Green Filament (that should come in many colours)


  • Classroom

    I haven’t looked into this at all, so do not consider this an endorsement. We received an email to the info account just now to alert people about a kickstarter campaign, which claims to have a plan for producing environmentally friendly filament for 3-d printing. Here is the link, I plan to check it out later, but would be interested to hear what the 3-d printheads and skeptical environmentalists thoughts are.

    https://www.kickstarter.com/projects/3dprintlife/biopetg-the-worlds-first-eco-friendly-petg-3d-fila?ref=5zn580



  • PLA is biodegradable and made from corn. If you have ever had a plastic grocery bag spontaneously turn into tiny flakes of powder (that acts as fertilizer) you know how PLA breaks down. PETG is significantly different to print with. ABS and PLA are the “easy” filaments. PET, PETG, Nylon, etc require different extruders, temperature profiles, special treatment to prevent steam bubbles etc… If you want to get into exotic filaments, I have access to some ninjaflex. You’ll like it, it makes flexible 3-d printed parts. Super swoopy stuff is possible.


  • Member

    Don’t buy to all the specialized and specific filaments they are a pain :P



  • When I was at KIC, there was always spools of crazy experimental filament coming in, and getting passed around. If you wanted working parts though, the easy stuff was the answer.


  • Classroom

    I had not even clicked on the link when I posted it, just noticed a 3d printing sustainability claim at the info box. After doing a very minor amount of research I would agree that PLA filament looks like a much more sustainable product than PETG. With biodegradable polymers the potential for biodegradation is much higher based on the relative amount of oxygen in the monomer (the repeating unit which makes up the polymer). The oxygens kind of acts like a handle at the molecular level allowing a chemical attack to grab hold.
    PLA
    Polylactic acid is composed of repeating units of lactic acid. It is available from a renewable biostock as Pierre pointed out, and it degrades into harmless byproducts.
    0_1490162390479_Polylactid_sceletal.svg.png

    PETG
    Polyethylene terephthalate’s monomer is ethylene terephthalate. It’s synthesis involves much harsher chemicals, and has raised concerns about its potential activity as an endocrine disruptor. Based on the structure I would also say that under combustion it very likely produces a whole host of carcinogens.
    0_1490161901456_500px-PET.svg.png

    To sum it up I would call bullshit on this kickstarter, this appears to be a clear case of greenwashing. I just wish that the 3 people that have contributed $2500 since I first posted the link knew that…



  • The vast majority of the 3d printing we did for work was in ABS, both because the parts are stronger and because the biodegradable nature of PLA would have required us to regularly inspect and reprint parts every few years. The labour of inspecting, printing, re-and-re… The extra material cost and waste, the power and time needed to print the same part more than once. Plus we were driving to Vancouver to install this stuff. I’m pretty sure the non biodegradable part is better for the environment in our use case. Unfortunately many green initiatives are driven by an appeal to the emotions of innumerate people. I like the idea of PLA for prototypes and ABS for installed unit, but unfortunately we had some difficulty getting the PLA parts to have the same dimensions as the ABS ones.



  • Everything has its use. The most clever use I read about was using PLA as a support material for ABS. Then you can wash the support material away when you’re done.
    Thanks for the primer on PLA. some biodegradable plastics, like plastic garbage bags, are really non biodegradable plastic mixed with corn starch. It “degrades” into tiny pieces of plastic.



  • @Grant-Fraser the garbage bag thing is interesting… I was under the impression (because I’d been told they were made from corn) that the garbage bags are PLA. The cornstarch and LDPE stunt is dirty pool. Bags that are not reusable, don’t biodegrade well, and are harder to recycle, marketed as a green initiative. LDPE melted and mixed with paraffin wax actually makes a very interesting machinable wax for lost-wax casting.

    PLA is not easily water soluble though. (They fume smooth it with tetrahydrofuran, water would be much easier) I think you are thinking of PVA as the support material.



  • @pierre My understanding is that ABS shrinks more than PLA, and this is what causes the size differences when printing the same STL file using the different filaments. I believe PLA shrinks by about 0.1-0.2% where ABS is 0.4-0.8% This is also part of why ABS warps more than PLA.

    @Grant-Fraser I think you’re confusing PVA with PLA. PVA (which is essentially white glue) can be washed away. PLA, is definitely not going to wash away.


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