Engineering: Area Printing, Metal Additive Manufacturing a Hundred Times Faster
Engineering – April 18, 2022
By Issac Maw
One of the most exciting things about following the emerging additive manufacturing (AM) technology space is that unlike more traditional, established manufacturing processes such as machining or fabrication, there are always new innovations that don’t just improve a small aspect of a long-established process but also try to radically reinvent the entire process using a new method. For example, consider the filament extrusion-based printers of the early academic labs compared to systems that use light to cure liquid resin or lasers to sinter powder material. Technologies like Fabrisonic even use two-dimensional metal foil layers to additively build parts.
The latest innovative 3D printer technology comes from Massachusetts-based Seurat Technologies. Seurat’s technology is called Area Printing. The company claims that with this technology, powder material can be sintered by a laser working in square areas at a time, rather than sintering one tiny dot at a time with a moving laser focal point.
How Does Seurat’s Area Printing Technology Work?
The company name, Seurat, provides a hint to how its technology works. French painter Georges Seurat was the originator of Pointillism, a style in which an image is formed using many tiny point-shaped brushstrokes, allowing the painter to create a range of tones, values and textures. According to the company, “Like Georges Seurat’s brush technique, Seurat Technologies applies the same basic principle to laser light and powdered materials. Unlike traditional additive manufacturing, Area Printing from Seurat uses a powerful laser containing over 2.3 million pixels—like brush strokes—to micro-weld thin metal powder layers to the area below it, manufacturing entire renderings at once in a single defined area.”
To generate this laser area, the machine shapes the infrared (IR) laser beam into a two-dimensional area using optics to create a homogeneous square field. Next, a generated projection of the area pattern with a blue light projector (at the same size as the square laser beam) is aligned with the laser beam.
The IR laser beam is then polarized horizontally where blue and IR light “pixels” overlap via an optically-addressable light valve (OALV). Where IR and blue do not overlap, the light is polarized vertically. Because the pattern and remainder areas are polarized 90 degrees apart, it’s then possible to split the vertically and horizontally polarized IR laser beams, sending the desired pattern to the powder bed to melt the layer of material, and dumping the rest.
Area Printing was developed at Lawrence Livermore National Laboratory, and the company has nearly 130 patents that are either granted or pending.
Area Printing Applications
While metal additive manufacturing has early adopters, it has so far achieved limited penetration into the manufacturing sector as a viable production option, relative to the vast number of metal parts that are produced daily across the globe. Currently, additive manufacturing wins as an option for high-value components at low batch sizes that require significant manual labor. Those three factors work together to create a perfect storm for traditional manufacturing, as the cost model of traditional processes, such as casting or machining, work based on economies of scale. With a high cost per part, high labor cost per part, and not enough volume to spread those costs, parts become prohibitively expensive. At that cost level, today’s metal AM becomes competitive. The flexibility of the technology to produce new shapes and geometries is a bonus.
By increasing the speed of printing, Seurat’s technology promises to continually drive down the cost per kg of printed parts, making additive manufacturing competitive in more and more cases across industries. As metal AM gains this market share as a viable production technology, it will continue to gain acceptance in the design world.
Shifting Design for Manufacturability Mindset
Currently, design for manufacturability is dominated by traditional concepts. For example, the limitations of molding and machining are well understood: molds require draft angles and gates to allow the material to flow into the molds and for parts to release from them. In machining, no end mill can cut a square inside corner, and certain features require more steps and increase costs. Designers are familiar with these rules, and parts are designed with them in mind. Because additive manufacturing is still relatively new, designers are often unfamiliar with the design capabilities it offers. For example, why print a living hinge when a functional, multipart hinge can easily be printed and fully assembled in the same amount of time? As additive manufacturing becomes more popular in industry, designers will continue to unlock new ways to build products and parts that make the technology increasingly essential and valuable.
According to Seurat, the value of the technology is in its potential to scale metal additive manufacturing by providing a much faster way to print accurate, detailed metal parts.
“Area Printing decouples resolution and speed, which is the secret sauce to making 3D printing a high-volume process,” said James DeMuth, cofounder and CEO of Seurat, in a press release.
In addition, the company claims that the machine provides superior surface finish and accuracy, achieving net-shape manufacturing. However, this claim may be taken with a grain of salt as it’s a common one in the metal additive manufacturing OEM space.
The company technology will find applications in the same spaces that existing metal AM technologies already have, such as aerospace and performance automotive. However, the faster process may enable it to add value in higher-volume production, such as in automotive, consumer electronics, and industrial applications.
Metal AM Environmental Consideration
One area of focus (no pun intended) for Seurat is the potential environmental benefits of area printing compared to traditional manufacturing methods, especially casting. Metal casting consumes a large amount of energy and produces significant waste. By displacing casting with additive manufacturing, material and energy waste can be reduced, producing less CO2 emissions and pollution. Leveraging Seurat’s production may help companies reduce their carbon footprint. However, it’s important to recognize that metal powder materials can be harmful to the environment and to the health and safety of operators, so proper handling, recycling and disposal are essential.
Seurat Area Printing Limitations
Currently, the technology and company are new, and there are a few limitations to consider. First and foremost, Seurat’s printers are not for sale. The only way to access the technology is through Seurat’s contract manufacturing service. The company focuses on high-volume production, so it may not be possible or practical to access the technology for a small run of parts.
The company is continuing to develop the portfolio of materials available on the machine. Currently, the company website states: “Our initial focus is on metal, with the more common alloys initially targeted by our customers, such as Steels, Nickels and reactive materials such as Aluminum and Titanium. All of our material and parameter development is customer-driven and begins after a production slot has been booked … and secured through a commercial agreement.”
The Future for Seurat Area Printing
As a new company, Seurat’s focus seems to remain on growing the company and attracting engineering talent. Seurat is also working on developing a Gen 2 version of its machine. The company claims that the Gen 1 machine is 10 times faster than today’s laser powder bed fusion (LPBF) processes and that Gen 2 will be 100 times faster.
To learn more about metal powder bed fusion processes, check out our Guide to Selective Laser Sintering.