Wood-based Panel Industry Research Articles

Production and characterisation of wood-fibre insulation boards (WFIB) from hardwood fibres and fibre blends

ABSTRACT Due to the rapid decline in coniferous (softwood) stands in Europe, the wood-based panel industry will be forced to adapt its products to the wood market supply. The production of wood fibre insulation boards (WFIB), which are usually made with softwood fibres, must therefore be converted to the use of hardwood fibres. The objective of this study was to investigate the properties of WFIB made from hardwood fibres and blends of softwood and hardwood fibres produced in a refiner by thermo-mechanical pulping (TMP). WFIB with a raw density of 100 kg m−3 were produced in a dry process with hot-air and hot-steam. The binder used was polymeric diphenylmethane diisocyanate (pMDI, 5 wt% related to the weight of dry fibre material) for stiff boards or 7 wt% bi-component (Bico) fibres for flexible mats. Mechanical strength results for pure hardwood fibres were significantly lower than for softwood fibres and for fibre blends, while water absorption was significantly higher. However, the thermal conductivity for pure hardwood fibres was higher than for softwood fibres and for fibre blends. The results showed that it is possible to produce WFIB from hardwood fibres with satisfactory properties. WFIB made from hardwood fibre blends with at least 20% softwood fibre content showed comparable results to those made from pure softwood fibres.

Evaluation of Starch as an Environmental-Friendly Bioresource for the Development of Wood Bioadhesives.

The environment is a very complex and fragile system in which multiple factors of different nature play an important role. Pollution, together with resource consumption, is one of the main causes of the environmental problems currently affecting the planet. In the search for alternative production processes, the use of renewable resources seeks a way to satisfy the demands of resource consumption based on the premises of lower environment impact and less damage to human health. In the wood sector, the panel manufacturing process is based on the use of formaldehyde-based resins. However, their poor moisture resistance leads to hydrolysis of amino-methylene bonds, which induces formaldehyde emissions throughout the lifetime of the wood panel. This manuscript investigates the environmental profile associated with different wood bioadhesives based on starch functionalization as a renewable alternative to formaldehyde resins. Considering that this is a process under development, the conceptual design of the full-scale process will be addressed by process modeling and the environmental profile will be assessed using life cycle assessment methodology. A comparative study with synthetic resins will provide useful information for modify their development to become real alternatives in the wood-based panel industry. The results obtained show the enormous potential of starch bioadhesives, as their environmental impact values are lower compared to those based on petrochemicals. However, certain improvements in the energy process requirements and in the chemical agents used could be developed to provide even better results.

Eco-friendly natural rubber latex and modified starch-based adhesive for wood-based panels application- A review

The use of formaldehyde-based synthetic adhesives for the development of wood-based panels has increased rapidly in the industry. Synthetic adhesives are regarded as a threat to human health and a pollutant because they emit formaldehyde's carcinogenic gas. The breakthrough has prompted to seek for a long-term solution to the formaldehyde threat with natural resources. There has been a significant rise in bio-based adhesive technology and development in the wood-based panel industry. The current review article is intended to present the potentials and the drawbacks of the development of bio-adhesives from sustainable resources such as natural rubber latex (NRL) and starch. This review also discussed the chemical modification and crosslinkers of starch to improve water resistance and adhesion properties. Moreover, this article discusses the compatibility of modified rice starch and NRL for their conclusive applications as wood-based panels adhesive. The findings suggested that bio-based adhesives could replace more synthetic-based adhesives with comparable performance in the near future.

PREFAB Framework - PRoduct quality towards zEro deFects for melAmine surface Boards industry

Abstract Zero Defects is one of the ultimate targets for manufacturing quality control and assurance. Such systems are becoming common in advanced manufacturing industries but are at an initial stage in more traditional industrial sectors, such as wood panels, laminates production, pulp and paper processing and composite panels production. This paper proposes the PREFAB framework, applied to the wood-based panels industry, to minimize rejected products using AI, machine learning and IoT devices. The framework was built through action research with a Portuguese wood-based panel manufacturing. This framework delivered an innovative decision support system that provides relevant and timely recommendations for shopfloor decision making and to support process/product engineering.

