Wood Fiberboard Research Articles

Chemical and Thermal Exposure Risks in a Multi Compartment Training Structure

Providing NFPA 1403 compliant live-fire training can present thermal and chemical exposure risk to instructors and students. To reduce risk, training academies, fire departments, instructors, and standards setting technical committees need more information on how different training fuels used in common training structures can impact the environment in which firefighter training occurs. This study utilized a traditional concrete training structure with multiple compartments to characterize training environments with three different fuel package materials [i.e., low density wood fiberboard, oriented strand board (OSB), and wood pallets]. Exposure risks for a fire instructor located on either the first or second floor were characterized using measurements of heat flux, air temperature and airborne concentrations of several contaminants including known, probable, or possible carcinogens. It was hypothesized that utilizing a training fuel package with solid wood pallets would result in lower concentrations of these airborne contaminants [aldehydes, polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs)] than wood-based sheet goods containing additional resins and/or waxes. Additionally, it was hypothesized that these concentrations would be lower than in the single compartment Fire Behavior Lab presented in a companion manuscript. For all measured compounds other than hydrochloric acid, airborne concentrations were 10 to 100 times lower than in the Fire Behavior Lab. OSB-fueled fires produced the highest median concentrations of total PAHs and VOCs such as benzene, while the pallet fuel package produced the lowest median concentrations of these compounds. These trends generally followed the qualitative visual obscuration created by each fuel. Additional tests were conducted on the OSB-fueled fires with increased ventilation and an alternate means of reducing visibility through smoldering smoke barrels. This OSB experiment with increased ventilation resulted in the highest temperatures in the fire room but the lowest impact on visibility throughout the structure, as well as the lowest overall concentrations of contaminants in this study. In contrast, the smoldering straw-filled smoke barrel created a highly obscured environment (with minimal impact on thermal environment) and some of the highest concentrations of the targeted contaminants of any test. These data may be useful in balancing obscuration for training with potential exposure to thermal stressors and contaminants.

A pyrolysis‐gas chromatography/mass spectrometry study of volatile compounds produced by wood‐based materials

AbstractThe pyrolysis by‐products of five common wood‐based construction materials (low‐density wood fiberboard, oriented strand board, pine, particle board, and plywood) were studied using pyrolysis‐gas chromatography/mass spectrometry. Samples of wood‐based materials were pyrolyzed under helium from 300 to 800°C to further understand the production of compounds that may become airborne and available for respiratory and dermal exposure. Benzene, toluene, ethylbenzene, p‐xylene, styrene, and naphthalene were specifically targeted since these compounds are common by‐products of pyrolysis. These compounds have been measured in previous live fire scenarios and are associated with human health concerns. The generated pyrolysates were separated and identified with a gas chromatography/mass spectrometry instrument. The results from total ion chromatograms and selected ion monitoring chromatograms were analyzed to compare the abundance of chemicals of interest generated during pyrolysis. Oriented strand board and plywood generated the greatest total concentration of the targeted volatile organic compounds. Plywood and particle boards generated the largest variety in results. Samples from solid pine boards generated the smallest number of volatile compounds, followed by low‐density wood fiberboard that is manufactured with wood fibers, starch, and wax. Notably, pyrolysis by‐products are not the sole compounds generated during the combustion of biomass and these products evolve when they are exposed to the conditions of combustion. Our future work plans to study the combustion by‐products of these materials.

Sustainable Composites Containing Post-Production Wood Waste as a Key Element of the Circular Economy: Processing and Physicochemical Properties

This paper develops a technology for manufacturing a biocomposite using post-production wood waste as filler, but also as an alternative material that can substitute traditional composites. Three types of post-production wood waste, i.e., ash wood chips, oak chips and medium-density wood fiberboard (MDF), were used in this study. Three different biocomposites were produced for each of these materials, differing in the content of waste to polymer. The biodegradable and compostable bioplastic Mater-Bi (CF05S) was obtained using the pioneering proprietary technologies of Novamont company using starches, cellulose, vegetable oils and their combinations. Mater-Bi was used as the matrix of the composite, which, due to its chemical composition, allows the production of fully biodegradable composites. The physicochemical properties, such as static tensile, impact, water absorption and hardness, were investigated. The results provide the basis for a detailed analysis of the properties of the biocomposites and made it possible to accurately determine their properties. The results show that the optimal solution is the Mater-Bi biocomposite with 20 wt.% oak filler content, which shows the most favorable adhesion strength and water absorption. The research conducted here is in the context of issues related to sustainability and a circular economy, through waste management, as well as through the production of biodegradable construction products.

