Composites Manufacturing Magazine

The 3-D Printing Boom

From automotive and aerospace to biomedical and building, more industries are discovering the versatility of additive manufacturing.

The 3-D composites additive manufacturing industry is experiencing steady growth, spurred by the flexibility, speed and lower cost that the technology can offer. SmarTech Publishing, which specializes in 3-D printing industry research and data, is bullish on the market, forecasting total revenues for composites additive manufacturing reaching $580 million by 2026.

As the use of 3-D printing technology becomes more widespread, manufacturers are finding innovative ways to use it. Here’s a look at what four companies are doing.

Driving Innovation

Penske Racing has understood the benefits of additive technology for over a decade. It began with stereolithography (SLA) 3-D printers to scale model parts for wind tunnel testing for NASCAR and IndyCar vehicles. Over the years, Penske has expanded its 3-D printing capabilities, enabling the company to better tailor the properties of the printed products to specific applications.

Penske uses specific resin systems with SLA that produce the desired stiffness for wind tunnel models, but result in parts that are often brittle. Printed components such as mockups, jigs and fixtures can’t suffer from this brittle characteristic. Partnering with Stratasys, Penske brought in a fused deposition modeling (FDM) printer, which extrudes polymers layer by layer.

“The FDM materials are more durable compared to our SLA resins. Prototype, jig and fixture parts can be mocked up, bolted and dropped without breaking,” says Andrew Miller, composite engineer at Penske Racing. The FDM technology filled a void in Penske’s additive manufacturing program, enabling the company to produce jigs and tooling faster for improved on-track performance.

Penske uses many FDM materials for its applications, including durable and chemical-resistant Nylon 12 for jigs and fixtures and temperature-resistant ULTEM 1010 for composite tooling. “With our composite tooling, in some cases we are curing components under high temperature and pressure – 90 psi, 250 degrees F – so we use ULTEM 1010, which has really high strength and temperature capability,” says Miller.

Furthermore, the FDM printer has freed up machine shop resources. “We are able to print our tools and patterns much quicker than we could traditionally machine them, especially parts that would involve five-axis machining, which gets to be expensive and time consuming,” say Miller.

Using the FDM printer, Penske recently produced a fuel probe handle and housing for IndyCar teams. A mechanic who fuels up a car at a pit stop uses a large probe with a handle assembly that alerts him with sensors and lights when the tank is full. Previously made from fabricated aluminum, the handle was heavy and not well integrated into the probe. Penske engineers designed a lighter and better integrated composite handle for the Indy 500, but the turnaround time was tight and there were challenges in making the part.

“We came up with a method of using the ULTEM 1010 to print the master pattern tooling, which enabled us to get our tools much quicker,” says Miller. “Since the geometry internals were quite tight, we weren’t going to be able to use the traditional bagging method. One of the other benefits of the FDM technology is that they have some materials that are soluble in a detergent solution. We can laminate the part around a soluble core, and once the part is cured in a solid we can dissolve the core out from the inside.”

With the 3-D technology, Penske met the deadline while saving money. Master patterns built using traditional tooling would have cost $8,500 and taken three to four weeks; with the FDM printer, it cost just $870 and took less than a week.

Penske also uses a selective laser sintering (SLS) printer to produce race car components such as carbon monoxide filters for drivers’ helmets, brackets and wiring housings for vehicle interiors, and exterior parts like brake ducts. They are printed with a low-density carbon fiber-reinforced nylon that provides strength and, when needed, temperature resistance.

To further expand its additive technologies, Penske added a PolyJet printer through its Stratasys partnership. “It’s like a traditional inkjet printer, but instead of printing ink, it’s printing a curable liquid photo polymer that is cured by UV light,” explains Miller. Penske designers will use this machine to produce part mockups, freeing up the SLA machines for steady wind tunnel model part demands.

The PolyJet will also offer unique flexibility in mockup parts design. An inkjet printer has several color cartridges that can combine to create a variety of hues; similarly, the PolyJet cartridges can hold several different polymer systems that can be combined in various ratios for different material properties.

Miller says Penske hopes to see more large-format 3-D printers that can work with continuous fiber reinforcements and materials with higher temperatures in the future and closely monitors that space in the additive industry. “There’s the potential that you could get higher strength and more structurally optimized components with it,” he adds.

