Hemp in biocomposites

Erwin Lloyd

BioComposites Solutions, P. O. Box 2928, Blaine, WA 98231-2928

        Economically attractive opportunities exist for incorporating bast fiber plants, including hemp, into composites.  Careful consideration of product development, however, is important in order to improve the potential for success.  In order to maximize the potential of a hemp-based composite, it is important to consider the production costs relative to a similar product made from competitive materials such as wood.  This assessment is particularly important in regions that experience rather low-costs for competing fibrous materials.  Even the least expensive portion of hemp, the core section, is generally more expensive than such wood residue as sawdust or shavings, which may be used to form particleboard and, increasingly, medium density fiberboard (MDF).
        Hemp as an annual crop has special challenges relative to a “year-round harvestable” product such as wood.  These become obvious concerning the Fall harvest, raw material transportation logistics, additional storage costs, and biological degradation during storage.  These factors further detract from the commercial viability of agriculture-based composite materials.   These disadvantageous factors are magnified when hemp materials are competing against low-cost wood residue produced in large-scale operations.  In light of these factors, commercially viable products need to be competitive in terms of both performance and cost.
        On the other hand, wood costs are generally rising with demand surpassing supply.  In fact, the international wood-based fiber supply balance is now beginning to shift in favor of alternative fiber materials, including industrial hemp.  In light of these changes, hemp fiber may become increasingly competitive in price relative to wood, particularly since only aspen and poplar, fast-growing tree species, are alternatives to conventional wood sources in northern latitudes such as the northern United States and Canada.
        Many rural communities, particularly those which are struggling, are keenly interested in opportunities to augment their manufacturing base and their overall economy.  This strong desire to find solutions provides the impetus to assist in providing necessary support to bring such a project together.  When considering the best products to be made from hemp, one must determine the distinctive properties of the particular agricultural material in question and pay particular attention to hemp’s advantages in terms of economics or performance, relative to established similar applications with conventional materials.   The following recommendations apply.
        Develop a product that accentuates its advantageous features, while minimizing its negative aspects: for example, the higher yields and greater strength of hemp fibers.  Look for products which can better use hemp in its natural form.  Greater effort, energy, and cost is needed to break hemp stalks into small pieces for particleboard, as compared with the already small size of wood sawdust or shavings.  Consequently, a better choice for hemp may be select a product that would use longer lengths of the stalk.
        Review the history of similar products or raw materials such as flax, kenaf or other bast materials.  Many good ideas in the past have died due to a change in personnel or a cut of research and development budgets.   Today’s market may have enhanced the economic viability of an idea or product from the past.  Explore recent technological developments.  New technologies may reduce processing costs and can certainly bring enhanced features and performance to composites.  This can make a hemp-based composite an economically viable and even lucrative venture.  In recent years, more groups have begun to focus on these areas.
        Adapt various processing and product development ideas from other industries.  Most new inventions, especially processes, are simply new combinations of existing ideas.
        Consider the level of production anticipated, relative to that of the closest competition.  In recent years, non-wood bio-based composites output has generally been 10-50% that of a comparable wood-based facility.   This disparity generally grants much greater economies of scale to any similar wood-based product.  The lower level of production of agriculture-based composite materials is due somewhat to the unproved nature of these non-wood material ventures, but primarily it is due to a lack of funding.
        If competing on a commodity basis, try to maximize capacity.  Generally, added productivity far outweighs additional line costs for processing machinery.  For example, in a recent feasibility study, 14% additional total project capital costs devoted to larger machinery in a single line yielded an increase in productivity of 40%.  If limited funding restricts a group to consider only a smaller-scale production plant, then it generally is best to try to target a specialty or niche market for the product.
        In order for hemp products to be economically viable under today’s conditions, it is preferable for them to be distinguishable from wood-based products made from low-cost raw materials.  This is especially true for particleboard and to a lesser extent MDF.  If applications for products such as particleboard or MDF are considered, it is preferable for them to have specialty uses commanding a higher price.  Static-free particleboard for use in electronic clean rooms commands a price 2.5 times greater than that of conventional particleboard, through the addition of a special charged substance.  Moreover, lower levels of production, common in non-wood composite operations, may well be more compatible to this application’s volume-limited niche or specialty market.
        Evaluate adhesive costs, especially those relative to those costs for competing applications.  In traditional large-scale wood composite plants, such as MDF plants, the total raw material adhesive costs are generally equal to their fiber costs.  These adhesive costs may be US$ 7 million per year or more.  Such costs with non-wood materials, including hemp, are often 1.5 - 3 times more expensive for a given volume, than that of wood-based composites.  Consequently, this is a crucial consideration in terms of overall financial viability.
        In business plans and financial modeling, be certain to calculate profitability over the full breadth of historic product prices — both highs, and especially, lows.  This analysis is particularly relevant for commodity products such as particleboard, MDF, and oriented-strand board (OSB).  Many raw material, adhesive, and processing choices will be profitable and viable in time of high or even average product prices.  The real test is whether a plant, with its rather expensive equipment and high capital investment, can be profitable, or at least break even, during the historic lows of product pricing which invariably will occur.
        Consider hemp’s compatibility with other, preferably nearby, materials in composite products.  For example, bast fibers such as flax, hemp, or kenaf can provide fiber reinforcement as a substitute for glass fibers as structural reinforcing agents in other materials, such a concrete, wood, and straw.   Straw in a lower density form could provide internal insulating features, while higher density straw or bast fibers may supply strength in exterior portions of the product.

        For further information contact Erwin Lloyd at: Tel: (604) 738-4180, Fax: (604) 738-4180, E-mail: biocomp@intergate.bc.ca, Home page: http://www.forestnet.com/cascade/index.html