Method of Stabilizing Heavily Spalted Big Leaf Maple as a Decorative Coating Veneer Layer for Engineered Wood Flooring

Abstract

Spalted wood, wood colored by fungi, has been popular in woodcraft for centuries. Most spalted wood, however, is found in an advanced state of decay and cannot be utilized. This project describes the use of viscoelastic thermal compression (VTC) to investigate the potential increase in spalted woods’ strength and stiffness, with the main objective of converting so-called “punky” wood into the top layer (veneer layer or “coating”) on commercial flooring. Spalted Acer macrophyllum logs were cut into veneers of size 7 mm × 7.8 cm × 25 cm and were then VTC-treated at 150 °C and 50 psi for 11.5 min. Statistical analysis on the mixed linear models showed significant increases for both the density and hardness of spalted wood (p < 0.0001). Density and Brinell hardness increased by 84% and 209%, respectively. FTIR analysis revealed that the wood polymers present in spalted wood were more susceptible to degradation imposed by the heat of the VTC treatment compared to sound wood. Additionally, the color analysis of the wood specimens showed statistically significant changes in color after the VTC treatment (p < 0.0001), which turned the wood surface darker and redder. The use of the VTC technology to transform spalted wood into wood flooring is viable. However, when exposed to moisture, the VTC-treated spalted wood showed a high percentage of set recovery (78%), which was significantly different from the set recovery of the sound wood (71%, p = 0.004). Successful use of VTC-treated spalted wood for flooring will require addressing of the swelling issue, and additional studies are needed to fully characterize the anatomy of VTC-treated spalted wood.

The Dark Side of Fungal Competition and Resource Capture in Wood: Zone Line Spalting From Science to Application

“…Knowledge of the latter is of high importance during the application process, as determining the length of time required before stopping the spalting process is critical to provide zone-lined wood products that maintain strong mechanical properties. Determining the length of time for zone-line production also prevents the need to brace the wood, a common procedure in spalting when wood is left to decay for too long [16]. The timing of zone-line development will have to be considered during the upscaling process, as large pieces of wood will take longer to spalt.…”

The Ball Response on the Beech Parquet Floors Used for Basketball Halls

“…The conclusion of the study was that the reaction of the ball will increase by increasing its internal pressure. De Oliveira et al [22] in their study described the use of viscoelastic compression to investigate the increase in strength and stiffness of chemically modified wood. Brinell density and hardness increased by 84% and 209%, respectively.…”