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Kenyan recycles plastic waste into bricks stronger than concrete

• Triv888 6y ago
  "Does not crack" doesn't mean that it is stronger at what concrete is good for. Try to build a 70 story building with that stuff, for example. Diamond is good for scratching, steel can be good for hitting....
• terse_malvolio 6y ago
  https://preciousplastic.com/ https://preciousplastic.com/
• sn_master 6y ago
  Polyethylene is highly flammable. The article isn't talking about how they're solving this (are they?). This has been a problem for quite sometime now, with many high-profile cases (https://www.bbc.com/news/uk-41680157 https://www.bbc.com/news/uk-41680157). This was an excellent ABC documentary I saw sometime ago on the same topic: https://www.youtube.com/watch?v=gnTZLzXq8fU https://www.youtube.com/watch?v=gnTZLzXq8fU
  • liamkinne 6y ago
    I would imagine the mixing in of sand would mitigate this mostly.
    • sn_master 6y ago
      I would love to see how that works. The ABC documentary is saying that even the big-industry produced polyethylene for buildings isn't properly flame-resistant, even the EU-approved ones.
    • adrianmonk 6y ago
      There was a Reddit thread where someone made a case why it wouldn't: https://www.reddit.com/r/worldnews/comments/ler5uc/kenyan_recycles_plastic_waste_into_bricks/gmi87cn/?context=3 https://www.reddit.com/r/worldnews/comments/ler5uc/kenyan_re... I'm certainly not an expert, and I don't know if the person writing in that thread is either (although their style of writing suggests they might be knowledgeable).
  • josefresco 6y ago
    FTA "These are high density polyethylene, used in milk and shampoo bottles; low density polyethylene, often used for bags for cerals or sandwiches; and polypropylene, used for ropes, flip-top lids and buckets." Are cereal bags, ropes, shampoo bottles and buckets highly flammable?
    • sn_master 6y ago
      Yes? https://www.sciencedirect.com/science/article/abs/pii/004060319080167W https://www.sciencedirect.com/science/article/abs/pii/004060... If you have a counter-source, please share it.
      • josefresco 6y ago
        I don't, I was genuinely asking. It would seem like given it's popularity that would be an issue. But, crazier things have happened when it comes to consumer safety regulations. Anecdotally I've probably touched an open flame to synthetic rope, milk jugs and maybe a bucket or two in my life but can't say I've ever seen any of these items react in an uncontrolled or dangerous way.
        • mediaman 6y ago
          Sure, they're flammable. But the amount of BTUs in, say, packaging, is negligible, because it's so lightweight. When you combine lots of recycled packaging into dense bricks, it becomes a lot of dense BTUs, so can provide a lot of fuel to a fire.
        • _jal 6y ago
          Plastic fires are nasty. Aside from toxic fumes, plastic melts, So gravity will help it spread, if there's a way for it to do so. You're not going to cause a runaway with a lighter and a pop bottle without working at it. But, say, an electrical short in a closet with hanging synthetics can take off pretty quickly.
          • why_Mr_Anderson 6y ago
  • darkwater 6y ago
    Wood also is highly flammable and that is not stopping one of the most developed country in the world to keep using it to build houses.
    • sn_master 6y ago
      Wood used for construction is required by law to be fire treated. https://www.fp-supply.com/st-louis-fire-treated-lumber.html https://www.fp-supply.com/st-louis-fire-treated-lumber.html
      • audunw 6y ago
        Where? In what contexts? It's not required for houses or town houses where I'm from at least. From the pictures I guess it's mostly relevant to larger buildings?
        • saltyshake 6y ago
          "Over 90% of the homes that are built in the United States each year are constructed using wood-frame construction" https://awc.org/codes-standards/firesafety https://awc.org/codes-standards/firesafety
          • rootusrootus 6y ago
            And close to 100% of those are built with garden variety untreated fir lumber.
