Plastic

[jadyn]

I have a Morphy Richards breadmaker about 20 years old that's still going strong. The body of the breadmaker is sheet metal but the lid is made of a rather peculiar type of white plastic. that seems to have degraded over the years.
I've recently put the breadmaker back into use after a ten year or so hiatus and noticed that the plastic lid surface looks like very fine crazy paving/crackle effect all over. In fact, it looks a bit like onion cells when I viewed them under a microscope in school years ago. Anyhow, when the lid is lifted by the handle, which is merely a bulge on the front of the lid, the plastic crumbles away like polystyrene without any effort. The underside of the lid in the area is not smooth but looks crumbly.
I've had to order a replacement breadmaker this afternoon because some of these plastic particles dropped off into the bread mix as I was closing the lid.
I've never seen a plastic behaving in this manner previously and I'm curious as to which plastic the lid is made from. The breadmaker has been exposed to sunshine on a windowsill for a while but I had no idea that plastic could be affected like this.

Thank you.

[atalanta]

Sunshine is powerful stuff. I once had a very large pair of white net curtains which had been hanging in tropical sun for a few months. When I took them down to wash them, they just dissolved in the water. Looked like sort of runny cream cheese.

[Old_Geezer]

Unsure what type of plastic but it's not uncommon. Seen it many times.