Scientists have made a disturbing discovery: human brains contain microplastics, and at higher concentrations than other organs. Worse, brain levels have jumped 50% in just eight years.
Plastic also has the benefit that it’s really easy to make in whatever shape with injection molding, and is totally permanent, which if you don’t care about disposal is great.
Meanwhile, making stuff out of a sheet of paper is a manufacturing challenge that has resulted in creative solutions like corrugation, and the container might seep through or soften or something.
There’s a thing called extended producer responsibility which basically is the idea of making disposal not free anymore for the manufacturer.
permenent? can’t plastic get melted down and recycled again?
once i put some plastic container in the dishwasher and it got too hot, it kind of melted a bit. it didn’t totally melt but the lid doesn’t fit anymore.
Not very well. Those long molecules break down into shorter segments every time they’re recycled, which makes for an inferior and eventually useless product. Some plastics are also thermoset and can’t ever be melted again, and some are just hard to recycle for other reasons and get picked out and landfilled. The whole idea of plastics recycling is basically greenwashing on a massive scale; the industry put a lot of money into promoting it to avoid scrutiny.
That being said, they’re also permanent in the good way. Plastics don’t biodegrade or erode. If you bury a plastic pipe in the ground, it may well still be there and intact in a million years. Anything natural will rot long before that, common metals will corrode, and concrete usually has metal rebar inside that pulls it apart as it corrodes. Plastic is also lightweight, which ceramics (stone-like materials) and metals are not, while still being strong under tension like metals.
Sunlight does slowly break down many plastics, but only into ever-smaller particles, which is where the microplastics in OP come from.
oh wow, i didn’t realize that, i thought it was infinitely reusable just by melting and re-forming it. thank you really much for the explanation.
what you wrote reminded me of silly putty, it’s really stretchy and elastic to start with, but if you play with it for a while, it starts to be less elastic and breaks apart.
does metal also break down? i’m thinking about like aluminium cans that are used for soda and stuff like that
Nope, metals are elements as opposed to molecule compounds and literally can be melted and cast forever. They say most of the gold ever mined is still in use today, so your modern ring might have bits of a ring melted down in ancient Egypt in it. Glass is like this too. Paper is more like plastic, albeit somewhat biodegradable when it eventually has to be thrown out.
In practice, there’s still a limit for many metals because they will get contaminated. Copper building up in scrap steel is a problem IIRC. It’s not a big issue with aluminum, though, unless you’re doing something like building an airplane where you need super high purity. Cans are almost all recycled into more cans.
There are ways to purify a metal melt, but they can be expensive and usually produce waste slag. I’ve never heard of glass being purified; it’s probably too cheap to not just make more of, since it’s derived from really common minerals.
A lot of metals are fairly easy to recycle. For others, being alloys (basically a mix of various metals in varying quantities), it’s more tricky as you can’t always really get a pure product out of recycling very easily, so it limits the types of things you can do with them. But all in all it’s way better than with plastics.
Plastic also has the benefit that it’s really easy to make in whatever shape with injection molding, and is totally permanent, which if you don’t care about disposal is great.
Meanwhile, making stuff out of a sheet of paper is a manufacturing challenge that has resulted in creative solutions like corrugation, and the container might seep through or soften or something.
There’s a thing called extended producer responsibility which basically is the idea of making disposal not free anymore for the manufacturer.
permenent? can’t plastic get melted down and recycled again?
once i put some plastic container in the dishwasher and it got too hot, it kind of melted a bit. it didn’t totally melt but the lid doesn’t fit anymore.
i dunno if it was injection molded though
Not very well. Those long molecules break down into shorter segments every time they’re recycled, which makes for an inferior and eventually useless product. Some plastics are also thermoset and can’t ever be melted again, and some are just hard to recycle for other reasons and get picked out and landfilled. The whole idea of plastics recycling is basically greenwashing on a massive scale; the industry put a lot of money into promoting it to avoid scrutiny.
That being said, they’re also permanent in the good way. Plastics don’t biodegrade or erode. If you bury a plastic pipe in the ground, it may well still be there and intact in a million years. Anything natural will rot long before that, common metals will corrode, and concrete usually has metal rebar inside that pulls it apart as it corrodes. Plastic is also lightweight, which ceramics (stone-like materials) and metals are not, while still being strong under tension like metals.
Sunlight does slowly break down many plastics, but only into ever-smaller particles, which is where the microplastics in OP come from.
oh wow, i didn’t realize that, i thought it was infinitely reusable just by melting and re-forming it. thank you really much for the explanation.
what you wrote reminded me of silly putty, it’s really stretchy and elastic to start with, but if you play with it for a while, it starts to be less elastic and breaks apart.
does metal also break down? i’m thinking about like aluminium cans that are used for soda and stuff like that
Nope, metals are elements as opposed to molecule compounds and literally can be melted and cast forever. They say most of the gold ever mined is still in use today, so your modern ring might have bits of a ring melted down in ancient Egypt in it. Glass is like this too. Paper is more like plastic, albeit somewhat biodegradable when it eventually has to be thrown out.
In practice, there’s still a limit for many metals because they will get contaminated. Copper building up in scrap steel is a problem IIRC. It’s not a big issue with aluminum, though, unless you’re doing something like building an airplane where you need super high purity. Cans are almost all recycled into more cans.
There are ways to purify a metal melt, but they can be expensive and usually produce waste slag. I’ve never heard of glass being purified; it’s probably too cheap to not just make more of, since it’s derived from really common minerals.
thank you for the explanation, it was really interesting and in-depth! you should be a teacher!
Thanks! I’m not sure I have the same presence IRL, haha.
ah don’t worry about that, lots of it is online now :3
A lot of metals are fairly easy to recycle. For others, being alloys (basically a mix of various metals in varying quantities), it’s more tricky as you can’t always really get a pure product out of recycling very easily, so it limits the types of things you can do with them. But all in all it’s way better than with plastics.