Albright Silicone launches rapid 3D LSR printing

BOSTON—Applications for the rapidly growing 3D printing industry include the ability to make hearing aids and jewelry, manufacture parts for NASA and replicate a human kidney.

And as the industry advances in technology and application, so do the capabilities for silicone molders.

Massachusetts-based Albright Silicone is one such forward-looking firm, recently disclosing the development of a lower cost, more rapid turnaround process for prototype 3D liquid silicone rubber molding, allowing customers to save on the bottom line in research, development and, ultimately, production costs, the company said.

"It's a similar process to what we've done in the past with our aluminum molding—it's just additive versus subtractive molding," said Cole Vincequere, project engineer for the firm's new 3D printing process. "It allows customers who perhaps don't have the funding or time to develop a final product. We can hit difficult geometries with this process and we can produce it rapidly to try to cut down lead time for the customer."

According to Matt Bont, product manager at Albright Silicone, the process offered by Albright can be a more efficient option—as opposed to more traditional RTV or TPE printing—for customers who are seeking a small number of parts for initial testing, but who may not be ready for metal tooling.

"Having strong communications between supplier and customer is key," Bont said. "We want the best recommendations from our customers to help push the part forward. We need to understand the production state and where the customer is in the research and design and development process."

Albright, which has been in silicone for 15 years, has printed parts for initial test prototypes, product launches with investors and some one-off functional parts, Bont said. But the market for Albright continues to be in prototype printing, and the company, so far, has had "very positive feedback."

"I would say it's been pretty positive," Bont said. "Customers have been receptive. The key for us is to try to have an honest conversation with them. There is no point in producing something that does not add value for the customer."

Bont said customers seek Albright's 3D LSR printing services at all stages of the development process.

"Some of our production is in end-device and manufacturing, while other devices are already established and we are just refining them for the final validation," Bont said. "This capability really is an extension of our 3D printing services, matching our service with what actually matters for our customers."

One of the advantages to Albright's rapid prototype process, Bont said, is using a final, commercial grade LSR, which allows the 3D prototype to have performance traits and thresholds that are "relatively similar" to the end product.

"It gives us the capability to print much more difficult geometries that we may not be able to do with a cutout of aluminum blocks," Vincequere said.

According to Bont, LSRs have a wide range of processing capabilities, including use in compression and injection molding. LSRs often represent the "middle ground" for properties for many applications, Bont said, and can lend themselves to high-volume production.

LSRs tend to have the viscosity range between honey and cold molasses, according to Albright, and a wide hardness range, between 10 and 80 Shore A durometer.

"Now with LSR, you can turn around a prototype at a lower cost, with a shorter lead time," Bont said. "This allows our customers to display a product at a trade show or at a product launch with investors."

From idea to functional prototype
According to Albright, rapid LSR prototyping is intended to answer the critical questions of feasibility, form, fit and function.

The process can help identify materials, tolerances and behavior of a part, and the methods typically balance quality, speed and cost, according to Albright.

Assuming a customer is coming to Albright early in their development process, perhaps only with an idea, a 3D part typically begins with a mock-up using handcrafted parts, such as clay or cut material slabs.

"The customer could be in their garage figuring out their design concepts, and may want to go through few different iterations of the product," Vincequere said. "From there they can decide to go all the way up to a production-style tool."

Conversely, Albright notes that 3D printing of a part may represent ideas, which in turn allows for "refinement of individual concepts but leaves functionality and accuracy to be desired," Albright said.

"This can kick-start ideas for a product at this stage," Bont said, "while others will use the 3D capability for internal feasibility and functional testing."

A 3D part then transitions to a rough working model, a stage that sees materials finalized into a general form by building a tool and molding samples. This helps refine the functional copy, Albright said.

The functional prototype then is printed using tight tolerances and dimensionally accurate parts, and can be used for design qualifications and early-stage use, according to Albright.

"We've done surgical-related parts, foundational pieces used for training surgeons," Bont said. "Doctors tested these functional prototypes to become certified in the use of the tool."

Bont noted that 3D LSR printing, which uses heat and compression to cure the product, can benefit customers who are who are looking for a range of hardness with their LSR; who require color matching; who need components molded with complex shapes and undercuts; who need two to 10 parts quickly; and who need to test the first stage of overmolding.

In addition, Bont said Albright's rapid LSR prototyping process helps reduce revisions further in the development cycle, allows for a technical understanding of the part and saves time.

Outside of the 3D prototyping and casting processes, Albright offers traditional LSR product molding, slitting and assembly services for the medical implant, pharmaceutical, industrial, consumer and military/aerospace industries. Its customers include Johnson & Johnson, NASA, Philips, General Electric, Covidien, Alcon and Boston Scientific, among others.

Silicone is everywhere, Bont said, and the demand for 3D printing will continue to grow just as the technology that surrounds it advances.

"The industry is expanding," he said. "We see capabilities in silicone—as well as the capabilities of materials in support of silicone—expanding. With that being said I don't see how the industry won't continue to grow."