Analysis of the influence of larch fibers and particles on selected properties of fiber- and particleboards

Analysis of the influence of larch fibers and particles on selected properties of fiber- and particleboards. The paper presents the results of the research on the effect of the addition of fibers and particles obtained from European larch wood (Larix decidua Mill) from plantations on selected properties of fiber- and particleboards in comparison to the boards of the same structure based on typical industrial raw material (pine wood) uses by European wood based panels industry. The differences were shown in the tests, i.e.: modulus of rupture (MOR), modulus of elasticity in static bending (MOE), internal bond (IB), thickness swelling after 2 and 24 hours soaking in water and density profile. In the MOR and MOE tests, larch boards with a minimum 50% fiber share were characterized by comparable values of the properties determined to pine boards, while in the other variants, boards made of pine wood had better properties. In most cases, the larch boards were characterized by significantly lower values of swelling by thickness (with the exception of boards made of fibers) than boards made of wood from forest cultivation. The density profile of the boards on the cross-section of the plantation raw material did not differ from the boards made of pine raw material.

Synthesis of polymeric isocyanate microcapsules via interfacial polymerization and their characterisation using spectroscopy and microscopy techniques

Wood adhesives are holding a key in improving the efficiency of using raw materials in the wood-based panel industry and in durability of the panels during their life in service. Massive progress has been made on research and development of wood adhesives over the past century, but many important challenges are still remaining. In this study, an alternative cross-linker for wood adhesives named microcapsules polymeric 4,4 methane diphenyl isocyanate (M-pMDI) were synthesized at different conditions via interfacial polymerization, and were characterized using spectroscopy and microscopy techniques. Three factors were taken into account to examine the characteristics of M-pMDI, namely isocyanate content, microencapsulation temperature, and microencapsulation agitation rate. Attenuated total reflectance Fourier transform infrared spectroscopy revealed that the isocyanate (-N=C=O) groups of pMDI at 2,250 cm−1 disappeared after microencapsulation due to the reaction of pMDI and ethylene glycol to form urethane (-R-NH-C=O-) linkages at 1,650 cm−1 as microcapsules shell. Digital microscopy and micro confocal raman imaging hyperspectral spectroscopy confirmed the formation of microcapsules and urethane shell. The results showed that concentration of isocyanate remarkably affected the yield of M-pMDI, while microencapsulation temperature and agitation speed influence the formation of microcapsules itself. Prel-liminary investigation using ATR-FTIR spectroscopy confirmed that free–NCO groups could be released by applying pressure. This study suggested that a combination of 5 mL of pMDI, 60°C of microencapsulation temperature, and 600 rpm of microencapsulation agitation speed could produce M-pMDI with high yield as an alternative cross-linker for wood adhesives in the future.

Thermal and Fire Properties of Medium-density Fiberboard Prepared with Huntite/hydromagnesite and Zinc Borate

Effects of mineral-based fire retardants were investigated relative to the thermal and fire properties of medium-density fiberboard (MDF) via thermogravimetric analysis (TGA), limiting oxygen index (LOI), and thermal conductivity testing. Mineral-based chemicals containing huntite /hydromagnesite and zinc borate (ZB) were used at different concentrations. Changes in all values were observed depending on the type and concentration of chemicals. According to TGA evaluation, the residual weights in the MDF samples manufactured with mineral-based chemicals were higher than the residual weight in the control MDF sample. Limiting oxygen index testing results showed higher values for the MDF samples manufactured with mineral-based chemicals than for the control sample. The LOI values increased with the increment of chemical concentration, and the highest value was observed in group B12. The thermal conductivity trends of the MDF samples varied depending on the type and concentration of chemicals. Generally, the thermal conductivity values of the MDF samples manufactured with chemicals were found to be higher than the value of the control. These results suggested that these chemicals with various combinations should be evaluated as fire retardants for wood and wood-based panel industry.

Thermal and fire properties of medium-density fiberboard prepared with huntite/hydromagnesite and zinc borate

Effects of mineral-based fire retardants were investigated relative to the thermal and fire properties of medium-density fiberboard (MDF) via thermogravimetric analysis (TGA), limiting oxygen index (LOI), and thermal conductivity testing. Mineral-based chemicals containing huntite /hydromagnesite and zinc borate (ZB) were used at different concentrations. Changes in all values were observed depending on the type and concentration of chemicals. According to TGA evaluation, the residual weights in the MDF samples manufactured with mineral-based chemicals were higher than the residual weight in the control MDF sample. Limiting oxygen index testing results showed higher values for the MDF samples manufactured with mineral-based chemicals than for the control sample. The LOI values increased with the increment of chemical concentration, and the highest value was observed in group B12. The thermal conductivity trends of the MDF samples varied depending on the type and concentration of chemicals. Generally, the thermal conductivity values of the MDF samples manufactured with chemicals were found to be higher than the value of the control. These results suggested that these chemicals with various combinations should be evaluated as fire retardants for wood and wood-based panel industry.

