The positive relationship between wood density and mechanical properties drives interest in compression techniques. A significant challenge in this practice is the tendency of compressed wood to revert to its original dimensions, particularly when exposed to heat and moisture – a phenomenon known as set recovery. To tackle this problem, previous studies have investigated heating or steaming pre or post compression, resulting in greatly reduced set recovery, but generally reducing mechanical properties. Others have used toxic chemicals, most prominently phenol-formaldehyde resins, achieving great shape fixation, but posing challenges to work- and user safety. This study investigates a method to reduce set recovery by treating wood with a low-toxicity, water-based solution of citric acid and sorbitol, followed by hot-pressing and subsequent heat curing to induce poly-esterification.
Keywords: Wood, Set recovery, Citric acid, Sorbitol, Compression, Modification, Durability
Authors
Halvar Meinhard
Department of bioproducts and biosystems, Aalto university, Finland
Shiying Zhang
Department of bioproducts and biosystems, Aalto university, Finland
Shennan Wang
Department of bioproducts and biosystems, Aalto university, Finland
Lauri Rautkari
Department of bioproducts and biosystems, Aalto university, Finland
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