Hygrothermal Modelling of one-dimensional Wall Assemblies: inter-model Validation between WUFI and DELPHIN

Various Heat-Air-and-Moisture models may give divergent results for the same case, due to differences in assumptions, simplifications, or approximations. Inter-model comparisons have been used as ‘peer review’, but common limitations and/or mistakes may remain concealed. Recent validation efforts, confronting simulations with measured datasets, use limited materials, configurations, and boundary conditions. A thorough and stepwise assessment is still lacking. In this study, dedicated hygrothermal experiments on four wall assemblies (comprising calcium silicate board, mineral wool, wood fiber board and vapor barrier in different configurations) are conducted in a hot box-cold box at KU Leuven, Belgium as a benchmark. Temperatures, relative humidity, heat fluxes and moisture mass are monitored while the thermal and hygric properties of the materials from the same batch are measured. One dimensional simulations in WUFI and DELPHIN are employed to reproduce the experiments in three stages: (1) “similar” materials (with the closest properties) from respective databases provide realistic trends but also significant deviations; (2) “same” materials (attained by mathematical translation) give better agreement but uncertainties in material properties and simplifications still have great influence; (3) monitored datasets are employed to compare with simulated results using measured material properties, based on which a collaborative inter-model blind-box validation has been initiated.

Properties of Wood-Fiber Board Manufactured with the Use of UFC-FF Modified Urea–Formaldehyde Resin

Properties of Wood-Fiber Board Manufactured with the Use of UFC-FF Modified Urea–Formaldehyde Resin

Exposure Risks and Potential Control Measures for a Fire Behavior Lab Training Structure: Part B—Chemical Gas Concentrations

Firefighters’ or instructors’ exposure to airborne chemicals during live-fire training may depend on fuels being burned, fuel orientation and participants’ location within the structure. This study was designed to evaluate the impact of different control measures on exposure risk to combustion byproducts during fire dynamics training where fuel packages are mounted at or near the ceiling. These measures included substitution of training fuels (low density wood fiberboard, oriented strand board (OSB), pallets, particle board, plywood) and adoption of engineering controls such as changing the location of the instructor and students using the structure. Experiments were conducted for two different training durations: the typical six ventilation cycle (six-cycle) and a shorter three ventilation cycle (three-cycle) with a subset of training fuels. In Part A of this series, we characterized the fire dynamics within the structure, including the ability of each fuel to provide an environment that achieves the training objectives. Here, in Part B, airborne chemical concentrations are reported at the location where fire instructors would typically be operating. We hypothesized that utilizing a training fuel package with solid wood pallets would result in lower concentrations of airborne contaminants at the rear instructor location than wood-based sheet products containing additional resins and/or waxes. In the six-cycle experiments (at the rear instructor location), OSB-fueled fires produced the highest median concentrations of benzene and 1,3 butadiene, plywood-fueled fires produced the highest total polycyclic aromatic hydrocarbon (PAH) concentrations, particle board-fueled fires produced the highest methyl isocyanate concentrations, and pallet-fueled fires produced the highest hydrogen chloride concentrations. All fuels other than particle board produced similarly high levels of formaldehyde at the rear instructor location. The OSB fuel package created the most consistent fire dynamics over six-cycles, while fiberboard resulted in consistent fire dynamics only for the first three cycles. In the follow-on three-cycle experiment, PAH, benzene, and aldehyde concentrations were similar for the OSB and fiberboard-fueled fires. Air sampling did not identify any clear differences between training fires from burning solid wood pallets and those that incorporate wood-based sheet products for this commonly employed fuel arrangement with fuels mounted high in the compartment. However, it was found that exposure can be reduced by moving firefighters and instructors lower in the compartment and/or by moving the instructor in charge of ventilation from the rear of the structure (where highest concentrations were consistently measured) to an outside position.

