PCM (Patternless Casting Manufacturing) was developed by the Laser Rapid Prototyping Center of Qinghua University. This applies rapid prototyping technology to the traditional resin sand casting process. First, the cast CAD model is obtained from the CAD model of the part. The STL file of the mold CAD model is layered to obtain the profile information of the section, and then the control information is generated by the layer information.
In the modeling, the first nozzle is precisely controlled by a computer to spray the adhesive on each layer of the paved sand, and the second nozzle sprays the catalyst along the same path, and the two are glued together to form a layer of solidified sand. Stacking and forming. The local sand in which the binder and the catalyst work together is solidified together, and the sand in other places is still in a particulate state. After curing one layer, the next layer is bonded, and after all the layers are bonded, a space entity is obtained. The raw sand is still dry sand where the adhesive is not sprayed, and it is easier to remove. By cleaning out the intermediate uncured dry sand, a mold with a certain wall thickness can be obtained, which can be used for casting metal after the inner surface of the sand type is coated or impregnated.
Compared with traditional mold manufacturing technology, the moldless mold manufacturing technology has unparalleled superiority. It not only makes the casting process highly automated and agile, reduces the labor intensity of workers, but also breaks through many obstacles in traditional technology. , the design and manufacturing constraints are greatly reduced. The specific performance is as follows: short manufacturing time, low manufacturing cost, no need for wood mold, integrated molding, simultaneous molding of the core and core, no drafting angle, and a mold with a free curved surface (curve). At home and abroad, there are other similar processes that introduce RP technology into sand or ceramic casting. Typical examples include the 3DP (Three Dimensional Printing) process developed by MIT and the sand manufacturing process of Generis of Germany.