Polyamide turns on the jets

Polyamide 46 harness connectors used in sensor systems that hook into jet engines during development and qualification face tough conditions ranging from extreme vibration to broad fluctuation in temperature.

Stanyl TE250F6 PA46 from DSM Engineering Plastics, Evansville, Ind., (www.dsm.com) is one of only a few high performance thermoplastics used in aerospace engines. It finds application in harness connectors for sensor systems hooked into jet engines during development and qualification. The connectors face tough conditions ranging from extreme vibration to broad fluctuation in temperature. The heat-stabilized polyamide 46 (PA46) has higher crystallinity and a faster crystallization rate over competing engineering plastics, including PA6, polyesters, semi-aromatic polyamides (PPAs), polyphenylene sulfide (PPS) and liquid crystal polymers (LCPs). Stanyl TE250F6's 280°C heat deflection temperature makes it suitable for lead-free soldered electronics. It's good flow properties and strong weld lines let designers build thin-walled connectors with dense pin counts and pitches. Good dimensional stability of the PA46, particularly creep resistance, helps ensure pins won't loosen during qualification tests where connectors see multiple, rapid setups and tear downs under tough aerospace conditions. The PA46 also has faster molding cycle times than competitive high-temperature thermoplastics. "The key to success was working with the test equipment producer to optimize the connector design in Stanyl," said Marco van Moll of Stanyl's Application Development Technical Service. "It soon emerged that TE250F6 balanced moldability, overall cost and, most importantly, long service life."