SEDL / STP / STP1395-EB / STP12513S

Test System to Study the Ignition of Metals by Polymers in Oxygen

Shoffstall, M
Project Engineer, AlliedSignal Technical Services Corp. Team, NASA JSC White Sands Test Facility, Las Cruces, NM

Stoltzfus, J
Mechanical Engineer, NASA JSC White Sands Test Facility, Las Cruces, NM

Pages: 13    Published: Jan 2000

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Abstract

A new test system that uses laser energy to ignite a polymer promoter has been developed at the NASA White Sands Test Facility (WSTF). It will facilitate the study of kindling chain ignition, such as the spread of fire from a burning polymer material to surrounding metal. The test system can be used to answer questions regarding configurational effects on ignition and combustion.

Test results from this system verify that ignition of a metallic sample by kindling chain ignition propagation is dependent not only on pressure, material type, and temperature, but also on the configuration of both the polymer promoter and metallic sample. Both 6061 aluminum and 316 stainless steel rods were tested with Buna-N, silicone, Teflon®, and Viton® O-rings as promoters. The system ignited all four types of O-rings in oxygen at pressures ranging from ambient to 69 MPa. However, neither the 316 stainless steel nor the 6061 aluminum rods on which the O-rings were mounted were ignited in any tests.

Future testing may be done on the rod and O-ring configuration to evaluate the lack of ignition in these tests. Other configurations may be tested including samples pressurized on one side only and configurations based on fire-damaged components. Any ignition propagation data obtained from this test system could also be used to develop mathematical models for analyzing the effects of configuration on ignition and combustion.