dimension lumber
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2021 ◽  
Vol 71 (4) ◽  
pp. 371-378
Author(s):  
Azadwinder Singh Chahal ◽  
Jaya Tripathi ◽  
Daniel Ciolkosz ◽  
Sarah Wurzbacher ◽  
Michael Jacobson

Abstract Sufficiently valuing small-diameter-stem (diameter < 9 in.) woody material in Pennsylvania forest product markets may incentivize increased utilization of that material, a resource opportunity that would provide economic and ecological benefits to the state's forests and forest products community. Debarking is one primary process that could enhance the value of these small-diameter-stem materials for secondary markets. The wood products community in Pennsylvania was surveyed as to their perceptions of the status and value of economical small-diameter-stem debarking. The largest perceived current market for debarked, small-diameter-stem material identified by respondents is for chips for pulp and paper, and anticipated future demand is expected to be highest for chips for pulp and paper, chips for energy, and small-dimension lumber. Respondents who currently supply a given market tend to be more optimistic about that market than respondents who do not serve that particular market. Shredded wood/hog fuel and mulch are the two markets with the lowest overall scores for anticipated benefit of additional processing by debarking. Seventy-six percent of all respondents indicated that economical small-diameter-stem debarking would benefit their operation.


Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1148
Author(s):  
Qiongyao Wu ◽  
Liangliang Huo ◽  
Enchun Zhu ◽  
Shuang Niu ◽  
Huajie Wang

In this study, DOL of structural timber and the clear wood and DOL of modulus of elasticity of wood were investigated. The dimension lumber of Spruce-Pine-Fir of Grade No. 2 and Grade No. 3 and the small clear specimens of the same species of the dimension lumber were used to conduct the short-term and the long-term bending test. The short-term strength distributions of the dimension lumber and the small clear specimens were obtained. The long-term tests were conducted under constant environmental conditions for 18 months. The sample matching technique was used to estimate the short-term strength of the specimens that underwent long-term tests. It was found out that there is virtually no difference in DOL between different grades or quality of lumber and no difference between structural timber and clear wood, and DOL obtained from the test of this study is more in agreement with Wood’s curve. A threshold stress ratio of about 0.55, loaded above which the wood began to experience strength loss, was revealed from the test. Making use of the threshold ratio concept, the DOL of wood can be obtained not only from failed specimens under load in the process of the long-term loading, but also from the ramp loading test of the specimens that survived the long-term test. Sustained load also poses DOL on the modulus of elasticity of wood, though to less degree than DOL of strength of wood.


2021 ◽  
Vol 4 ◽  
Author(s):  
Robin R. Sears ◽  
Peter Cronkleton ◽  
Medardo Miranda Ruiz ◽  
Matías Pérez-Ojeda del Arco

On-farm timber production is an important subsistence and economic activity of smallholder farmers around the world. Farmer investment in wood production and the degree of formality in the sector depends on access to and conditions of the market, the nature of the regulatory frameworks that govern rights to and movement of timber, and access to financing. We evaluate the process of formalization of a thriving and adaptive existing supply chain for small-dimension lumber originating in the fallows of smallholder farmers in the Peruvian Amazon. Through field research over three years based in semi-structured interviews with diverse actors in the Amazon, we found that the supply chain for fallow timber is driven entirely by informal and some illegal transactions. A key reason for this is the lack of an appropriate regulatory mechanism by which producers can gain authorization to harvest and sell this timber. We identify conditions necessary to formalize this sector, and evaluate the degree to which these are met under several scenarios. We recommend that the state develop mechanisms that recognize property rights of long-term residents and establish a simple fallow forestry registration mechanism; and that local governments or non-governmental organizations adopt adaptive and collaborative approaches to support farmers and provide training, information and networking among actors. State recognition of and support for fallow forestry, coupled with producers organizing for collective action on processing and marketing their timber, could result in the formalization of a significant volume of timber, improvements in income security for rural people, and the development of local entrepreneurial activities.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 883
Author(s):  
Zhaopeng Tian ◽  
Junhua Xu ◽  
Mingyue Li ◽  
Zhaohui Wang ◽  
Erik Serrano ◽  
...  

The density and modulus of elasticity (MOE) distribution can provide information on the effectiveness of parametric and non-parametric methods in calculating the characteristic value of MOE. In this study, we aim to determine the optimal distribution model of the actual measured data of the lumber. We also estimate the lumber’s MOE characteristic value and compare the difference in density and MOE between natural and planted larch. Approximately 1200 pieces of dimension lumber of 4 m × 140 mm × 40 mm in size, made from larch and planted larch, were obtained, tested, and the corresponding standard MOE value was calculated. Results revealed the 3-parameter Weibull distribution to be optimal in fitting the natural and planted larch distributions. The parametric method proved effective in calculating the characteristic value of both larch groups, with characteristic MOE values of 9.73 kN/mm2 and 8.84 kN/mm2, and characteristic density values of 530 kg/m3 and 460 kg/m3 for natural and planted larch, respectively. Moreover, the MOE and density values followed grades C40 and C35. Thus, the conclusion is that the parametric method should be used to determine these characteristic values for natural and planted larch.


2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Murzabyek Sarkhad ◽  
Futoshi Ishiguri ◽  
Ikumi Nezu ◽  
Bayasaa Tumenjargal ◽  
Yusuke Takahashi ◽  
...  

Abstract The quality of dimension lumber (2 by 4 lumber) was preliminarily investigated in four common Mongolian softwoods: Pinus sylvestris L., Pinus sibirica Du Tour, Picea obovata Ledeb., and Larix sibirica Ledeb. to produce high quality dimension lumber for structural use. In total 61, 39, 67, and 37 pieces of lumber were prepared for Pinus sylvestris, Pinus sibirica, Picea obovata, and L. sibirica, respectively. The lumber was visually graded and then tested in static bending to obtain the 5% lower tolerance limits at 75% confidence level (f0.05) of the modulus of elasticity (MOE) and the modulus of rupture (MOR). In addition, the effects of sawing patterns on bending properties were also analyzed. The f0.05 of the MOE and MOR were 4.75 GPa and 15.6 MPa, 3.39 GPa and 11.0 MPa, 3.78 GPa and 11.7 MPa, and 6.07 GPa and 22.3 MPa for Pinus sylvestris, Pinus sibirica, Picea obovata, and L. sibirica, respectively. These results suggested that with a few exceptions, characteristic values of MOR in the four common Mongolian softwoods resembled those in similar commercial species already used. In visual grading, over 80% of total lumber was assigned to select structural and No. 1 grades in Pinus sylvestris and Pinus sibirica, whereas approximately 40% of total lumber in L. sibirica was No. 3 and out of grades. Sawing patterns affected bending properties in Pinus sylvestris and L. sibirica, but did not affect Pinus sibirica and Picea obovata. Dynamic Young's modulus was significantly correlated with bending properties of dimension lumber for the four species. Based on the results, it was concluded that dimension lumber for structural use can be produced from the four common Mongolian softwoods.


2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Bayasaa Tumenjargal ◽  
Futoshi Ishiguri ◽  
Yusuke Takahashi ◽  
Ikumi Nezu ◽  
Bayartsetseg Baasan ◽  
...  

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