April 16th, 2015 – If I told you there was a way we could manufacture most of what we use in a way that is renewable, biodegradable, has a reduced carbon footprint and has augmented mechanical properties, and still competitively priced relative to our current methods wouldn’t you be wondering why it isn’t already in use?
Hemp plastic is a composite material made up of a polymer base augmented with the use of fiber additives. To understand the resulting material, first we need to take a look at its components.
Industrial hemp is the term for high growing varieties of the Cannabis Sativa plant. What many are not aware of is that hemp is not the same as its psychoactive sister, marijuana. Industrial hemp contains less than 0.3% THC (Tetrahydrocannabinol), the psychoactive component in marijuana. Therefore it is not possible to get “high” from hemp. It even contains a substance called Cannabidiol (CBD) which blocks this high, plus has many other beneficial medicinal properties. This crop was once the stable of the American economy but was made illegal in the 1930’s. It is still grown in abundance worldwide and produces one of the strongest natural fibers known to man. It has many useful applications including medicine, biomass, textiles, papers, foods, and bioplastics.
Hemp plastic is a bioplastic that is made using industrial hemp. There are different grades of the material which differ by the ratio of hemp fiber to polymer base. They can vary from standard plastics reinforced with fibers to a 100% hemp cellulose structure. This allows for a wide range of mechanical properties which are tailored to the desired application.
There are many benefits that hemp plastic has compared standard oil based polymers. Listed below are just a few in detail:
Increased Strength And Lightweight
The addition of the organic hemp fibers strengthens the base polymer matrix. These fibers are spread in a more random arrangement making the increase in strength come in every direction, unlike carbon fiber or bamboo where certain orientations are much weaker. Compared to your standard oil based plastic Polypropylene (PP), hemp plastic boasts a 150% increase in tensile strength, the maximum strength to break, and a 250% increase in rigidity, the force required to bend or deform the material.
With the addition of hemp fibers the material still remains lightweight. While the material’s strength increases greatly the overall density only increases marginally. This results in a composite that has a very high specific strength, the ratio of density to strength. This allows the possibility for it to be used to save weight in applications such as automotive and aerospace.
Biodegradable And Recyclable
When made with a biodegradable polymer hemp plastic is fully biodegradable and recyclable. Here lies the great potential for this material. Normally we think of recycling as a reuse or reshaping of mechanical parts, though if we were to use more biodegradable materials we could introduce a whole new cycle that would be much more environmentally friendly.
The cycle starts as plants are harvested and broken down into the necessary components for production. As a result, a product is produced. After its life or use, the component is put into a landfill where nature does its work. The product is broken down into the necessary nutrients which are essential for the plant’s growth, thus completing the cycle. Hemp plastic is a truly sustainable solution to oil based plastics.
Hemp is known for its ability to absorb carbon dioxide (CO2), it breathes in four times the amount trees do during its quick 12-14 week growing cycle. Producing hemp plastic requires 22-45% less energy than fossil fuel based plastics. Taking into account the amount of carbon emissions absorbed during cultivation, carbon emission savings are upwards of 70% with most coming from processing and machinery. As technology improves with growing adoption this is surely to decrease.
The price for the prepared hemp plastic raw material is only marginally more than standard oil based plastics. Hemp crop is very easy to grow and can be done so from pretty much anywhere. Hence why some may say it grows like a “weed”. It also replenishes the soil greatly. Farmers will use it as part of their seasonal cycle to replenish the soil with nutrients that were absorbed by other crops. The only problem here… it is illegal to cultivate in the US except in Colorado, requiring most companies to have it imported.
Hemp plastic is fully plastic injectable, allowing it to be used to produce many of the same items we use every day. This process works by filling up a hopper which melts down the raw material and extrudes it into a mold cavity. Once it has solidified the part is finished. This process is very efficient and can produce many parts at a low cost with high complexity and detailed geometries.
With the benefits hemp plastic and the legalization of industrial hemp could bring to our society it is a shame that in 2014 it is still illegal to cultivate in the US. Lotus Boards is on a mission to raise awareness for the widespread use and to educate. We encourage you to Join the Hemp Revolution and stay posted throughout our development.