Strength, lumber tensile

Johnson BR and Gonzalez GE (1976) Experimental preservative treatment of three tropical hardwoods by double-diffusion processes. Forest Products Journal, 26(1) 39-46 Johnson JW and Kunesh RH (1975) Tensile strength of special Donglas-frr and Hem-Fir 2-inch dimension lumber. Wood and Fiber, 6(4) 305-18 Jozsa LA and Middleton GR (1994) A discussion of wood quality attributes and their practical implications. Special pnblication No. SP-34. Forintek Canada Corporation, Western Laboratory, Vanconver, BC... 

Table 8.6 shows tensile strength of wood and some plastic lumber and wood fiber-plastic composite materials. Pressure-treated lumber (PTL) is described in the... 

Wood fiber - recycled plastic composite lumber is a relatively new development and is similar to PS addition to plastic lumber because the potential exists for improved mechanical properties and dimensional stabilities. Wood fiber addition can serve as an excellent reinforcement for plastics, and wood fibers are abundant, lightweight, nonabrasive, nonhazardous and inexpensive. An effort is being made to examine the incorporation of treated and untreated aspen fibers into recycled HDPE milk bottles [Yam et al., 1990]. The work has shown tensile strength and Izod impact strength below that of HDPE alone when aspen fiber is added. Tensile modulus and flexural modulus are increased significantly above HDPE alone with the addition of wood fiber. Dispersion of the fiber in the resin has been reported as a dominating factor in the process thus far. 

Cellulose fibres are obtained from softwood and hardwood. Softwood fibres are 30-45 pm in diameter and 3-7 mm long. Hardwood fibres are thinner (10-20 pm) and shorter (1-2 mm). Their tensile strength is by an order greater than that of the wood for example, lumber wood without macro-defects may have tensile strength equal to 70 MPa and a single fibre, 700 MPa. The fibres are extracted from wooden pulp by different chemical and mechanical processes. 

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