      • LegitShady 6y ago
        This is too general a blanket statement to be true. Plenty of wood in construction is not treated for fire. Fire ratings are generally done for assemblies, not components of assemblies, and there are ways to build fire rated assemblies without treated wood. Also, not all assemblies need fire ratings. Sometimes its just the exterior walls adjacent to neighbouring structures, etc.
    • audunw 6y ago
  • coderintherye 6y ago
    These are mostly used for paving stones (or at least they were when I met Nzambi a couple years ago), so the flammability issue is not as much of a concern since they are not inside buildings but rather used for walkways usually placed in the dirt.
    • londons_explore 6y ago
      I could totally imagine a walkway made of polyethylene blocks could catch fire in a big way... You wouldn't want that walkway to be all around your house...
• deleted 6y ago
  [deleted]
• foofoo55 6y ago
  Interesting she doesn't work with PET. I wonder what happens to the waste from deburring and installation, and the microplastic dust from cutting and wear & tear. I sometimes feel the only option for waste plastic is incineration.
  • warent 6y ago
    Incineration would probably be much, much worse, because all you're doing is releasing toxic pollutants into the air/atmosphere Unless you're talking about plasma gasification, in which case I wholeheartedly agree it appears to be a very promising solution, and wish I had resources to invest in that.
    • toomuchtodo 6y ago
      I too would love to work in the plasma gasification space, but it doesn't seem like there's a lot of interest in investment in that area even with the waste to energy and environment benefit potential. We could have self powered ocean platforms collecting and plasma gasifying plastic waste, instead of dragging all of that waste back to land for processing.
      • warent 6y ago
        I've been dreaming about this for years. Most people who hear about it think it's nonsense. You could even set up plants near landfills and deploy little Wall-E robots to dig up and transport landfill for syngas. Feeling like we'll see this in the next 100 years. Part of the reason there's little investment is apparently because the energy generation is barely above net neutral with current technology. Still though, even at neutral it seems like it would be good to clean up soil and create slag for construction. It would probably work best as a nonprofit/government project
        • toomuchtodo 6y ago
          Keeping my eye out for natural gas processing ships going for a song.
• plosticks 6y ago
  Polyethylene is a wonderful material for subtractive manufacturing, especially parts that you might otherwise 3D-print or make out of wood. It's easy to make "bricks" by melting and pressing chips and shredded material in a mold, and those bricks make excellent machine stock. You can't use it as a building material, but I like the idea of mixing in sand and using them as paving stones. After all, we frequently pave playgrounds with flammable material made out of shredded tires. I do wonder about microplastics flaking off of them, though. PE is pretty remeltable, but like most plastics it gets a bit more brittle with every cycle. Most recycling outfits mix some virgin plastics in with the recycled stuff for that reason.
  • trhway 6y ago
    >I do wonder about microplastics flaking off of them especially under strong light/UV of equatorial Sun. While the story looks great at first, i wonder whether it can succeed under more strong environmental review.
    • dylan604 6y ago
      The article says the factory has been running since 2017. That's going on 4 years of stuff from the factory being in the sun. I have seen plastic items last less than one Texas summer in the sun. Either they've done a brilliant PR campaign to keep the "sun kills this product" stories, or it is less of an issue than HN wants it to be.
      • bluGill 6y ago
        There are UV inhibitors that are added to plastic. They give you more time in the sun, though eventually you are done.
      • LegitShady 6y ago
        Or nobody really cares about these bricks except for puffy PR pieces and questions about material lifespan aren't really interesting to the reporter printing about bricks stronger than concrete.
  • 6y ago
• ttul 6y ago
  She should do YC.