VOC Emission from Lightweight Wood Fiber Insulation Board

The aim of the presented research work was to determine and analyze emissions of volatile organic compounds (VOCs) from experimental lightweight wood fiber insulation board produced in dry technology. Until now, there have been no rigid insulation materials made of wood fibers produced in such low density and made in dry technology. Among the typical parameters such as thermal conductivity and the mechanical performance of the lightweight board, attention was also paid to their influence on indoor air quality. Therefore, an attempt was made to determine the kind of substances emitting from wood fiber insulation boards produced at defined production parameters as well as the dynamics of emission reduction over time. Additionally, the influence of fire retardants used for protection against lightweight wood fiberboard fires on the emission of VOCs was analyzed. Tests on VOC emissions were carried out using the chamber method according to the applicable ISO 16000 standards. The main components emitting from lightweight insulation fiberboards were acetic acid and aldehydes such as pentanal, hexanal, heptanal, octanal, nonanal, decanal, furfural, and benzaldehyde. The percentage of acetic acid in total volatile organic compounds (TVOCs) was within the limits of 17% to 65%. From the aldehydes group, the most concerning substance was furfural due to a very strict limit value. In the presented research, depending on the variant, the emission of furfural was from 0 up to 10 µg/m3 after 28 days of measurement. Other substances such as terpenes or aromatic hydrocarbons were at a very low level. The reduction in VOCs over a period of 28 days was significant in most cases from 22% up to 61%. The tests carried out also showed a substantial impact of fire retardant, used in the production of lightweight insulation fiberboard, on the emission of VOCs from fiberboards, and thus on their quality.

Exposure Risks and Potential Control Measures for a Fire Behavior Lab Training Structure: Part A—Fire Dynamics and Thermal Risk

National Fire Protection Association standard 1403 provides the fire service with guidance for conducting effective live fire training with the goal of minimizing health and safety hazards. The document provides guidelines for materials to be included in the training fuel package, but the fire service has raised questions about the use of specific types of wood products for this purpose. In this study, the fire dynamics generated when utilizing five different Class A materials that have been historically employed as training fuels [low density wood fiberboard, oriented strand board (OSB), pallets, particle board, plywood] in a single compartment fire training structure (Fire Behavior Lab) were characterized. A specific focus was placed on understanding the thermal and visual environment created for firefighters located at typical locations for instructors (front and rear of structure) and students (middle of the structure). The pallet fuel package required the longest time to transition through the six ventilation cycles while the OSB fuel package was the quickest. Additionally, the most consistent fire dynamics were demonstrated with the OSB fuel followed by particle board and plywood, while fiberboard and pallets resulted in less repeatable flashover or rollover demonstration. The OSB fuel package resulted in the highest peak heat fluxes and pallets resulted in the lowest. The most severe exposures were measured at the front instructor location. To control thermal risks when conducting training in the Fire Behavior Lab structure, instructors and students should orient themselves as low as possible in the observation area and behind the interior baffle when possible. Considering the high radiant exposures for the front instructor location, providing a local shield and reducing the time in the training structure can also reduce risk for thermal injury or personal protective equipment damage. Overall, different fuels can impact thermal exposures to firefighters, but varying fuels also affects the consistency of the fire dynamics being presented to the firefighting students.

Analysis of Circular Saw Tooth Marks Profile on Material Machined Surface After Filtering with Fast Fourier Transform (FFT)

The article presents theoretical analysis of machined surface roughness after sawing on circular saw and implementation of fast Fourier transform (FFT) as a possible simple filtering method for filtering out just the saw blade and saw tooth influence on the surface roughness. Surface roughness profile is represented as a signal that can be obtained as a sum of complex periodic signals that represent theoretical profile of tooth marks and lateral movement of tooth due to saw lateral movement and signals that represent structural roughness of wood combined with machining roughness, represented as a Gaussian noise. The application of FFT based filtering on such a signal can be effectively used to extract the main frequency components due to tool influence on total surface signal and the time domain of filtered signals display can then be obtained by use of the inverse Fourier transform. In order to test the theoretical assumptions, the machining tests in sawing of solid oak wood (Quercus robur L.) and medium density fiberboard (MDF) was conducted. Machined surface roughness was measured and analyzed in accordance with theoretical assumptions. It was concluded that a combination of discrete Fourier transform of surface roughness profile and standard roughness parameters can give a more complete representation of machined surface roughness after sawing with circular saws and that filtering of surface roughness profile signal with FFT filter can be used as a simple and effective method in quantifying tool influence on machined surface roughness after sawing on circular saw in varying machining conditions and on different workpiece material.

