4 ms·

PLA can be recycled with near perfect efficiency and is available today. Also it's extremely biodegradable so throwing it out isn't the end of the world.

by swiley 6y ago

tomcam 6y ago
TIL. Can you tell me more about the recycling process for PLA?
- mnouquet 6y ago
  Shred, heat and extrude.
  - tomcam 6y ago
    Thank you very much. Not sure why my question was downvoted.
    - dheera 6y ago
      I do wish it were required to give a reason or comment to downvote. I upvoted you to compensate since the downvoter did not do this.
      - tomcam 6y ago
        I would dearly love a world in which you provided a reason to download a comment on this site.
  - neltnerb 6y ago
    Wait, wait, let's not give the wrong impression. Yes, you can recycle PLA to an extent but you can't mix it in with your recylables. Few cities can recyle PS, much less PLA or at least they aren't set up to handle it. If you are curious about the tech, sure, it's recyclable. For practical purposes you may as well throw it in the trash ahead of time and avoid contaminating the recycling. Plus if you try to put it in most commercial composting it will not degrade enough to be usable and has to get removed to avoid damaging the compost. So if you happen to not have the right kind of composting facility you can't handle it. Yeah, it's on paper no worse than other plastics, but you have to have a plan to handle it -- it's not just a thing you can toss in the recycling bin.
dheera 6y ago
PLA is pretty useless as a material though for anything but art. Almost everything I print has a functional purpose and either (a) needs mechanical strength (b) will be placed outdoors in the California sun or (c) will be used to house electronics that may reach temperatures as high as 70-80 C. PLA is basically useless to me and pretty much all roboticists. I use PETG for almost everything because it works perfectly for all my needs; unfortunately I often need to go through about 2-3 versions of many parts I make and wish there were a better, more efficiently recyclable option that has the same or better properties as PETG.
- swiley 6y ago
  If the part doesn't have to last long or is subjected to smaller forces and the robot is kept in a controlled place PLA is fine. We used them it to make parts for robotics competitions in college.
  - dheera 6y ago
    It really depends on what you're building. For controlled environments that's fine, but unfortunately I'm not building for controlled environments, and tend to do quite extreme things with parts. I need them to be subjectable to force and reasonable amounts of heat. There is no way around it in my applications. Point is PETG works, sometimes I need to go to CF-Nylon, I'm just looking for something that's as good mechanically and can be recyclable. I wonder if the plastics in the article would work.
    - mnouquet 6y ago
      > It really depends on what you're building. For controlled environments that's fine, but unfortunately I'm not building for controlled environments, ... Sample size fallacy right here. Just because it's useless to you doesn't mean it's useless. Plenty are doing fine with PLA.
- mrfusion 6y ago
  I’ve just been living with the downsides of pla. Should I just switch to petg? I have my printer in my bedroom though. Is petg toxi to breathe?
alpaca128 6y ago
No, it's not. Despite what store pages love to tell you at every corner, PLA does not degrade by itself. It requires exposure to 60+ degrees Celsius for at least 6 months. Good luck building recycling plants handling this in an environmentally-friendly and economical way. Don't throw out PLA, it's barely less problematic than other materials.
- Dma54rhs 6y ago
  Temperature at land fills get rather high. Not sure about 6 months, it depends where.
- labawi 6y ago
  I've personally seen how PLA degrades in good compost in about three weeks (can go for less if you're more active). True, it is important to go through a stage of 60+℃ for a day or so, to soften up so bacteria get in, otherwise it may indeed take 6 months to get through a solid chunk, but that is quite different from 6+ months of 60+℃. Yes, PLA can cause some issues in nature as it is acidic (lactic acid) and in quantity throws off pH balance in soil/compost, so many composters don't like to take PLA. OTOH, it is not a difficult problem to solve, and importantly, lactic acid is not inherently toxic in reasonable quantities (muscles generate it) and it shouldn't take too long for microbes to snatch it up once it is small enough. To put that in contrast, typical plastics consist of toxic components that you do not want in your system, or even in your garden. They are mostly inert while intact, but they tend to slowly decompose and often leach even while in use. Examples of compositions: ABS - acrylonitrile (toxic at low doses [1]), butadiene (Group 1 carcinogen [2]), styrene (known carcinogen [3]); PET, PETG: phtalate (Endocrine disruptors [4]) [1] https://en.wikipedia.org/wiki/Acrylonitrile [2] https://en.wikipedia.org/wiki/Butadiene [3] https://en.wikipedia.org/wiki/Styrene [4] https://en.wikipedia.org/wiki/Phthalate

