3D Printing Milk (5/17/2017)

Have you ever had the thought that your life was missing something, just for the person sitting behind you in class to mention “milk plastic” as an idea for the science fair? Yeah, I know, probably not., it isn’t exactly a very common situation. Either way, That’s pretty much what happened to me.

I hadn’t ever heard of “milk plastic” before, and so, armed with way too much confidence and an old Printrbot 1405 I had already modified so many times, I got to work. I went through an abbreviated research phase, learned that the “plastic” was actually casein molecules that unfolded and formed chains when heated and exposed to acid, and that seemed like enough.

My first attempts were to take casein, wash it, and roll it out onto baking sheets to let it dry. After it dried, I broke it up into small crystals, and tried to extrude it into filament through a filastruder I had. This didn’t really work, so I had to rethink my strategy a bit.

My second idea was to pump the not-yet-dried casein into a standard hotend. I designed and printed my own pump using a large syringe and a stepper motor. This actually almost worked, but there was too much pressure and the pump broke. After re-printing the broken parts, I decided it would be easier to just see if it worked to tie a tube to the hotend and pump the casein through that, which yielded better results. I determined that it would in fact be possible to do this if the casein had just the right consistency, and then was baked after printing to solidify it.

I ultimately ran out of time to finish this before the science fair, but I think that this could actually work if I gave it another try.