• lmilcin 6y ago
  Just because the brick is able to withstand throwing it on the rocks doesn't mean it is not going to deform under load. Brick strength is measured in ability to withstand deformation under load and as far as I know there isn't any popular "plastic" that can do comparably. For a single story house this probably doesn't make any difference, but for a larger structure the load could cause bricks to loose shape, creep and cause the structure to fail. Also, plastics tend to get soft rapidly at temperatures. I don't think plastic bricks exposed to sun (Kenya?) would fare for long. Another issue is that plastics tend to deteriorate in UV. That could be fixed with a good paint but it also costs. (Edit: for the pavement this is horrible idea as the plastic is going to be broken down and dispersed in environment in large amounts)
  • jay_kyburz 6y ago
    I only skimmed the article, but I thought they were just pavers. (For making a path). Buy yes, I came to say something similar, if you just compress the plastic into a block and lay it down to make a path then as it deteriorates surly you are just contaminating your environment with mico-plastic particles.
    • londons_explore 6y ago
      Ssssh... People prefer to distribute their problem into invisible pieces put into the environment slowly over 1000 years than to just bite the bullet and incinerate plastics that have reached their usable lifespan...
      • smeyer 6y ago
        There are real reasons to not want microplastics in your local environment, but I think your dismissiveness of spreading a problem out over 1,000 years is unwarranted. There is a huge difference between a problem that has to be solved in a year and a problem that has to be solved in 100 or 1,000 years, because time is an incredibly valuable asset. Delaying some of the carbon we put in the atmosphere for hundreds of years is massively useful, because it buys us time to try stave off and ameliorate some of the effects of climate change.
• coderintherye 6y ago
  Oh wow, this is great to see! I know Nzambi from a trip to Kenya! She's been working on this for years and despite a great performing product she really struggled to find funding. Hopefully this coverage will help with that. If anyone is interested in funding her and wants to get in touch I can reach out on your behalf.
  • robbmorganf 6y ago
    That's awesome! Don't personally have funding, but I'm wondering what if anything is holding this back from being deployed more widely? Why aren't other companies pursuing this?
    • coderintherye 6y ago
      Nairobi has a particularly acute problem of plastic trash everywhere which this really scratches the itch of helping solve this in an economically incentivizing way. I'm sure there are likely other places where the problem is prevalent. I'd certainly buy these if they were available and competitive with concrete paving stones in the U.S. There are some use cases where I think they would be preferable as they would be less likely to crack than concrete.
  • bogidon 6y ago
    Hey! I was thinking about funding while reading the article. I would love to have a conversation. Please do reach out to the email in my profile if you have the time.
• Animats 6y ago
  Nice. Using it for pavers makes sense, too. It will have some elasticity, which is fine for pavers but bad for structures. There are a few variants on this idea already. One is just to compress trash plastics into blocks, with no sand.[1] Another is a process more like brick making, where the material is melted.[2] That process is 20% recycled plastic, 80% sand etc. There are problems. UV deterioration. Cracking at low temperatures (probably not a problem in Kenya). Flammability. Poor adhesion to mortar. In the end, it's still polyethylene. [1] https://www.byfusion.com/ https://www.byfusion.com/ [2] https://www.irjet.net/archives/V6/i4/IRJET-V6I4238.pdf https://www.irjet.net/archives/V6/i4/IRJET-V6I4238.pdf
• latchkey 6y ago
  What about leaching chemicals into the soil and groundwater?
• solarkraft 6y ago
  The talk about it mainly being used on path ways means it's especially exposed to the environment, making me concerned about plastic particulate being released. Some research on the topic would be nice. Is this really the best use for plastic, can't you do a lot more with it than that? Doesn't mixing it with sand make it much harder to recycle later? Isn't cement a just fine binder for sand (which is the actually scarce resource)? With all those concerns, though, that she's a materials engineer calms my inner voice eager to scream "scam".
• scythe 6y ago
  The world produces four billion tons of cement per year, about half of which is produced in China. For comparison, polyethylene, used for these bricks, is produced at about 100 million tons per year. In other words, even if all of the waste polyethylene in the world could be recycled like this, it would make, at best, a roughly 2.5% dent in the demand for concrete. (There are aggregates in both cases, so you can't just lean on that.) It's useful if it offers functionality cement doesn't have, which in this case it seems to. But the idea that plastic waste, in any form, or for that matter any other wastes (aside from asphalt, which was once a waste product), can substantially replace building materials, is mostly a popular misconception rooted in humans' difficulty with large numbers. Comparing the bricks to concrete just isn't really apples-to-apples.