Systematic assessment of wheat extenders in condensation resins for plywood production: Part I - physico-chemical adhesive properties

ABSTRACT The use of additives for resins modification is common practice in wood-based panel industry and wheat flour has been one of the most widely used extenders for decades. The amount of wheat flour to be added is determined through a sense of proportion, mainly based on experience, as systematic scientific studies on the effect of its individual components are limited. In this study, we added wheat flour, wheat starch and wheat protein as extenders in various quantities to urea (UF) and phenol formaldehyde (PF) resins and analysed their structure, pH value and buffer capacity through closely examining their interaction with the resins as well as their effect on viscosity and bonding strength development. As a result, wheat protein proved to be the most effective on both resins. Despite influencing adhesive properties in uncured state, no effect on the curing behaviour of the resins could be observed.

Productivity Analysis of Modified Farm Tractors in Forwarding Industrial Wood Products

Public demands for forest products and services have been increasing gradually in many countries all over the world. Among the forest products, mostly round woods are produced in Turkey due to high economic value. On the other hand, there is a significant increase in demand for industrial woods in the domestic market in recent years. The reason behind this increase is the need of domestic companies in the wood-based panel industry for a large amount of wood raw material. . Farm tractors are the most widely used forest machinery in the extraction of industrial wood in Turkey. Farm tractors can be effectively used in mechanized harvesting operations after receiving some modifications and additional attachments. The modified farm tractors are affordable machinery for small logging contractors since their initial purchasing costs and hourly operating costs are quite low comparing with the forest harvesting equipment (i.e. skidder, forwarder, cable yarder). In this study, productivity of a modified farm tractor was analyzed during forwarding of industrial wood products. The study was implemented in Pinus nigra stand located in (?) the city of Afyonkarahisar in Turkey. In the study, the effects of forwarding distance on productivity were evaluated using statistical analysis. The results indicated that the most time-consuming work stage was unloading the truck and piling the wood products at the landing area, followed by ( in terms of time-consumption) collecting woods and loading the tractor at the stump. The average productivity of the forwarding operation was 6.06 stere/h (stere is the amount of wood pile with the height, width, and depth of one meter). It was also found that the productivity of the forwarding was significantly affected by the forwarding distance.

Process modification involving strong-acid step in urea-formaldehyde resin preparation

Urea-formaldehyde (UF) resin adhesive for wood-based panel industries are commonly manufactured using conventional alkaline-acid process. This paper reports a process modification of a conventional UF resin preparation by incorporating a strong-acid step, involving simultaneous methylolation and condensation reactions at very low pH at the beginning of the processing step. The experiment showed that this additional step should be carried out at short duration and at high enough temperature in order to avoid gelation or separation problems. In order to control temperature rise caused by the exothermic nature of the reactions, the modified process requires a higher initial formaldehyde-to-urea (F/U) molar ratio compared to the original. For the same reason, the first urea should be fed incrementally to ensure high F/U ratio at any time during the strong acid step. Using regular formalin concentration as raw material at the same F/U molar ratio, the modified resin showed lower free formaldehyde content thus have lower reactivity in comparison to those of the original. However, when the same procedure was applied using higher formaldehyde concentration at higher solid content, the produced resin showed comparable free formaldehyde content and shorter gelation time. Application test for making plywood showed that the modified process gave a very significant improvement in both the internal bonding strength and formaldehyde emission.

Wood-Based Panel Industry Wastewater Meets Microbial Fuel Cell Technology.

Although the wood-based panel industry is not considered to be a water-consuming sector, it generates ca. 600 M m3 of wastewater every year on a global scale. The wastewater is usually highly polluted and environmentally toxic even after dilution. Common wastewater treatment techniques require high-energy input or addition of various chemicals to the treated wastewater, which cause secondary pollution and production of toxic sludge. Microbial fuel cells (MFCs) have become an attractive technology, allowing for zero-energy treatment of various types of wastewater with simultaneous production of electric current. Recent investigations have shown that MFCs can also be utilized for sustainable treatment and energy production from the wastewater generated by the wood-based panel industry. This article contains a critical summary of the investigations in this field as well as a discussion of the research needed and perspectives for the future.

