A heat bed is an additional module for a 3D printer that makes the cooling process of 3D-printed materials more controlled, for better results.
Heat beds prevent issues like poor adhesion to the print bed, poor adhesion between layers, thermal runaway and warping. The result of using a heat bed can be greater precision and less waste, due to the prevention of early or uneven cooling. The use of heat beds helps ensure ideal conditions for best printing results, especially where local conditions are less controlled or colder. Heat beds are a requirement for working with some materials such as ABS plastic.
Often heat beds are at least partially user-made additions even when used on consumer 3D printers, although some units have the feature built in. Heat beds can be made from printed circuit board (PCB) heater designs with heat spreaders made of aluminum or silicon. Heat is regulated by a thermistor to a target temperature, generally about 70 degrees. A power level of .04-.07 watt/cm is required with higher heat making the startup process quicker by faster heating. The power requirements can be calculated based on the size of the print bed.
Heat beds lay on the surface upon which the printer head prints its media. To make removal of parts easier, the heat spreading surface is often covered in either painter's tape or Kapton tape. Heat beds are generally insulated from melting the plastic parts of the printer bed they reside with cotton or wool, often over a wood layer.