Automatic fabrication for bridged laminated object manufacturing (LOM) process

Laminated object manufacturing (LOM) is one of the most popular rapid prototyping (RP) techniques in terms of speed and cost effectiveness. Despite the advantages of the LOM process, some problems are yet to be overcome. One of the major difficulties encountered in the current LOM practice is the metallic part cannot be fabricated. Focusing on the drawback inhered in LOM, a new Bridge-LOM process and its associated building algorithm are proposed in this paper. The process starts with the construction of the bridge structures to link a stack of 2D geometry contours to the outer frame based on the proposed bridge building algorithm. Afterwards, laser is directed to cut along the contours, and then the upper pressing head is pushed down and the layers are bonded. Spraying adhesive on the top of bonded layers follows this. The procedures of cutting, bonding and adhesive spraying are repeated until the complete part is produced. The proposed Bridge-LOM process has overcome two problems, support and position. Regarding the function of position, in order to ensure the proper bonding treatment, as well as holding a precise position between layers, the processes from cutting to bonding in the process should maintain the same X–Y position. Therefore, worries of not having a fixed positioning would then be eliminated. Regarding the function of support, bridge has taken the place of the supporting function of waste material in the current LOM process. The metallic part can be built directly based on the efficiency of on-line waste material removal in the process. From the experiments, it is verified that the proposed Bridge-LOM process and its associated building algorithm not only save laser-cutting time, the time on waste material removal is also reduced significantly. Furthermore, the metallic part and mold can be fabricated and their performances are investigated.