Processing high-performance woody materials by means of vacuum-assisted resin infusion technology

Abstract

Abstract High-performance materials derived from natural wood have been vigorously developed, however, their commercialized products are very limited owing to the lack of industrial production efficiency and increase of environmental concern. This study is aimed at developing a clean process for large-scale production of high-performance woody materials without involving any chemical methods. The industrialized vacuum-assisted resin infusion (VARI) process was initially applied to solid wood for manufacturing woody materials with excellent flexural performances. VARI process can provide better control over harmful volatiles generated by resins than that of the traditional open mold techniques, making them compliant with “clean production”. The porosity was reduced from 66.0% to 33.8% after infusing epoxy into wood through the VARI process, and further reduced to 22.6% after being compressed. The flexural modulus and strength were significantly increased by 142.2% and 142.8%, respectively. The flexural strength (304.9\u202fMPa) reached the range of alloy, between Alloy 2024-T3 (345\u202fMPa) and Steel alloy 1040 (260\u202fMPa). Due to its relatively low density, the specific flexural strength was only slightly lower than diamond. The dramatic reduction of porosity was deemed to be the major contribution to those improvements. The fabrication of high-performance woody materials does not use chemical treatment; therefore, it could be considered as a clean production. Additionally, the contribution to clean production of this study was further confirmed by life-cycle assessment (LCA). The comparisons of environmental impacts of the woody material, steel alloy and aluminum alloy were carried out using LCA, revealing that the global warming, acidification, human health (HH) cancer, HH noncancer, HH criteria air pollutants, eutrophication, ecotoxicity, smog, natural resource depletion, habitat alteration, and ozone depletion, were reduced by 1.72–667.06 times when the woody material was used to replace steel alloy, while were reduced by 7.34–636.21 times when the woody material was utilized to replace aluminum alloy, respectively.