The hemp plant has been cultivated for at least 10,000 years and probably a lot longer. The ancient Chinese and Mesopotamians, among others, were known to have used the crop for food and fiber. As you know by now, industrial hemp is not marijuana. While they both come from the genus Cannabis, hemp has 0.3% THC or less.
As well as making clothes from hemp, civilizations soon learned that the added strength of hemp made it ideal for rope. It was even used to make paper! During the 17th century, certain colonies in North American made hemp cultivation a mandatory requirement.
You may be shocked to learn that Henry Ford once dreamed of creating a car manufactured and fueled by hemp. He went as far as creating a prototype, although the body contained less than 10% hemp cellulose fiber. In 1938, Popular Mechanics referred to hemp as a ‘billion-dollar crop.’ Sadly, the Marihuana Tax Act of 1937 had already made the plant illegal. It also received the same Schedule I classification as marijuana in the Controlled Substances Act in 1970.
Finally, in December 2018, the Farm Bill was passed into law. At the time of writing, it is legal to grow industrial hemp in the United States. Although it has happened 80 years too late, hemp is finally going to be a legal billion-dollar crop, and the potential of hemp biocomposites is mind-blowing.
What Are Hemp Biocomposites?
To answer that question, you first need to understand a couple of other terms:
- Composite Material: A material made from at least two or more constituent materials with different chemical or physical properties. When combined, this ‘composite’ material will produce a material with traits different to the separate components. Composite wood such as plywood is a prime example.
- Biocomposite Material: A composite material formed by a matrix (resin) along with reinforced natural fibers. The resin is formed by polymers which come from non-renewable and renewable sources. The resin protects the fibers from mechanical damage and degradation from exposure to the environment. The bio-fibers used include recycled wood, cotton, flax or hemp.
Using this information, we can now say that a hemp biocomposite actually means using hemp as reinforcement in composites. Blending materials include polyethylene, polyester, and polypropylene. It is possible to use a 100% biocomposite because you can add canola, corn, or soy as plant-based resins.
Hemp biocomposites are used in various consumer products including furniture and automotive interior substrates. Manufacturers use hemp fiber to produce mineral-based composites in a manner akin to using glass fiber to reinforce plaster or cement.
We live in an era where companies are desperately trying to develop sustainable, recyclable, and biodegradable materials. Hemp fibers, which are found in the stem of the plant, fit the bill on all three counts. They are also extremely strong and durable. For reference, hemp fibers can hold nearly double the weight of steel before it will crack and break.
Hemp fiber also has 62% greater tear strength and double the tensile strength of cotton denim. Hemp also produces over 2.5 times the fiber of cotton and seven times the fiber of flax when you use the same amount of land. Each hemp plant that grows can save 12 trees, and it can be grown without the need for pesticides. Finally, it only takes hemp 3-4 months to grow.
Here are a few most likely uses for hemp biocomposites.
Hemp fiber’s strength means it is a viable, cost-effective option for companies looking to maintain environmentally-friendly and sustainable building practices. Hemp can be made into almost any building material including wallboard, flooring, cement, paint, paneling, bricks, and plaster.
In August 2010 in Asheville, North Carolina, the world’s first home made entirely from hemp was built. Other examples of building composites that involve hemp are roofing shingles. There is even ‘hempcrete’ which is a mixture of hemp hurds and lime. When these two materials combine, they create a chemical reaction that binds the mixture, and it continues to get harder until they fossilize. Houses made with hempcrete could last for hundreds of years!
Interiors and Exteriors
Hemp oil is perfect for use with natural wood sealants and paints. It offers exceptional performance with no concerns about Volatile Organic Compounds (VOCs). It dries quickly and penetrates deep into the wood for outstanding all-around protection.
Did you know that hemp fiber has antibacterial properties? It is claimed that hemp fibers kill various types of surface bacteria such as E-Coli. As a result, hemp biocomposites could be used in the creation of baby toys, kitchen implements, and exercise mats.
The qualities of hemp fiber make it an outstanding option in the textiles industry. It is the strongest and toughest of all natural textile fibers and holds its shape. Therefore, garments made from hemp are less likely to become stretched out or distorted.
A Golden Opportunity
The potential for hemp biocomposites was well known long before the Farm Bill was passed. According to a Market Report released in September 2015, the global natural fiber market was forecast to grow at a CAGR of over 8% from 2015 to 2020. The report stated that the main driver for the growth of the hemp market was increased demand for environmentally-friendly, sustainable, and lightweight composite materials in applications such as building & construction and the automotive industries.
An April 2016 report, imaginatively titled ‘Natural Fiber Composites Report’ analyzed the increased demand for hemp biocomposites for applications including window and door frames, park benches, railings, floors, and outdoor deck floors.
Ford Wasn’t Crazy – Hemp Cars Could Become a Real Thing
Practically every report that outlines the growth of the hemp biocomposites market notes that demand is at its greatest in the automotive industry. This is down to the greater need for safer, lighter, and more fuel-efficient vehicles. Already, major car-makers including General Motors, Audi, and BMW, are using non-wood fiber composites for the design of exterior and interior parts.
The latest Corporate Average Fuel Economy (CAFE) standards on the reduction in vehicle weight for greater fuel efficiency, means that the demand for hemp biocomposites and other natural fiber composites is set to skyrocket.
An estimated two million vehicles made in North America use biocomposites. Nonwoven hemp matting and epoxy or polypropylene are pressed into parts including trunk liners, package trays, and luggage racks. They are used instead of fiberglass composites which are heavier and not as safe.
The idea of making cars from hemp is more than a fad as major manufacturers are preparing for the hemp revolution. Researchers in England and Australia have been working on developing materials from hemp for almost 20 years. When carmakers finally embrace hemp, they will find that even creating an outer shell from hemp fibers will make a difference; imagine a scenario where a car’s body doesn’t rust or rot?
In the United States alone, over 11 million vehicles reach the end of their useful lives each year. Admittedly, all but 4% of these vehicles are processed by different facilities, 25% of the vehicles by weight become waste. This waste is mainly compromised of fibers, foams, rubber, glass, and plastics.
In theory, a car made from hemp could be buried when it is finished and eaten by bacteria! At present, it is mainly European companies looking to make the leap, but the movement of GM in the United States, plus the fact that industrial hemp cultivation is now legal, means that other car firms will have to update their manufacturing processes or risk being left behind.
Final Thoughts on Hemp Biocomposites
Hemp was an important crop for thousands of years and was used to make everything from clothes to rope. It was arguably on the verge of a mainstream breakthrough in the United States in the 1930s until the Marihuana Tax Act ruined everything. The likes of William Randolph Hearst and the DuPont family had paper and nylon empires to protect respectively, which meant that hemp, a real threat to their existence, had to go.
80 years later, it has finally received the green light, and you can now legally grow industrial hemp in the United States. This new and improved legal status means that hemp fiber will once again be widely used. It is remarkably strong and tough, grows quickly, and is the cost-effective, biodegradable, and renewable material that manufacturers in several industries have been waiting for.