Smoother Sailing

Daniele Cevola and Francesco Belvisi are co-founders of Livrea Yacht, a yacht design and manufacturing company based in Palermo, Italy. They introduced their first yacht model with 3-D printed parts – the Livrea 26, Born by the Wind – at the Miami Boat Show in 2014. Most of that boat was built using carbon fiber molds and conventional composite manufacturing techniques, but some small sections were 3-D printed. “Our partner, the CRP Group, used only sintering 3-D printing technology, so there were limitations on the size of the parts we could build,” Cevola explains.

Since that time, the partners have continued to explore design possibilities that additive manufacturing offers to boat builders. To produce larger parts, they developed a specialized extruder and partnered with KUKA Robotics, software provider Autodesk Inc. and LEHVOSS, a German chemical company that specializes in high-performance carbon and glass-fiber reinforced polyamide (PA).

One of the big advantages to this printer setup was its six axes of movement. “The first time we had to put our extruder in a CNC machine with three axes, x, y and z. But with six axes we can find a different configuration that can better solve many problems in the dynamics of the movement of the robots. This allows for more precision in the part,” says Cevola.

With 3-D printing, Cevola can find different solutions to boat building challenges. “We want to change the rules for sailboat and motor boat manufacturing, because right now they are designed and built the same way they have been built for 50 or 60 years,” he says. “There needs to be more innovation in the marine industry.”

Boat builders typically produce a wooden model, build composite molds from these models and then use the molds to build the hull or other parts with FRP materials. This can be both expensive and time consuming, Cevola says. “We propose a new era for the production of boats – building without the production of molds.”

Working with molds is limiting, since you have to respect the “rules” of the mold when designing a boat hull, deck or other component, says Cevola. For example, the part has to be shaped so that it can be successfully extracted from the mold. “With 3-D printing, you can create shapes that enable you to design new functions into your object. You can integrate many different functions when you don’t have to follow the rules of the mold,” says Cevola. “It’s a new vision, a new possibility for design.”

The Livrea Yacht partners have a specific goal in mind as they experiment with manufacturing boats through the 3-D printing process. They intend to enter a 3-D printed yacht in the 2019 Mini Transat, a 4,000-mile solo race that starts in France and ends in South America.

It would be the first 3-D printed boat in history, says Belvisi. “In the Mini Transat project, we are exploring new ways to produce a high-performance boat, thanks to the possibility of integrating multiple functionality and of manufacturing complex and optimized structures that aren’t possible to build in the traditional way.”

Cevola believes that Livrea Yacht’s 3-D printing technology will become available for many shipyards within the next few years, but he thinks boat builders will use it primarily for high-end, custom yachts, much as Porsche, Lamborghini and Ferrari are using 3-D printed parts for their higher end cars.

Magnetic Reinforcements

Startup 3DFortify has attracted attention with its unique method of fine-tuning the properties of composite products it builds using additive manufacturing. Josh Martin, president and co-founder, notes that injection molders have been reinforcing their composite tools with carbon and glass fibers for years, but 3-D printed tools have not usually included that additional fiber strengthening. Now, using its custom-made 3-D printers, 3DFortify introduces magnetized carbon fiber technology to composite tools.

The founders of Livrea Yacht designed their own robotic extrusion 3-D printer to produce hulls and other larger sections of yachts. Photo Credit: Livrea Yacht

“Magnetizing the fibers gives us the ability to control their alignment in real time during the additive manufacturing process,” says Martin. As a result, 3DFortify can print very complicated, high-resolution shapes that can be individually fine-tuned to create desired mechanical and thermal properties in different parts of the tool. “We are able to provide highly detailed and also very robust parts. In a lot of other processes, you can get high strength but you usually sacrifice resolution,” adds Martin.

3DFortify’s process dramatically reduces the time required to produce composite parts. One consumer products customer has dozens of items that require short runs of around 1,000 parts. The typical manufacturing process for a conventional tool could take four to six weeks. 3DFortify can make a similar tool in about four to six hours, saving the customer both time and money.

3DFortify uses a light-based stereolithographic 3-D printing process. “It’s been proven to be one of the most scalable 3-D printing methods,” says Martin. To date the company has been able to print tools for injection molding everything from ABS to polycarbonate, and it continues to look for ways to print composite products with tougher and stronger resins that can handle high temperatures. While 3DFortify is now limited to printing tools that are 3 x 4 x 12 inches (in the x, y and z range respectively), the company is moving toward scaling up to print up 12 inches in each direction.