  • why_Mr_Anderson 6y ago
    Not to mention there are so many different types of concrete tailored to meet specific requirements that it's very unlikely anything could even make a dent in our need for concrete.
  • Bakary 6y ago
    The goal here is to create an incentive to remove waste. Changing the concrete industry would only be a side-effect, if at all relevant.
• adambcn 6y ago
  Stronger how? Torsional strength? Compression strength? Tension strength? Hardness? Yield strength? Or just random person throwing it on the floor?
• nexthash 6y ago
  A lot of people here are asking the same question and I can't find it addressed anywhere: how does this product not heavily pollute the environment? Since the bricks contain plastic they are prone to flaking and the formation of microplastic particles, which can last for thousands of years and get into the digestive systems of animals and humans. Also, the plastic might crack from constant UV radiation under the Kenyan sun. Could somebody explain what the rationale might be for putting 1000 plastic bricks/day into the environment or if there's something I'm missing?
  • deleted 6y ago
    [deleted]
  • ahepp 6y ago
    The entertainment industry loves stories about inventions in Africa. Occasionally, people make the honest mistake of thinking it's newsworthy. I am quite confident you will never hear or see of these bricks, that they are numerous different ways they are not commercially viable, and that they are probably as bad or worse for the environment than just throwing the garbage in a landfill. (although I'd certainly be glad to be wrong)
    • Bakary 6y ago
      In all honesty, it's more newsworthy than yet another post about some superfluous, polluting, or outright damaging software startup/service/toy for adults.
  • ineptech 6y ago
    > how does this product not heavily pollute the environment? They do. Everything pollutes the environment, including breathing. Do you think solar panels don't have toxic chemicals in them? The sensible way to judge this relative, not absolute. The question you should be asking is not whether plastic bricks are bad, it's whether they're worse than whatever happens to the plastic waste in Kenya that isn't used to make bricks.
    • unloco 6y ago
• ahepp 6y ago
  Simply based on the face that this article lists the cost of recycled bricks, but not the cost of traditional bricks, I feel quite confident saying this is an entertainment piece, and the bricks have no serious commercial prospects outside of being a conversation piece. "News" sites really love stories about inventions in Africa, but if you read this crap you almost certainly come away with a worse understanding of the economy in whatever state they're talking about. I stopped reading Quartz entirely, because their emerging markets coverage was composed entirely of this stuff. If you're really interested about innovation in the African economy, the investments China is making are what you should be reading about. That's what's actually going to change the future of Africa. FT has some good coverage of it all (although they're expensive).
  • ChrisMarshallNY 6y ago
    I'm not so sure that China's involvement may work out as well as you may think. Africa was badly damaged by colonialism, and what China is doing smells a lot like that. Africa is insanely resource-rich, with faltering administrative infrastructure (governments). Great place for rapacious capitalists. They love that kind of situation.
    • ahepp 6y ago
      I don't know whether it will turn out well, rather that it's the newsworthy topic in Africa now (afaik).
• kristo 6y ago
  About the microplastics and deterioration : would it be better if we just buried the trash in a landfill? Seems the bricks might offer a slight improvement or break even there
• ggm 6y ago
  There is a role for plastics as fibre as a reinforce in cast concrete. It's well known from bricks with straw. Alters the strength under load, strength to weight. Has a role in post earthquake survivability rates. If you can make it resist flexion (remember, concrete is strongest in compression) then there is a better chance to get out of the building alive, and then have a chance to fight the inevitable post-quake fires. The fires do a lot of damage because they wreak havoc on already weak structure from the quakes too. Anything which makes them more resilient, reduces the immediate event death rate. You have to rebuild, sure. Nothing stops that. Is it magic? No. There is no magic. But, its possibly useful, depending how its formed and how it's used and incorporated. Iran does a lot of work in this. There are two reasons. The good reason is that they have a lot of social housing construction, 2-3 story, concrete constructions with low-doc compliance, and earthquakes. The other reason is that they needed to understand if the stuff withstood bunker-buster bombs. Not the houses. Other facilities.
