From Photopolymers to Composites, EnvisionTEC CEO Discusses the Company’s 3D Printing Tech
Michael Molitch-Hou posted on November 03, 2016 |
In an interview with ENGINEERING.com, EnvisionTEC CEO Al Siblani discusses the company’s latest tech...

Earlier this year, 3D printing stalwart EnvisionTEC unveiled new technology and partnerships that proved that it wasn’t satisfied with dominating the photopolymerization market, but that it aimed to take an even bigger stake in industrial 3D printing. To learn more about the company’s plans, ENGINEERING.com turned to EnvisionTEC CEO Al Siblani.

The Founding of EnvisionTEC

Before founding EnvisionTEC in 2002, Siblani worked for the now-defunct Helisys, the 3D printing firm behind the laminated object manufacturing process. He then went onto to invent his own 3D printing technology, filing a patent in 1999.

EnvisionTEC soon became a leader in the 3D printing industry with its digital light processing (DLP) 3D printers. In 2002, the company began selling its first Perfactory DLP 3D printers, which used DLP projectors from Texas Instruments to cast UV light onto a vat of resin, curing large swaths of photopolymer a layer at a time with speed and precision.

One issue associated with DLP 3D printing, however, is the fact that the resolution possible with the technology begins to decrease as the light source grows farther from the resin or the size of the object increases. EnvisionTEC solved this problem when it unveiled its Scan, Spin and Selectively Photocure (3SP) process in 2013. Instead of a DLP projector, 3SP directs a multicavity laser diode through a spinning drum and casts the light onto the vat of resin, making it possible to maintain high resolution regardless of the size of a 3D-printed object.


The EnvisionTEC 3D-Bioplotter Developer Series. (Image courtesy of the author.)
The EnvisionTEC 3D-Bioplotter Developer Series. (Image courtesy of the author.)

EnvisionTEC also brought to market one of the commercial bioprinters, the 3D-Bioplotter, in 2000. Meant to be versatile and easy to use, the 3D-Bioplotter enabled researchers to begin developing new tissue engineering methods. These techniques could play a role in bioprinting complete organs, but have also led to entirely new techniques for 3D printing novel materials, such as graphene and artificial bone. Since the initial launch of the 3D-Bioplotter, EnvisionTEC has both upgraded and expanded the technology, resulting in the release of the Starter, Developer and Manufacturing models.

The diversity of these technologies should have provided some indication that EnvisionTEC had never intended on sticking to one 3D printing process, but was ultimately intent on becoming a 3D printing powerhouse in the industry. This year, the company made announcements related to three 3D printing technologies that could aid them in that quest: Selective Lamination Composite Object Manufacturing (SLCOM), sand mold and sand core 3D printing, and Continuous Digital Light Manufacturing (cDLM) technology.

The SLCOM 1

The SLCOM 1 3D printer may have been the biggest news of the RAPID 2016 event, if not figuratively then at least literally. The massive machine is capable of 3D printing fiber reinforced thermoplastic objects as large as 24 in x 30 in x 24 in and weighing up to 500 pounds.
The SLCOM 1 3D printer is capable of 3D printing large-scale composite parts. (Image courtesy of the author.)
The SLCOM 1 3D printer is capable of 3D printing large-scale composite parts. (Image courtesy of the author.)

News of the machine may have come as a surprise to some, as composite 3D printing is quite a new direction for EnvisionTEC. Siblani explained that the decision to head in that direction was a calculated one, with a goal of disrupting the market.

“When looking at the growth of composite materials compared to, say, metals, we thought that there was more growth opportunity and—even more importantly—more opportunity to add value with composites,” Siblani said. “The creation of composite materials and parts is a very long, complex and labor-intensive process. We thought we could really simplify and automate it, and really help composites become more cost-competitive with metals.”

The SLCOM printing process works as follows: the machine is loaded with a roll of fiber reinforcement material—such as carbon fiber, Kevlar or fiberglass—that is pre-impregnated with thermoplastic—such as Nylon 6, Nylon 11, Nylon 12, PEEK, PEKK, or polycarbonate. This material is fed into the print chamber layer by layer. Then, a heated roller passes over the sheets of material, melting the thermoplastic. Next, an inkjet head makes a pass, depositing wax and a binding agent onto each layer. This is all followed by a carbon blade and ultrasonic emitter, which cuts away any area coated with wax and leaves only the desired object.

Siblani further commented that 3D printing can provide great potential to the world of composites manufacturing. “We believe we have an advantage by using pre-impregnated woven fiber composites, which have great X-Y strength. Some people are using chopped fiber in a matrix,” Siblani said. “But, overall, there are many parts of the composites creation process where additive technologies can play a role in delivering more automated and efficient processes. And that is necessary because demand for composites is expected to continue to grow and the market needs to deliver more product faster.”

