Production Of Wood-based Panels Research Articles

Eco-friendly fiberboards with low formaldehyde content and enhanced mechanical properties produced with activated soybean protein isolate modified urea-formaldehyde resin

Urea-formaldehyde (UF) resin is one of the most widely used resin adhesive for wood-based panels. The main concern of UF resin bonded wood-based panels is formaldehyde emission and poor water resistance. In this study, activated soybean protein isolate (SPI) was used to modify UF resin for the production of eco-friendly fiberboard panels. The effects of different activated SPI on the properties of UF resins and the resin bonded medium-density fiberboard (MDF) panels were investigated. The free formaldehyde content of the urea-activated SPI modified UF resin was only 0.13 %. Approximately 27.8 % lower than that of the unmodified UF resin. The resin bonded MDF panel with a density of 760 kg/m3 shows a modulus of rupture (MOR) and modulus of elasticity (MOE) of 45.73 MPa and 4005 MPa, which is increased by 25 % and 15 % compared to the unmodified UF resin group. The internal bonding strength (IB) reaches 0.71 MPa, which is about 15 % higher than that of the unmodified UF resin group. The tested 24-hour thickness swelling (24 h TS) of the modified UF resin group is only 8.1 %. The tested formaldehyde content of the sodium dodecyl sulfate (SDS)-activated SPI modified UF resin bonded MDF panel is only 4.8 mg/100 g, which is 20 % lower than that of the control UF resin group. The activated SPI modified UF resin shows great improvement in bonding strength and lower formaldehyde content for MDF panels as compared to the pure UF resin. The chemical groups, crystalline properties, and thermal stability of the pure and the modified UF resins were characterized via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric (TG) analysis. It is confirmed that the activated SPI modified UF resin has similar chemical structure, higher ratio of crystalline regions, and slightly lower thermal stability with compared to the pure UF resin. This study proposes a practical and applicable solution for the utilization of eco-friendly UF resin in wood-based panel production.

An alternative pathway to negative emissions – revitalising the wood-based panel production in Sweden

Among different possibilities to mitigate climate change, the utilisation of carbon sinks has rendered increased interest with the emergence of net-zero targets. In Sweden, despite large forest resources, the product category wood-based panels has turned from being a carbon sink to an emission source. Production data and the Intergovernmental Panel on Climate Change (IPCC) accounting approach has been used in this paper to construct the pool of biogenic carbon sequestered in wood-based panels. We used indices to compare this development and found that it is unparalleled in other countries. We show that it is possible to achieve an increased carbon sink in harvested wood products in Sweden and argue that all options producing real and quantifiable carbon sinks should be given opportunities in the regulatory frameworks for climate change mitigation. We conclude that the increased importance of carbon sinks to mitigate climate change justifies a critical discussion of bioenergy policy in Sweden and the rest of Europe. Additionally, we suggest a policy direction that will promote the cascading use of by-products for wood-based panels without proposing a mandated hierarchy of biomass use.

Desirable Strong and Tough Adhesive Inspired by Dragonfly Wings and Plant Cell Walls.

The production of wood-based panels has a significant demand for mechanically strong and flexible biomass adhesives, serving as alternatives to nonrenewable and toxic formaldehyde-based adhesives. Nonetheless, plywood usually exhibits brittle fracture due to the inherent trade-off between rigidity and toughness, and it is susceptible to damage and deformation defects in production applications. Herein, inspired by the microstructure of dragonfly wings and the cross-linking structure of plant cell walls, a soybean meal (SM) adhesive with great strength and toughness was developed. The strategy was combined with a multiple assembly system based on the tannic acid (TA) stripping/modification of molybdenum disulfide (MoS2@TA) hybrids, phenylboronic acid/quaternary ammonium doubly functionalized chitosan (QCP), and SM. Motivated by the microstructure of dragonfly wings, MoS2@TA was tightly bonded with the SM framework through Schiff base and strong hydrogen bonding to dissipate stress energy through crack deflection, bridging, and immobilization. QCP imitated borate chemistry in plant cell walls to optimize interfacial interactions within the adhesive by borate ester bonds, boron-nitrogen coordination bonds, and electrostatic interactions and dissipate energy through sacrificial bonding. The shear strength and fracture toughness of the SM/QCP/MoS2@TA adhesive were 1.58 MPa and 0.87 J, respectively, which were 409.7% and 866.7% higher than those of the pure SM adhesive. In addition, MoS2@TA and QCP gave the adhesive good mildew resistance, durability, weatherability, and fire resistance. This bioinspired design strategy offers a viable and sustainable approach for creating multifunctional strong and tough biobased materials.

