i don't reply to too many threads but this one I do have some expertise in. For a start don't mount any smoke detectors on the wall because as a rule that will be the last place the smoke will travel, obviously as heat rises it hits the ceiling and then moves across. If you ever get to watch a video of how fast a fire can take hold in a room then you will see that having the detectors in the right place are critical.
Domestic smoke detectors are made in two general formats. Ionisation and Photo-electric. Ionisation detect fast burning fires from natural sources such as wood and paper with large smoke particles, Photo- electric detect smouldering fires from synthetic products like seat cushions and plastics with small smoke particles.
If your sandwich maker is destroying them then have you got the right detector in the right place. If you are buying them from a hardware store then probably not. Ionisation near the kitchen and photo electric everywhere else is the rule of thumb. Go to your nearest electrical wholesaler ( where electricians buy their stuff ) and they should set you straight.
Annoys the hell out of me when people buy the cheapest detector they can find when you consider what's at stake. Your home and family are surely worth the best you can afford.
Having said that any detector can false alarm but the more you pay the less trouble you should have. Without pimping brands buy a Clipsal, Brooks, or PSA. They have been in the game way before anyone else. Not broom proof though