Sand molding is the "must step" in various metal castings for foundry products, however conventional molding methods require patterns, physical toolings etc. that are expensive, time consuming and labor intensified, especially much frustrated in molding design at time of facing complex geometric, hollow and multiple angles objects.The Innovative Industrial 3D Printings is to transform any CAD designs in complex digital package to solid objects realized by our AMSKY 3D printers, which accumulate material layers one by one, eg. silica sand, starting from the bottom of printer job box while each time printhead "scans" over the sand bed, the binder is saturated and deposited into the material as one thin layer. The timing and location of binder jetting are strictly directed by the integrated computer that has digital 3D geometric designed patterns stored. Once each layer as thin as 0.15-0.3 mm is printed, the job box is lowered to match the synchronization pattern in the computer, alongside with the continuous feeding of the material into the job box until sandbox is full, in order to get the sand molds/cores whchi are always buried at the very right top surface position. The repetitions of hundred and/or thousand times of such monitored movements shall eventually pile (print) layers to a solid sand mold desired.

Such Binder Jetting Technology is widely adopted in 3D printing process where no heating, no sintering and no coating are involved in, binder can be easily understood if it is literally described as "glue" to solidate the material layer by layer until the printing process properly accomplished.