How Warping Occurs in 3D Printing and What You Can Do About It

If you’re involved in 3D printing, you’ve probably encountered other challenges besides ghosting and stringing. Especially if you are using an FDM 3D printer, you may have encountered warping. Warping is an upward curvature in the additively manufactured object that occurs primarily in the first layers that adhere to the print bed. Here, the curvature of the individual layers can be so strong that even during the printing process, the upwardly curving part of the model detaches from the print bed and thus the entire 3D printing process fails. But why does this unpleasant phenomenon occur during 3D printing and how could this be prevented for your future printing? We took a closer look!

To first answer the question of ‘why’, warping is at its heart connected to temperature. As such, it can happen on any part but especially those made with high temperature materials. Extremely large or long parts made with said materials may also be particularly at risk due to the fact that temperature control may be more difficult. This is due to the fact that the plastic used tends to shrink after cooling. If, for example, you use ABS at a printing temperature of more than 200 °C and then let it cool down to a usual room temperature, you can expect a reduction of almost 1.5 % – or even more, depending on the size of the part! And since the curvature effect starts with the first layers, it will continue throughout the entire printing process until the part is finally almost completely deformed.

Photo Credits: Two Trees

Physically explained, when the material is heated, thermoplastics become liquid, but at the same time they expand. When they subsequently cool down again (to room temperature, for example), they also contract again, which means that movement occurs. And it is precisely during this movement in the already extruded plastic that the reason for warping during 3D printing is to be found! The already cooler layer contracts and at the same time takes the still heated layers with it, which in the end results in the material warping.