Literature

Joint Industry Foam Standards and Guidelines

SECTION 5.0

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.