Utilization of low-grade yellow-poplar (Liriodendron tulipifera) lumber would provide for alternative structural lumber sources and promote the growth of cross-laminated timber (CLT) manufacturing facilities within the Appalachian Region. A significant amount of low-grade yellow-poplar lumber (i.e., National Hardwood Lumber Association [NHLA] No. 2A and Below Grade) is utilized for wood pallets. In practice, this material is not graded for structural purposes. Additionally, research on yellow-poplar for structural use has focused on grading lumber from a small population of selected logs, not by regrading NHLA lumber from manufacturing facilities. Therefore, the research's objective was to investigate the structural grades of a typical population of NHLA graded No. 2 and lower lumber and evaluate their potential to meet structural grades necessary for CLT panels. NHLA graded lumber was regraded and assigned to visual structural grades following Northeastern Lumber Manufacturers Association rules and evaluated for flatwise bending modulus of elasticity (MOEb) by nondestructive proof loading. The results of the study indicated that 54.6 percent of the boards possessed a minimal structural visual grade required for CLT panels according to American National Standards Institutes/The Engineered Wood Association (ANSI/APA) PRG 320-2019 (2020). Splits were the most common limiting defect that downgraded boards to nonstructural grades. Also, 96.6 percent of the boards evaluated had a MOEb above the required minimal board value of 1.2 ×106 psi (8,274 MPa) listed in ANSI/APA PRG 320-2019 (2020). The results of the study indicated that a majority of NHLA low-grade yellow-poplar, when regraded for structural purposes, meets or exceeds minimum lumber grade values necessary for use in CLT panel production.Abstract
Firms engaged in producing, processing, marketing, or using lumber and lumber products always invest in futures markets to reduce the risk of lumber price volatility. The accurate prediction of real-time prices can help companies and investors hedge risks and make correct market decisions. This paper explores whether Internet browsing habits can accurately nowcast the lumber futures price. The predictors are Google Trends index data related to lumber prices. This study offers a fresh perspective on nowcasting the lumber price accurately. The novel outlook of employing both machine learning and deep learning methods shows that despite the high predictive power of both the methods, on average, deep learning models can better capture trends and provide more accurate predictions than machine learning models. The artificial neural network model is the most competitive, followed by the recurrent neural network model.Abstract
This paper focuses on designing a methodological workflow to fill a knowledge gap for determining the cost of capital for commercial forestry projects. Upon reviewing the literature, a method to determine the cost of capital for profit-oriented forestry seems to be lacking. Accordingly, we selected and analyzed 42 companies that do businesses worldwide, are present on the stock exchange, and possess or lease forest land. Based on their business activities (growing forest, sawmilling, final production, paper production), these companies are classified into four subgroups. An algorithm has been devised using the concept of risk diversification and the capital asset pricing model for three groups of investors and four forestry subgroups. In doing so, the real risk-free rate (0.43%) is set as the difference between an average return on 10-year US government bonds (2.59% nominal) and the 10-year average US inflation rate (2.16%). The measure of forestry systematic risk (beta coefficient) varies between 0.83 and 1.41, while the equity (stock exchange market) risk premium is set to 6%. Unsystematic risk is determined using a process of mapping which takes into account all risk elements marked as relevant for the forestry sector. This approach provides results that reveal the cost of capital varying between 5.41% and 16.55% based on the current level of an investor's portfolio diversification and the risk characteristics of the forestry subgroup. Finally, the forestry companies meeting the investor's expectations are noted as preferable investment opportunities.Abstract
Glued Laminated Timber, commonly referred to as Glulam, is an important structural wood product, suitable for use in exterior applications provided it is protected against decay by building design, natural durability, or treatment. Bonding treated lamina made from refractory species is challenging because resurfacing after treatment can remove much of the treated zone and create a waste disposal challenge. It was hypothesized that use of roll-pressing rather than resurfacing could address this. When an adhesive modifier was used to prevent the adverse effects of wood preservatives on adhesive bonding, treated lamina that were replaned before gluing had similar shear strength to untreated planed lamina. However, the treated lamina that were roll-pressed before gluing had lower shear strength than the replaned lamina. The consequence of this weakening was evident in an above-ground field test where delamination was observed in several test units after 12 years of exposure. Decay resistance was evaluated in above-ground, ground contact, and ground proximity tests. The decay resistance of treated glulam was high with only low levels of decay reported in all tests, while untreated controls showed advanced decay or failure. Yellow cedar glulam, included as a reference in the ground proximity test, showed moderate decay after 10 years of exposure.Abstract
