Spatial 3D Printing of Plastic for Space Frame Structure
Spatial Curves project, to maximize the possibility of the fabrication of lightweight Space Frame structures, through 3D printing that uses lightweight composites, which are plastics, proposed an integrated structure fabrication method. Previous 3D printing methods which are universally used, make contours based on the z layer by divide the structure into layers, and by treating each layer as a 2D shape, and uses the method of stacking the layers on top of each other. Using high heat, the melted plastic is extruded through the nozzle of the extruder, and the layers are stacked one on top of the other. In the previous method, the diameter of the nozzle was small (0.1~0.5mm), which required a large amount of melted plastic was required, resulting in high operation costs and a slow printing speed, which is not appropriate for the fabricating of architectural structures.
CurVoxels has developed customised 3D spatial printing extruders which can extude 4~6mm diameter thickness. The industrial robot drags extruded plastic from the exturder in the air where it is cooled down. The whole chair consists of a single, continuous and seamless line.
Curvoxels has also experimented the extruder design which can print with different thickness. Three nozzles are focused on one point, and are able to be controlled separately, resulting in different print diameters. In zones of high stress, thicker lines can be extruded within one singular tool-path.
Through the use of a 3D Printing Tool that uses 3 different size diameters, in addition to contributing to structural reinforcement, by applying different materials to each of the Nozzles, it was possible to apply different material characteristics. Three nozzles are focused on one point, and are able to be controlled separately, resulting in different print diameters. In zones of high stress, thicker lines can be extruded within one singular tool-path. by improving the previous single material characteristic to be used with other material characteristics, Curvilinear Space Frame Printing with different densities was made to possible. Because there was the additional problem of hardness that needed to be solved due to the pliable properties of plastic, in addition to structural optimization using Octree mentioned previously, plastic extruding of various diameters, which is a new fabrication model, was proposed. This is significant in that it uses computational structure analysis to assign different densities to the internal structure to optimize the structure.