Processing pulp fiber into high strength composites

ABSTRACT The mechanical performance of wood fibre-based panels is unsatisfactory for many advanced engineering structures and applications; it also releases free formaldehyde. Here, we report a simple and effective strategy to transform wood fiber (pulp fiber) into high strength composite panels without adhesive bonding. Our two-step process involves layer by layer self-assembly of bleached cellulose mixed with microcrystalline cellulose (MCC) and dibasic calcium phosphate (DCP). This was followed by hot-pressing, leading to the complete densification of the wood pulp fiber with highly aligned cellulose nanofibers. The result showed that the flexural and tensile strength could reach up to 147MPa and 58 MPa, respectively, which are much stronger than those of existing types of wood fiberboard, mainly resulting from the synergistic effects of hydrogen bonding and ionic bonding between the pulp fibers and DCP sheets.

Dry grinding of waste wood fiberboard: Theoretical and practical aspects affecting the resulting fiber quality

This paper presents the results of research on the treatment of secondary wood fibre semi-finished materials using a dry-grinding-type rotary cutting mill and the possibility of their use in finished products for various purposes. The physical phenomena, processes, and regularities of the treatment of secondary wood fibre materials in dry processing conditions were determined and evaluated. The influence of grinding plant design parameters on wood fibre quality indices was evaluated. Mechanical effects on wood fibre waste of face-cross cutting (cutting, crumpling, collapsing, and breaking) and the dry grinding environment (breaking, collision, defibering, and fibrillation) was studied. These phenomena contribute to the formation of external and internal fibrillation of secondary wood fibre and an increase in the specific surface area. This is achieved in the absence of high temperatures and pressure, in the absence of chemical additives, and without the application of water and vapour. The effectiveness of secondary wood fibre semi-finished material treatment was demonstrated under dry processing conditions, thus confirming the environmental and economic feasibility of this method.

Granulometric Characterization of Wood Dust Emission from CNC Machining of Natural Wood and Medium Density Fiberboard

The aim of this paper was to determine the particle size composition of wood dust emission from CNC milling of natural wood and medium-density fiberboard (MDF) and evaluate the associated occupational exposure risks. The paper is focused on some of the most commonly used materials in the woodworking and furniture industry, i.e., solid wood (beech, oak, and spruce) and composite materials (MDF panels). In addition to the influence of the machined material, the effect of the technical-technological parameters, namely, feed speed and depth of cut on the particle size distribution, was also investigated. The selected values of the technical-technological parameters used in this study followed the common work practice in small wood processing companies. The particle size distribution was evaluated by using sieve analysis of samples from the total mass of collected wood dust. The results demonstrated that machining of natural wood is characterized mostly by the formation of coarse dust fractions (2 mm–1 mm sieves), whilst the processing of MDF was associated with generation of fine dust fractions with a size below 100 μm. The results obtained can be used for optimizing the technological programs of CNC milling machines, thus, reducing the occupational exposure to harmful wood dust emissions in the wood-processing industry.

Influence of heat transfer on the estimation of water vapor diffusion coefficient in transient regime

The use of bio-sourced materials for thermal insulation of buildings is growing mainly for environmental reasons. It has already been demonstrated that since these materials are highly hydrophilic, mass transfer may have significant influence on their temperature field. We first develop a heat and mass transfer model with a limited number of parameters and we use it to simulate the mass and temperature fields during a typical transient experiment dedicated to vapor diffusion coefficient estimation. Estimations made from these simulations with a simple mass transfer model show that the estimation error can be greater than 30 % in some cases. A sensitivity study shows that the vapor diffusion coefficient, the thermal conductivity and the external mass transfer coefficient can be estimated separately from a mass recording, with the coupled model. An experimental study carried out at 15°C, 25°C and 35°C on a wood fiber board confirms the results of the theoretical study. The deviation between the vapor diffusion coefficient estimated with and without taking into account the heat transfer was 13.3 % at 35°C. It is finally shown that the isosteric heat of sorption has no effect on the estimation of the diffusion coefficient.

