Environmental Product Declarations (EPDs) are standardized reports of environmental impacts linked to a product or service. In ISO terminology an EPD is a Type III environmental label. EPDs and their applicability to the wood products industry have been extensively discussed in the Forest Products Journal1 and elsewhere in recent years.2 The US forest products industry in 2013 published industry-wide Environmental Product Declarations (EPDs) for key softwood products, making it the first basic materials industry in the nation to issue transparent, third-party verified environmental labeling of products. Now, all building materials manufacturers are facing pressure to develop
Long-term durability data are needed to improve service life estimates for treated wood products used as critical structural supports in industrial applications. This article reports the durability of longleaf pine (Pinus palustris) posts pressure treated with ammoniacal copper arsenate (ACA), chromated copper arsenate (CCA), creosote, or pentachlorophenol and exposed for 50 years in southern Mississippi. During inspections, posts were subjected to a pass/fail evaluation by applying a load to the top of the post. No failures occurred in any of the 125 posts treated with CCA or in any of the 75 posts treated with pentachlorophenol. Three of 25 ACA-treated posts and 5 of 25 creosote-treated posts failed. Estimated times to 50 percent failure in the ACA- and creosote-treated posts were calculated as 96 and 78 years, respectively. The estimated years to failure for the CCA- and pentachlorophenol-treated posts could not be calculated because of the lack of failures but presumably would be greater than that calculated for the ACA- and creosote-treated posts. The durability of the posts is notable because the exposure site presents a severe biodeterioration hazard. The results of this study indicate that in-service posts, poles, and piles treated to standardized retentions with these industrial preservatives will be highly durable.Abstract
Wood guardrail posts are the most common wood materials currently used in highway construction. Maintenance crews and engineers are often faced with the challenge of rapidly assessing the extent of decay or damage in individual posts. Many conventional intrusive techniques are unsuitable for inspecting guardrail posts because they are too time-consuming. Acoustic detection could be an ideal inspection method because of its rapid assessment. The potential for using acoustic inspection for wooden guardrail posts was assessed on treated hem-fir guardrail posts removed from western Washington State. The posts were tested nondestructively using an impulse hammer, and then increment cores were removed from each post for assessing preservative treatment and fungal colonization. The posts were then tested to failure in bending to determine flexural properties. All but one of the posts met the minimum threshold for strength according to the American Association of State Highway and Transportation Officials. There was a weak correlation between acoustically predicted modulus of elasticity (MOE) and actual MOE. Correlations between acoustically predicted MOE and modulus of rupture were slightly better but still weak and lower than would be acceptable for this method to be used in the field. The results indicate that acoustic methods might be useful for detecting the presence of advanced decay but failed to provide definitive estimates of post properties.Abstract
Eucalyptus has become an important substitute material for the burgeoning plywood industry in China, whereas the corresponding fire retardant–treated products remain to be developed. This study preliminarily evaluated the feasibility of manufacturing fire retardant–treated eucalyptus plywood in the traditional industrial plant by veneer impregnation. Eucalyptus saligna and Eucalyptus dunnii veneers were impregnated by a commercial fire retardant at room temperature and atmospheric pressure. After redrying, the veneers were hot pressed into fire retardant–treated plywood in a conventional way. Fire performance was evaluated by cone calorimeter test. Basic properties (i.e., moisture content, bonding strength, and formaldehyde emission), mechanical properties (including modulus of rupture and modulus of elasticity), and hygroscopicity were also investigated. The fire retardancy of plywood was significantly improved by the fire retardant treatment, in terms of decreased heat release rate and increased residual mass fraction. The flame spread index values for plywood, which were calculated from the results from cone calorimeter tests, indicate that the fire performance of plywood improves from Class III to Class II after the treatment. The basic properties of fire retardant–treated plywood meet the requirements of GB/T 9846 (Standardization Administration of the People's Republic of China 2004). The mechanical and hygroscopic properties of fire retardant–treated plywood satisfy demands of general interior applications. The veneer treatment could be a suitable approach for Eucalyptus plywood factories to manufacture fire retardant–treated products.Abstract
