Abstract

In this study, we compare the panel performance of plywood made with phenol-formaldehyde (PF) resins modified and blended with phenol-rich bio-oil produced from pyrolysis of biomass. The modified PF resins were synthesized with phenol-rich bio-oil at phenol substitutions of 10, 25, 50, and 75 percent. The blended PF resins were prepared by blending control PF resin with phenol-rich bio-oil at 4, 13, 23, and 38 percent by weight. These resins were examined with Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) and evaluated as plywood binders. The results indicated that the apparent viscosities of modified PF resins were similar to those of control PF resin, while the apparent viscosities of blended PF resins increased with the addition of phenol-rich bio-oil. As the amount of phenol-rich bio-oil increased, the gel times of both modified and blended PF resins decreased first and then increased. FTIR results showed that modified PF resins with up to 25 percent substitution had FTIR spectra similar to those of control PF resin, while blended PF resins with a higher amount of added bio-oil had spectra more like those of bio-oil. TGA results showed that at temperatures of 25°C to 400°C, both modified and blended PF resins with high bio-oil content had better thermal stability than the control PF resin. Panel tests showed that modifying or synthesizing PF resin with phenol-rich bio-oil up to 50 percent increased both dry and wet bond strength. Blending PF resin with phenol-rich bio-oil up to 13 percent increased both dry and wet bond strength compared with control PF resin.

Abstract

Underutilization of some wood species can be largely attributed to a dearth of scientific information. Therefore, identifying the acoustic characteristics of lesser used wood species such as Boscia angustifolia and Albizia adianthifolia wood is expected to encourage their use in acoustic applications. Thus, studying their acoustic properties and the relationship among these properties will help reveal their use potential for acoustic purposes and also highlight possible predictor variable(s) for other acoustic parameters in wood acoustics. This study aimed at measuring the acoustic properties of B. angustifolia and A. adianthifolia wood and investigating the correlation among these properties. Three trees of each species were felled, and a total of 270 wood samples of 20 by 20 by 300 mm³ were collected. The samples were conditioned before acoustic measurement. The longitudinal free vibration method was adopted to measure the acoustic properties. Some of the mean acoustic results obtained for B. angustifolia and A. adianthifolia wood were 835.89 Hz, 3,657.51 m/s, 0.008, 13.59 GPa, 935.39 m⁴ kg⁻¹ s⁻¹, and 807.78 Hz, 3,542.66 m/s, 0.009, 12.65 GPa, 731.75 m⁴ kg⁻¹ s⁻¹, respectively, for fundamental sound frequency (FF), velocity of sound (V), damping factor (tan δ), specific dynamic modulus of elasticity (Es), and acoustic conversion efficiency (ACE). The correlation of FF with tan δ was negatively significant (−0.59), while it was positively significant with Es and ACE (0.99 and 0.74). This study found the two wood species suitable for making frame boards only and highlights sound frequency and velocity of sound as the major predicting acoustic variables for measuring good acoustic wood.

Abstract

Many wood-based businesses rely on forklifts and pallet jacks to load, unload, or move product around facilities. The use of forklifts or other powered industrial trucks (PITs) to facilitate movement and storage of goods is expected to grow steadily over the next 10 years. Unfortunately, forklifts are known to be a common source of occupational injuries and fatalities. The purpose of this article is to examine severe injuries related to the use of forklifts and pallet movers in various segments of the wood-related industries. We used data from an Occupational Safety and Health Administration (OSHA) database to investigate all severe injuries related to forklifts or pallet jacks in the 5 years from 2015 to 2019. Our focus was on various wood products and paper manufacturers, as well as wood building material dealers and wholesalers; this provides a broad overview of the hazards associated with forklifts and pallet trucks across the spectrum of wood-related businesses. Results show there were 17 fatalities and 211 severe injuries during the 5-year period. Building material dealers saw the highest number of injuries, followed by a wood manufacturing segment. Fractures were the most prevalent type of injury, with the lower extremities being the most vulnerable to serious injury. The most prevalent injury event type was pedestrians hit by a forklift or other PIT. Improper use of PITs is a regular source of OSHA fines for wood-based businesses. Implications are drawn for businesses that use forklifts and pallet jacks to reduce the likelihood of injuries from this type of equipment.

