A steady market for recycled fibers and resins and for biomaterials is essential to a more sustainable composites industry. Companies are beginning to recognize the opportunities.
The World Federation Sporting Goods Industry and McKinsey & Company have identified sustainability as one of eight trends that will shape the sporting goods industry in 2021. Encore, a manufacturer of high-quality wheels for racing and training bikes based in Milford, Mich., is doing its part by incorporating sustainable carbon fiber into its products.
Vartega, located in Golden, Colo., is supplying high-grade carbon fibers produced through a proprietary process from various dry fiber and prepreg scrap sources. “Vartega’s carbon fiber has the same mechanical properties as virgin carbon fiber, at a fraction of the cost,” says Andrew Maxey, Vartega’s CEO.
Photo Credit: EuCIA
Photo Credit: EuCIA
Photo Credit: EuCIA
Encore uses computer-aided technology to design the wheels, then injection molds them using carbon-fiber reinforced nylon supplied by The Materials Group (TMG) of Rockford, Mich. Encore’s wheels are highly stable, aerodynamic and have excellent structural integrity, according to the company. The carbon fiber provides superior lateral stiffness, which makes the wheels very good at cornering and at transferring the maximum amount of power from the pedal to the ground.
The wheel has thin cross-sections which can be difficult to mold, but the material with the recycled fiber is doing the job. “We are filling thin areas with tricky knit lines and also maintaining a very nice finish,” says Ed Giroux, Encore’s founder. “Vartega has stepped up to the plate and offered a material that has fulfilled our requirements. TMG has offered the support that was necessary to accomplish this.”
Maxey says that Encore’s wheels are a great example of what’s possible when world-class design meets top-notch materials. “Sustainable carbon fiber sets a new bar for reinforced thermoplastics,” he says.
Smooth Sailing
Another example of setting new bars for sustainability is the Flax 27. The sailboat’s deep, clear finish showcases the sustainable materials used in its construction. The flax fibers in the boat’s composite structure and the cork decking give the Flax 27 a look akin to a wooden boat. The epoxy resin that provides the glossy finish contains 31% bioresins made from linseed oil. Although the sandwich layers between the composite shells aren’t visible, they are also sustainable, filled with material made from recycled plastic bottles.
Designed and built by GREENBOATS, the vessel represents a decade of biomaterials research by Friedrich Deimann, the company’s founder and managing director. When he first used composite materials as an apprentice boat maker, he was excited by their lighter weight and the freer form possibilities they provided. But he didn’t like working with the glass fibers and the resins.
Deimann began researching material alternatives in 2010 and built his first boat from biocomposites as his project to become a master boat builder. He founded GREENBOATS in 2013 to continue this work and introduced the Flax 27 in 2019.
Using biocomposites for the boat didn’t require sacrifices in the composite properties. The flax fibers have the same tensile strength as glass fiber but at half their weight. Most important from the sustainability standpoint, flax fibers require only 20% of the energy required to produce glass fiber and only 5% of the energy needed for carbon fibers.
GREENBOATS has expanded its portfolio of sustainable materials to include cellulose fiber and recycled carbon fiber and has produced a resin made with 88% biomaterials.
“When we’re developing something for a client, we always keep three main variables in mind. One is performance – stiffness, weight and so on. Another is cost. And the third is sustainability,” says Deimann. The work always includes a life cycle assessment. “We have a quantitative approach toward sustainability. We always try to measure the exact impact in terms of CO2 and input energy,” says Jan Paul Schirmer, who partners with Deimann at GREENBOATS.
Using biomaterials can add a 20% to 30% premium on a product’s initial cost. But Schirmer says GREENBOATS’ customers need to consider the operational expenses over a lifetime, including the cost of disposing of it when it reaches the end of its useful life. Recyclable biomaterials provide a real economic advantage at that point.
While GREENBOATS will continue to build boats, it is now pursuing other industries. “The idea is to create applications that give us more of an opportunity to standardize production and become cost competitive,” says Schirmer. Panels for transport vans are one possibility.
Sustainable 3D
The composites industry is continually developing biomaterials and new applications for them. Oak Ridge National Laboratory (ORNL) has partnered with the University of Maine’s Advanced Structures and Composites Center, home to the world’s largest 3D printer, to develop sustainable feedstock for large-scale composite printing comprised of bio-based resins and fillers.
The research team has been working with nanocellulose, composed of nanofibrils isolated from cellulosic material. Since Maine has a large forest products industry, the team primarily derives the cellulose from trees and wood pulp, but is also exploring other sources, such as plants, agricultural wastes and recycled cardboard. Cellulose nanomaterials are lightweight with a high tensile strength, low density and high thermal stability.
“As a forest product, cellulose nanomaterials could rival the properties of traditional metals and petroleum-based materials, and their successful incorporation into plastics shows great promise for a renewable feedstock suitable for additive manufacturing,” says Soydan Ozcan, senior R&D scientist and sustainable manufacturing thrust lead at ORNL. Researchers have already printed a 1,200-pound mold for a boat roof using a thermoplastic polymer (PLA) composite containing microcellulose and nanocellulose fibers. The team at ORNL and the University of Maine is also exploring other applications of large-area, bio-based composite printing in the marine, building/construction and packaging industries.
“We are working in the areas of cellulose production, material formulation and development, and manufacturing technologies in order to bring more sustainable, cost-effective and high-performance products to the market,” says Ozcan. Cellulose nanomaterials manufactured in industrial quantities at relatively low cost will be an attractive option for many industries, including construction. For example, instead of having carpenters build specialized concrete molds, a company could 3D print them more quickly and more cost-effectively.
Biomaterials will be an important factor in a more sustainable composites industry. “In the past, we only looked at a material’s mechanical performance and its costs. Today, however, we also look at whether the feedstock is sustainable and renewable,” says Ozcan. “We are also looking at the life cycle assessment of the product. What can be done at end of life? How many times can it be used or recycled? What could be the next life for this material?” Discussing these issues at the design and manufacturing stages and making more sustainable choices will help keep composite materials out of landfills.
“People are waking up to the fact that we are consuming 1.75 planets a year in terms of the earth’s ability to renew resources,” says Forsyth. “We are going into a deficit with the planet.” Creative solutions are needed, and the composites industry needs to play a part in developing them.