Review of the industrial applications of bacterial cellulose

Review of the industrial applications of bacterial cellulose. Bacterial cellulose (BC) differs from plant cellulose in fibre diameter, which for BC is between 20 and 100 nm. Literature data indicates that BC has a crystalline level of 90% and is thermally stable and has higher mechanical properties than plant cellulose. The purity of BC is estimated in the range of 98% because it is not contaminated with lignin, pectin and hemicelluloses like plant cellulose. The BC is used in medicine, cosmetics, electronics, food, paper and packaging industries. So far, bacterial cellulose has not been implemented for technological applications in the wood-based panels industry. Current research and development trends in the wood-based panels industry include the use of plant-based nanocellulose to improve selected properties of wood-based panels of various types. It should be assumed that BC may be a full value material ingredient in the production of wood-based panels, simultaneously improving mechanical and physical parameters of composites manufactured with its participation.

Integrated planning of inbound and outbound logistics with a Rich Vehicle Routing Problem with backhauls

This paper addresses the integration of the planning decisions concerning inbound logistics in an industrial setting (from the suppliers to the mill) and outbound logistics (from the mill to customers). The goal is to find the minimum cost routing plan, which includes the cost-effective outbound and inbound daily routes (OIRs), consisting of a sequence of deliveries of customer orders, pickup of a full truck-load at a supplier, and its delivery to the mill. This study distinguishes between three planning strategies: opportunistic backhauling planning (OBP), integrated inbound and outbound planning (IIOP) and decoupled planning (DIOP), the latter being the commonly used, particularly in the case of the wood-based panel industry under study. From the point of view of process integration, OBP can be considered as an intermediate stage from DIOP to IIOP. The problem is modelled as a Vehicle Routing Problem with Backhauls, enriched with case-specific rules for visiting the backhaul, split deliveries to customers and the use of a heterogeneous fleet. A new fix-and-optimise matheuristic is proposed for this problem, seeking to obtain good quality solutions within a reasonable computational time. The results from its application to the wood-based panel industry in Portugal show that IIOP can help to reduce total costs in about 2.7%, when compared with DIOP, due to better use of the delivery truck and a reduction of the number of dedicated inbound routes. Regarding OBP, fostering the use of OIRs does not necessarily lead to better routing plans than DIOP, as it depends upon a favourable geographical configuration of the set of customers to be visited in a day, specifically, the relative distance between a linehaul that can be visited last in a route, a neighboring backhaul, and a mill. The paper further provides valuable managerial insights on how the routing plan is impacted by the values of business-related model parameters which are set by the planner with some degree of uncertainty. Results suggest that increasing the maximum length of the route will likely have the largest impact in reducing transportation costs. Moreover, increasing the value of a reward paid for visiting a backhaul can foster the percentage of OIR in the optimal routing plan.

Facile Approach for Glutaraldehyde Cross-Linking of PVA/Aluminophosphate Adhesives for Wood-Based Panels

The application of aluminophosphate adhesives in wood-based panel industries is limited by the adhesives’ inherent disadvantage of poor water resistance caused by their mesoporous nature. In this s...

Effect of Pine (Pinus Sylvestris) Bark Dust on Particleboard Thickness Swelling and Internal Bond

Increasing demand for wood resulted in competition between different branches of wood-based production. High intensity production, like the production of wood-based panels, is forced to look for other lignocellulosic resources. Bark is a possible source for wood-based panel industry, especially for particleboards. Bark chips were crushed into bark dust, which were used for the production of single-layer particleboards. The share of bark dust was 0 %, 0.5 %, 1 %, 5 % and 10 %. The boards were tested on thickness swelling (immersion in water, exposure to humid conditions) and internal bond. The highest internal bond was determined in the particleboard with 1 % bark share. Thickness swelling of boards with added bark was higher compared to boards without bark. The highest swelling was observed in boards with 10 % bark dust (immersion in water) or 5 % (humid conditions). Bark based boards absorbed less water.

