Properties Of The Western Juniper (Juniperus Occidentalis) Strandboard

Western juniper (Juniperus occidentalis) is an invasive tree species that is widespread in the western United States. Western juniper woodlands are in Oregon, California, Washington, Idaho, and Nevada (Bedell et al. 1993; Swan 1995). These woodlands occupy approximately 3.4 million hectares, and the majority (over 2.6 million hectares) are in Oregon (Azuma et al. 2005; Miyamoto 2017; Eastern Oregon AgriculturalSuperscript/Subscript AvailableABSTRACT This work investigated the feasibility of using western juniper (Juniperus occidentalis) as a material to manufacture oriented strandboard (OSB) panels. Four different material combinations of juniper sapwood, heartwood, and fibrous bark were compared with regular southern yellow pine (Pinus sp.) strands. The OSB panels were made at an oven-dry density of 560 kg/m3. One pine control panel was also made at a higher density of 650 kg/m3 with a 5% addition of phenol formaldehyde (PF) resin and a 0.5% addition of wax. The single-layer panels were formed with a hot press, and the physical and mechanical properties were tested according to the ASTM standard D1037 (2020). The testing indicated that western juniper is a potential material for manufacturing of OSB panels. The properties of the juniper panels were equivalent or slightly better than those of the southern yellow pine panels at the same density level, except for the modulus of elasticity (MOE). The lower density of the juniper OSB panels may have benefits in construction applications and can decrease transportation costs.