Upward Movement in the UV-Curable 3D Printing Industry

by Dianna Brodine, managing editor, UV+EB Technology
The ring was printed by Brad Hill on a LittleRP UV DLP resin printer, specifically designed for small, highly detailed parts. Resolution is approximately 60µm X, 45µm Y, 25µm Z. The projector was an Acer X1240 with a 1024×768 pixel resolution printed with roughly a 3500ms exposure time per layer. Photo courtesy of Maker Juice.

Undeniably, 3D printing is the new media darling. Whether forming tennis shoes or limbs, the technology is riding a definite wave of increased interest from those involved in discovering potential industrial applications and consumer hobbyists alike. However, 3D printing may be the latest buzzword, but not everyone has a grasp on the chemistries involved or its limitations.

UV+EB Technology contacted four companies involved in the production of resins and equipment for the 3D printing industry: Lance Pickens, CEO and founder, MadeSolid; Brian Adzima, materials scientist, 3D Printing, Autodesk; Ken Kisner, CEO/president, Molecule; and Shane Graber, research chemist, MakerJuice Labs. Each was asked a series of questions about the future of the UV-curable 3D printing market.

As the UV-curable 3D printing market shows strong growth, are end users developing an understanding of the UV-curable technology behind these printers or do most users treat it as “Black Box” technology, operating without an understanding of how it works?

Pickens: End-use customers with niche-specific applications, particularly those with an engineering bent, have a more thorough understanding of what their needs are and the value of what the technology can do, but they don’t want or need to understand the base chemistry. Beyond a general understanding of the process, there are so many nuances of the UV cure itself that a fairly high level of chemistry knowledge is needed to understand the challenges and limitations, and that’s too much to ask of industrial customers. We had to do a lot of education in the beginning, but now our customers understand the general concept.

A print in Vorex Black of a GE Jet Engine, 50um layer height, Autodesk Ember printer. Photo courtesy of MadeSolid.

Adzima: Currently, I interact with experts who want to apply 3D printing to specific problems where it has not been used. Consequently, some of these users are very interested in the chemistry, and a few even prepare their own formulations to get the performance they need with UV-curing photopolymer resins. As any given 3D printing application matures, this level of interest in the chemistry may change.

Kisner: There are two very different users in the market. The small-sized service bureaus and hobbyists largely do not have a deep understanding of UV-curable technology. As an industry, it’s important to continue to educate to help the industry grow at its current pace. We are finding the larger service bureaus and the large industrial end users (automotive manufacturers such as Tesla and GM, footwear manufacturers such as Nike and Adidas, aerospace manufacturers such as Boeing and Lockheed Martin) tend to have highly educated personnel with strong knowledge about the technology behind UV cure.

Graber: The bulk of what I see is end users becoming familiar enough with UV-curable technology so they can successfully print with UV resins – and, that is about as far as their interests extend. Most understand a high intensity light or laser turns the liquid into a solid using “something called a photoinitiator” and that there is a general cleaning and post-curing procedure required after the print finishes, but they really do not have an interest in understanding the process beyond that point. Some, however, do go the extra mile and try to understand the underlying technology better, but those end users tend to be in the minority.

Do you see a greater interest from end users for industrial applications or consumer/personal applications?

Pickens: On the consumer side of things, there’s an increased interest in UV cure because the consumer is concerned about surface finish. UV cure is definitely better than FDM printing because the layer heights are so small, but unfortunately every machine out there leaves a lot to be desired from the consumer experience side.

There have been a lot more requests for industrial, however, in the form of individuals wondering, “How can I use this in my industry?” End-use functionality is an issue though, and the technology isn’t gaining quickly enough. Users want to have parity in what they’re getting out of thermoplastics. If UV cure really wants to supplant a lot of that, we’ll have to be focused on resin chemistries and equipment that can provide results that equal or surpass current methods.

Adzima: The most compelling use cases for 3D printing fall in between industrial-scale farms of tens or hundreds of printers and consumer use. Architects, jewelers, engineers, dental labs and anyone else who quickly needs a customized object or prototype can benefit from the DLP/SLA machines available now. While it is clear that 3D printing makes sense for such low-volume applications, I would not write off mass production either. 3D printing enables the production of highly complex geometries and details that are difficult to achieve with injection molding. There are definitely cases where 3D printing at scale makes sense. On the consumer side, the market for consumer machines is small. Unless, a new application comes along, the same people that have milling machines and MIG welders at home will probably be the only consumers with 3D printers.

Kisner: The 3D printing market has wide interest. Even our grandmas or aunts have a bit of knowledge concerning 3D printing, or at least some of the existing industries using the technology. While there have been tens of millions of filament printers sold to hobbyists for use in consumer and personal applications, the UV technology which utilizes photopolymers tends to target industrial applications. We strongly believe the technology will be pushed to new levels by the industrial applications; however, the “garage entrepreneur” also is pushing the technology forward at an alarming pace.

Graber: I would have to say the biggest growth we have seen has come from the consumer/personal area in the last two years as a number of key UV-curable 3D printer patents have recently expired. Users are wanting more color options and more physical property options to choose from when purchasing formulated products, and they are looking to resin formulators for those solutions. Specialty items also are gaining traction, such as investment casting resins for jewelry and dental applications, resins for high-temperature resistance applications and biocompatible resins.

What do you see as the most critical needs for the UV-curable 3D printer market to grow?

Pickens: Safe and efficient chemistries, outside of acrylates, will be needed for broad-scale consumer adoption. Also, non-leachable photoinitiatiators should be a big focus, but regulatory approval is extremely difficult. Those chemistry advances also would bring the cost down and open up markets in food and beverage packaging.

