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New plant-based plastics can be chemically recycled with near-perfect efficiency
- dheera 6y ago"Mobile phone case made with 3D printing, using recycled plastic." I do a lot of 3D printing and I always feel bad every time I have a bad print or design error and need to throw it in the trash. I really hope we can see some of these filaments on the market soon especially considering how popular 3D printing is becoming.
- swiley 6y agoPLA 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 agoTIL. Can you tell me more about the recycling process for PLA?
- mnouquet 6y agoShred, heat and extrude.
- tomcam 6y agoThank you very much. Not sure why my question was downvoted.
- neltnerb 6y agoWait, 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 agoPLA 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 agoIf 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 agoIt 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 agoI’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 agoNo, 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 agoTemperature at land fills get rather high. Not sure about 6 months, it depends where.
- labawi 6y agoI'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
- loosetypes 6y agoAgreed. If you print a dinosaur skull out of ABS, I wonder if the cast would survive longer than a real fossil.
- thret 6y agoThat is a sombre thought.
- swiley 6y agoThey say "new ... plastic" but the paper looks like it's talking about Polyethylene (not too sure what "polyethylene-like" means, different degrees of polymerization?)
- giantg2 6y agoThere's also a company working on a plastic replacement for mushroom grow bags. It would be biodegradable.
- scyzoryk_xyz 6y agoOoh - do you happen to have a link?
- giantg2 6y agoMushroom bags that have additives to biodegrade the plastic - https://www.shroomsupply.com/mushroom-grow-bags/biodegradable-mushroom-grow-bags https://www.shroomsupply.com/mushroom-grow-bags/biodegradabl... Plastic like bags that are made from cassava and dissolve in water - https://www.onegreenplanet.org/news/company-makes-cassava-based-plastic-bags-that-dissolve-in-water/ https://www.onegreenplanet.org/news/company-makes-cassava-ba... And also, cellophane is biodegradable too.
- ArkanExplorer 6y agoPlastic recycling seems heavily motivated by emotion and virtue signaling. In reality, only about 5% of our crude oil use goes towards plastic. If we rolled out EVs, and then just burned all the plastic trash (using waste-to-energy plants), we would still be far ahead. The biggest challenges with plastics are hormone disruption, and microplastics (particularly in the 3rd world without sufficient landfill or W2E infrastructure or societal environmental concern). If these new plastics are less molecularly stable, these issues may actually be worsened.
- jariel 6y ago? Oil being used to make plastics was never a problem. Oil is not evil. It's the Co2 bit that's a problem. The problem you missed was at least to some extent recycling: we can't reuse the material at all, and while theoretically burning is practical, we still don't separate everything and burning still leaves a byproduct that has to be buried. I suggest the alternative is going to have to be something that truly disintegrates, i.e. more organic.
- 8note 6y agoBurying it as is makes it a carbon sink. If we take plant, turn them to plastic that doesn't regards quickly, then bury them, we're sequestering that co2
- jariel 6y agoOil for plastic use just is not a CO2 issue, it has nothing to do with sequestration. Oil for plastics is more akin to the use of any other natural resource in a product or good. The above commenter indicated 'issues with extraction', well yes, but we have the same issues with extracting everything else. Also, frankly, most oil extraction is not very damaging directly - if we were only using oil for plastics, we'd probably only use the easiest to access oil, like from the Middle East where we pop a straw in the ground and that's it aside from refining. Burned 'anything' that we put in landfills is actually better than raw garbage as it's considerably reduced and more dense - but it's still landfill. We should strive for a solution that doesn't require landfill.
- ratsmack 6y ago>plant-based What they're based from isn't the problem, it's chemicals added to the base, such as chlorine compounds, that is the problem.
- specialist 6y agoPlease say more. My efforts to buy least processed cotton and wood pulp products have been largely unsuccessful. I don't need my toilet paper or t-shirts to be white.
- rarefied_tomato 6y agoYour concerns sound more related to https://en.wikipedia.org/wiki/Optical_brightener https://en.wikipedia.org/wiki/Optical_brightener than chlorinated plastics.
- nine_k 6y agoFor some reason, products made of minimally treated hemp or linen are more widely available.
- DenisM 6y agoLook into wool. Expensive, but super comfy and likely not bleached. Given the higher price some of the brands make it a point to detail the environmental and animal welfare impact.
- srswtf123 6y agoI suggest using a bidet/washlet, and a dry towel. Toilet paper isn’t truly necessary - to me. As a particularly hirsute gentleman, I find it both cleaner and more comfortable. YMMV.
- himujjal 6y agoHow are people still using toilet papers in developed countries? It still amazes me. I am from a developing country and it costs around $15 to fix a new bidet/handheld-shower to my existing pipe connection. There is the cost of water though. But then again. I am in a rainy area. Water crisis might never occur here. Plus all the waste is going to ground. So, not much to worry here. But seriously. Use bidets or at least handheld-showers
- mrfusion 6y agoIsn’t plastic in landfills actually a great way to sequester carbon?
