Structural Hempwood: Driving Resilient and High-Yield Solutions

In 2017, HempWood® patented its first prototypes of hemp-based structural panels and beams, intended for use in subfloors, walls, and roofing. This material, termed "oriented hemp board" or OHB, could directly replace wood-based oriented strand board (OSB) using a much faster-growing and more efficient carbon sequestering natural material. Traditional OSB is made using poplar or pine trees harvested after 15-20 years of growth and is offered in different grades depending on its structural integrity and water resistance, with grade 1 being nonstructural and subject to water damage and grade 4 being structural and certified for use in damp, outdoor environments. Currently, every commercial grade of OSB includes a phenol- or urea-formaldehyde based adhesive, with some grades also including a polyurethane. Formaldehyde-based adhesives are known to release toxic volatile organic content (VOCs) over time, leading to respiratory tract and skin damage. Since 2019, HempWood® has created products that do not include any formaldehyde-based resins, instead using a bio-based adhesive approach to achieve the mechanical performance required for non-structural, interior applications. Currently, HempWood® lumber and composite flooring is being manufactured and sold; however, these materials are for interior use only. In order to achieve the mechanical robustness and water resistance of commercial OSB, the current adhesive used must be improved. With the assistance of several experienced collaborators, HempWood® will research and develop structural OHB panels utilizing a formaldehyde- and VOC-free adhesive with properties that rival commercial grade OSB.The approach taken to achieve OHB production is three-fold. First, HempWood® will take existing OSB adhesive technology (polyurethane, formaldehyde-free) and apply this knowledge to hemp in order to understand the curing and manufacturing challenges that exist in switching from forest-based raw materials. The goal of this first objective would be to produce pre-production OHB panels (18" x 18") with mechanical and water resistance properties which match OSB grade 2 materials. In the second phase, HempWood® will begin to explore avenues in which we reduce or eliminate the polyurethane, which is often prepared from toxic polyisocyanate precursors, with a bio-based, renewable alternative. This objective will be completed with partners in academia and government research labs who have experience in formulating and testing novel adhesives which are not known to the commercial OSB community. The goal of this objective would be to prototype several of these bio-based alternative adhesives in pre-production OHB panels, allowing HempWood® and its collaborators to compare and contrast with polyurethane-only panels and commercial OSB panels. The third phase, which will be ongoing throughout the project timeline, is to assess the life cycle analysis (LCA) and carbon footprint of OHB panels in order to create a direct comparison with commercial OSB panels, evaluating the impact that HempWood's OHB would have on reducing VOCs and the creation of healthier building materials.Ultimately, through the work proposed here, HempWood® will create transformational and disruptive carbon-negative hemp building materials that are good for people and planet. The new OHB product will be cost-competitive, healthier, and 100% made in the USA! As a cradle-to-gate solution to replace OSB with a better product the United States will be on track to improve our indoor air quality and better future generations. It has been shown in 20 years of test results from the EPA and NIH that improved indoor air quality leads to more alert decision making and improve congestive ability. Further, the development of the proposed hemp-based building and construction (structural) materials would align closely with the USDA's desire to develop novel non-food, bio-based products from new industrial crops. The utilization of hemp and a bio- based adhesive would lead to a transformative product, targeting 2-3% of the current 360+ billion USD global oriented strand board (OSB) market, which is often derived from forestry sources with toxic formaldehyde-based resins.