The effects of chemical components and particle size on the mechanical properties of binderless boards made from oak (Quercus spp.) logs degraded by shiitake fungi (Lentinula edodes)

Abstract

Binderless boards are composite boards that rely on self-bonding mechanisms for inter-fibre bonding. Quercus acutissima and Quercus serrata logs degraded by Lentinula edodes (shiitake fungi) were used in this study to investigate whether physical and chemical changes induced by shiitake fungi can enhance board mechanical properties. Binderless boards were manufactured with 0.8 g/cm 3 target density, 220 °C pressing temperature, 5 MPa pressure, and pressing duration of 10 min. Boards made from logs degraded for ≥ 26 months were stronger than control boards and met modulus of rupture (MOR) and internal bonding (IB) requirements for fibreboards. Chemical composition and particle size distribution of the wood powder used to make the boards were determined to elucidate the drivers of board mechanical properties. The proportion of small particles (< 150 µm) showed a strong positive correlation with MOR for both species and hot water extractives showed a strong positive correlation with IB for Q. acutissima boards. Introduction of shiitake fungi pre-treatment to the production process may enhance the mechanical strength of binderless boards.

Structural, Thermal, and Mechanical Properties of Spent Mushroom Substrate (SMS) and Rubberwood Sawdust (RWS) Binderless Particleboards

“…It is obvious that the average particle size of SMS (~686.7 µm) is smaller than RWS (~852.6 µm). This observation can be supported by Liu et al, [24] in a study on various properties of binderless boards made from oak logs degraded by fungi. It was also reported that the reduction of the particle size can influence the mechanical properties of the binderless particleboard [36].…”

“…In the current study, 13.81 % of the extractives were measured from the SMS fiber, while 4.46 % from the RWS. Higher concentration of extractives in SMS can be due to the presence of a larger amount of sugar content in the fiber [24]. As mentioned before, lignocellulose-degrading enzymes play a crucial role in converting lignocellulose into carbohydrates and noncarbohydrates components [33].…”

“…The breakdown of hemicelluloses into small sugar monomers, and also degradation of lignin during enzymatic pre-treatment can contribute to the self-bonding between the fibers [21][22][23]. The current can improve the mechanical properties of the particleboard [21,24]. The determination amount of lignocelluloses component that undergoes degradation during mushroom growth activity is important.…”

“…Previous studies report that the chemical composition of wood fiber is important as it will affect the mechanical performance of the board [21,24]. The determination amount of lignocelluloses component that undergoes degradation during mushroom growth activity is important.…”

Optimization of processing parameters for the manufacturing of jute stick binderless particleboard

“…It seems that fine particles work as fillers in coarse particles for JBPB-M [36]. Lui et al [37] reported that adding fine particles contributes to the improvement of the bonding strength of the board. Since, fine particles provide a larger contact area among particles compared to coarse particles, resulting in stronger bonding of JBPB-100 compared to JBPB-0 [26].…”