Storage is a key component within the woody biomass supply chain, especially when year-round harvesting is impossible. To determine whether chipped biomass is a better form for in-woods storage than unchipped biomass, and to examine the effect of weather factors on wood chip quality, this study was designed and conducted at three study sites in Michigan. From July to December 2013, samples were collected twice a month and tested for moisture content (MC) and higher heating value (HHV). Results showed that during the 4-month field storage, unlike unchipped biomass, the small particle size and high degree of compaction in the wood chip pile caused biomass MCs to increase. Results also indicated that a smaller sized pile and higher initial MC could lead to a wetter middle layer in a wood chip pile. Owing to the high MC and microbial activity, declining trends in biomass HHV were detected. Whole tree chips were found to have higher HHV variation than pure stem wood chips because of the different content and types of lignin and extractives. Different positions within a wood chip pile did not affect the biomass HHV. Regression analysis showed that at Site 3, monthly cumulative rainfall was significant in predicting biomass MC in three models, and average air temperature was significant most of the time. However, none of the preselected variables were tested to be significant at the remaining two study sites because the biomass HHV change was small over storage time. Other more sensitive variables need to be considered in future studies.Abstract
This article presents the influence of stem size of thinned trees on the amount of ash in wood pellets. If wood can be used with bark, material efficiency of pellet production increases. The article initiates discussion related to typical questions in the pellet industry, such as the applicability of pine with bark to produce wood pellets that meet European Union standards (EN 14961‐2:2011 A1). The article shows that unbarked Finnish scots pine trees (Pinus sylvestris L.) over 11.16 m in length can be used as raw material without quality loss or ash content out of the range of the wood pellet standard. Three different diameter groups of pine were tested, and none exceeded the ash content limit (0.7%) set in the EN 14961‐2:2011 standard.Abstract
Heat treatment is one effective method of improving dimensional stability and durability of wood. However, it usually decreases the bending strength of wood. Vacuum heat treatment, which is one way that does not use a thermal medium, had little influence on wood elasticity or bending strength in our previous study. But until now, few studies have reported on the changing mechanism of vacuum heat–treated wood. In this article, chemical composition and crystallinity of untreated and treated Eucalypt pellita wood were investigated under vacuum heat treatment temperatures from 80°C to 280°C for 4 hours. The results showed that lignin content increased and that holocellulose and α-cellulose decreased when the temperature was raised. Alcohol benzene extractive increased at the initial stage and then decreased when the temperature was above 240°C. Crystallinity of wood increased with a temperature increase from 80°C to 200°C and reached a maximum value of 52.57 percent. Fourier transform infrared spectroscopy analysis indicated that absorption intensity of a benzene skeleton at 1,600 cm−1 increased and that the hydrogen bond absorption band at 3,423 cm−1 shifted to a lower wave number as temperature increased.Abstract
This article introduces an insulation system that takes advantage of the low thermal conductivity of still air and is made of wood and paper. The insulation, called the Mirrorpanel, is constructed as a panel of closely spaced layers of coated paper and held together in a frame of wood or fiberboard. Panels have been fabricated and tested at the laboratory scale, whole wall scale, and the building scale. A 1.2-m by 2-m by 0.185-m-thick wall section had an apparent thermal conductance of only 0.204 W m−2 K−1 including the structural wood frame, which is equivalent to a US R-value of 27.9 h ft2 °F Btu−1 (3.8 h ft2 °F Btu−1 in.−1 for the 7.3-in.-thick wall section). The Mirrorpanel could be used as an environmentally friendly alternative to foam insulation in high-performance residential buildings and would fulfill the continuous insulation requirements in the 2012 version of the International Energy Conservation Code.Abstract
Chipper-canters are used in primary wood industries for processing small-diameter logs. Knife geometry is one of the principal parameters significantly affecting the chip size and cant surface properties. This work studied the patterns of tool wear as edge recession (ER) in chipping and canting knives of a chipper-canter head. In addition, analytical investigation of wear mechanisms was carried out to better understand the ER phenomenon. The test head contained eight sets of separate chipping and canting knives. ER was measured after 0, 8, 16, 32, 48, and 80 hours of machining. Microscopic measurements at intervals of 1 mm along the cutting edge were carried out to characterize ER from knife replicas. The ERs after 80 hours of machining were 544 and 549 μm for chipping and canting knives, respectively. There was no significant variation in ER between the types of knives at 0 and 80 hours of machining. However, significantly different ERs were found between the chipping and canting knives at the intermediate stages of machining. Scanning electron microscopic observation showed that apart from abrasion and chipping phenomenon, there were also deformation of chipping knives and cracking of canting knives.Abstract
