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SECTION 5.0
Joint Industry Foam Standards and Guidelines
Published: 7/94
ONE INCH DEFLECTION IFD STANDARDS AND GUIDELINES
5.1 Explanation of Need
This test method is intended to be a quick, simple quality control screening
method for full size unwrapped cushions and slabs. The acceptable IFD
ranges, as determined by the 1" Deflection Test Method, are to be specified
by agreement between supplier and buyer. A one inch indentation deflection
test is a useful tool as a "quick check" or screening method for approximating
25% IFD ranges on the fabrication or furniture factory floor. It can be
used as a quick inspection for the correct grade of foam or to observe
if a cushion meets an "at thickness" specification without cutting the
cushion down to a 4" thickness.
5.2 Explanation of Method
5.2.1 For test specimens 3" to 4" in thickness:
Length and width of the test specimens are a minimum 24"x24". Using
the indentor foot, measure the original height of the foam specimen
using the one pound preload procedure in ASTM-D3574. Then preflex the
test specimen 75% of its original thickness two (2) times. Before removing
the test specimen from under the indentor foot, draw the diameter of
the indentor foot on top of the test specimen using a felt tip marker.
When circumscribing the indentor foot on the test specimen, be certain
that the test specimen is not moved laterally in any direction from
the exact location where it was preflexed with the indentor foot. The
circumscribed circle will be used for exact relocation of the indentor
foot after the required waiting period. After preflexing, a waiting
period of 6.0 minutes plus or minus 1.0 minute is to be observed before
performing the 1" deflection IFD. The preflex indention speed, the indentor
foot, and the final indention speeds are the same as specified in ASTM
D-3574. After the six minute waiting period, the test specimen height
is again measured by using the one pound preload procedure in ASTM-D3574.
The indentor foot is indented into the foam exactly 1.0" and after a
sixty second plus or minus 3 second wait, the 1.0 " indentation IFD
is read from the force gauge.
5.2.2 For test specimens 4.0" to 6.5" in thickness:
On 4.0" to 6.5" thickness test specimens, the amount of deflection during
preflexing shall be precisely 3.0". All other parts of the test are carried
out as described above and in ASTM D-3574.
5.3 Limitation of Method
The 1" deflection IFD method is recommended for production screening
and quality control on full size cushions only. The test method is designed
to give a test value equal to the IFD on a 4" thick piece of foam when
the actual thickness is within the range listed in the test method.
In case of disagreement, the referee method is the IFD procedure in
ASTM-3574 Test B1.
All contents copyright © 2000 Polyurethane Foam Association,
Inc.
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