Clamp the specimen in the fixture with a 100-mm
This revision includes the addition of the following: an ISO equivalency
unsupported overhang. Primed or painted surfaces are to be
statement, a material specifications statement, and a keyword section. This revision
also includes a change in the minimum height requirement of the test fixture, an
mounted facing up.
expanded description of the test figure, a change in the oven specification, a change
7.3 After 5 min 6 10 s, measure the distance between the
in the accuracy requirement for the scaled rule, and a
...