Literature

Joint Industry Foam Standards and Guidelines

APPENDIX A1.0

Published: 7/94

Task Group on Acceptable IFD Ranges

A1.1
Flexible polyurethane foam for use as furniture cushions is produced in a continuous process where huge slabs of foam often eight feet wide, four feet high, and several hundred feet long are poured. The hardness of this foam is affected by a number of variables, including TDI index, polyol temperature, cell size, air flow, and density. These processing variables limit control of foam hardness levels to roughly +/- 10 percent.

A1.2
The Joint Industry Polyurethane Foam Standards and Guidelines Committee recommends a +/- 3 lb. spread on a nominal 30 lb. IFD foam to be acceptable ( +/- 10% on harder grades of foam).

A1.3
The committee recognizes that some furniture manufacturers require tighter control of IFD levels in their cushions. In these cases, foam cushions of the desired hardness level shall be supplied on an individual basis by agreement between the foam supplier and the manufacturer through selective cutting and grading.

A1.4
The measurement of IFD in foam cushions is affected by a number of variables. Some factors which may affect the IFD value measured include temperature, humidity, state of foam cure, equipment differences, and test procedure differences. The committee therefore recommends that for refereeing purposes the procedure described in ASTM D- 3574 test B1 be strictly followed.