Abstract

Growing world demand for processed goods made from wood and a large supply of native timber in tropical regions combined with development incentives from national governments have driven rapid growth in the forest products industry in many developing countries. Contract farming schemes have emerged as an important mechanism to ensure an adequate supply of raw timber for processing. These contracts also encourage secondary forest establishment, which is argued to reduce harvesting pressure on ecologically valuable native forests. We explore whether there exists a potential for efficiency gains within the forest products industry given the current installed capacity in the state of Andhra Pradesh, India. We estimate a stochastic production frontier function for this industry based on Annual Survey of Industries data from 2010 to 2013. We present evidence that there is space for efficiency gains and that the marginal value product of wood as a raw input is high enough to justify the engagement of companies and farmers in wood supply agreements as a means to reduce pressure on native forests.

Abstract

The potential for using peanut (Arachis hypogaea) husks as an alternative fiber for particleboard production was examined at five different levels of melamine-urea-formaldehyde resin (MUF). The resulting panels were evaluated for moisture absorption, thickness swell, flexural properties (modulus of rupture [MOR] and modulus of elasticity [MOE]) and internal bond (IB) strength. MOR, MOE and IB values of panels containing ≥6 percent resin met or exceeded American National Standards Institute standards for multiple grades of particleboard although they were weaker than previous reports of commercially produced wood particleboards. Moisture uptake and thickness swell also improved markedly at resin levels >6 percent. The results suggest that peanut husks are an attractive alternative fiber source in combination with the MUF resin system.

Abstract

In this study, bio-based rigid polyurethane (PU) composite foams were prepared by a free-rising method, with the addition of wood particles (10 and 20 weight percent by the foam mass) and kraft lignin (5 and 10 weight percent by the polyol mass) as reactive reinforcing fillers. The resultant PU composites were evaluated for chemical structure, density, morphology, compressive properties, water uptake, and thermal stability. Fourier-transform infrared analysis confirmed the formation of characteristic urethane bonds in all foam samples. The foaming process was slowed down by the incorporation of lignin and wood particles. The apparent density of lignin-incorporated wood–PU composite foam ranged between 77 and 105 g/cm³. Compared with the neat PU foam, addition of wood particle resulted in decreased compressive properties and increased water uptake of the foams, whereas incorporation of lignin had a positive effect on the compressive properties and water resistance. In general, the PU foam sample with the incorporation of only 5 percent lignin (PUL₅) exhibited the optimal physical–mechanical properties, with the compressive strength increased by 74 percent and 24-hour water uptake decreased by 28 percent compared with the control PU foam. Thermogravimetric analysis showed that the incorporation of lignin and wood particles did not significantly affect the thermal degradation pattern of foam but rather increased the mass of char residue.

Abstract

Panelized light wood frame construction is becoming more popular due to the faster construction time and shortage of onsite skilled labor. To use light wood frame panels effectively in panelized floor systems, panel-to-panel joints must be fastened adequately to allow load transfer between panels. They must also possess in-plane shear strength and stiffness comparable to stick-built, staggered-sheathed assemblies. This study was designed to develop efficient and effective panel-to-panel joints for connecting adjacent floor panels built with wood I-joists and evaluate the efficiency of the joints in achieving diaphragm action. At first, a number of these panel-to-panel joints were tested in the laboratory using a small-scale diaphragm test setup to determine their efficiency in transferring in-plane forces between panels. Test results showed that a small decrease in in-plane stiffness was expected for the most effective joints, but their strengths were significantly higher than at the same location in a conventional site-built floor diaphragm. The presence of blockings and use of two-row nailing were found to considerably improve stiffness and strength. These features can be used to mitigate the potential reduction in mechanical performance of panelized floor construction, in comparison with the site-built wood I-joist floor.