Improving feedstock quality control in formaldehyde-based resin and wood-based panel production through near infrared spectroscopy

To assure the quality control of industrial processes, it is important to adopt reproducible and efficient methodologies. Spectroscopic methods, such as near infrared (NIR), are a good option as they are fast and may be used to indirectly estimate multiple physicochemical properties. In this study, NIR spectra of key feedstock samples used in the production of formaldehyde-based resin and wood-based panels, namely urea, ammonium sulfate, ammonium nitrate, sodium hydroxide, and acetic acid, were acquired. Multivariate data analysis was applied to establish the correlation between the spectra and the properties being measured. Quantitative models were then created using partial least squares regression to predict the concentrations of feedstock samples. This study presents quantitative models that were created by combining spectra measured on two probes, which achieved similar prediction results as single-probe based models. The performances of the best models were compared with the reference methods for each of the evaluated samples. For the samples under study, the proposed approach is suitable for routine analysis across multiple equipment configurations using the same quantitative model. NIR spectroscopy combined with chemometric models could be a valuable complement to support in-line raw material monitoring and plant digitalization in the wood panels industry.

Comparison of the properties of phenolic resin synthesized from different aldehydes and evaluation of the release and health risks of VOCs

Different amounts of glyoxal and paraformaldehyde were used to synthesize phenol-glyoxal (PG) and phenol-paraformaldehyde (PPF) resins, which were compared with conventional phenol-formaldehyde (PF) resins. Glyoxal oxidation leads to a pH value of 9.83 for PG 2.2. With the addition of polyformaldehyde, PPF 2.2 exhibited the highest viscosity at 17333.33 mPa s. The PPF 2.0 plywood has a maximum bonding strength of 1.94 MPa. The formaldehyde emission of PG 1.8 plywood is found to have a minimum value of 0.025 mg/m3, reaching the ENF limit (≤0.025 mg/m3). Acetaldehyde is found only in volatile organic compound (VOC) emissions from PG plywood and is associated with increased glyoxal. PPF plywood emitted more aromatic and total VOC (TVOC) than the other two plywood types. The measured TVOC for PPF 2.2 is 196.07 μg/m3. The results showed that the total cancer risk (TCR) values of PPF 1.8, PPF 2.0, and PG 1.8 were above the threshold of 1.00E-4, indicating a definite carcinogenic risk. Acetaldehyde in the PG plywood exceeded the safety threshold for noncarcinogenic risk. The use of paraformaldehyde in the wood-based panel production is been considered a possible means of improving the bonding strength of plywood. Glyoxal has also been shown to be a viable method for lowering the formaldehyde emissions from plywood. The VOC emissions from plywood changed significantly depending on the aldehyde used. Limiting VOCs that present high health hazards is crucial for reducing the negative impact of plywood on both indoor environments and human health.

Export Growth and Quality Determination of Wood Forest Products: Evidence from China

The rapid-developed scale of China’s trade in wood forest products has undergone a considerable uptick. Concomitant with the evolution of high-quality development paradigms, product quality within trade frameworks has gained escalating scrutiny. Based on the statistical analysis of the export characteristics of China’s wood forest products, this study leverages BACI data spanning from 1998 to 2017. Utilizing regression-based inverse methods, the study quantifies the quality attributes of these export products, dissects fluctuations in quality, and places particular emphasis on the markets within “Belt and Road Initiative” economies to elucidate dynamic trends and spatial distribution characteristics of export quality in this geoeconomic domain. Based on this, the fixed effect model, random effect model, and system GMM are used to empirically examine the influencing factors of China’s wood forest product export quality. This study found that wood-based panel products have the highest quality, followed by paper products and wood furniture among the three major categories of wood forest products. Besides, the overall quality levels of the three products exported to countries participating in the Belt and Road initiative haven’t significantly changed, while notable changes are evident across divergent export destination markets. In addition, an empirical study on the influencing factors of the export product quality of wood forest products is conducted, which indicates that total factor productivity, R&D investment, capital intensity, labor costs, and foreign direct investment are influencing factors. Finally, based on the research conclusions, suggestions are provided on how to improve the export quality of wood forest products.