• ummonk 6y ago
  What happens when these erode - wouldn’t plastic particles contaminate water?
• balozi 6y ago
  I hope this is not laying the groundwork for developed nations to ship their plastic waste to Africa. China won't take the waste anymore so now we ship it to Kenya, to make paving bricks.
  • dirtyid 6y ago
    There isn't enough trade surplus with Africa to generate enough empty containers that made shipping plastic waste to Asia workable. Maybe there's going to be indigenous recycle brick industries to deal with local plastic waste, or ship the finished products to Asia on empty containers because I surmise the chances of plastic waste passing conservative construction industry standards is not high.
• qwerty456127 6y ago
  What about fire safety?
• Uptrenda 6y ago
  'hey we found a cool way to recycle plastic' HN: NOOoooo!! ;____; NOOOO that cant possibly work!! noooo!!! HN: I am not an expert but here is my totally unsupported speculation why this cant possibly work!!!! ;_________; HN: I bet [this material engineer working on this for 3+ years in the real world] didn't even think about how strong the brick are!! --puffs out chest-- HN: It will still break down. Therefore SHIT Honestly, what the fuck is wrong with you people. This isn't critical thinking its grandstanding. What a negative, toxic shit hole.
  • catillac 6y ago
    This is absolutely a thread that nails the “smarter than thee” HN toxicity. You hit the nail on the top.
    • haram_masala 6y ago
      To be fair, I come to HN because most posters here are in fact smarter than I am. One person’s toxin is another’s tonic.
  • readflaggedcomm 6y ago
    The story lacks details, since the journalist asked or included none of the obvious questions a reader might have, so commenters are filling the gaps in creative ways. They should be seeking out better information, instead, but filling the gaps is what link aggregation sites are about now.
  • slingnow 6y ago
    Feel free to return to Reddit, where mundane things are met with endless praise instead.
    • MajorBee 6y ago
      I am 100% sure this is way worse on reddit, that paradise of armchair experts.
  • haram_masala 6y ago
• hmmokidk 6y ago
  We're leaving future generations with so much pollution, and now microplastics. Realistically this is a nightmare and it is unfortunate that the world we live in is so dystopian, so in need of wealth, that we're resorting to using garbage to build homes when there's a plethora of environmentally friendly materials we could use if only wealth wasn't centralized in so few hands. But at least they get homes, I suppose. I know if I was in their position and needed a home I wouldn't care if it was made up of plastic bricks or not.
  • Bakary 6y ago
    It's one thing to lament the unfortunate aspects of the world... but are you willing to make even the most basic lifestyle concessions to improve the situation?
  • throwaway2037 6y ago
    You wrote: "we're resorting to using garbage to build homes". Do you also consider recycled (1) concrete, (2) steel rebar, or (3) asphalt in the same "garbage" category? Thirty years ago (~1990) there was very little of those three being recycled -- think landfills(!). In many high income countries, homes, schools, and office buildings are using one or more of these.
• jpollock 6y ago
  This looks pretty cool. I wonder how much sand it contains! We use plastics in non-structural building material replacements already. Fencing, railings and decking all have plastic variants, or plastic + wood. Mixing it with sand might turn it into mechanically stabilized earth? The load is born by the sand, and the plastic keeps the sand from shifting. https://practical.engineering/blog/2016/5/15/mechanically-stabilized-earth-aka-mse-reinforced-soil https://practical.engineering/blog/2016/5/15/mechanically-st...
• kumarvvr 6y ago
  These solutions are terrible. For one, initial strength is a moot point. Important factors are compression or deformation under load, disintegration under different weather conditions, releasing of micro plastic particles, etc. This is just a feel good story about alternative uses of plastic. Like the solar road thing. Sounds good, but practically useless.
