Offer food safe plastic like PA, PP oder PMMA

Discussion in 'Suggestions & Feedback' started by zynic, Feb 9, 2014.

  1. zynic
    zynic New Member
    Why don't you offer one of the materials mentioned above? It would give the designers so many possibilities, like making furniture for cages of rats, hamsters etc.
    Also designing salat bowls and other stuff would be possible.
  2. AmLachDesigns
    AmLachDesigns Well-Known Member
    wsf is PA - it is not food safe because it is sintered, creating a porous solid.
  3. stannum
    stannum Well-Known Member
    Some PAs "are" food safe. The 2201 is "bio compatible according to EN ISO 10993-1 and USP/level VI/121 °C" and "approved for food contact in compliance with the EU Plastics Directive 2002/72/EC (exception: high alcoholic foodstuff)" if the processing is done to meet those rules.
  4. wedge
    wedge New Member
    like AmLachDesigns told.
    The problem is not the Material. WSF is non toxic. The Problem is the Printing.
    The Printing crates a porous which can not be easy cleaned. So it5 is in a industrial context not food save because you can not clean the material. But the porous is part part of the Printing process.
  5. stannum
    stannum Well-Known Member
    So PA2201 magically becames non porous?
  6. FreeRangeBrain
    FreeRangeBrain New Member
    That's like saying that because knives are made of steel, and my car's fender is made of steel, my car's fender must be sharp.
    A porous surface is not a food-safe surface, regardless of the material it's made of.
  7. stannum
    stannum Well-Known Member
    We are talking about the same process in the same machines, just loaded with different dust. Passing or failing the certications seems to be linked to the existance or lack of whitening, and probably cleaning of the premises. EOS doesn't declare anything about porosity factors or extra processing. 2200 (WSF at SW, white polyamide) is US Pharmacopeia Class VI Approved and 2201 (natural polyamide) Food approval FDA 21 CFR. So there is a way to get usable parts out of the printers, just Shapeways doesn't offer that.
  8. AmLachDesigns
    AmLachDesigns Well-Known Member
    This is quite an interesting debate.

    I agree (with Stannum) that the EOS website and data sheets certainly seem to indicate that PA2201 is food safe (with certain, noted, exceptions). And since they make equipment for sintering this material we might infer that a sintered product made of PA2201 is also food safe.

    However, I do not believe that this can be the case. To me a sintered product, no matter what it is made of is not food safe for normal situations (i.e. at home). Such a structure will never be capable of being physically cleaned, and unless you can autoclave this stuff for a decent time, it will not be possible to kill all bacteria.

    So I believe that the PA2201 material is food safe, but I do not believe that a model made of it would be food safe.

    Which is all moot, since SW offer only PA2200.
  9. stannum
    stannum Well-Known Member
    You should read the info provided for HP3 by EOS. The plot thickness. ^_^

    Or visit they Medical section, they got a handful of examples, plastic & metal.

    But the point still holds, "if the processing is done to meet those rules", 2200 is USP class VI but SW doesn't offer whatever makes the material fit for those uses.

    And that is the interesting part of the debate, it could mean SW would need separate machines and extra support machines, in separate workshop, get certifications & staff, etc.
  10. Youknowwho4eva
    Youknowwho4eva Shapeways Employee Community Team
    It's all in the process. The reason Ceramics is certified food safe has nothing to do with the printing. It's all to do with the glazing which is a certified process. To get WSF certified for example, we'd have to provide a process for producing parts in a manner that is consistently food safe. Have you ever ordered a hollow WSF model? Then I'm sure you've received loose powder. The material may be safe to eat off of, but I doubt it's safe to consume. So either the design rules would have to change to get the process certified, or our process would have to change to be more labor intensive. Either way would make it cost more, and even some models would no longer be able to be produced. Or we'd have to create a new "material" that would cost more, have rules closer to that of ceramic, and we'd have to go through the certification process. And still in the end, the product from these machines are porous, and would quickly stain and more than likely be great at growing bacteria.
  11. FreeRangeBrain
    FreeRangeBrain New Member
    That's the crux of the matter. Ceramics probably aren't safe to consume, though more due to mechanics than chemistry, I'd say. Porosity is the big problem here. No wood will be found in commercial or industrial food processing facilities for the same reason - no guarantee of killing all the bacteria in the texture of the surface.