Comparative evaluation of alternatives for management of wood wastes by using multi-criteria decision tools

In Turkey, the wood industry is a prevailing sector generating economically valuable by-products such as sawdust, wood chips and wood shavings. The utilization of these materials supports an important contribution to the revival of the economy. Selection of the best management alternative considering economic and environmental factors synchronously requires the application of statistical decision-making methods. The significance of this study is to determine the suitability of promising alternatives for the utilization of wood wastes (production of pellet, panel, cemented wood composites and pyrolysis) by using multi-criteria decision-making methods (PROMETHEE and FPROMETHEE). Super Decision Program was used to evaluate the importance of the selected criteria (environmental impact, operation risk, installation cost, applicability, operation cost and market competition) based on data obtained from the 9-scale questionnaire. In PROMETHEE and FPROMETHEE applications, both equally weighted and calculated importance of criteria was considered. According to results of AHP, installation cost was the most important criterion with 31% ratio. Results of the study showed that pellet production was the best alternative in all applications with the highest-ranking values. Wood-based panel production was followed by pellet production; however, it was seen that the production of cemented wood composites and pyrolysis are not suitable for the utilization of wood wastes.

Reinforcement of urea formaldehyde resins with pectins derived from orange peel residues for the production of wood-based panels

Pectin is a high molecular weight carbohydrate polymer that can be utilized in various applications in many sectors. The current study involved extracting pectin samples from orange peel residues and utilizing them as additives in water-based adhesive systems for producing composite wood panels. Three pectin types were used, named Pectin-A (extracted from orange peels with HCl), pectin-B (extracted from orange peels with H2SO4) and a commercial pectin called Pectin-C. The aim of the study was to examine the possibility of enhancing the efficacy of wood-based panels, such as particleboard, by strengthening amino resins like urea-formaldehyde resin (UF) using pectin samples. Three methods were utilized to incorporate the pectins into the adhesive systems: pectin 0.1% w/w dry/liquid resin added during the initial (1) and final (2) stage of the resin’s synthesis and pectin 0.1% w/w dry/liquid resin was incorporated into the glue mixture (3), which was then sprayed onto wood particles for the production of particleboard (PB) panels. It was found that pectins improve the performance of the final particleboards, especially when added during the UF resin synthesis. In addition, they may provide the adhesive and wood panel producers with a more environmentally friendly bio-additive for their products.

Melamine Acetate Preparation as a Urea-Formaldehyde Resin Additive for Particleboard Production

Urea-formaldehyde (UF) resin binders for wood-based panel production often use melamine as an additive to improve both mechanical properties and environmental compliance. Direct fortification for efficient use of melamine remains a problem due to low solubility. Pizzi & coworkers suggested the use of more soluble melamine salts and demonstrated success in terms of product performance. However, their preparation method showed low productivity and inefficient use of material and energy. In their scheme, a batch reactor fed with 1 kg of water and 75 g of a stoichiometric amount of melamine and acetic acid produced only around 25 g of solid melamine acetate crystal. In contrast, the remaining 50 g remained dissolved in 991 g of water, which requires high of energy to evaporate. This paper reports an attempt to increase batch productivity and work towards the more efficient use of material and energy. The experiment showed that the successive addition of melamine and acetic acid to the batch up to the solubility limit of melamine at the same reaction condition increased melamine and acetic acid fed from 75 g to 165 g. This was followed by a significant increase in dry crystal yield from 25 g to 117 - 132 g. Feeding the mother liquor to the next batch decreased the water use to only 8% of the original requirement. This resulted in a highly efficient process, eliminating the need for energy-intensive melamine acetate recovery from the mother liquor. The addition of 2% - 4% wt. of the product to UF resin resulted in particleboard with significantly lower thickness swelling, an increase in MOR & IB strength, and lower formaldehyde emission.

