/diy/ - Do It Yourself

>>2735897
https://lt728843.wixsite.com/maskrelief/post/the-final-say-in-food-safe-3d-printing

>Brass is food safe, lead additive in it isn't.
The amount of lead in a brass nozzle is about 1.5% for a standard 3 gram, 0.4mm nozzle.

1.5% of 3 grams is 0.045 grams of lead. Now, 21% (0.63 grams) of a 3 gram standard 0.4mm nozzle is removed for the filament to flow into. This also means that 21% of the 0.045 grams of lead were removed as well, leaving a total number of 0.035 grams of lead remaining in the TOTAL nozzle. This means even less is in contact with the filament as it passes through. The filament is only in contact with 21% of the TOTAL amount of lead, which means a total possible contact with 0.007 grams of lead.

Masses of new nozzles compared to used nozzles (1000 hours of use) show that either no mass was lost due to printing, or the amount lost due to friction was so small, that the scale did not pick it up, meaning, such an extremely small amount of lead had been friction rubbed onto the thousands of meters of filament over 1000 hours of use.

There is more lead in your tap water than a 3d printed part.

>an additional chapter about bacteria playground due to the inherit structure produced by FDM
I took my NIH approved 3D printed 2- part mask I have been wearing for 16 months, in which I have purposely not sanitized it for 3 months. I swabbed it, then prepared the dish, and incubated it for 7 days of growth.

I then separated the mask into its two counter parts, washed (no scrubbing with a brush) one with soapy water (120F). Before washing I made sure that the swab contained contamination from both parts of the mask, not just one.

You can see that there has been roughly a 90% reduction in bacteria, this is good. This keeps it below the ID (infectious dose) number. The ID number is specific to the bacteria being tested. IE, a certain amount of salmonella will not make you sick, but if you go past that number, chances are, you will get ill.