Assessment of a Medium-Scale Polyurethane Foam Flammability Test.
Assessment of a Medium-Scale Polyurethane Foam
Flammability Test.
(1852 K)
Ohlemiller, T. J.; Shields, J. R.
NIST TN 1495; NIST Technical Note 1495; 45 p. February
2008.
Keywords:
polyurethane foams; flammability tests; flame
retardants; fabrics; cushions; test methods; chairs;
flexible foams; heat release rate; experiments; fire
behavior
Abstract:
Six polyurethane foams of widely varying flame retardant
levels have been tested in two modes: as four,
fabric-wrapped cushions in a chair mock-up based on
California Technical Bulletin 133 and in a two foam slab
Vee configuration that uses multiple propane flames to
simulate fabric burning. The latter test was developed
as a way to: (1) use less foam to assess real world foam
flammability behavior and (2) avoid the use of fabrics
in this assessment since they do not have reproducible
properties. For the six foams tested as chair mock-ups
with a polypropylene fabric, the Vee test correlates
well for peak heat release rate but not for time to that
peale In a more limited assessment of chair mock-ups
having polyester fiber wrap between the fabric and foam,
it was found that this material overwhelms even high
levels of flame retardants and gives a serious fire
regardless of the nature of the foam. One foam, which
contained expandable graphite, gave very good
initial fire behavior by suppressing foam melt flow
entirely. However, it ultimately began to disintegrate
and yielded a serious fire as a result of the dropping
of burning, solid foam chunks. New non-melting foams
based on carbon nano- fibers, now under development,
will have to have to exhibit greater "char" coherence if
they are to avoid this performance pitfall.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899