The characterizations of nanofluid type urea formaldehyde resins

For reducing the emission of formaldehyde, urea formaldehyde (UF) resin adhesives used in the wood-based panel industry are mainly synthesized by adding urea in stages to reduce the molar ratio of formaldehyde and urea. Although the lower molar ratio UF resin has lower formaldehyde emissions, it also has the defects of longer curing time and lower bonding strength when being used in wood-based panel products. In this study, nanofluid type UF resins adhesives were prepared by dispersing SiO2 and TiO2 nanoparticles with six concentrations levels, 0%, 0.2%, 0.4%, 0.6%, 0.8% and 1% into UF resins with 1.0 and 1.3 M ratio by the assistance of ultrasound, respectively. It was found that the excellent thermal conductivity of the nanofluid type adhesives could eliminate the defects of the low molar ratio UF resins. When nano-SiO2 and nano-TiO2 were incorporated, the viscosity increased as the nanoparticles concentration increased, the maximum viscosity increased by 11.7% (1.0UF) and 15.0% (1.3UF) with nano-SiO2, the free formaldehyde content, curing time, and pot life of UF resins declined in varying degrees with nanoparticles loading level increased, the maximum amount of free formaldehyde content reduced by 41.2% (1.0UF) and 43.9% (1.3UF) with nano-TiO2, the maximum reduction of curing time was 25.80% (1.0UF) and 42.6% (1.3UF) with nano-TiO2, the pot life maximum decreased by 39.7% (1.0UF) and 43.0% (1.3UF) with nano-SiO2. Nanofluid type UF resins had much higher bonding strength with lower formaldehyde emission than pristine UF resins after being treated with same hot-pressing in plywood manufacture. The maximum of bonding strength increased by 28.1% (1.0UF) and 28.8% (1.3UF) with nano-SiO2, and the maximum amount of formaldehyde emissions reduced by 48.7% (1.0UF) with nano-SiO2 and 41.9% (1.3UF) with nano-TiO2. Meanwhile, the results showed that nanofluid type UF resin used in plywood manufacture exhibited the ability to decrease the hot-pressing temperature or shorten the hot-pressing time.

Effect of Photoinitiator Concentration and Film Thickness on the Properties of UV-Curable Self-Matting Coating for Wood-Based Panels

Matte coatings have found wide-ranging applications across diverse industries. In this study, self-matting films with surface wrinkles were produced by exposing UV-curable polyurethane acrylate (UV-WPUA) resin to 172 nm Xe2* excimer and medium-pressure mercury lamps. The gloss values, micromorphologies, water contact angles (WCAs), roughness values, and friction behaviors of UV-WPUA films with different photoinitiator (PI) concentrations and thickness were investigated for the first time. The results indicate that the gloss values of the films at the same thickness enhance with the increase of PI concentration, while the amplitude of wrinkles, roughness, and WCAs decrease; however, the friction coefficient shows insignificant variations. While the PI concentration is unchanged, an increase in film thickness results in a decrease in gloss value and an increase in roughness and friction coefficient. Nevertheless, the WCA is relatively constant. The PI concentration of 0.5 wt% (lowest gloss value of cured film) was utilized to prepare the UV-WPUA wood coating. The cured coating film exhibited low gloss (4.9 GU at 60° and 5.2 GU at 85°) and outstanding mechanical properties, including 3H pencil hardness, grade 0 adhesion, excellent wear resistance, and tensile property. These findings can be utilized to guide the development of self-matting wood coatings and the production of wood-based panels used in industrial finishing.

Capability of producing lignin-based phenol formaldehyde adhesive for oil palm mesocarp fiber particleboard production with lignin extracted from industrial waste liquor from the kraft pulping process

Phenol-formaldehyde (PF) resin is one of the most important adhesives used in the production of wood-based panels. However, the health effects associated with chronic exposure of workers to phenol and formaldehyde during the process are unavoidable. As a result, replacing phenol with green and safe material, like lignin, is a potential alternative due to its similar structure to phenol. This study aims to investigate the substitution of phenol with lignin precipitated from black liquor (BL) by preparing lignin-based phenol formaldehyde (LPF) adhesive at various ratios and various types of lignin precipitated from black liquor by using an inorganic acid (sulfuric, LPFS) and organic acid (acetic (LPFA), citric (LPFC) and formic acid (LPFF)). The synthetic LPF was used to fabricate particleboards from oil palm mesocarp fiber and tested for mechanical properties in accordance with ASTM D790, plus the thickness swelling from EN317. It was found that the particleboards that bonded with LPFC40 and exhibited the highest MOR and MOE of 6.41 MPa and 555.67 MPa respectively. Therefore, lignin-based phenol formaldehyde replaced by citric acid, has potential in phenol replacement and increase the mechanical properties of the particleboard, as well as being more environmentally friendly.