Effects of growth rate of eastern poplar trees on the chemical and morphological characteristics of wood fibers

Attempts are underway to speed up timber production using genetic improvement and enhanced management practices. However, the impacts of possible morphological and chemical changes on the properties of secondary wood products are less studied. This research thus studied the relationship of tree-ring widths of eastern poplar trees (Populus deltoides Bartr.) and the morphological and chemical characteristics of the wood fibers. Cellulose, lignin, ash, and extractives contents were determined according to the Technical Association of Pulp and Paper Industry standards. Accordingly, the mean values of the various parameters measured, such as the fiber length and diameter, the diameter of the cell cavity, and the cell wall thickness along with functionality parameters such as Runkel, slenderness, and flexibility ratio, and the amounts of cellulose, lignin, extractives, and ash contents were determined. As a result, statistical analysis indicated significant correlations between tree-ring width and length and diameter of the fiber, cell cavity, Runkel ratio, cell wall thickness, cellulose content and wood density. On the contrary, there were no significant correlations between tree-ring width and slenderness and flexibility ratios, lignin, ash, and extractives contents. The investigation on the radial variation of wood properties showed from the pith to the bark, fiber length and diameter, cell wall thickness, cellulose, and density increased, and cell cavity, Runkel ratio, ash, extractives, and lignin contents decreased. Overall, increases in tree-ring width of eastern poplar improved wood quality, as raw material, for manufacturing of the most common secondary products in the wood industry, including paper and fiberboard with wide-ranging wood applications.

Validity of using Single Extruder in Wood Plastic Composite from Rice Straw and High Impact Polystyrene Wastes

This work mainly aims to study the validity of using the single extruder in achieving adhesion and compatibility between rice straw fibers and plastic wastes as an attempt for manufacturing wood plastic composite (WPC). A single extruder was used for mixing recycled high impact polystyrene (RHIPS) and Egyptian natural rice straw (RS) after being fibrated mechanically to produce an eco-friendly synthetic wood that can be named as rice straw plastic composite (RSPC). The components have passed through many operations such as drying, extrusion, shredding, etc.). To produce the final product, the flat press technique was used with a hydraulic press. Samples with 60 % mechanically fibrated rice straw (MFRS) ratio were produced. The density test was operated on the samples according to ASTM-D-792 to reveal the density of the composite. The water absorption was determined according to ASTM-D-570. Using the single extruder for blending the two components didn’t achieve high levels of compatibility. However, comparing the results with natural soft, hard wood and medium density fiberboard (MDF) synthetic wood. The prepared RSPC samples exhibited less water absorption and higher density than that of natural and MDF woods.

Biocomposites Produced from Hardwood Particles by Equal Channel Angular Pressing: Effects of Pre-Treatment

The benefit of using a combination of alkali pre-treatment and ball milling in processing hardwood particles into biocomposites via equal channel angular pressing (ECAP) was demonstrated. The penetration of bonding additives (polyethyleneimine and tannic acid) into hardwood structures was enhanced by the pre-treatment, resulting in plasticization and cross-linking derived from the additives during the particle processing. A significant improvement in the biocomposites’ mechanical properties was obtained, reaching flexural strength of 28–29 MPa and flexural modulus of 3650 MPa, comparable to those displayed by commercial wood fiberboard using thermosetting resins as the binding agent. This adds to the promise of developing biocomposites from industrial or agricultural waste through the simple and efficient ECAP technology in conjunction with common pre-treatment methodologies for wood particles.

The Effect of a Magnetic Field and Low-Intensity Laser Irradiation on the Destructive Activity of Filamentous Fungi During their Growth on a Number of Industrial Products

An assessment of the impact of low-intensity laser irradiation (LILI) and magnetic field (MF) on the biodegradation of a number of industrial products: wood fiberboard (WFB) and polyester caused by filamentous fungi is presented. It has been established that the magnetic field is capable of causing intensive destruction of wood fiberboard and polyester by fungi Alternaria alternata, Aspergillus niger, then the destructive process of WFB in the case of Penicillium cyclopium remained at the control level, and in the case of polyester it slowed down. The action of LILI, on the contrary, increased the destructive activity of Penicillium cyclopium in variants with WFB, and for polyester in the fungi Alternaria alternata, Aspergillus niger. Differences in the change in the resistance of products to fungi under the action of LILI and MF can be associated with both the physiological and biochemical characteristics of fungi and the aging process of polymers under the influence of the studied physical factors.