PLA can be recycled with near perfect efficiency and is available today. Also it's extremely biodegradable so throwing it out isn't the end of the world.

by swiley 6y ago

PLA can be recycled with near perfect efficiency and is available today. Also it's extremely biodegradable so throwing it out isn't the end of the world.

tomcam 6y ago

TIL. Can you tell me more about the recycling process for PLA?

mnouquet 6y ago
Shred, heat and extrude.
- tomcam 6y ago
  Thank you very much. Not sure why my question was downvoted.
  - dheera 6y ago
    I do wish it were required to give a reason or comment to downvote. I upvoted you to compensate since the downvoter did not do this.
    - tomcam 6y ago
      I would dearly love a world in which you provided a reason to download a comment on this site.
- neltnerb 6y ago
  Wait, wait, let's not give the wrong impression. Yes, you can recycle PLA to an extent but you can't mix it in with your recylables. Few cities can recyle PS, much less PLA or at least they aren't set up to handle it. If you are curious about the tech, sure, it's recyclable. For practical purposes you may as well throw it in the trash ahead of time and avoid contaminating the recycling. Plus if you try to put it in most commercial composting it will not degrade enough to be usable and has to get removed to avoid damaging the compost. So if you happen to not have the right kind of composting facility you can't handle it. Yeah, it's on paper no worse than other plastics, but you have to have a plan to handle it -- it's not just a thing you can toss in the recycling bin.

dheera 6y ago

PLA is pretty useless as a material though for anything but art. Almost everything I print has a functional purpose and either (a) needs mechanical strength (b) will be placed outdoors in the California sun or (c) will be used to house electronics that may reach temperatures as high as 70-80 C. PLA is basically useless to me and pretty much all roboticists. I use PETG for almost everything because it works perfectly for all my needs; unfortunately I often need to go through about 2-3 versions of many parts I make and wish there were a better, more efficiently recyclable option that has the same or better properties as PETG.

swiley 6y ago
If the part doesn't have to last long or is subjected to smaller forces and the robot is kept in a controlled place PLA is fine. We used them it to make parts for robotics competitions in college.
- dheera 6y ago
  It really depends on what you're building. For controlled environments that's fine, but unfortunately I'm not building for controlled environments, and tend to do quite extreme things with parts. I need them to be subjectable to force and reasonable amounts of heat. There is no way around it in my applications. Point is PETG works, sometimes I need to go to CF-Nylon, I'm just looking for something that's as good mechanically and can be recyclable. I wonder if the plastics in the article would work.
  - mnouquet 6y ago
    > It really depends on what you're building. For controlled environments that's fine, but unfortunately I'm not building for controlled environments, ... Sample size fallacy right here. Just because it's useless to you doesn't mean it's useless. Plenty are doing fine with PLA.
mrfusion 6y ago
I’ve just been living with the downsides of pla. Should I just switch to petg? I have my printer in my bedroom though. Is petg toxi to breathe?

alpaca128 6y ago

No, it's not. Despite what store pages love to tell you at every corner, PLA does not degrade by itself. It requires exposure to 60+ degrees Celsius for at least 6 months. Good luck building recycling plants handling this in an environmentally-friendly and economical way. Don't throw out PLA, it's barely less problematic than other materials.

Dma54rhs 6y ago
Temperature at land fills get rather high. Not sure about 6 months, it depends where.
labawi 6y ago
I've personally seen how PLA degrades in good compost in about three weeks (can go for less if you're more active). True, it is important to go through a stage of 60+℃ for a day or so, to soften up so bacteria get in, otherwise it may indeed take 6 months to get through a solid chunk, but that is quite different from 6+ months of 60+℃. Yes, PLA can cause some issues in nature as it is acidic (lactic acid) and in quantity throws off pH balance in soil/compost, so many composters don't like to take PLA. OTOH, it is not a difficult problem to solve, and importantly, lactic acid is not inherently toxic in reasonable quantities (muscles generate it) and it shouldn't take too long for microbes to snatch it up once it is small enough. To put that in contrast, typical plastics consist of toxic components that you do not want in your system, or even in your garden. They are mostly inert while intact, but they tend to slowly decompose and often leach even while in use. Examples of compositions: ABS - acrylonitrile (toxic at low doses [1]), butadiene (Group 1 carcinogen [2]), styrene (known carcinogen [3]); PET, PETG: phtalate (Endocrine disruptors [4]) [1] https://en.wikipedia.org/wiki/Acrylonitrile [2] https://en.wikipedia.org/wiki/Butadiene [3] https://en.wikipedia.org/wiki/Styrene [4] https://en.wikipedia.org/wiki/Phthalate