Two-dimensional inkjet technology has made great progress in colorful plane printing. However, color printing technology for three-dimensional model is currently only at the exploratory stage; there are few reports on this issue. In this article, a free-form surface-oriented five-axis single-point printing technology with exclusive color nozzle is proposed. The single-point color nozzle consists of four print heads: prints cyan, magenta, yellow, and black pigment. For high-efficiency color printing, each print head prints on the same single point when the color nozzle moves along the surface. The method of color printing along the surface normal direction is proposed as normal direction printing mode. The algorithm of print point generation is introduced, and the path planning method of self-adaptive slicing and self-adaptive printing filling is proposed. In addition, a five-axis single-point printing platform is designed. Experiments are done to demonstrate the feasibility of the printing system.

Great progress has been made in 2D color printing with inkjet technology, and mature related products have come out, but there still exists great developmental space in 3D color printing. Therefore, a new path planning method based on the offset curve for 3D inkjet technology is proposed in this paper. Offset curves are generated on a freeform surface with geodesic equidistance, and then points for color printing are generated along the offset curves. In this paper, the principle of color printing technology with a 5-axis platform and the offset curve path planning (OCPP) method are presented. In addition, comparisons between the OCPP and adaptive filling algorithm based on the section method (AFSM) have been implemented. The OCPP significantly increased the rate of the theoretical filling area from 0.89 to 0.99 on a freeform surface.