With more than 25,000 potential uses for hemp, Mark Lindlay calls it the “granddaddy of sustainable technology.”
Linday is CEO of Green Spring Technologies, a Texas-based company that uses biomaterials, including hemp- and beer-based filament, to 3D print everyday products. Currently, the company produces pens and nameplates, but Linday’s overarching goal is to use bioplastics for as many applications as possible.
“The discarded single-use plastic items are an epidemic of historic proportions and plant-based composites are a good alternative to plastic that is polluting the oceans and our landfills,” Linday says.
According to the Plastics Industry Trade Association, 34% of American adults were not at all familiar with bioplastics, but 50% said they would consider purchasing a product at a higher price after learning about the sustainable alternative. Bio-based products only represent 0.7% of the total plastics market right now, but at least 21 bioplastic polymers are currently in use or under development — some of which are reinforced with hemp.
Hemp is slowly gaining traction in the U.S. bioplastic market as more states introduce laws to allow farmers to grow the crop and processors glean insight from the established European and Canadian markets.
How It’s Made
At North Dakota State University, researchers are tackling three biocomposite categories: short natural fiber (using hemp hurd), long natural fiber (using hemp fiber) and biopolymer development (using vegetable oil).
Associate professor Chad Ulven, who has a Ph.D. in materials engineering, says he uses a sustainable, holistic approach when considering the development of these technologies.
“We don’t start with material and say, ‘What can we do with this?’” he says. Instead, Ulven and other researchers start with their objective and aim to design a material that meets those specifications.
During his speech at the Hemp Industries Association’s annual conference, Ulven said there has been a resurgence of natural polymers since World War II with manufacturers focusing on how to make natural products look, feel and perform like synthetics.
“The paradigm is shifting,” he says. “Now, we’re looking at what nature gives us. It has a brand new and unique structure, so how can we exploit it? How do we engineer and use and design it properly? We’re creating a new path for these materials.”
In 2011, Ulven co-founded c2renew to develop “proprietary biocomposite formulations” for agricultural residuals, renewable plastics and comprehensive parts. Among its existing are the c2cup, a coffee cup made of bio-based resin and coffee waste, and the Bogobrush, a biodegradable, plant-based toothbrush.
The company is also helping to create high-tech jobs by connecting businesses that haven’t worked together previously.
C2renew uses SunStrand as its natural fiber and biomass supplier. SunStrand uses a decorticator to separate the Kentucky-grown hemp fiber from its inner woody core — a process developed nearly a century ago. What was originally done by hand is now completed with a machine roughly the size and cost of a small house.
CEO Trey Riddle says that to his knowledge SunStrand is the only commercial industrial-scale hemp fiber processor in the U.S. that can produce a technical-grade fiber.
“At the end of the day, our goal is to provide a competitive product to traditional materials — be it plastics or glass or general synthetics,” Riddle says. “Hemp is an opportunity where it can compete with some of these products.”
After c2renew receives the processed hemp, it partners with 3dom Fuel, an expert in producing coffee-, beer- and hemp-based filaments for use with 3D printers. The material is a true natural brown color without dyes that is available in 1.75-millimeter or 2.85-millimeter diameters depending on printing and product needs. One company using the custom material is Green Spring Technologies.
“The plastic we’re using is a mixture of Kentucky hemp and corn from North Dakota,” Linday explains. “We’re making plastics with domestically produced hemp material. And 3D printing is a way to get the material out in the hands of as many people as possible.”
Strong Properties
On the other side of the globe, the Italian company Kanèsis recently celebrated a fully funded Kickstarter campaign to convert industrial hemp waste to hemp bioplastic that will be used as a filament for 3D printing.
According to the company’s website, hemp bioplastic is 20% lighter and 30% stronger than polylactic acid, which typically comprises 70% of 3D printing filaments.
Riddle says that the biggest difference between hemp and synthetic fibers is hemp’s higher strength and stiffness to weight ratio compared to synthetic fibers.
“It has some good attributes, but it still has to compete not only with other natural fibers, but with other synthetic fibers,” Riddle says. “[Hemp plastics are] fairly new in the U.S. commercial space, but because natural fiber composites are fairly well known, it’s just another opportunity that has some slightly different properties. So you can take what you know from other materials and apply it to hemp.”
There are certainly some challenges when it comes to hemp-based bioplastics and biocomposites. Aside from the limited hemp cultivation in the U.S., there hasn’t been enough testing yet to determine which fiber works best for particular products and applications.
Ultimately, Linday says the goal is to replace everyday items, such as kitchen utensils, cell phone cases and plastic bags, with hemp-based alternatives, and to teach people that imported chemicals are unnecessary.
“It’s about education and mainstream products,” he says.
Industry Impact
Riddle looks at the hemp plastic industry in two segments — artisanal and industrial. Niche artisans — small-scale producers who sell locally and use value-driven marketing techniques — “will impact some people in a big way, but not the country or the agricultural economy in a big way,” Riddle says. “The only way to do that is penetration in a big industry.”
Because the performance and acquisition of non-natural fiber materials is already well-established, it’s going to take time and investment from processors for hemp to gain recognition as a “viable, reliable and robust” option, Riddle says.
“Market demand will not grow if there’s no supply,” he explains. “Farmers will only grow if there is someone to buy it, and the only people who will buy it are the processors. It’s a challenge and someone has to make an investment and get out there.”
For those interested in joining the hemp plastic industry, Linday says it’s going to be a “steeper initial investment because the infrastructure isn’t there.” Although those entering the arena are likely doing it for socially conscious reasons, it will remain difficult to compete with Chinese or European markets — especially as activity in the United States is just now getting off the ground.
Considering the U.S. Department of Agriculture reports the bio-economy contributes $369 billion and 4 million jobs to the U.S. economy annually, it’s not hard to imagine the potential of hemp-based products. Mugs, pens and bottles are out there now, but the possibilities of the future are limitless.
“I think [the biocomposite] industry will begin to converge around hemp,” Riddle says. “Not because hemp as a fiber is special, but because hemp as a plant is special. As a package, hemp from an agricultural perspective is pretty robust and because of its different applications, it will become a dominant player in the fiber industry.”