Biomaterials, agromaterials, vs traditional plastics

Hey all,

I’ve been browsing core77 for a while to get inspiration, and now come to you to ask a rather tricky question, because I’m looking for the plastic with the lowest carbon footprint available for a project of mine

We all are under pressure from bioplastics manufacturers to use their products (like, PLA, polyactide) because these products are biodegradable and coming from natural sources (??).

I’m asking myself the question of using this kind of materials in my project, but I can’t decide because there are at least 3 unkowns I’d like more info on :

  • on agro-plastics (better term than bioplastics in my opinion) production : producers need to use corn, or sugar cane, to produce the agro-plastics. Do we have any evaluation of the environmental impact of the production (fertilizers, fuel used for growing & transporting the corn/cane etc.), and is it taken into account when comparing agro-plastics with other oil-based plastics ?

  • still on agroplastics production : has it an impact on soil usage - the same kind of concern we’ve seen growing when people starded doing agro-fuel : if you grow corn to produce agro-fuel, then you’re not growing it for food consumption, animal or human. Can this kind of ‘soil use competition’ happen, with the risk that ppl do grow what they don’t eat instead of what they could eat ?

  • lastly, it said that agro-plastics are biodegradable. However, it looks like agro-plastics can degrade when submitted to certain levels of humidity and heat, that no one can really reproduce at home to this day - and that there are no recycling plant accepting this kind of agro-plastic to do the biodegradation (at least in France where I live). Thus, a theoretic biodegradability ?

Having all these questions and limited answers at the moment, I’m considering using Recycled PET to use as the main material for a project of mine - having in mind that recycled PET is, well, already recycled.

Have some of you faced this kind of dilemna in the past ? How did you solve it ?

thanks for the help or links you know dealing with this question !

There is a lot to consider. Perhaps the trickiest parts are factoring in the manufacturing process your product requires and determining the expected life-span of the product. Without knowing at least those two things I think that confidently naming a material would be very difficult.

I’m quite excited about bioplastics in particular and would like to reactivate this thread if there’s no other one about this topic. I know that there have been some developments in furthering the production process and available materials, I’ve seen lots of things like grass, flax+PLA, potato starch, even tea and pine needles. I’m sure a material can be found to cultivate that doesn’t compete too much with agricultural soil for food production.

My concerns are more with how similar bioplastics can be to traditional plastics in terms of mechanical and aesthetic properties and especially production costs. Does anyone have experience producing with bioplastics and willing to share their experiences, or references to good articles?

Would be nice to expand this thread a bit.
The company i am working for tires to prevent the use of normal plastics as long as it makes sense.
We are working on offroad e-mobility and are using mostly metals and even wood, but I think it would be very interesting to see where those bioplastics would be a benefit.

I stumbled upon this company through their appearence at the auto show in geneva with this cool car:
They are using different materials. Not 100% bioplastics but cellulose and cellulose reinforced plastics and also biofuel and such. Recycabel or already recycled. Very nice concept that shows what is possible to an extent.

What other projects like this do you guys know, what other bioplastcs/materials are ready for implementation in this area?


Just to keep this topic somewhat alive, I would like to come back to the original question and post some info for those interested in general based on what I have learned in recent years:

  • Using recycled PET is fine, take into account that with every recycling process it lowers its quality to about 80%. After a few cycles new PET has to be mixed in. So we cannot call it recycling but it is downcycling. There are some recent indications of body toxicity with long-term exposure so possibly a reason to shun PET apparel and bedsheets.

  • PLA is not biodegradable. In the sense that it degrades in a natural environment. It needs a 57C or higher temperature which can only be induced in lab-based composting settings. So it is only compostable. It’s a marketing shtick. My own little experiments confirm; you leave some PLA prints outdoors and after 5 years no degrading has taken place whatsoever other than the expected weathering effects. So yes that ends up as microplastic, and we can only wait for the oceans to evolve the right trophic bacteria.

  • Since bioplastics use up only about 0.1% of land area vs. that for food production it is not really a competition between the two. But the land needed to produce a few pounds of PLA is already quite vast. In my eyes there is more future in lab-grown polymers by bacterial colonies.

  • I like the term agro-plastics as well as a subclass of bioplastics; those made of edible sources. Other subclasses would be those lab-grown plastics - vitro-plastics?, and those from lignin-based (non-edible) feedstock - ligno-plastics?

  • I would love to have more information on bio-based composites since that is very trendy right now. I am looking into possible replacements for silicone in the form of plant or cork leathers, so if anyone has more information I will praise you loudly.

Have a great ending of an awful year everyone!