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Joined 2 years ago
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Cake day: June 3rd, 2023

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  • The caveats you express are somewhat valid, but not totally correct. Printing correctly, with a food safe nozzle, path, and PLA formulation, is entirely possible. Simply printing in single layers, with a properly dialed in printer can eliminate your concerns. Medical items and implants are printed out of PLA, albeit with extreme production controls.

    However, printing these single use items would be absolutely un-economical. 3D printing shines in short runs, bespoke items, like replacement part that are out of production, or which are very difficult to manufacture by other methods like injection or machining.

    Its true that PLA, in unmodified form, has a much higher modulus than PP or PE, so squishiness is out of the question. What I have mentioned before is that I have bought single serve olive oil in PLA containers. From what I could see, these were injection molded and had a film top made from a plastic I never bothered to identify.

    These containers were surprisingly elastic when crushed, not as elastic as other plastics, like PET, PP or PE, but much more than I had come to expect from my experience with the material. I’m going to attribute this to molding vs. extruding.


  • I never said that these should be produced via 3D printing, it would be both economically unfeasible, and very difficult to achieve food safety, as I have mentioned.

    The process you are describing is injection molding, generally used for solid parts. In this case, a variation called blown injection molding, is used. In this case the material is injected into a mold, and then a gas is blown into the interior, to make the material stick to the inner mold, and create a cavity. Nozzles are involved, as they are used to inject the material into the mold. These nozzles can be made specifically to be food safe, with stainless steel, for example.








  • Sure, but PLA will eventually biodegrade, unlike things like polypropilene or polyethylene, which are incredibly useful precisely because of their imperviousness.

    EDIT: I’m willing to bet that PLA IS biodegradable in home settings if the correct method is used, like the Berkeley method, which produces much higher heat than “heap” methods. The Berkley method can produce compost in under a month, via endothermic processes that generate relatively high heat. All you need at home are the compostable materials, and a roughly 1m cube, which can be made out of pallets, for example.





  • A Spanish company (I imagine there are a few worldwide) develops compostable bioplastic containers using PLA, polylactic acid, the most used plastic in 3D printing, in food safe formulations. I suppose there are limitations on what it can contain, and I don’t know if soy sauce is compatible. I know that it’s used for single serving olive oil, for example. There are challenges, like storage life, but it’s a good start.

    I do a lot of 3D printing. Printing PLA things for food storage is not recommended, not because of PLA, but because filaments often have modifiers to enhance certain properties that may not be food safe, and because contact with materials and parts, like extrusion nozzles may add impurities that are probably not food safe…