[MjWhit]

I'm just learning about 3d printing and I was wondering what is the purpose of a heated bed?
Is it to keep the material at a workable temperature or is it to facilitate removing the part after it's complete.

[hoss2006]

Plastics, especially ABS won't stick well to a cold bed. A warm bed also helps prevent curling up at the edges as the print goes along.
ABS is notorious for this. PLA doesn't need much heat, I only heat my bed to 40C but ABS needs a good 90C or more.
You'd want the bed and part cooled down before removing the part.
Hoss

[MjWhit]

Thanks for the info.

[skip20]

Hoss is the MAN!

[Khalid]

I know he is not WOMAN at least

[MjWhit]

Just a follow up question.
Does the heat propagate up through the part and help in the layering?
Or is it primarily for the first few layers?

[Fastest1]

As Hoss said, it is mostly for adhesion and to minimize or eliminate warping. Some people turn it (the bed heater) off after they are into the print. I see no reason to, but to each his own. It doesnt help layering however if the part starts to curl or warp the extruder nozzle will drag thru the part. the dragging of the nozzle will either amke the part release prematurely or create a groove in the part.

[johnstevenjacob]

The purpose of heated print bed is primarily for the first layer to make the filament stick to the bed well when printing and prevent from warping. You have to lower the heat for the next layer to prevent the object from shrinking because overheated bed. That’s what I learned from printing 3d2print filament materials.