Carbon Dives into Ultra-Fast CLIP 3D Printing

With a stunning reveal during a TED Talk last year, Carbon quickly became the apple of the 3D printing industry's eye. While comparisons to Terminator 2 caught the mainstream media's attention, the speed and capabilities of Carbon's continuous liquid interface production (CLIP) 3D printing process suddenly revealed to mainstream manufacturers the possibility of 3D printing industrial grade parts in an instant.

The technology was further validated when one of the world’s largest manufacturers, GE, along with Nikon, JSR and BMW, provided Carbon with a whopping $81.1-million investment. To learn more about why this technology is worthy of such a large investment and what that money will be used for, ENGINEERING.com spoke with Kirk Phelps, VP of product management for Carbon.

What Is CLIP?

CLIP is a form of digital light processing (DLP) 3D printing, in that it relies on a projector to cast UV light onto a vat of photopolymer resin, hardening the resin until a complete 3D object is formed. It differs from conventional DLP in that this photocuring process is very fast. Projecting light through an oxygen-permeable window, CLIP is able to print objects continuously, without the need to pause between layers and mitigate the suction forces typically associated with DLP.

Not only does this allow CLIP 3D printing to fabricate objects at 25 to 100 times the rate of other systems, but it results in isotropic strength throughout a 3D-printed part. In parts produced with almost every other 3D printing technique, there are identifiable horizontal layers which have weak vertical bonds that make these components much weaker on the Z-axis than on the X and Y. With CLIP, however, parts are equally strong in every direction.

Phelps explained that this is a key reason that prevents 3D printing from being implemented in the production of end parts.

“Conventional 3D printing technologies all produce parts with layers, which compromise the quality of the parts because they have different mechanical properties along different axes,” Phelps said. “Engineers find this lack of consistency problematic. As a result, most conventional 3D-printed parts are limited to prototyping applications. In contrast, CLIP parts have consistent mechanical properties regardless of axis, similar to injection molded parts.”

CLIP Materials

Once a print has been produced, it undergoes a second curing process that further unlocks the potential of CLIP-printed parts for various engineering applications. Phelps was able to elaborate on how this second curing step differs from the initial 3D printing process.

“This two-stage cure is very important differentiator for us as it allows us to combine the resolution and surface finish of light-based 3D printing with engineering-grade thermoset mechanical properties,” Phelp said. “This combination has never before been achieved by additive technology and it is what allows us to make the final-quality parts that we do. Specifically, light crafts the shape of the part (stage one) and chemistry sets the mechanical properties of the part (stage two). Bottom line for engineers: CLIP parts have engineering-grade mechanical properties and extremely fine surface finish and resolution.”

So far, Carbon has been able to develop a variety of five different photopolymers that exhibit various mechanical properties. In addition to a general-purpose resin, Carbon has created rigid, flexible and highly elastic polyurethanes, as well as a high temperature–resistant and strong cyanate ester. These materials will only expand, given the fact that former DuPont Chair and CEO, Ellen J. Kullman, joined the Carbon Board of Directors and Carbon entered into a material development agreement with Kodak.

The M1 3D Printer

Uniquely, the M1 isn't something one purchases, but subscribes to. That’s because customers actually rent the system out at a price of $40,000 per year, which doesn't include the $10,000 installation fee and the cost of the material.

Some in the 3D printing industry have asked about the reasons behind this subscription model, so ENGINEERING.com asked Phelps for his explanation. Phelps suggested that this model offers “a more all-inclusive offering than simply buying a machine outright.”

Phelps listed the following as key benefits: “It allows us to partner directly with our customers to help them succeed with the product. We enable them to change the way their products are made and how their businesses are run, not just to sell them a piece of equipment. The model provides continual monitoring and proactive maintenance. Our service team is constantly monitoring the health of the customer's printer and provides proactive support if it is ever needed. Customers get continual software upgrades and full access to our growing number of resins, not dissimilar to getting smartphone updates.”

CLIP for End-Part Manufacturing

The subscription model has, so far, proved suitable for a number of high-level clients, including BMW and Delphi Automotive. Carbon added a whole new list of CLIP believers to its roster when it announced a $81.1-million funding round that included GE Ventures, Nokia and JSR, as well as BMW.

The value that these investors see in this technology may be related to the ability to 3D print end parts quickly, according to Phelp.

“Carbon brings end-use parts at quality and cost level appropriate for manufacturing,” Phelps said. “This means: Accelerated product development cycles, low to medium volume production where injection molding doesn't make sense and geometries that injection molding can't achieve.”

In terms of accelerated product development, Phelps explained that CLIP technology makes it possible to go from idea to functional prototype to end part with greater speed. “Speeding up the design process allows companies to learn more quickly about what works and what doesn’t, which in turn means that higher-quality, more cost-effective and groundbreaking products can make their way to market,” Phelps said.

In addition to prototyping, Phelps believes that CLIP makes it possible to 3D print actual end parts themselves. “Fulfilling low- to medium- volume production with CLIP empowers our customers to be more innovative in design,” Phelps said. “For example, people often assume that when discussing automotive manufacturing, it is always high-volume production and that is true in some cases, but when looking at high-end or specialty models, the production quantities of those models is typically less than 50,000 units. CLIP enables a company to create specific parts for those high-end cars and doesn’t limit the engineer’s creativity because they don't have to worry about designing their product around common, higher-volume components.”

It’s also possible to 3D print parts with CLIP that cannot be made with traditional technologies. “CLIP allows for the production of parts that injection molding simply cannot produce, such as a mesh,” Phelps explained. “Meshes are hugely useful because they allow for strong but very lightweight structures. Nature designs with meshes all the time, but today's engineers cannot because of the limitations of inject molding. With CLIP, mesh parts have a huge number of possibilities in aerospace and vehicle design, but also in countless other situations where a part must be both strong and light.”

As a result, Phelps believes that Carbon's technology will actually make it possible to incorporate 3D printing into end part manufacturing, which some see as the overarching goal for the industry. For 3D printing to reach widespread adoption, Phelps claims that the part quality, part cost and business use cases where 3D printing provides value will be key.

“We think we are well on our way to this becoming a reality,” Phelps said. “With CLIP we already have parts being used in the field by major Fortune 500 customers and numerous examples of low to mid-sized production runs, mass customization and impossible geometries such lightweight meshes. Because CLIP has made big advances in one and two above, we have the unique opportunity to collaborate with leading product companies to re-imagine the products they can make and the businesses they can run, which is quickly building up our list of use cases.”