What are the causes and preventive measures for model warping during FDM 3D printing?
Release Time : 2025-04-10
In fdm 3d printing, model warping and deformation are mainly caused by the thermal expansion and contraction characteristics of the material. When the plastic is extruded from the high-temperature nozzle and cooled, the internal stress generated by the volume shrinkage will cause the edges or corners to warp upward. In particular, high-melting-point materials such as ABS are more prone to warping due to their large shrinkage rate. In addition, factors such as uneven temperature of the printing platform, insufficient adhesion of the first layer, and ambient temperature fluctuations will also aggravate deformation. For example, if the temperature difference between the first layer and the platform is too large, the material will cool too quickly, resulting in poor adhesion, which will in turn cause warping.
Fdm 3d printing Selecting materials with low shrinkage is the key to reducing warping. For example, PLA materials are often the first choice for anti-warping due to their low shrinkage rate and strong adhesion. If ABS must be used, the hot bed temperature must be controlled between 100℃-110℃ to slow down the cooling rate of the material. Experiments show that when the hot bed temperature is insufficient, the warpage rate of ABS can be as high as 30%, and after appropriate heating, the warpage rate can be reduced to less than 10%.
The quality of the first layer print directly affects the stability of the model. It is recommended to set the first layer height to 0.2mm-0.3mm and increase the extrusion volume by 10%-20% to enhance adhesion. At the same time, ensure that the platform level error is less than 0.1mm to avoid uneven local pressure due to height difference. If the platform is uneven, the model may warp due to uneven force when cooling.
Ambient temperature fluctuations will aggravate material shrinkage. It is recommended to place the printer in a confined space or use a heat preservation cover to maintain temperature stability. Experimental data shows that in a constant temperature environment of 25℃, the model warpage rate is 40% lower than that in an open environment. In addition, when printing large models, the first layer cooling fan can be turned off and turned on after the material is initially solidified to avoid stress concentration caused by rapid cooling.
The risk of warping can be reduced through design improvements. For example, add "mouse ears" (circular protrusions) or skirts to the bottom of the model to increase the contact area; or design chamfers at key locations to disperse stress. Tests show that after adding skirts, the warpage height of the model edge can be reduced from 2mm to less than 0.5mm.
Applying PVP glue, masking paper or high-temperature tape on the printing platform can significantly improve the adhesion of the material. For example, PVP glue can increase the adhesion of the first layer of PLA by more than 50%. However, it should be noted that glue residue may affect subsequent printing. It is recommended to use washable glue or clean the platform regularly.
Adjusting the printing parameters through the slicing software can prevent warping. For example, reduce the first layer printing speed to 20mm/s-30mm/s to ensure that the material is fully extruded; or enable the "Raft" support structure to generate a larger contact surface at the bottom of the model. In addition, appropriately increasing the filling density (such as 20%-30%) can enhance the rigidity of the model and reduce deformation.
The warping problem in fdm 3d printing needs to be solved comprehensively from multiple dimensions such as materials, equipment, environment and design. By reasonably selecting materials, optimizing printing parameters, improving environmental conditions and improving model structure, the warping rate can be significantly reduced and the printing success rate can be improved.
