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|  MIL-E-82886(OS)
f.
Date of manufacture of sample.
4.5.3 Acceptance criteria. Explosive samples which fail to meet any of the requirements of 3.4
when tested by the methods specified in 4.6 shall be classed as defective with rejection of the batch
represented.
4.6 Test procedures. All explosive specimens, with the exception of samples used in the uncured
PBXN-109 analytical procedures (4.6.5.3 and 4.6.5.4), shall be cured at 30 to 60C, and shall pass the
hardness requirements of Table II prior to subjecting them to the tests of 4.6.1 through 4.6.5. The uncured
explosive samples should be cured after uncured compositional analysis.
4.6.1 Density test. Density shall be determined on two pie-shaped wedges cut from two separate
cured test samples (one sample taken from the beginning of the pour and one sample taken from the end of
the pour). Each sample shall weigh between 10 and 20 g. Density of the samples shall be determined on
an analytical balance equipped for underwater weighing. The sample shall be weighed to an accuracy of
0.1 milligram (mg), first in air, then in water. Calculate the density according the following formula:
Ωα
⋅ Ćω
Ć
Ωα Ωβ
where:
D = Density of test sample, (g/cc)
Dw = Density of water at test temperature, (g/cc)
Wa = Weight of test sample in air, (g)
Wb = Weight of test sample in water, (g)
4.6.1.1 Density acceptance criteria. If one sample fails to meet the density requirements specified
in Table II, another sample shall be taken from the same section of the mix and tested. If the second
sample meets the density requirements, the batch shall be considered to meet the density requirements of
this specification.
4.6.2 Stress and strain at maximum stress. Stress and strain at maximum stress shall be determined
in accordance with JANNAF Solid Propellant Mechanical Behavior Manual, CPIA Publication No. 21,
Section 4.3.2, Uniaxial Tensile Tests at Constant Strain Rate, November 1970. Class C testing shall be
used, and final specimens may be die cut or milled from the half inch slices from the bulk sample. The
specimens for testing may be selected from the first third of the batch or the final third when sampled as
described in 4.4.1.
4.6.3 Shore A hardness test. The explosive of 4.4.1 or 4.5.1, in a suitable form as in 4.6.1, shall be
tested for Shore A hardness. (Any sample which exhibits bleeding at the surface at the end of the cure
period shall not be tested.) The hardness of the cured material shall be determined using a Type A-2
Durometer, with a maximum dial indicator or hand, together with a constant load operating stand (Code
7
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