Abstract

This article introduces a total revenue forecasting tool designed for calculating the economic output of visually graded hardwood lumber. The tool integrates Monte Carlo simulation from previous studies' data, providing a pseudoestimation of total board-feet based on log grades. The lumber output from different log groups is modeled using probability distributions for each lumber grade. The estimated volume output is multiplied by the respective price for each grade, leading to an expected amount of economic output for given log-grades. The tool was implemented using Microsoft Excel 2016 and Visual Basic. This work provides hardwood lumber producers with a valuable and simple tool to determine different scenarios of total income from each log, as established by the user with a statistical perspective. This total revenue forecasting tool provides the industry with a way to reduce waste and estimate their potential revenue by maximizing the interaction between the log yield's variables and providing the economic output of log, leading to an improvement of the economy of the hardwood market.

Abstract

In order to investigate the decay mechanism in red oak (Quercus rubra) and Schima (Schima spp.) wood in the ancient building of Xichuan Guild Hall, the changes in chemical composition were determined using Fourier-Transform Infrared Spectroscopy. The results were as follows: (1) The absorption peak intensities that represented the structural contribution of carbohydrates, and the crystallinity index of the cellulose in the red oak components, decreased noticeably by 55.70 percent in H1039/H1508, and 26.85 percent in H1370/H2900; while those of lignin were increased as a result of the brown rot process. These changes indicated that the brown-rot fungi had stronger degradation effects on hemicellulose and cellulose over lignin. (2) The absorption peak intensities of the carbohydrates (a part of the lignin) and the crystallinity index of the cellulose decreased noticeably by 22.50 percent in H1039/H1508, 25.00 percent in H1508/H1735, and 21.74 percent in H1429/H897 after white rot in the Schima wood components. These findings indicated that not only cellulose and hemicellulose but also lignin were attacked by white-rot fungi. By comparison, the extent of fungal damage in the wood components was lower in the Schima wood components than that in the red oak components.

Abstract

The objective of this study was to determine if the same soldier:worker ratio could be used in the eastern subterranean termite (Reticulitermes flavipes) and the Formosan subterranean termite (Coptotermes formosanus) in standard tests. Native (R. flavipes) and introduced (C. formosanus) subterranean termite species were tested in an American Wood Protection Association E1 standard laboratory test. Statistically equivalent weight losses were found as long as the ratio was within 10 percent of the rate required by the standard.

Abstract

The effect of test-block grain orientation on laboratory termite tests using American Wood-Preservers' Association Standard E1-97 was evaluated using Coptotermes formosanus. This research revealed that testing of samples with the 6-mm direction in either the longitudinal or the tangential direction was appropriate. The E1 standard was subsequently modified to allow either.

Abstract

There is currently great interest in the production of wooden multifamily houses in Sweden, due to increased environmental concern combined with a demand for modern building solutions. The focus in industry and academia alike has been dominated by new innovative building solutions along with increased industrialization of the building process, aiming to improve the overall building quality and the profitability for the involved actors. However, little attention has been paid to what the residents perceive as living quality. Understanding residents' perceived living quality—compared with architects' perceptions—allows the possibility of adjusting the modern building solution of wooden multifamily houses in order to meet residents' actual expectations and, in the long term, to increase the wood-building industries' market share.

The purpose of this article is to compare how residents and architects perceive living quality and whether these stakeholders' perceptions differ regarding building type and material choice (i.e., multifamily wooden or concrete buildings). A survey was sent out to 485 respondents in Sweden to gain insight into living quality perceptions. The results revealed discrepancies in what is perceived to be important in new housing development, although neither group was willing to pay more to live in a wooden building compared with a concrete building.

Abstract

Living organisms require copper for several cellular processes. Yet intracellular concentrations of copper must be regulated to avoid toxicity. Not much is known about mechanisms of copper regulation in wood decay fungi. However, one putative annotation for a copper homeostasis CutC gene (FIBRA_00129), found in other brown-rot wood decay fungi, has been annotated in Fibroporia radiculosa. The aim of this study was to evaluate wood mass loss and differential expression of FIBRA_00129 during initial decay of untreated and copper-treated wood by two copper-tolerant F. radiculosa isolates (FP-90848-T and L-9414-SP) compared with copper-sensitive Gloeophyllum trabeum. Untreated southern pine (Pinus spp.) and ammoniacal copper citrate treated southern pine at three concentrations (0.6%, 1.2%, and 2.4%) were used in a 4-week-long standard decay test. Results showed G. trabeum was unable to decay copper-treated wood while both F. radiculosa isolates successfully decayed southern pine at all copper concentrations. G. trabeum and F. radiculosa L-9414-SP showed no detectable FIBRA_00129 expression over the course of this study. F. radiculosa FP-90848-T showed greater FIBRA_00129 downregulation on copper-treated wood than on untreated wood (P = 0.003). Additionally, there was greater FIBRA_00129 downregulation in F. radiculosa FP-90848-T at week 3 compared with other weeks (P = 0.015). Future studies are needed to further evaluate FIBRA_00129 during the decay process to determine its potential role in copper-tolerance.