3DFortify is currently concentrating its efforts in the injection molding, aerospace and automotive industries, but Martin says the process will be valuable in the biomedical industry and several other markets that require high-strength, customizable composites.

Going Green

Researchers at Oak Ridge National Laboratory (ORNL) have been exploring the use of biocomposite materials for additive manufacturing. In 2016, they produced a 3-D printed table made from a bamboo composite. So when SHoP Architects of New York contacted them last summer about using that bamboo material to build sections of two pavilions, researchers were eager to participate. But they were also a little daunted by the task. “We were going to go from a small table to a structure that required 10,000 pounds of material,” says Soydan Ozcan, a senior R&D scientist in composites and additive manufacturing at ORNL.

SHoP won a competition to design two entrance pavilions for the 2016 edition of Design Miami, a yearly showcase for architects and design professionals. The firm tapped Branch Technologies to print the overhead structural trellis/framework for the pavilions – named Flotsam & Jetsam – and asked ORNL to manufacture the support legs, seating areas and counter space.

The entire structure was printed using a 100 percent biobased and biodegradable composite material – a bamboo-fiber reinforced biopolymer formulation, made with 20 percent bamboo and 80 percent polylactic acid (PLA), a biodegradable, thermoplastic polyester.

“Making the material printable is the No. 1 manufacturing challenge,” says Ozcan. “We had to go to the manufacturer to modify the material and adjust it for the layer time. In order to get the needed strength when the two layers are bonded together, the first layer needs to be fully solidified before putting the second one on.” ORNL researchers worked with Sunstrand, which fillibrated the bamboo materials to the correct micro size so they could be used in the composite material.

ORNL researchers also wanted a material that could move through the printer more quickly and was UV-resistant so it could survive the harsh Miami sun.

The laboratory used its Big Area Additive Manufacturing (BAAM) printer to produce the pavilion components. With BAAM, ORNL can manufacture parts up to 20 feet wide, six feet long and eight feet high. The laboratory printed the pieces in about a week working around the clock, processing about 50 pounds of the bamboo composite per hour. Ozcan says the manufacturing process took longer because this was ORNL’s first big structure and they had to work out some kinks in the process. The BAAM machine is capable of nearly double that speed using the biomaterial composite.

The biodegradable bamboo composite has one-third of the embodied energy and a carbon fiber footprint that’s 90 percent less than a comparable carbon fiber composite, Ozcan says. Although it might not offer the same strength properties as carbon fiber, the bamboo composite was more than strong enough for this application, and it offers many other advantages. One of those is cost; bamboo composites are 40 to 50 percent cheaper than carbon fiber composites.

“Bamboo is a very, very renewable material; some species grow more than three feet in a day. When harvested, it will grow new shoots from its extensive roots, so there is no need for additional planting or cultivation, and it also absorbs 35 percent more carbon dioxide per hectare than trees,” says Ozcan. Bamboo can grow in a variety of climates without the use of fertilizer, pesticides or herbicides and, unlike carbon fiber, requires very little energy to produce.

The Flotsam & Jetsam pavilions, the largest “green” structures ever printed, attracted a lot of press attention when Design Miami opened. They were later moved to a more permanent location in the city, where ORNL researchers hope to observe how the material stands up to the hot, humid, salt-laden air. (The pavilion was disassembled and stored prior to Hurricane Irma.)

Ozcan says ORNL is also exploring a variety of other renewable materials, including those made from forest products, for use in additive manufacturing. “Nanocellulose – the next generation reinforcement – is extremely strong, highly stiff and we are trying to find a commercial way of using it for 3-D printing,” he adds.

Using additive manufacturing with locally grown, biocomposite, biodegradable materials opens up a range of possibilities and opportunities for creating local businesses and local jobs, says Ozcan. “I really believe that down the road there will be a rethinking of manufacturing and the growth of the sustainability portion of it.”

Technology Trends a Topic of the GCC

Advances in additive manufacturing impact the composites industry’s global supply chain. To learn more about the global footprint of hot topics like 3-D printing and other emerging technology trends, attend the Global Composites Conference, co-produced by ACMA and NetComposites, Jan. 31 – Feb. 1, 2018, at Caesar’s Palace in Las Vegas. Register today at http://globalcompositesconference.com/.