Prediction model and compensation method for curing shrinkage of inkjet 3D printing parts

Abstract

Inkjet 3D printing has huge potential for applications in electronics printing, ceramic printing, and other fields, primarily due to the excellent dimensional accuracy of printed products, which is particularly important for device performance. However, in inkjet 3D printing, the fusion and solidification of droplets can cause the samples to shrink in various directions, resulting in a deviation from the designed target size, and subsequently affecting the performance of the part. In this study, the curing shrinkage behavior of parts in inkjet 3D printing is examined. First, a shrinkage model of the droplet element is established using the finite element method in accordance with the material parameters, and the linear shrinkage rates of different droplet groups are obtained. A curing shrinkage prediction model of the printed parts is then established, and the size and shape of the cured parts are predicted accordingly. A height calculation model of the printed parts is established according to the concept of volume conservation, and the height prediction of the printed parts is realized according to the number of printed layers and their resolution. An approach for compensation of the print model graphic layers is developed using the established prediction model. Experiments using two printing materials with different degrees of shrinkage are conducted to verify the feasibility of this method. The results indicate that the proposed curing shrinkage prediction model can seamlessly capture the curing shrinkage behavior of printed parts for materials with different shrinkages. Furthermore, after shrinkage, the model-based print compensation method achieves the measured sizes that are closer to the target size than that without compensation. The dimensions of inkjet 3D printed parts can be accurately controlled using this method.