What is the purpose of using a heated bed in 3D printing?

Using a heated bed in 3D printing primarily serves to prevent uneven thermal expansion during the printing process. When a 3D print starts, materials can cool and contract at different rates, especially if the bed temperature is not controlled. This can lead to warping or curling of the printed object as it cools, which affects adhesion to the print bed and ultimately the quality of the final product.

A heated bed helps maintain a consistent and elevated temperature for the first layers of the print, ensuring that the material stays pliable and securely bonded to the surface. This ensures better adhesion and minimizes the risks of thermal stress that can lead to misalignment or defects in the print. Additionally, maintaining an optimal temperature can also result in improved layer bonding, contributing to a stronger and more accurate final object.