- orev 6y agoIt’s not really a benefit if the original carbon came from oil, because the carbon that was originally deep underground is now at the surface. If anything it’s only neutral, however the carbon emitted during oil extraction and the manufacturing process still results in a net negative. Landfill isn’t the worst option, but it’s still better to try to avoid the manufacturing of it to begin with.
- TeamXe 6y agoREDUCE, Reuse, Recycle. People forget (or never realized) the order was intentional.
- snarf21 6y agoAlthough you are right, I don't think it is that people don't know this. Recycle is easy, through it in the blue bucket. Reduce requires a complete re-imaging of our society. This won't happen without substantial taxation on plastics and single use packaging. But that is a bad way to get re-elected and how will we get next day shippping?
- jrowen 6y agoTo go a bit further, I feel like "reduce" just isn't really in the vocabulary of living organisms. Once any particular cat is out of its bag, it's not going back in (though I'd love to hear some examples to the contrary). It seems like our best bet really is an ever more Rube Goldberg-ian stack of attempted fixes for the problems we create.
- samatman 6y agoModern cultures have substantially reduced their use of tobacco and alcohol, have reduced their birthrate below replacement, cut 95% of trans fats out of their diets, and use practically no tetraethyl lead and no DDT at all. We don't have to continue using endocrine disrupting plastics either. It can't be a blanket ban, we use them in too many places. But they can be phased out.
- williesleg 6y agoWait, plants take carbon dioxide out of the atmosphere and produce oxygen. Why kill more plants?
- benjohnson1707 6y agoAs always, scale matters. Plastic will be superior to all the alternatives as long as it's a cheap waste by-product of oil refinement. Make alternatives economically competitive to basically free oil refinement by-products, and we're talking. EVs might help here, it seems.
- 29athrowaway 6y agoCheap to produce. Infinitely expensive in the long term.
- profvyas 6y agoThe real problem with plastics is that they are really cheap.
- xorfish 6y agoNo, the problem is missing infrastructure for waste processing.
- 29athrowaway 6y ago"Really cheap" in the short term perhaps. Very expensive in the long term. What price do you put in the extinction of a species? Millions of years of evolution flushed down the toilet so one person can have their disposable water bottle.
- DFHippie 6y agoThe problem is externalized cost: the people making the decision to use the plastics aren't the ones holding the bill for its disposal.
- peteretep 6y agowhich is because they don't have externalities priced in
- nostromo 6y agoIt’s more that plastics are a byproduct of oil production. As oil consumption falls, plastics will rise in price as there is less raw materials produced by oil refining. Much like if demand for beef and milk fell, leather could be more expensive.
- johnisgood 6y agoWhat do you propose, how should it be resolved? What would your proposal's potential consequences be (both cons and pros)?
- dmos62 6y ago
- Animats 6y ago"The one disadvantage of the new materials Mecking identified was their cost." Oops. Biodegradable plastics are available. They're useful for things likely to be discarded with ordinary trash, like food packaging. Some are made from starches.
- ivan_ah 6y agoHere is one of those bio-product bags https://www.youtube.com/watch?v=vQRqwoSD94w https://www.youtube.com/watch?v=vQRqwoSD94w at 0:30 the video explains bags are made of "polyvinyl alcohol and raw materials like limestone" not sure how costly these primary materials + production are, but given final "state" is non-toxic, would be worth paying for this. Why are grocery stores not moving into this big time? Seems like a no-brainer to me.
- 127 6y agoI've heard composting PLA is pretty bad for the environment as it produces a lot of methane, which is much worse greenhouse gas compared to CO2. It also seems PLA doesn't degrade in landfills. It requires a built to purpose composting facility.
- neltnerb 6y agoIt contaminates compost if you put PLA into a regular composter. It requires a special industrial compost facility to handle it and most aren't. So it's trash. If you put PLA in the recycling bin it is making sorting even worse because if you get a bit of PLA mixed in with your other plastic it's not going to be good. So it's definitely not even slightly recyclable. So it's trash. PLA is trash. Unless you have an industrial composter. It's horrible.
- deleted 6y ago[deleted]
- robthebrew 6y agoThe process involves dissolving the plastics in ethanol at almost double its boiling point. So this requires pressure and presumably a batch process. That adds to the cost quite substantially.
- Havoc 6y agoThe diversity of responses in this thread as to what the real problem is is deeply alarming. Apparently hn - presumably an educated crowd - can't even agree what the problem is let alone how to fix it.
- lrossi 6y agoIt’s a complex problem for which solutions have many ramifications, so it’s perfectly normal to see different opinions. Personally, I enjoy the friendly and constructive discussion I have seen so far, and can say that I learned a few things.
- neltnerb 6y agoThe "real problem" is a futile entity to identify. There are an awful lot of real problems. I really like this technology. It's not going to fix the world. I like that the source is biological because it won't depend to the same extent on petrochemical supplies. I like that it is designed thoughtfully to have good mechanical properties while being nearly entirely recoverable. It's clever. I don't understand the hate. It's a silver BB but it's at least cool tech.
- johnisgood 6y agoWhat is the current status with regarding to using hemp or mushrooms?
- Hypocritelefty 6y agoWon't be long before tesla shills turn this in to EV is the mother of all solutions BS