ASTM D5944-96

Test Method for Determination of Temperature of Deflection Under Load (Withdrawn 1998)

General Information

• Status: Withdrawn
• Withdrawal Date: 09-Apr-1998
• ICS: 17.200.01 - Thermodynamics in general
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.61 - US TAG ISO/TC-61 on Plastics

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NOTICE: This standard has either been superseded and replaced by a new version or discontinued.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 5944 – 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 Guide for
Describing the General Principles for Determining the
1
Temperature of Deflection of Plastics Under Load
This standard is issued under the fixed designation D 5944; 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. Terminology
1.1 This guide covers procedures for determination of the 3.1 Definitions:
temperature of deflection under load (bending stress under 3.1.1 deflection—the distance, at mid-span, over which the
three-point loading) of different types of material. top or bottom surface of a test specimen deviates, during
1.2 This guide is identical to ISO 75-1. This guide is flexure, from its original position. It is expressed in millime-
comparable to Test Method D 648, but neither standard should tres.
be substituted for the other. The two standards may differ with 3.1.2 flexural strain—the nominal fractional change in
respect to test specimen dimensions, test specimen condition- length of an element at the surface of the test specimen at
ing, test equipment, testing conditions, etc. The two procedures mid-span. It is expressed as a dimensionless quantity.
may not give the same results. 3.1.3 flexural stress, s—the nominal stress at the surface of
1.3 The procedures specified are suitable for assessing the the test specimen at mid-span. It is expressed in megapascals.
behavior of different types of material at elevated temperature 3.1.4 standard deflection, s—the deflection that will result
under load at a specified rate of temperature increase. The in the flexural strain, at the surface of the test specimen, which
results obtained do not necessarily represent maximum use is specified in the relevant part of this guide. The standard
temperatures because, in practice, essential factors such as deflection depends on the dimensions and position of the test
time, loading conditions, and nominal surface stress may differ specimen and the span between the supports. It is expressed in
from the test conditions. millimetres.
1.4 The values stated in SI units are to be regarded as the 3.1.5 temperature of deflection under load, T —the tem-
f
standard. The values given in parentheses are for information perature at which the deflection of the test specimen reaches
only. the standard deflection as the temperature is increased. It is
1.5 This standard does not purport to address all of the expressed in degrees Celsius.
safety concerns, if any, associated with its use. It is the
4. Principle
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 4.1 A standard test specimen is subjected to a bending stress
to produce one of the nominal surface stresses given in the
bility of regulatory limitations prior to use.
relevant part of this guide. The temperature is raised at a
2. Referenced Documents
uniform rate, and the temperature at which a specified deflec-
2.1 ASTM Standards: tion occurs is measured.
D 648 Test Method for Deflection Temperature of Plastics
2 5.
Under Flexural Load
3
2.2 ISO Standards:
6. Apparatus
ISO 75-1 Determination of Temperature of Deflection Un-
6.1 Means of Applying a Bending Stress:
der Load—Part 1: General Test Method
6.1.1 The apparatus shall be constructed essentially as
ISO 291:1977 Plastics—Standard Atmospheres for Condi-
shown in Fig. 1. It consists of a rigid metal frame in which a
tioning and Testing
rod can move freely in the vertical direction. The rod is fitted
with a weight-carrying plate and a loading edge. The base of
the frame is fitted with test specimen supports; these and the
1
Bias This guide is under the jurisdiction of ASTM Committee D-20 on Plastics
vertical members of the frame are made of a metal having the
and is the direct responsibility of Subcommittee D20.61 on USA Technical Advisory
same coefficient of linear expansion as the rod.
Group for ISO/TC 61 on Plastics.
Current edition approved June 10, 1996. Published August 1996.
6.1.2 The test specimen supports consist of cylindrical
2
Annual Book of ASTM Standards, Vol 08.01.
metal pieces at a distance apart, defined in the relevant part of
3
Available from American National Standards Institute, 11 W. 42nd St., 13th
this guide, with their lines of contact with the specimen in a
Floor, New York, NY 10036.
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D 5944
FIG. 1 Typical Apparatus for Determination of Temperature of Deflection Under Loa
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