Waste rubber is abundant worldwide and threatens to be an environmental hazard for decades to come. This has led to an interest in the use of recycled rubber materials in value-added products. One such possible use is in the wood products industry. The research analyzed the strength and acoustic properties of composite pine particleboard that contained 10, 20, 30, and 40 percent micronized rubber powder, a dry powdered elastomeric crumb rubber, by weight. Methylene diphenyl diisocyanate was used as the bonding adhesive to produce five particleboard samples, including a control board. Test samples were cut from the five parent boards for use in strength and acoustic testing. Measured displacement values for a simply loaded and simply supported load scenario were used to calculate the modulus of rupture and apparent modulus of elasticity for each composite particleboard. Acoustic measurement by impedance tube provided comparisons of the sound absorption coefficient for frequencies ranging from 60 to 6,300 Hz. Results revealed that the addition of micronized rubber powder led to a decrease in modulus of elasticity and no significant difference in modulus of rupture values as compared with the control. Statistical analysis indicated a decrease in sound absorption in particleboard that contained micronized rubber powder when compared with the control.Abstract
When sawing a log into lumber or other products, the saw blade removes material to separate the wood fibers between the resulting two parts, a loss of material that is commonly referred to as saw kerf. Thicker kerfs result in greater waste and less material available to produce lumber. Over the past decades, with the advancement of materials and technology, saw blade thickness has decreased. However, the reduction in material loss owing to a reduction in saw kerf may not always translate into a statistically significant increase in lumber product recovery. In this study, we explored the effect of saw kerf thickness on lumber recovery for a range of hardwood log diameters using the US Forest Service's Log Recovery Analysis Tool (LORCAT) sawmill simulation tool. Results indicate that the recovery gains realized depend upon the log diameters sawn, the lumber target thickness, and the change (reduction) in the thickness of the saw kerf.Abstract
One of the largest contributors to the economic loss from floods is the complete or partial destruction of residential buildings, and finding ways to eliminate or minimize this loss is important. Oriented strand board (OSB) is a wood product commonly used in home construction, so a better understanding of how flood water affects its mechanical properties is warranted. In this study, the moduli of elasticity and rupture (MOE and MOR, respectively) of representative samples removed from full-size (4 by 8-ft [1.2 by 2.4 m]) OSB panels were examined following the submergence of the panels in potable and salt water (surrogates for flood water) for increasing periods of time (i.e., 8, 24, 48, 72, 168, and 336 h). The results of our study show that after 8 hours of panel submersion in potable water, MOR and MOE is reduced by 15 percent and 16 percent, respectively; no significant change was observed in MOR and MOE for panels soaked in salt water. After 168 hours, the MOR loss was 43 percent for panels soaked in potable water and 38 percent for panels soaked in salt water. For MOE, there was a 35 percent loss regardless of water type. Submersion of panels in either water type for an additional 168 hours resulted in no significant change in MOR or MOE. The MOR and MOE of samples removed from the edges of the submerged panels, for both water types, were lower than those of the interior samples. Finally, the decreases in average MOR and MOE following submergence in either water type were approximately independent of brand.Abstract
Industry 4.0, a term referring to the digitization of manufacturing, enhanced automation, and data-driven production systems, promises to bring rapid change to the secondary woodworking industry. Manufacturers in this sector, many being small in size and scale, may be challenged to remain competitive without understanding how Industry 4.0 principles might affect their operations. A study conducted with subscribers to a major secondary wood industry trade journal found that few North American woodworking companies were familiar with the term “Industry 4.0.” However, that did not mean they were not making decisions about, investing in, and implementing digitization–computerization (digit–comp) in their manufacturing operations. Well over half of study respondents indicated that their firms had made a significant investment in digit–comp over the past 3 years. Several respondents stated that software and technology integration was the most unexpected problem encountered, and that skilled labor was difficult to find. A variety of training types were sought by firms that had made significant Industry 4.0-related investments, especially training related to machine operation. Although a plurality of respondents from both small and large firms indicated that increased digit–comp would not change their number of employees, small firms were more likely to say more employees would be needed and large firms were more likely to perceive a decrease in employees. Perhaps the greatest challenge to successful implementation of Industry 4.0 will be the lack of a strategic plan—just 19 percent of small firms indicated having a vision of how digitization might affect their business.Abstract