Understanding Hemp Plastics
Sana Packaging is known for using plant-based, reclaimed, and recycled materials. Plant...
Sana Packaging is known for using plant-based, reclaimed, and recycled materials. Plant-based hemp plastic is one of these materials, and we often hear questions regarding what “hemp plastic” actually means.
We have found that there are several common misconceptions about hemp plastics. This article will address these misconceptions and outline the current state and ideal future of hemp plastics.
We will also shed light on the composition of the plant-based hemp plastic we use and the reasoning behind choosing specific material inputs.
From an agricultural perspective, hemp is an ideal feedstock for bioplastics because it is both a rapidly renewable and regenerative resource.
Hemp grows faster than other industrial crops. It also requires less water than other industrial crops and none of the pesticides.
Furthermore, hemp presents a superior carbon sequestration potential as 1 metric ton of hemp sequesters about 1.5 metric tons of carbon.
Cambridge University researcher, Darshil Shah, also claims “hemp can capture atmospheric carbon twice as effectively as forests while providing carbon-negative biomaterials.”
Unlike many industrial crops, hemp is also a canopy crop, meaning it protects the soil from overexposure to the sun. Lastly, hemp is an ideal rotational crop because it remediates the soil it's grown in.
The domestic hemp industry is growing somewhere between 15 percent and 30 percent per year, depending on the source of your information. As is the case with many emerging industries, early industry growth reports were more bullish than recent industry growth reports.
Regardless of the domestic hemp industry’s true growth rate, the point is that cultivating hemp for industrial goods presents a very real opportunity to help reinvigorate economically stifled agricultural communities across the United States.
Hemp has already proven to be a successful and sustainable input for paper, textiles, building materials, and more – so using hemp as an input for bioplastics makes a lot of sense.
The State of Hemp Plastics
At Sana Packaging, we made a conscious decision to incorporate and highlight hemp as an important manufacturing input in our plant-based plastic products.
Unfortunately, there is a significant discrepancy between the current state of hemp plastics and how hemp plastic products are marketed to businesses and consumers.
Most, if not all, commercially available hemp plastics on the market today are biocomposites. More specifically, they are fiber-reinforced biocomposites – i.e. hemp fiber is used to reinforce an existing polymer.
Simply put, hemp stalks are decorticated and the hurd – the innards of the stalk – is micronized and then mixed with an existing polymer to create a fiber-reinforced biocomposite.
In other words, polymers are not yet being derived directly from hemp at a commercial scale. And not all of the polymers used in hemp biocomposites are plant-based. In fact, many of the polymers used in hemp biocomposites today are petroleum-based.
An unfortunate result of this is that many hemp plastic products marketed as “sustainable” are just conventional plastics mixed with hemp fiber.
These materials cannot be recycled and do not have any tangible sustainability benefits, so marketing petroleum-based hemp plastic products as “sustainable” can be considered greenwashing.
Other hemp biocomposites are made using plant-based polymers, such as PLA, which is typically derived from corn or kenaf. However, in the United States, it’s very difficult to find PLA that is not derived from corn.
While there are drawbacks to corn-based PLA, sustainability is often about tradeoffs, and using corn-based PLA as a base resin for a hemp biocomposite has some very tangible sustainability benefits.
Looking first at the drawbacks of corn-based PLA, there are both upstream and downstream issues to consider.
Some of the upstream drawbacks of corn-based PLA include the amount of water and pesticides needed to grow corn and the nature in which corn is subsidized and monocropped in the United States.
Growing corn as a monocrop provides some short-term benefits to farmers from a productivity and efficiency standpoint.
In the long-term, however, growing corn as a monocrop leads to high pesticide use, high water use, a decrease in biodiversity with a particularly negative impact on pollinators, and soil degradation in the form of erosion and fertility loss.
The primary downstream drawback of corn-based PLA is the material’s end of life cycle and more specifically, how the material interacts with our waste management infrastructure. While most PLA is certified compostable, industrial composting infrastructure in the United States is severely lacking.
GreenBlue states that only 27 percent of the population in the United States has access to industrial composting programs. And according to BioCycle, less than 5 percent of composting facilities in the United States accept compostable packaging materials like PLA.
The benefits of corn-based PLA – beyond being derived from a renewable resource – include a smaller carbon footprint and a reduction in energy use compared to traditional petroleum-based plastics.
According to a study commissioned by NatureWorks, producing PLA uses 65 percent less energy than producing traditional petroleum-based plastics. Furthermore, a peer-reviewed lifecycle assessment conducted by Total Corbion PLA confirms that PLA has a 75 percent smaller carbon footprint than traditional petroleum-based plastics.
Our Hemp Based Plastic
At Sana Packaging, we pride ourselves on our transparency. We market our hemp plastic as “plant-based hemp plastic” in order to differentiate it from petroleum-based hemp plastic and we refrain from marketing our plant-based packaging as “biodegradable hemp plastic” or “compostable hemp plastic” because they are misleading terms often used to greenwash.
Our hemp bioplastic is 100 percent plant-based and chemical-free. More specifically, it’s a fiber-reinforced biocomposite made from 30 percent micronized hemp hurd and 70 percent corn-based PLA. We also use biobased binders so the material is truly 100 percent plant-based.
We primarily use hemp plastic to manufacture pre-roll tubes, like the Sana Hemp Tube 78mm and the Sana Hemp Tube 110mm. Our hemp plastic pre-roll tubes are great for king-size pre-rolls, mini pre-rolls, blunts, and vape cartridges.
The Future of Hemp Plastics
Biocomposites have been around for decades and their use cases for packaging are limited due to, among other things, their rigidity. In other words, hemp biocomposites are not the future of hemp plastics.
The future of hemp plastics lies in hemp-based polymers. Similar to other plant-based polymers, a hemp-based polymer is derived directly from the plant’s cellulose.
Hemp-based polymers have already been developed at the lab level but unfortunately, these polymers are not yet commercially viable.
The primary obstacle hemp-based polymers face in their journey towards commercialization is our industrial hemp industry’s fledgling infrastructure. Like developing a robust infrastructure for any industry, this will take time, money, and public and private buy-in.
Similar to other plant-based polymers, another challenge hemp-based polymers will face is their end of life cycle and how they interact with our waste management infrastructure. We need more robust industrial composting infrastructure and this too will take time, money, and public and private buy-in.
The good news is that there is a bright future for hemp plastics, we just need to be patient.
Plant-based is the direction we need to be moving in for single-use products, like packaging. And ultimately, all virgin feedstocks used for plastics and other packaging materials should be sustainably sourced from rapidly renewable and regenerative resources.
As more companies start using plant-based hemp biocomposites and, eventually, hemp-based polymers, it will help generate the demand and momentum we need to further develop our industrial hemp infrastructure and our industrial composting infrastructure.
The future of hemp plastics is circular and regenerative. In fact, the future of all plastics and other packaging materials is circular and regenerative.
We need to transition away from virgin petroleum-based materials and towards biobased, reclaimed, and recycled materials. And these materials need to be reused or recycled in closed-loop systems with adequate end-of-life cycle plans like anaerobic digestion or composting.
In short, we need to transition away from our linear “take-make-dispose” economic model and towards a circular economic model meant to eliminate waste and pollution, keep products and materials in use, and regenerate our natural systems.
It is also important to emphasize that there will likely never be a “silver bullet” when it comes to solving our plastic and packaging waste problems.
The solution to these problems is a large-scale systemic change that addresses every piece of the material sourcing, compounding, manufacturing, distribution, and waste management value chain.
By Galen Kuney
Supply Chain Director
This op-ed was originally published by Packaging Strategies.