Potential use of textile dust in the middle layer of three-layered particleboards as an eco-friendly solution

Textile (cotton) dust, which is harmful to humans and the environment, is one of the largest wastes in the textile industry. The aim of this study was to investigate the potential use of this waste in high value-added materials. Physical and mechanical properties and formaldehyde emissions of the three-layered particleboards with textile (cotton) dust in the middle layer were investigated in this study. A phenol formaldehyde resin was used as the binder in particleboard production. Four different amounts of textile dust (10%, 20%, 30%, and 40%) based on the oven-dried weight of the wood were obtained from a commercial textile manufacturer as industrial waste. The density, thickness swelling, modulus of rupture, modulus of elasticity, internal bond, and formaldehyde emissions of the produced panels were determined. The physical and mechanical properties and formaldehyde emissions of the particleboards were negatively affected, which decreased with the addition of a high amount of textile powder. At low rates, the use of textile dust in the middle layer did not significantly decrease the particleboard properties. Textile dust can be a partial solution for the raw material demand of the wood-based panel industry.

Reducing formaldehyde emission from wood-based panels by modification of UF and MUF resins with condensates obtained from kiln-drying of wood

Abstract Liquid condensates collected during drying of lumber, sawdust or wood powder are usually discarded. The objective of this study was to investigate the potential utilization of such condensates from oak, beech and walnut, focusing on those obtained in a 7.8 MHz vacuum dryer. The condensate was replaced with the deionized water (5%) in the production of urea-formaldehyde (UF) and melamine-urea-formaldehyde (MUF) resins in the reactor. The technical properties of the resins and chemical properties of the liquid condensates were determined. Particleboards (PB) and middle density fiberboards (MDF) were produced from the control and modified resins. The technical properties of both modified resins were between the limit values of commercial UF and MUF resins used in the wood-based panel industry. The formaldehyde (F) emission from PB and MDF decreased significantly by incorporation of the condensates into the UF and MUF resins.

Technological Characterization and Use of Babassu Residue (Orbygnia phalerata Mart.) in Particleboard

The wood-based panel industry is growing all over the world, and in many countries the raw material is becoming increasingly inadequate and increasingly expensive. Therefore, new inputs are needed to reduce production costs. The residue of babassu palm fruit after nut extraction process is an alternative, due to its fibrous characteristics, the high availability in the large agroindustrial complexes in the North of Brazil and the low cost. Thus the research was: (i) to determine the mechanical characteristics (tensile strength and elasticity), physicochemical characteristics (density, pH, extractives content and chemical composition) and micro-structural of the babassu residue, comparing it with the particles of Pinus sp., used in commercial panels; (ii) to evaluate the quality of panels manufactured with babassu residue by physical conditions (swelling in thickness and water absorption) and mechanical characterization (elasticity and rupture) based on Brazilian Technical Standards (NBR 14810-2: 2013), American (ANSI A208.1: 2009) and European (EN 312: 2003). Statistical analysis of the data was performed with the aid of Infostat software through analysis of variance using Tukey test at the 5% probability level. The babassu residue has technological characteristics that allow its use in particleboard production. However, there are particularities that may compromise its use, such as high silica content and high density. Particleboard made from babassu residue presented mechanical performance above that required by current normative documents. However, for the physical properties, especially for the porosity of the particleboard of babassu, the obtained values were lower than the required minimum.

Evaluation of carbon footprint for wood based panel industry in Turkey

In wood-based panel industry, the importance of carbon footprint has increased due to global warming and climate change all around the world. So this topic has been studied extensively in the world, especially in developed countries. Eventhough wood based panel industry is one of the most important industry in Turkey there is not any comprehensive study in this field so this study was planned to meet the requirement in industry which release a lot of emissions to the environment. In recent years the use of wood-based panels such as fiber board, particleboard, oriented strand board, plywood etc., have been increased due to the fast growth in bulding trade in Turkey. The world’s largest board producers are China, USA, Germany and Turkey respectively. This charges the industry a great responsibility for the environment because sustainable development is a development that meets the needs of the present without making a concession the ability of future generations to meet their own needs. From this perspective, it is essential to know the current status of the sector concerning CO 2 footprint, energy footprint and water footprint. This study is aimed to investigate one of the largest board producer industry of Turkey whether clean production (less emission) is carried out or not. Besides, it is aimed to present some improvements to decrease the emission. Carbon footprint values are calculated as statistically with Tier method during the particle board production, and Pareto anaysis method is used for determine the footprint’ problem. Consequently, a liveable environment will be provided and environmental oriented production will be supported to contribute to these properties in the industry for this issue in the scope of this research. Also, this study shall provide a general view and perception for the importance of the carbon footprint in the industrial sector.