3d printing with Polylactic acid, adhesion to print bed

[rcq090]

I recently built a 3d printer that extrudes PLA or Polylactic acid for the material. When printing on a glass bed the pla drags behind the extruder because it won't stick to the glass. On the other hand printing on a sheet of acrylic the PLA sticks so well that it is difficult to remove after the print is done. Why is it that the PLA sticks better acrylic than glass even though they look the same?

 

[Lok]

Materials are usually attracted to other materials with similar properties. Glass is ionic in nature so it will usually attract polar or other ionic materials. PLA and PMMA have quite similar functional groups and will probably (not a chemist) attract each other.

Yet this is not necessarily the problem here. The PLA and acrylate you have might have similar melting points which means when you print the PLA welds to the PMMA. And that is a totally different bond.

 

[M528morgan]

You have to experiment a little in order to find which method is working the best for you. Do nothing, just print. You can try printing on top of 3M blue painters tape (blue color seems to be better than the other colors available). Just a tip, avoid overlaps of tape.
You can also try to print on top of Kapton tape or use some Hairspray (extra strong versions recommended) on the print platform; this one works well with my http://www.3d2print.net/shop/product/pla-traffic-red/

 

[gfd43tg]

Something we did at my lab to alleviate that problem was like the user above me posted regarding blue painters tape, but also we would use a glue stick and rub it on the base

 

[Danger]

Have you tried switching to a steel bed?

 

[mesa]

That is super cool that you built a printer to handle PLA, how is progress coming along?