Exploring the Potential of Mycelium Composites as Natural Board Materials

Abstract

Mycelium composites are an attractive alternative to turn to more sustainable construction materials. Mycelium, the vegetative growth of fungi, is formed by a network of hyphae (elongated fungal cells). This mycelium network has the capacity to partly degrade carbon-rich fibres while binding them together. In this way, a biological process can serve to create biobased composite materials, in which the fungal biomass functions as inherent adhesive while the fibres provide the structural support. Finished mycelium composites can be heat-pressed into sheet materials. In this research, mycelium composites are heat-pressed to explore their potential as board material. We studied the influence of the substrate, heat-press process and increased thickness on the flexural strength of the materials. The used mycelium composites consisted of straw fibres, or a combination of rapeseed straw (RS) and cellulose, bound together with the fungus Ganoderma resinaceum. Through systematic study of the process parameters pressure, time and temperature, an optimized heat-press process was determined by flexural strength performance. As opposed to literature this project found flexural strengths within the range of glue-bound board materials such as particleboard and MDF. Mycelium composites made 100% of RS reached a flexural strength of 19 MPa, while mixed cellulose and RS showed a flexural strength of 12 MPa. Thicker materials were also produced and showed a flexural strength similar to thinner boards. This study showed that substrate composition, and heat-press process can influence material properties of mycelium boards.