• throwaway888abc 6y ago
  Recently thinking without proper answer :-) Would it be possible to "dissolve plastic by liquid into other liquid" which would potentially not impact environment that much ? Better than land field or burning ? Like throwing some sort of eco friendly acid on it ? Layman question, answer appreciated. Obviously the outcome should be causing less harm to environment.
  • 6nf 6y ago
    To what end? Putting the plastic that we can't recycle into landfill is not a disaster.
• pippy 6y ago
  Plastic recycling by and large is a farce. The majority of all "recycled" plastics in western countries winds up being exported to developing nations who then extract a tiny percent that can be melted down and reused. The rest winds up in rivers, or the ocean, or being burnt. It's horrific that countries like his is being used as a global rubbish dump. If western countries actually want to make a difference, we need to take a hard line and ban all single use plastic.
• known 6y ago
  In India recycled plastic is used to lay roads;
• nicetryguy 6y ago
  I'm excited to see where this technology goes. I'm surprised it's taking so much flack in this thread for not being fully fleshed out and compared to materials in use for thousands of years like wood, metal, and concrete by people with barely functional github projects.
• ropable 6y ago
  All the well-heeled nerds internet-sniping about microplastics: this is a female African engineer/entrepreneur who is taking a waste product (destined to be dumped or burnt) and recycling it into a durable building material (with every chance of being in use for decades), using machines that she invented herself. Pull your heads in until you've actually solved a real-world problem yourself.
  • owlmirror 6y ago
    Her sex and nationality does not make it less of a problem that such a product is a bad idea because of the lasting and irreparable pollution it will cause. You don't need to have solved a "real-world" problem, which I'm sure many here do every day, to see that. Please be more respectful. There is a need for a solution for the plastic waste, but this ain't it. Maybe take a look at how other countries solve it or are not solving it. Burning with adequate filtering seems to be the best candidate for it, besides not producing it in the first place.
    • mschuster91 6y ago
      The thing is: we're talking about Africa here, where trash is often enough either dumped somewhere or burned without any filters at all. Many Western trash burners are only operating because of old licenses, they would not pass inspections if constructed today ffs. A solution that disposes of the plastic in a form that doesn't cause more harm while being more usable to the people is always the better thing to do.
      • owlmirror 6y ago
        But does it really disposes the plastic in a form that does not cause more harm? That's the entire argument. It's just as bad for the environment as it would be if you'd just dump it on landfills. But than you can dig out landfills later on, when you've got a better solution, in a centralized and known location. But who is going to track down and demolish all the pavements in the decades to come? These bricks are essentially guaranteeing that the plastic used will cause micro plastic pollution for generations to come. And even if you never find a solution, having the plastic in a landfill makes it possible to at least control the circumstances. You can burry it, reducing the exposure to the elements, like sun and wind. The more I think about these bricks the more I'm sure that's the worst thing you can do with plastic, except for just dumping it into the ocean.
• Paul_S 6y ago
  They're not really bricks, you can't build a house out of them (at least not using traditional techniques where the bricks provide the structural strength). Otherwise a feel good story.
• anticensor 6y ago
  anticensor liked the idea yet feels like this project will be blocked by oil lobby in near future.
• lurquer 6y ago
  There’s no way this is cheaper than concrete. Unless it’s subsidized in some way — perhaps people paying a premium for the bricks to meet some ‘green’ building standard — this isn’t a viable business. Who knows, though? Maybe the lower weight makes it attractive. You could probably accomplish the same green goals and make more money by shredding the plastic and mixing it with ordinary concrete... so you wouldn’t have to use as much aggregate or sand... because we all know how expensive aggregate and sand are... right? Scratching head...
• kevincox 6y ago
  > “Our product is almost five to seven times stronger than concrete,” It bugs me when people combine ranges with "fuzzy" wording. Is it 5-7 times or is it almost 5 or almost 7? Maybe it was partially a language barrier but in that case maybe we don't need to quote this line and can replace it with the actual numbers. Although "stronger than concrete" is very ambiguous anyways.