It's a small plastic injected piece that will be submitted to short period of time (2 seconds) of high temperature (95-105ºC approx.) in every cycle; this high temperature is produced by a filament where electric current passes through (like a house light bulb but hotter) for no more than 2 seconds in the process cycle. A complete process cycle last for about 45 seconds where the piece has time to cool off again. This plastic piece has to work for about 45-50 complete process cycles. PP or Nylon will work well (PE is very hard to flame retard and has a much lower softening point). I would however suggest that you look at a flame retarded nylon 6 or 66 that is specifically designed for this type of exposure. You want to look at the Glow Wire Flammability Index (IEC 60695-2-12) of the grade. You want to make sure that the materials rating (maximum temperature) is higher (maybe 50-100°C higher than your conditions, temperature, exposure time, part thickness, I say this because it is very difficult to estimate the radiated heat and resultant temperature). These grades are made by Sabic-IP (under the Starflam tradename), Lati, RTP, BASF and others.