Predictive boosted regression tree (BRT) models were developed to predict modulus of rupture (MOR) and internal bond (IB) for a US particleboard manufacturer. The temporal process data consisted of 4,307 records and spanned the time frame from March 2009 to June 2010. This study builds on previous published research by developing BRT models across all product types of MOR and IB produced by the particleboard manufacturer. A total of 189 continuous variables from the process line were used as possible predictor variables. BRT model comparisons were made using the root mean squared error for prediction (RMSEP) and the RMSEP relative to the mean of the response variable as a percent (RMSEP%) for the validation data sets. For MOR, RMSEP values ranged from 1.051 to 1.443 MPa, and RMSEP% values ranged from 8.5 to 11.6 percent. For IB, RMSEP values ranged from 0.074 to 0.108 MPa, and RMSEP% values ranged from 12.7 to 18.6 percent. BRT models for MOR and IB predicted better than respective regression tree models without boosting. For MOR, key predictors in the BRT models were related to “pressing temperature zones,” “thickness of pressing,” and “pressing pressure.” For IB, key predictors in the BRT models were related to “thickness of pressing.” The BRT predictive models offer manufacturers an opportunity to improve the understanding of processes and be more predictive in the outcomes of product quality attributes. This may help manufacturers reduce rework and scrap and also improve production efficiencies by avoiding unnecessarily high operating targets.Abstract
The forest products industry (FPI) is an important component of local, state, regional, and national economies. Thus, assessing its economic contribution can provide valuable information to policymakers and forestry interests. IMPLAN, an input–output model, was used to assess the economic contribution of the FPI in 13 US southern states for the year 2009, individually as well as regionally, and to compare it with that in 2001, the last comprehensive study of the industry in the South. Two aspects of economic contribution, direct impacts and associated economic multipliers, were estimated for three primary FPI sectors (lumber and wood products, paper and allied products, and wood furniture). The FPI in the South employed 470,000 individuals and generated $133 billion of gross output. The industry's employment decreased by 33.9 percent while gross output increased by 15.1 percent between 2001 and 2009. Study findings reveal that the FPI reduced employment relative to total industry output to maintain production during the recession period providing evidence of capital substitution for labor. This implies that despite the disproportionate impacts of the great recession of the 2000s, the industry is still an important component of the South's economy. Thus, this article will provide insights about how the economic contribution of the FPI changes over time. In addition, results of this study will be helpful in identifying important industry shifts and help formulate policies and regulations to support the FPI.Abstract
Production and consumption trends of China's pulp and paper products are discussed as well as imports of two principal raw materials: wood pulp and recovered paper. We developed an augmented gravity model to understand trade behavior between China and its trading partners using panel data from 1995 to 2012. The results show that China's economic growth is an important driver for wood pulp and recovered paper imports. Exporters' economic size has positive impacts on wood pulp exports and is also a significant factor in determining recovered paper exports. Distance has a significant negative impact on China's wood pulp and recovered paper imports. Finally, China's accession to the World Trade Organization increased both its wood pulp and recovered paper imports.Abstract
Since the end of the last century, exports from the Chinese wood processing sector have experienced very rapid growth and played an increasingly important role in the world's wood product trade market. Based on data from Chinese wood product companies for 1998 to 2007, an empirical analysis of the factors influencing wood product exports was conducted using a panel Tobit model. We discovered that companies in the eastern regions can export more easily compared with those in the midland and western areas; larger companies enjoy more favorable export conditions, with more advantageous outcomes during risk taking and higher sunk costs; enterprises with a higher proportion of foreign capital tend to export more, as do enterprises whose capital originates principally from Hong Kong, Macao, or Taiwan; the original equipment manufacturer or original design manufacturer still predominates in the wood processing industry; exporting made negative influence for wood processing enterprises' performance during that time; capital density makes no impact on wood processing enterprises' exports; and, finally, companies' registered addresses have no direct connection with exports of wood processing enterprises.Abstract