Better living through chemistry is a phrase that could be applied to the company Carbon. The founders’ goal is to make real final parts through a form of digital light processing. Parts so good, they rival conventional injection molded parts. Joe DeSimone, Co-founder and CEO, wants to deliver an alternative technology to injection molding through the additive process often known as 3D printing (3DP). Although DeSimone uses the term “grow” rather than 3D print.
Meeting several executives of the company at the recent AMUG Conference, it’s clear that these are smart and experienced people with doctorates aplenty and work experience in many tech companies, including Apple.
Build speed is a key differentiator of Carbon’s technology from other additive technologies. In typical UV stereolithography approaches, a build tray dips into a vat of photo-reactive resin where a UV light cures that one layer. Then the tray dips into the resin again and another layer is cured onto the previous layer, and so on. DeSimone figured out how to eliminate the dips, shaving a lot of build time off the entire process. Depending on the part, the speed improvement is 100 fold or more.
The ability to skip the dips is the molecular science part of Carbon’s process. The printer injects oxygen at a key point in the build, which inhibits the resin from curing too quickly. This curing delay delivers parts with very smooth features, on par with injection molding. Plus, without layers, the risk of fractures along the build layers is reduced or eliminated entirely, so parts are inherently stronger than those built through other 3DP processes. The controlled curing, part of the Continuous Liquid Interface Production (CLIP) process, also makes it seem as if the part is “growing” out of the printer. As with any additive process, you can make any geometry you like.
This oxygen injection process is controlled through software, which is another key part of Carbon’s development. The oxygen is injected into a hardware part called the Window, located at the bottom of the build interface.
The software monitors and manages this build zone where light, oxygen and other factors are tracked. The software calculates all the parameters needed to ensure a proper build.
All of Carbon printers are internet connected. This approach is an interesting use of the Internet of Things concept. Users can combine Carbon resins in many ways; the data from such a build goes back to Carbon, where they are added to the software database and updated code generated as needed. In this way, users are partners of Carbon, helping to explore and expand this additive process.
Post processing involves a solvent wash to eliminate residual resin or some supports. The next step is the part is baked to install specific mechanical properties. The resultant parts can be machined and cut. Some material combinations will behave like real rubbers.
One of the goals for Carbon is to move 3D printing closer to an on-demand manufacturing process.