ASTM D2648-70

Recommended Practice for Measuring Time to Failure by Rupture of Plastics Under Tension in Various Environments (Withdrawn 1976)

General Information

• Status: Withdrawn
• Technical Committee: D20 - Plastics

Standards Content (Sample)

~~l~ Designation: D 2648 - 70
Standard Recommended Practice for
MEASURING TIME-TO-FAILURE BY RUPTURE
OF PLASTICS UNDER TENSION IN VARIOUS
ENVIRONMENTS'
This Standard is iuucd under the fi-.cd designation D 2648: the number immediately following the designation indicates
the year or original adoption or. in the case or revision. the year or last revision. A number in parentheses indicates the
year or lut reapproval.
I. Scope
S. Reagents
1.1 This recommended practicei covers a 5.1 Purity · of Reagents-Reagent grade
procedure for measuring the time-to-failure chemicals shall be used in all tests. Unless
by rupture of plastics in specific environments
otherwise indicated. it is intended that all
and under a constant tensile load. reagents shall conform to the specifications
1.2 Environmental stress-rupture tests of the Committee on Analytical Reagents of the
should be limited to suitable combinations of American Chemical Society. where such speci­
1
loads and temperature in each environment to fications arc available. Other grades may be
attain reasonable failure times. used, provided it is first ascertained that the
reagent is of sufficiently high purity to per­
2. Summary
mit its use without lessening the accuracy of
2.1 The recommended practice consists of the determination.
applying a range of fixed loads in tension to 5.2 Purity of Water-Unless otherwise in­
specimens in specific environments at con­ dicated, references to water shall be under­
stant temperature and measuring the time-to­ stood to mean distilled water or water of
equal purity.
r ailure.
5.3 Specified Reagents-Should this rec•
3. Significance
ommended practice be rc:f crenccd in a mate­
3.1 Experimental data from stress-rupture
rial specification, the specific reagent to be
lif c tests arc of importance in comparing the
used shall be as stipulated in the specification.
ability of materials to support continuously
5.4 Standard Reagents-A list of standard
applied loads for long periods of time. Various
reagents is also available in ASTM Method D
environments acting on the surface of the
543. Test for Resistance of Plastics to Chemi­
stressed specimen arc known to reduce drasti­
cal Reagcnts.4
cally the time a specimen can support a load
continuously.
' This recommended practice is under the jurisdiction or
~- Apparatus
ASTM Commiuee D-20 on Plastics and is the direct re•
sponsibility or Subcommlllcc D-20.50 on Permanence Prop­
4.1 Testing Machine. capable of applying
enie~.
on/_r a constant tensile load. such as by dead
Effective Oct. 2. 1970
weight. on the specimen. The stress on the 'Sec Carey, R. H . ··creep and Stress Rupture Behav­
ior or Polyethylene RC5olns," Industrial and Enginrrring
specimen should be known within 5 percent.
Cltrmisrry. IECHA, Vol 50. 1958, pp. 1045.1048.
4.2 Grips-The grips and gripping tech­
• "Rea1ent Chemicab. American Chemical Society
Spccifi,auons," Am. Chemical Soc., Wuhington, D.C. For
nique should be designed to minimize eccen­
suggestions on the testiag of reagents not listed by the
tric loading of the specimen. It is recom­ American Chemical Soacty, sec "Reagent Chemicals and
Standards." by Joseph Rosin, D. Van Nostrand Co .• Inc .•
mended that a swivel or universal joint be
Ne• York. N.Y .• and the "United States Pharmacopcia."
u~ with each grip.
• A1111wal &,oA: of ASTJil S1a""'1ra,, Pan JS.
Reproduced 8\' GLOBAL
ENGINEERING DOCUMENTS
Wilh The Permission or ASThl
Under Ro).tlty Agn:cmc:111

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0 2648
8.2 Typical alternative preconditioning.
6. Safety Pr«autioos
procedures arc as follows:
6.1 Safety precautions should be taken to
8.2.1 Subject the specimens to the test
avoid persona! contact, tc eliminate toxic
temperature and relative humidity to be used
vapors, and to guard against explosion haz­
in the test for a period of time sufficient to
ards in accordance with the hazardous nature
obtain dimensional stability before starting
of the particular reagents being used.
test, or
7. Tnc SpttimftlS
8,2.2 Subject all specimens to the test tern·
peraturc to be used in the given series of tests
7.1 Test specimens may have either circu­
for a period of time sufficient to obtain dimen•
lar, square. or rectangular cross--sections and
sional stability, or
may be made by casting, injection, or com­
8.2.3 Start the test 48 h after the specimen
pression molding, or machining from sheets,
has attained the test temperature.
plates, slabs, or similar material. The speci­
mens given in· ASTM Method D 638. Test for
9.- Proadurt
Tensile Properties of Plastics.4 or in ASTM
Method D 1822. Test for Tensile Impact En­ 9.1 Set the test temperature to the selected
ergy to Break Plastics and Electrical Insulat­ value and maintain the test space to ±2 C or
ing Materials• arc generally used. less. Small variations in temperature can pro­
7. I. I The specimen should have a cross­ duce larg
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