3D printers start to build factories of the future

August 27, 2017

#3Dprinters…factories of the future
https://www.Economist.com/news/briefing/21724368-recent-advances-make-3d-printing-powerful-competitor-conventional-mass-production-3d digital light synthesis, a software-controlled chem rxn, now economic viable


“Carbon’s printer uses a process called digital light synthesis, which Dr DeSimone describes as “a software-controlled chemical reaction to grow parts”. It starts with a pool of liquid polymer held in a shallow container that has a transparent base. An ultraviolet image of the first layer of the object to be made is projected through the base. This cures (ie, solidifies) a corresponding volume of the polymer, reproducing the image in perfect detail. That now-solid layer attaches itself to the bottom of a tool lowered into the pool from above. The container’s base itself is permeable to oxygen, a substance that inhibits curing. This stops the layer of cured polymer sticking to the base as well, and thus permits the tool to lift that layer slightly. The process is then repeated with a second layer being added to the first from below. And so on. As the desired shape is completed, the tool lifts it out of the container. It is then baked in an oven to strengthen it.

Dr DeSimone says that digital light synthesis overcomes two common problems of 3D printing. First, it is up to 100 times faster than existing polymer-based printers. Second, the baking process knits the layers together more effectively, making for a stronger product and also one that has smooth surfaces, which reduces the need for additional processing.”