3D printing can duplicate a monochrome dimensional “you” in any proportion, but a novel technology can improve the “color texture” of “you”, even the dyed color of your hair. The research team, led by Prof. ZHOU Kun of the State Key Lab of CAD & CG, Zhejiang University, worked in collaboration with researchers from Columbia University to develop a technique that enables hydrographic printing, a widely used industrial method for transferring color inks on a thin film to the surface of manufactured 3D objects, to color these surfaces with the most precise alignment ever attained.
3D printing is perceived as a potent driving force for the Industry 4.0 Revolution. Although enormous advances have been achieved in recent years, there remains to be a formidable barrier to printing full-color 3D objects with elaborate patterns and customized features. Some 3D printers can produce color printing, but they are stunningly costly and extremely slow. Moreover, this type of 3D color printing is confined to very few materials, such as plastics and plaster. “We hope that we can break through this bottleneck in 3D printing by means of a computational model,” said Prof. ZHOU Kun.
Used in mass production for transferring repeated color patterns to a 3D surface, hydrographic printing can be applied to various materials, including metal, plastic, wood, porcelain, and rubber. The process uses a PVA film with printed color patterns placed on top of water. An activator chemical is then sprayed on the film, softening the color film to make it easily stretchable.
A core scientific issue is to reduce a 3D design to a 2D stretched pattern. Researchers from ZJU and Columbiapioneer in modeling the color film stretch during the hydrographic printing process. This model predicts the stretch and distortion of color films and creates a map between the locations on the film and the surface locations to which they are transferred. With the map, it can compute a color image for printing on the PVA film and then, after the hydrographic immersion, it forms the desired color pattern on the object’s surface.
With the incorporation of this simulation model, researchers are able to compute a color image to feed into their hydrographic system for precise texture registration. To avoid severe film distortion and the danger of the film tearing, they introduce a multi-immersion design: the object can be dipped multiple times, each with a different orientation and a film printed with a different color pattern. The computation of color patterns allows the transferred colors from individual immersions to be combined into the desired “final” surface decoration.
This research will be presented at ACM SIGGRAPH 2015, August 9 to 13, in Los Angeles.
As soon as a video about this research got uploaded at Youtube, this research has riveted the attention of various media, including Wired and Science Daily. In a single month, the video had 500,000 hits. Meanwhile, this technology has inspired many world-renowned enterprises to seek partnership with researchers, for they have spotted an enormous potential for this personalized and customized 3D printing technology.
“This represents an intimate fusion of informatization and industrialization and it is a prime example of smart manufacturing,” said ZHOU Kun, “The starting point of this discovery is to tackle the “color” problem in 3D printing, but in actual fact, its application goes far beyond 3D printing and it can be applied to any 3D object. In a deeper sense, this technology is, in essence, concerned about how to project a point on the surface of a 3D digital model onto a point on the surface of its corresponding physical object with pinpoint accuracy. The interaction between the virtual world and the real world opens up a greater scope for future technological development.”