Can plastic melt in a microwave oven? How does this process work? Can plastic burn in a microwave oven? – HD
Most plastics are unaffected by microwaves and do nothing at all in a microwave oven. For them to absorb energy from the microwaves, the plastics must either conduct electricity or their molecules must undergo the twisting motions that water molecules experience in the microwave oven. There are a few conducting plastics and these may melt or burn in a microwave as the microwave electric fields propel electric currents through them. There are also some plastics that trap water molecules and these may also melt or burn as the water molecules gather energy from the microwaves. I suppose that there are also a few plastics that have polar molecules in them that respond to the microwaves the way water does. However, most plastics do none of these and only melt or burn if they accidentally come in contact with very hot food or pieces of metal that happen to be in the microwave oven.