Durability of Wood Exposed to Alternating Climate Test and Natural Weathering

Abstract

The use of wood-based materials in the automotive industry is currently under discussion and investigation. One of the major material requirements for such applications is sufficient weathering stability. This can be demonstrated by an accelerated aging process in which the samples are exposed to changing climatic conditions and a spray mist of an aqueous NaCl solution. The effects of media salt (NaCl) on the mechanical and physical properties of wood have scarcely been investigated. The presented study investigated the changes in bending strength (MOR), modulus of elasticity (MOE), and impact bending strength (α) of naturally and artificially weathered oak (Quercus spp.) and birch (Betula pendula Roth) wood. The tests provided comparable results. The decrease under natural weathering of oak was 3.73%, 4.69%, and 6.45% for MOR, MOE, and α. Under artificial weathering the decrease observed for oak was 7.33%, 10.87%, and 16.29% and 3.2%, 8.21%, and 4.03% for birch respectively. It is remarkable that α increased for birch wood at the beginning of the artificial weathering cycles. The penetration of the aqueous NaCl solution into the wood substance resulted in an increase in the wood’s equilibrium moisture content (EMC), which can be explained by the stronger hygroscopic properties of NaCl compared to wood. The higher impact strength at the beginning of artificial weathering can be partly explained by this increase in EMC. In order to investigate the penetration behavior of salt into the wood substrate, the artificially weathered samples were examined by means of energy dispersive X-ray analysis (EDX) and it was shown that the salt concentration changes significantly over the weathering cycles and sample cross-section.

Effect of climate and wood type on elastic modulus of heat-treated wood and its optimization by the Taguchi method

“…Elastic modulus values of wood exposed to artificial air conditioning conditions varied depending on the amount of moisture it contained. (Stadlmann et al 2020). In line with previous studies, the elastic modulus values of oak wood were higher than those of Scots pine and chestnut wood among wood types and were parallel to the literature.…”

“…It was determined that the elastic modulus values of sessile oak wood were higher than Scots pine and chestnut wood(Todorović et al 2022). Elastic modulus values of wood exposed to artificial air conditioning conditions varied depending on the amount of moisture it contained (Stadlmann et al 2020)…”

Interfacial Adhesion and Mechanical Properties of Wood-Polymer Hybrid Composites Prepared by Injection Molding

“…However, low mechanical properties and poor creep behavior of polymer-based components without fiber reinforcement (e.g., dashboards, claddings or wheel cases) negatively affect the applicability for load-bearing components in automotive parts. In addition to the properties of wood in terms of load-bearing capacity and lower density compared to most polymers, wood also provides good resistance to accelerated weathering in salty environment [ 15 ]. Therefore, back-injection molding or overmolding is a suitable technique for combining the good properties of wood with the durability, weather resistance and elasticity of polymers [ 16 ] to create wood-polymer hybrid composites.…”