Adzima: New materials tailored to particular applications will accelerate growth. Most of the current materials were either designed just to print in a particular machine or meet a poorly defined performance characteristic, like “flexible.” Many potential applications depend on more than just mechanical properties, and designing materials that meet those needs is paramount.

Kisner: Molecule is focusing on “engineering grade” photopolymers. Engineers must be able to make mathematical calculations to assure the product will perform as needed, which requires an understanding of the specific properties of materials. High-durability materials that consistently meet engineering properties are important for 3D printing to hit the next level, as are products that are safer to handle and ship.

Graber: I see three main areas that are critical: 1) ease of use, 2) health and safety and 3) physical property options.

The pigment depth of cure study was printed on the Roland ARM-10 DLP printer with Molecule’s engineering-grade plastic rigid resin. Resolution is 200µm X, 200µm Y, 50µm Z. Photo courtesy of Molecule.

Ease of use is key for both printer design and software control in order for the UV-curable 3D printer market to grow. The high-end printer manufacturers have this well under control. However, mid-level printers targeted at more affordable price points (<$5,000) need a bit of polish, as does the available software. Much of the software in this area is open source and/or being developed by individual software developers, which takes a while to “get it right.”

Health and safety is another area that is critical for formulators to “get right” when it comes to chemistry. In light of many users not wearing adequate personal protective equipment (PPE) when working with resins, it is highly important for formulators to select low irritancy oligomers, monomers and additives when developing formulations for sale to consumers.

I also see physical property options as something highly important to the end user, and their needs are dependent on what they want to do with the printed parts. Some people want tough resins for structural applications; others want highly flexible resins; others target specific physical attributes, such as high temperature-resistance, low ash, high detail, etc.

A print by Qingnan Zhou at New York University demonstrates that even very hard materials can be made soft through design. Here, 200 micron features on an Ember print enable Autodesk’s open source PR48 formula to become flexible. Photo courtesy of Autodesk.

One of the concerns in UV-curable 3D printing is the safety and environmental aspects of handling UV-curable materials by inexperienced end users. What can be done to improve this situation?

Pickens: More work needs to be done, particularly on the front of disposal of unused product. Currently, there is a hodgepodge of regulations that can be horrible to navigate. A standard set of guidelines for disposal methods that could be packaged for end users or machine makers would help adoption quite a bit.

Adzima: Safety is a very big concern and is one of the barriers to broadening the use of UV-based printers. Vat-type printers are messy, and the print cleanup process creates a lot of waste. Our workspace has very clear rules on where resins can be handled, and what tools are to be used with or without gloves. This, along with PPE and constant cleaning, keeps us safe.

The use of UV cure in nail salons and dental offices prove these materials can be safely used in other environments, and it shows that training users is very important. Safety and environmental concerns also translate to real costs for users in terms of waste disposal and training. Eliminating the sensitization concerns and environmental toxicity would make the technology more attractive and allow these technologies to be deployable in new areas, such as schools and offices.

Kisner: Humans are around chemicals all day, every day. It is critical, no matter what type of chemical we are working with, that we understand the potential hazards. Education is extremely important when working with any type of chemistry. Government regulation requires the industry to understand and properly mark the chemistries, while industry itself must continue to find new chemistries that have lower hazards. A continued focus by all material manufacturers must formulate chemistries that are safer to use, reduce or eliminate the environmental impacts and, when possible, utilize renewable resources.

Graber: Education about the chemistry, hazards and required personal protective equipment (PPE) necessary for working with UV-curable resin chemistry is very important as usage is adopted by end users. There are many misconceptions about the chemistry, ranging from toxicity concerns to complete lack of adequate PPE at the other end of the spectrum. I have seen quite a number of end users not even wearing gloves when handling resins, which greatly concerns me. Disposing of residual resin also is a concern. The blanket statement of “dispose of in accordance with state and local regulations” does nothing to help the end user know how to properly dispose of residual or waste resin. Some contact information on where to find this information would be highly beneficial.

Company Descriptions:

Lance Pickens, MadeSolid. MadeSolid (www.madesolid.com) was founded to discover and deliver materials that make it easy for anyone to turn creative ideas into physical form. MadeSolid’s advanced materials are easily scaled and integrated into every phase of the product lifecycle, from early prototyping to full-scale production.

Brian Adzima, Autodesk. Autodesk, Inc. (www.autodesk.com), is a leader in 3D design, engineering and entertainment software. Since its introduction of AutoCAD software in 1982, Autodesk continues to develop the broadest portfolio of 3D software for global markets. Customers across the manufacturing, architecture, building, construction and media and entertainment industries use Autodesk software to design, visualize and simulate their ideas before they’re ever built or created.

Ken Kisner, Molecule. Molecule (www.moleculedigital.com) is a uniquely creative, technology-driven enterprise focused on discovery and product innovation in the additive manufacturing space. Molecule provides UV-curable chemistries for the jetted materials market, as well as the stereolithographic market. Molecule is committed to meeting the needs of its customers through innovative, reliable products and to achieving a positive economic impact while being responsible global citizens focused on a holistic approach to environmental stewardship.

Shane Graber, MakerJuice Labs. Founded in 2013, MakerJuice Labs, LLC (www.makerjuice.com) designs, develops and manufactures UV-curable 3D stereolithographic resins for 3D printers. Resins produced at the facility are compatible with a wide range of printers, including Formlabs SLA printers, B9Creator, MakeX M-One, Kudo3D Titan, LittleRP, among other printers. Graber was key to the inception of MakerJuice Labs and spearheads the development of its newer and industry-leading resins.