He added, “Our technology also creates a new automated process for the 3D creation of a variety of woven fiber composites, both unidirectional or multidirectional woven fibers. That includes carbon fiber, fiberglass and more, and by impregnating the fiber with certain thermoplastics, you can really tailor the part for certain functional characteristics.”

For EnvisionTEC, the ultimate value of the SLCOM process is in bringing down the cost of composites manufacturing and, thus, making it increasingly possible to replace metals. The obvious customers for such technology would be the defense and aerospace industries.

“We have already seen interest from the defense and aerospace markets,” Siblani said, “which tend to be early adopters of manufacturing technology in general, as well as manufacturers of performance and exotic cars. These companies are increasingly interested in lighter-weight composites, as well as a diversity of composites.”

3D Printing Sand Cores and Molds

Another surprise at RAPID was the announcement that EnvisionTEC was partnering with a relatively new 3D printing company called Viridis3D, which had developed an interesting process for 3D printing sand cores and molds.

Viridis3D was founded by Jim Bredt, who previously cofounded ZCorp. Viridis3D breaks the binder jetting technology commercialized by ZCorp out of the box with a technology dubbed robotic additive manufacturing (RAM). RAM features an inkjet head attached to an industrial robotic arm, which swings back and forth to deposit layers of sand and liquid binder onto a print platform.

This scalable process could be used to produce custom, geometrically complex sand molds and cores on demand, ultimately reducing the need for sand mold inventory and making it possible to cast metal objects at a lower cost compared to other techniques.

A sand mold 3D printed with the Viridis3D platform to cast a metal part. (Image courtesy of the author.)
A sand mold 3D printed with the Viridis3D platform to cast a metal part. (Image courtesy of the author.)

While RAM has so far been demonstrated fabricating objects made from sand, Siblani explained that the process could be modified for 3D printing with other materials. “When it comes to sand casting, we simply had a more cost-effective method to bring to market than what’s out there,” Siblani said. “But we see other applications for the robotic additive manufacturing that motivated our exclusive strategic partnership with Virdis3D. For example, we are working to develop robotic 3D printing of PMMA (polymethyl methacrylate), an acrylic plastic, for direct investment casting, especially of large parts.”

Continuous DLP

Just because EnvisionTEC is venturing into new industrial 3D printing technologies doesn’t mean that it's given up on evolving its own. The company also announced this year the release of a faster DLP process that, while it sounds similar to a certain continuous DLP technology developed by a famous 3D printing start-up, was actually patented by EnvisionTEC much earlier.

Siblani explained, “EnvisionTEC has always been known for offering a fast DLP machine, which also offers the highest resolution and accuracy. That performance comes from our experience, which goes back more than 15 years when we originated commercial DLP printing. We patented our continuous process back in 2011, which noted ‘uninterrupted exposure and/or continuous motion of [the] support plate.’”

EnivisionTEC's new Micro Plus cDLM 3D printer relies on a UV LED light engine to 3D print objects at speeds of up to 10 to 20 minutes per inch on the Z-axis. With a build size of 45 mm x 28 mm x 75 mm (1.8 in x 1.1 in x 3.0 in), an integrated PC with Wi-Fi and a built-in touchscreen, the 3D printer is meant to be capable of 3D printing directly castable objects for the jewelry market.

Siblani elaborated on the technique: “We decided to launch our faster cDLM technology earlier this year to the jewelry market, so it could show customers patterns for castings more quickly. Our cDLM is truly a high-speed 3D printer. It's very similar to our DLP, except for the fact there is a continuous motion of the build plate, so there's never a complete stop of the plate during each exposure.”

The Vision

Of the changes experienced by the company since its inception, Siblani said, “In 2017, EnvisionTEC celebrates its 15-year anniversary. Looking back, it's been an amazing journey. We were the first ones to deliver extremely high resolution parts using our DLP technology, without sacrificing speed. Because of that, we were the first ones to bring mass customization of finished goods to market, with the hearing aid and jewelry markets.”

He added, “Today, there are obviously more competitors, although a few key companies like ours have always dominated the market. We worry some cheaper entries may be turning off less experienced 3D printer users from the market when machines don't work consistently or are more difficult to use than promised. At trade shows, we've been talking to a number of customers who feel ripped off by low-priced machines, and we feel that is unfortunate because those companies don’t offer the installation, training and support that we do.”

In addition to improving its existing technology, EnvisionTEC has entered into new territory, creating a company with an increasingly diverse portfolio. This has been a part of a larger strategy, according to the CEO.

“The vision is to look at all 3D printing technology platforms that would give us the chance to disrupt existing traditional manufacturing processes,” Siblani said. “So we engage and we invest and we innovate in areas that have the biggest chance of taking us where there is an opportunity to add the most value.”

With new trade shows right around the corner, it's obvious that the already productive firm will be releasing more new printers. Siblani provided a hint of at least one that is on its way.

“We always have new products in the works and we have a popular large frame 3SP model that will see a new derivative before year's end. But we like to keep people in suspense, so more new products are always on the way,” Siblani concluded.


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