Abstract

Seventy-five years of research in wood protection at the Forest Products Lab at Mississippi State University are described. A history of wood protection is presented along with an overview of the facilities supporting the research. Program objectives are presented along with the personnel responsible for building the program. A brief presentation of research areas is given followed by some program metrics.

Abstract

Mass timber building materials such as cross-laminated timber (CLT) have captured attention in mid- to high-rise building designs because of their potential environmental benefits. The recently updated multistory building code also enables greater utilization of these wood building materials. The cost-effectiveness of mass timber buildings is also undergoing substantial analysis. Given the relatively new presence of CLT in United States, high front-end construction costs are expected. This study presents the life-cycle cost (LCC) for a 12-story, 8,360-m² mass timber building to be built in Portland, Oregon. The goal was to assess its total life-cycle cost (TLCC) relative to a functionally equivalent reinforced-concrete building design using our in-house-developed LCC tool. Based on commercial construction cost data from the RSMeans database, a mass timber building design is estimated to have 26 percent higher front-end costs than its concrete alternative. Front-end construction costs dominated the TLCC for both buildings. However, a decrease of 2.4 percent TLCC relative to concrete building was observed because of the estimated longer lifespan and higher end-of-life salvage value for the mass timber building. The end-of-life savings from demolition cost or salvage values in mass timber building could offset some initial construction costs. There are minimal historical construction cost data and lack of operational cost data for mass timber buildings; therefore, more studies and data are needed to make the generalization of these results. However, a solid methodology for mass timber building LCC was developed and applied to demonstrate several cost scenarios for mass timber building benefits or disadvantages.

Abstract

This article explores the benefits covering waterborne preservative systems that include an oil emulsion treatment. Waterborne preservatives have a long history of protecting wood products in severe exposures. Enhancing the surface of these products can increase their service life. Oil emulsion treatments were originally developed to improve the climbability of waterborne poles by utility linemen. Over time, these products have shown that they can improve other surface characteristics, such as checking, flammability, and, with added pigments, ultraviolet exposure.

Abstract

This study aims to investigate the potential of using lignin sourced from South African black liquor as a total phenol substitute in phenol-formaldehyde resins (PFRs), with a particular focus on bonding strength and curing properties. Four South African pulping-based lignins were used to synthesize these lignin-phenol formaldehyde resins (LPF100 resins), namely Eucalyptus Kraft lignin, Pine Kraft lignin, Bagasse Soda lignin, and Bagasse Steam Exploded lignin. Fourier-transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry were used to determine structural and curing properties. These resins were then used directly (unmodified) as adhesives to test shear bonding strength (R₀ LPF100 adhesives). To improve the bonding properties of the unmodified LPF100 adhesives, the LPF100 resins were modified via the addition of a crosslinker (hexamine) as well as a hardener (either glyoxal, R₁, or epichlorohydrin, R₂). All R₀ LPF100 adhesives fell below the GB/T 17657-2013 plywood standard of ≥0.7 MPa, with the Bagasse Soda LPF100 adhesive recording the highest bonding performance of 0.5 MPa, and the lowest curing temperature of 68°C. From the modified adhesives, the best performing were the Pine Kraft (R₁) and the Eucalyptus Kraft (R₂) LPF100 adhesives, recording 1.4 and 1.3 MPa, respectively. The curing temperatures of both these resins were 71°C and 80°C, respectively. Ultimately, the results of this study indicated that favorable adhesive properties may be obtained with the use of South African pulping-based lignins as a 100 percent phenol substitute in PFRs.