Hemp Shives Mycelium Composites - An Alternative Material for Traditionally Used Plastic Packaging

Abstract

Plastic waste is an ever-growing concern, causing harm to many ecological and human health aspects, one of the major contributors to this problem being packaging. Mycelium composites (MC) are ecologically safe materials, well suited for the short-life usage as packaging materials. In our study we made MC using fine and coarse granulometry hemp shives applying them in 3 substrate variants – with added bran, with added bran and birch bark, and as the sole substrate. We assessed material's water absorption and mechanical properties, chemical decomposition, biodegradability, mold resistance and fungal biomass. Granulometric effect was observed only when using shives as the sole substrate, where larger particle size gave poorer results. Bran did not significantly improve mechanical properties or water uptake. Bark reduced water uptake by ~200 %, but lowered mechanical properties, and provided no benefits to mold resistance which was low for all specimens. Overall, hemp MC showed complete biodegradability after 12 weeks, mechanical properties up to 0,235 MPa, compatible with expanded polystyrene, but very high water uptake of up to 1000 %. Future studies are needed to reduce water absorption and improve mold resistance, as well as invent consensus methodology for better cross-study comparison.

Mycelium-grown composites as a multidisciplinary way for the development of innovative materials for design and architecture

“…In practice, the triggering point on studies about mycelium was the obtainment and the measurement of compression strength, since the uses envisaged involved basically the design of large thickness objects, therefore mainly resistant because of their geometry: therefore, even cyclic compression studies of mycelium structure were investigated (Islam et al, 2017). In the case of substrates, such as hemp shives (Loris et al, 2022), compression properties were sufficient, indicating a strength of 235 kPa, hence compatible with what obtained with expanded polystyrene foam, depending on the density (Krundaeva et al, 2016). On the other side, hemp shives demonstrated to be a particularly flexible material, still abundant in cellulose (ca.…”

Use of hemp waste for the development of mycelium-grown matrix biocomposites: A concise bibliographic review

“…Myco-composites with hemp shives substrate achieved a compression strength of 235 kPa, fast biodegradability in 12 weeks, as compatible with composting standards, yet water absorption peaked at 1000% (Loris et al 2022). Another study incorporating hemp shives substrate in a Trametes versicolor mycelium resulted in a mycelial growth of 0.8:1, a compression strength of 190 to 200 kPa, yet an increase in stability and comparatively reduced water absorption, between 600 and 880% (Irbe et al 2022).…”