Treesearch

The 3rd North American Mass Timber Research Needs Assessment Workshop sponsored by the US Forest Service, Forest Products Laboratory was held September 20-22, 2022. The purpose of the workshop was to convene experts on mass timber and cross laminated timber to develop a prioritized list of research needs for the North American mass timber industry. Invited workshop participants included design professionals, academics, industry leaders, and government employees. The workshop built upon prior mass timber research needs workshops that were conducted in 2015 and 2018.

This study conducted a cradle-to-grave life-cycle assessment (LCA) of engineered wood flooring manufactured in the eastern United States. System boundaries in this study included the following information modules: raw material extraction (A1), raw material transportation (A2), product manufacturing (and packaging) (A3), product transportation (A4), installation (A5), product use (B1-B7), and end-of-life (C1-C4). Two disposal options were considered for flooring products at the end of useful life: landfilling and burning. The burning option captures heat, which displaces use of natural gas....

This study conducted a cradle-to-grave life-cycle assessment (LCA) of solid hardwood flooring manufactured in the eastern United States. System boundaries in this study included the following information modules: raw material extraction (A1), raw material transportation (A2), product manufacturing (A3), product transportation (A4), installation (A5), product use (B1-B7), and end-of-life (C1-C4). Two disposal options were considered, landfilling and burning. The burning option captures heat, which displaces natural gas (D stage). A functional unit of 1 m2 of flooring with a weighted average...

Of the many observations reported in cellulose literature, the phenomena of “cocrystallization” and “moisture-induced shift in XRD” (XRD-shift) need re-examination. Does cocrystallization really occur or, entirely, something else is going on? Recent research carried out by the authors suggests that upon hydrothermal treatment of wood-cellulose, where cocrystallization has been reported to be occurring, the cellulose becomes partly crystalline from the pre-existing non-crystalline arrangement.(1, 2). Similarly, although the XRD-shift of wood’s (200) diffraction plane is real, based on the...

The native state of wood-cellulose has proven to be difficult to explore. Contrary to the traditional acceptance of wood-cellulose being crystalline, in 2016, the authors' research reported that the cellulose was not crystalline.[1] New evidence, presented here, further supports the non-crystalline model. This evidence consisted of 64% H2SO4 hydrolysis of tension- and opposite-aspen woods (TW and OW, respectively), anatomical examination of the TW- and OW-woods, presence and absence of the 93 cm-1 Raman band, respectively, in TW G-Iayer and TW S2 layer, and Raman spectra of TW-CNCs, wood...

The use of cross-laminated timber (CLT) has gained popularity during the past decade in North America, with many advances stemming from completed research and construction projects located in other countries. In particular, CLT has been utilized in vertical construction projects where many of its inherent features have been maximized. Despite these advances, the use of CLT in bridge structures has been limited and CLT has not been adopted into governing bridge design codes. This paper reports the results and conclusions of the laboratory investigation of the feasibility of CLT as a primary...

Carboxylated cellulose nanocrystals (OA-CNCs) isolated by aqueous recyclable oxalic acid hydrolysis from degreasing cotton were used to observe its self-assembly behavior and chiral nematic properties. The oxalic acid here served as the sole catalyst to esterify and hydrolyze the degreasing cotton. The results indicated that the obtained OA-CNC suspensions were spontaneously phase-separated into a chiral nematic mesophase above a critical concentration, and the occurrence of chiral self-assembly is highly dependent on the aspect ratio and the surface charge of the OA-CNC suspension....

Wood is one of the most abundant biomaterials on Earth, which has been used for centuries in construction applications including furniture, roofing, flooring, and cabinetry. However, wood chips—which are a low-quality and plentiful waste byproduct of lumber milling, woodworking, and shipping operations—have low economic value and complicated disposal methods. In this paper, we propose a strategy for wood chip reuse through the fabrication of bio-based building insulation foam. Through a high-temperature chemical treatment delignification process, we introduced additional small pores within...

The search for more-sustainable materials has motivated research on lightweight, porous structures for thermal insulation and noise reduction, such as for construction and cold-chain transportation. Wood, known as one of the most renewable materials on Earth, has been widely and long used in construction for its high strength/weight ratio, wide abundance, low cost and relative sustainability. However, natural wood is much less effective at reducing noise or preventing heat loss than conventional petroleum- and mineral-based porous structures (for example, expanded polystyrene foam and...

Cellulose nanofibril (CNF) substrates that are inexpensive, biodegradable, and quickly incinerable, are potential substrates for disposable RF applications. In this paper, high-performance flexible microwave lumped elements and filters fabricated on flexible CNF substrates are reported. A spiral inductor with a resonance frequency of 29.8 GHz and quality (Q) factor of 8.5 and a metal-insulator-metal (MIM) capacitor with a resonance frequency of 45 GHz and Q factor of 85.2 were achieved in a 200 μm thick CNF substrate. Meanwhile, the inductor and capacitor exhibit outstanding mechanical...