Tree bark insulation panels for special purpose insulation: evaluation and discrete modeling of structure property relationships

Bark is a highly efficient natural tree protective layer with outstanding properties. It is a classic by-product of the wood industries and most of the time directly burned where it accrues. The present study focuses on using bark as a material in form of thermal insulation panels. Therefore, insulation boards out of softwood (Larix decidua) bark were produced using different resins as a binder. Also, the orientation of bark particles within the boards was controlled in the experiment. The boards were analyzed for their physical-mechanical properties. Additionally the boards were scanned with an industrial computed tomograph (CT) in order to study the structure of the boards. That knowledge of the board's microstructure enabled the application of a numerical model for thermal conductivity based on the finite difference method (FDM). A theoretical discussion of the heat flow processes within the boards was used to propose optimization potentials in order to lower their thermal conductivity. An integrative discussion of physical-mechanical and structural bark insulation board properties was conducted to define potentials for industrial application.