Large Printer and Plastic Recycling
We are planning to run a $100k reward campaign on HeroX next year. We switched from cordless drill to large, high T printer with 4x4x8' build area, vertically. This is to address real needs, namely related to housing. The large printer would include filament making infrastructure for producing filament. We are not doing a pellet printer, since we want to work with filament printing for leveraging the existing base of fused filament printers. Given the 20 lb/day limits of Supervolcano style printheads, we don't see an issue with throughput. We also plan on doing a 4-headed version, so we have 80 lb/day print capacity with a single printer. There is the extra step of making filament, but at our documented electricity cost of 1 cent/kg to do this (https://docs.google.com/presentation/d/1M9p8GeZDAs0EJgMdgtnzObiqp-38ZpG-YwhImb645nw/edit#slide=id.g920dac51f5_0_0), energy inputs are not an issue either.
Is it true that pellet-based printing still needs some development to be available in the open source? That is why we want to go with the filament route at this time.
In any case - I wanted to ask if you see any limits to using FFF to make PVC-ABS-polyolefin blends for 3D printing of large objects. This would allow for absorbing all the waste plastic from typical consumer waste streams and turning them into bulk printing filament for construction applications.
What do you see as the major blocks to taking PVC/ABS/polyolefin wastestreams and blending them for bulk construction printing? Or would you suggest something else? I know people are talking about PET as a good candidate for recycling - but there is much more PVC available. There are of course the outgassing safety issues to consider. (nice work on the coatings for outgassing paper, btw).
$100k reward is really impressive!!
The high T 4x4x8' printer is going to be a large challenge I think for most makers vs the drill. We have a 4x4x8' printer - but it still isnt particularly smooth. To go to high T -- you need to enclose, go all metal hot end, and extra heater.. like we did with the small system https://www.appropedia.org/Open_Source_High-Temperature_Reprap_for_3-D_Printing_Heat-Sterilizable_PPE_and_Other_Applications...but you need it for the large one....large power requirements big machine! Very much in OSE's wheel house.
I don't think the filament step is necessary - but it would lead to better quality (as of now) - the re:3D gigabot x is marketed as open source and is 1m3 that prints directly from pellets and shards - but the quality goes a lot to the flow of the particles. We have also done it on the small scale and it seems to work but it is challenging. https://www.appropedia.org/Mechanical_Properties_of_Direct_Waste_Printing_of_Polylactic_Acid_with_Universal_Pellets_Extruder:_Comparison_to_Fused_Filament_Fabrication_on_Open-Source_Desktop_Three-Dimensional_Printers
There is already available PVC filament and pellets - https://www.chemson.com/en/loesungen/3d-filament/
I don't think there are any major road blocks - just sweat equity to get the processes worked out. Probably will need ventilation capture of emissions. We need better feedback for filament making (we are working on it now with open CV - should push out soon; and real time monitoring of printing - we are also all over that and getting very close), we made a shredder - that I think OSE could improve - maybe scale down a bit in cost - https://www.appropedia.org/Open_Source_Waste_Plastic_Granulator
We have been working our tail ends of on the PET -- but that is a real pain - demands drying and keeping out of humidity....PVC is promising - it would just be the fumes. The other area worth exploring is the composites opportunities - we have been looking a lot at stamp sand+waste plastic -- sadly makes it worse but does allow for getting rid of two waste streams at the same time - https://www.appropedia.org/Potential_of_distributed_recycling_from_hybrid_manufacturing_of_3-D_printing_and_injection_molding_of_stamp_sand_and_acrylonitrile_styrene_acrylate_waste_composite
It would be nice if we could go up the food chain instead of down it through....