MIL-PRF-121G
4.6.2.2.2 Test at room temperature. The six 1-inch-wide specimens selected for this test
(see 4.6.2.2.1) shall be opened and one end of each specimen shall be clamped so that the other
end of the specimen hangs freely. A 3-1/2 pound weight shall then be carefully attached to the
free end of the specimen so as not to impact load the seal. The weight shall be allowed to act for
5 minutes, whereupon the weight shall be removed, and the specimen examined for separation of
the heat-sealed faces. Any evidence of delamination of one ply away from the other in the
heat-sealed area shall be cause for rejection. The evaluation shall be limited to the heat-sealed
area specified in 4.6.2.2.1.
4.6.2.2.3 Test at 100 °F. The six 1-inch-wide specimens selected for this test (see 4.6.2.2.1)
shall be tested the same as those specimens tested at room temperature (see 4.6.2.2.2) except that
specimens shall be clamped in a forced draft circulating air oven maintained at 100 ± 2 °F with a
weight of 2 pounds ± 1/2 ounce acting on the free end of the specimen for 1 hour. The rate of air
circulation shall be held to the minimum required to maintain uniform temperature throughout
the oven. In no case shall the rate of air circulation cause any movement of the weighted
specimens. The weights shall be attached after the specimens and test clamp fixtures have been
placed in the oven. The weights shall be removed prior to taking the specimen from the oven in
order to avoid excessive loading due to swaying action. After one hour, the weights shall be
removed and the specimen examined for separation of the heat-seal faces. Any evidence of
delamination of one ply away from the other in the heat-sealed area specified in 4.6.2.2.1 shall be
cause for rejection.
4.6.2.2.4 Test at 160 °F. The six 1-inch-wide specimens selected for this test (see 4.6.2.2.1)
shall be tested the same as those at 100 °F (see 4.6.2.2.3) except that the weight shall be
10 ounces ± 1/2 ounce and the temperature in the forced draft circulating air oven shall be
160 ± 2 °F. The rate of air circulation shall be held to the minimum required to maintain uniform
temperature throughout the oven. In no case shall the rate of air circulation cause any movement
of the weighted specimens.
4.6.2.3 Seam strength sealed before aging.
4.6.2.3.1 Test specimens. The six sections for this test (see figure 1) shall be folded in half
with the crease parallel to the long axis. The open or unfolded length shall be heat-sealed by
clamping in the sealer and simultaneously drawing a sharp-penciled line on the backing along the
edge of the sealer jaw. The folded length of the test section shall then be cut off 1/2 inch from
the end. After heat-sealing, the samples shall be aged in a circulating air oven maintained at 160
± 2 °F for 12 consecutive days (288 hours). After aging, 1-inch-wide specimens, as specified in
4.6.2.2.1, shall be cut from the sections for test at room temperature, 100 °F, and 160 °F.
4.6.2.3.2 Test at room temperature. The six 1-inch-wide specimens selected for this test
(see 4.6.2.3.1) shall be tested as specified in 4.6.2.2.2.
9
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business