On the surface, this proposition may seem ludicrous to the uninitiated - How can the humble hemp plant possibly be a match for the strength of steel?
I'm feeling a deep David vs. Goliath vibe just from the thought of it, right...
I mean, let’s first take a look at steel; Kingdoms have been won and lost with the swing of a steel sword, our modern world is built upon steel from the cars we drive to the skylines of our cities - we're living in a world where our very safety and security is placed in steel daily.
Even in writing this introduction, I’m struck by a funny vision of stick fighting as a child with friends and imagining my friend having a steel sword against my hemp stalk - In this situation, it’s easy to see that it would be “stronger” and we're happy to concede that steel is better for swordmaking...
So with that in mind, I think It’s important that we start with setting the parameters for this premise.
There are two key application criteria and tests that we will look at today in demonstrating ways that hemp is stronger than steel.
Firstly we're going to look at the sheer tensile strength - this is the “bending and mending strength.” Some materials will bend rather than break under intense pressure. Therefore, any material that can withstand bending AND can mend itself or return to its original shape. Thus, when comparing the “bending and mending strength”, Hemp has about six times higher strength than steel.
The second test that we’re going to look at is the “cracking and breaking strength” strength of each. The easiest example of this is a green tree branch that's able to easily bend, sway and flew - while that same tree branch dried out will easily snap and break.
Again, this comparison is not between hemp plant but hemp fibre and steel (in this case, hemp fibre plastic). That would be like comparing the raw materials used to make steel (which are only rendered "useful" after a range of resource taxing processes, techniques and technology that's been refined over thousands of years) which you could easily mistake for a pile of rocks...
In this case, we give a massive point to hemp being extremely useful and versatile from the moment of harvest (and even before it's harvested through phytoremediationthis).
When comparing the cracking and breaking strength, hemp requires twice as much pressure as required for steel. In addition, hemp fibres have a higher strength to weight ratio than steel, which in a construction scenario means lower overall weight and reduction of materials required.
Furthermore, growing hemp is a strategy for reducing atmospheric carbon. It also improves the soil texture and structure, which optimizes farming. In addition, hemp is less expensive to manufacture than steel.
In fact, the cultivation of hemp fibre crops has proven to restore mine soil! In 1941, Henry Ford unveiled the first hemp car. The dream was to create an automobile with fewer negative effects on the environment. More so, the hemp car could run on hemp fuel or vegetable oil. Only the tubular welded frame of the car was made of steel. The car's body was estimated to be about ten times stronger than steel. However, Henry Ford was not one to live in speculations. So, he used an axe on the car’s panel.
Interestingly, the axe could not cut through the hemp material. This would not have been the case if used on a steel panel. Sadly, this invention never experienced mass-scale production.
In 2017 Renew Sports Cars revealed their carbon-neutral car. Again, it is not surprising that hemp is key a component of the car. The sports car body was made from 100 pounds of cannabis, the result was a car lighter than fibreglass with high resistance to dents. The car was named Canna 225 was a lightweight beast.
One time, the founder of Renew Sports Car, Bruce Dietzen, was on a Tv Show, Jay Leno’s Garage. As talks progressed about the incredible new car, leno took the car for a test drive which he loved. In addition, Dietzen and Leno hit the car with their fists remarking that "It’s also ten times stronger than steel". Hemp did not fail to surprise the world as it absorbed the hits without a dent.
The Canna 225 Sports Car weighs about 2,500 pounds. It comes with 225 horsepower. Furthermore, a larger model, The Canna 525, weighs 2800 pounds with a 525 horsepower LS engine. It only gets better as these cars can also run on biofuel.
Throughout history, scientists have stumbled upon materials with incredibly high tensile strength. For example, in an experiment conducted by Thomas Edison in 1879, he heated bamboo splinters at a very high temperature. The result was carbon strands that could withstand incredible heat and conduct electricity.
In 1958, Roger Bacon created synthetic whiskers that were three-time stiffer than steel. In addition, they had a tensile strength that was stronger than steel. These fibres are now largely produced as carbon fibre. But, surprisingly, hemp fibres have greater tensile strength than even carbon fibre.
Graphene is another material with incredible tensile strength. Discovered in 2004, this form of carbon has a thickness equivalent to an atom.
In addition, it is about 100 times stronger than steel. Further, graphene has a better conduction ability than copper. Just 1% of graphene mixed with plastics is enough to make the material a conductor. You must be wondering, how can hemp trump this super material?
In 2014, scientists created supercapacitors by heating hemp stalk to high temperatures. The resulting supercapacitors rival the conducting strength of graphene.
Although graphene makes an incredible supercapacitor, it is extremely expensive to produce. Although hemp cannot do all the wonders of graphene material, it is a less expensive option for energy storage. Furthermore, the cost of farming, harvesting and manufacturing supercapacitors from hemp is very low compared to graphene.
Due to the undeniable tensile strength of hemp, it's no wonder seeing many mainstream industries and companies not only adopting hemp but seeing it as a key material moving forward.
Even military contractors and designers are getting in on the action by creating bullet-proof vests that incorporate hemp fibres that provide a lightweight and durable option.
This point causes a touch of internal conflict due to the military-industrial complex and the suffering in leaves in its path.
However, with the war on drugs drawing to an end (at least in respect to hemp) - I find it rather ironic how full circle this has come that there are potential soldiers on the front lines fighting in real wars who could be wearing hemp as part of their standard-issue uniform.
Find out more about industrial hemp through our 6 part YouTube series covering everything from farming, processing, products, building and more!