A heated build platform, also known as a heated bed, on a 3D printer is where the part is printed out, layer by layer. By having the build platform heated, there will be less warping and curling of the plastic by evenly distributing the cooling process for a part.
How Heated Build Platforms in 3D Printers Work
ABS and PLA plastic can sometimes shrink and curl up at the edges as the part cools. This causes a problem as more layers are added, which causes the part to warp. To solve this problem, heated build platforms are used to keeps the bottom layers of the part warm as layers are added, which helps the part to cool evenly. The heated bed is insulated so that the parts do not soften or melt. Heated bed material includes glass, metal, or ceramic. Heated build platforms should be about 120º Celsius for ABS plastic and 55º Celsius for PLA plastic.