Toxicity of formaldehyde, polybrominated diphenyl ethers (PBDEs) and phthalates in engineered wood products (EWPs) from the perspective of the green approach to materials: A Review

Adhesives, flame-retardant chemicals, and paints are used in engineered wood products (EWPs) to increase some of the properties of wood. Most of the engineered wood composites, including plywood, particleboard, and fiberboard, used as furniture components contain formaldehyde resins as an adhesive. The International Agency for Research on Cancer (IARC) added formaldehyde to the list of human carcinogens (Group 1) in 2004. Flame-retardant chemicals are semi-volatile organic compounds that can migrate from the products to the air. There are developmental neurotoxic effects from flame-retardant additives, among which polybrominated diphenyl ethers (PBDEs) are commonly used in EWPs. The flexibility and durability of plastics are increased using phthalates, which are a class of synthetic chemicals, by adding them to the polyvinyl chloride (PVC) that is used in the wood-plastic composites (WPC). Formaldehyde, PBDEs, and phthalates are toxicants that are commonly present in value-added furniture products. This review summarized the toxic effects of these chemicals from the aspect of human health and from the perspective of green products.

PEMANFAATAN LIMBAH PENGGERGAJIAN KAYU SENGON (Paraserianthes falcataria) MENJADI PAPAN SERAT

Fiberboard can be made from a variety of berligno-cellulose fiber materials. One of the berligno-sesulose fiber materials is Sengon wood which is a waste of sawmills. Efforts to use sengon wood waste can be used for high density fiberboard. In this study we want to see the quality of sengon wood fiber board with TRF adhesive (Tanin Resolsinol Formaldehyde). The sengon wood fiber board was tested according to the JIS A-5905-2003 standard. The parameters tested were the physical-mechanical quality of the fiberboard, namely density, moisture content, water absorption, thickness development, elastic modulus, fracture modulus and internal adhesive strength. TRF is applied in three levels, namely: 0%, 6% and 8%. The results showed that the physical-mechanical quality that met the JIS A-5905-2003 standard was density (0.935 - 1.204 g / cm3), moisture content (9.840 - 12.2%), modulus of elasticity (313.55 - 355.53 kg / cm2), broken modulus (36,672 - 39,341 kg / cm2) and internal adhesion strength (4,244 - 4,371 kg / cm3). While the nature of water absorption (65,875 - 79,856%) and the development of thickness (27,665 - 39,295%) did not meet the JIS A-5905-2003 standard, at all TRF levels.

Thermal and hygric properties of biomaterials suitable for interior thermal insulation systems in historical and traditional buildings

Historical and traditional buildings account for 10–40% of the building stock in various countries and regions. Retrofitting of their building envelopes aimed at the improvement of thermal performance is often feasible using interior thermal insulation systems only. The effectiveness of systems without vapor barrier depends on the application of modern insulation materials with enhanced water transport properties contributing to fast liquid moisture redistribution and mitigating the risks related to water vapor condensation. In this paper, thermal and hygric properties of several biomaterials potentially applicable as thermal insulation boards on the interior side of historical building envelopes are investigated. The obtained experimental data include all transport and storage parameters necessary for appropriate hygrothermal- and energy-related assessment of buildings provided with interior thermal insulation systems using advanced computer simulation tools. Wood fiberboard, flax fibers, hemp fibers, jute fibers, and sheep wool are found to have, at the same time, low thermal conductivity (∼0.05 W m−1 K−1) and high moisture diffusivity (1.1 × 10−6 – 1.2 × 10−5 m2 s−1) which can classify them as good candidates for the use in interior thermal insulation systems without water vapor barrier. They exhibit convenient water vapor diffusion parameters and hygroscopic properties as well, which favors their use on the interior side. The natural origin presents another benefit. In a comparison with conventional materials (calcium silicate, hydrophilic mineral wool) having similar thermal and hygric properties, they bring more harmony to the process of retrofitting historical building envelopes.