Characteristic of particles created by preparatory operationsof the particleboard production process

Characteristic of particles created by preparatory operations of the particleboard production process.The production of wood-based panels, taking into account material innovations, involves the need to adjust the operation of technological devices to the properties of basic and auxiliary materials. In this study, it was decided to check the particle sizes after sorting raw materials representing 3 groups: forest biomass – pine branches, agricultural biomass - oilseed plant straw, and post-production material. Fractions were taken from the 2.00 mm mesh sieve of a sorter for the core layer of the particleboard and the fractional composition was determined by sieve analysis. The average linear particle dimensions and bulk density of each lignocellulosic raw material were also determined. Due to the varying proportions, it is necessary to adapt the parameters of the technological operations to the specifics of the raw material being processed or to introduce guidelines for the selection of particle sizes guided by their actual average size. Studies have shown differences between the individual materials. This is particularly important, as proper preparation of the raw material translates into the quality of the boards produced from them and the efficiency of the entire process.

Greenhouse gas footprint assessment of wood-based panel production in China

China is one of the largest manufacturers, consumers, and traders of wood-based panels (WBPs) globally. The Chinese manufacturing process for WBPs is significantly different from that used in other countries and the greenhouse gas (GHG) footprint assessment of this process has not yet received attention. And a comprehensive evaluation of the effect of different approaches to estimate the delayed emission of biogenic carbon on the GHG footprints of different WBP types is still missing. This study aims to quantify: i) the GHG footprint of WBPs produced in China, and ii) the influence of different methods to assess the delayed emission of biogenic carbon. Cradle-to-gate life cycle models are developed for plywood (PLY), fiberboard (FB), particleboard (PB) and oriented strand boards (OSB). Based on two common end-of-life (EoL) destinations (i.e., incineration and landfill), three approaches to the estimation of the delayed emissions of biogenic carbon in cradle-to-grave assessments are compared. The cradle-to-gate results show that the GHG footprints of PLY, FB, PB and OSB without considering biogenic carbon storage are 538 kg CO2 e/m³, 406 kg CO2 e/m³, 348 kg CO2 e/m³ and 552 kg CO2 e/m³, respectively. For the four types of WBPs, resources extraction stage provides the largest contribution to the GHG footprints (55%–81%), followed by the production process (18%–31%) and raw material transportation (1%–18%). The methodologies used to assess delayed emissions in cradle-to-grave WBP GHG footprint assessments play an important role, especially for incineration scenarios. Finally, emission reduction measures are proposed based on reducing the consumption of adhesives and of energy use in the production process.

Nitrogen Migration and Conversion in Chars from Co-Pyrolysis of Lignocellulose Derived Pyrolysis Model Compounds and Urea-Formaldehyde Resin Adhesive

In thermal conversion utilization, nitrogen-rich biomass such as waste wood-based panels will release a large amount of NOx into the atmosphere, causing serious harm to the surroundings. By means of co-pyrolysis, N in waste wood-based panels can be fixed in chars instead of discharging into the atmosphere in the form of volatile matter, which can reduce NOx emission and lay a foundation for the preparation of nitrogen-rich carbon materials with high added value. As the most commonly used adhesive in the production of wood-based panels, urea-formaldehyde resin adhesive (UF) is the main nitrogen source in waste wood-based panels. Therefore, the purpose of this paper is to explore the effects of glucose, ethyl maltol and 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) on nitrogen migration and conversion during UF pyrolysis by adjusting the different proportions of model compounds and UF. Thermogravimetric analysis showed that ethyl maltol and DMHF had lower thermal stability and the pyrolysis process was concentrated in the range of 90–168 °C, which does not coincide with the mass loss temperature of UF. UF can promote the pyrolysis of these three model compounds at the initial stage to some extent. The elemental analysis showed that the N retention in co-pyrolysis chars increased in varying degrees with the increase of the addition of model compounds; the nitrogen retention in chars of glucose-UF, ethyl maltol-UF and DMHF-UF increased by 28.47%, 3.48% and 16.45% with the increase of the model compound content from 50% to 90%, respectively. The XPS results showed that the relative content of N-6 in chars increased with the increase of ethyl maltol content, and the relative content of N-5 in chars increased with the increased addition of DMHF. Glucose had little effect on the distribution of N-functional groups in chars.

Analysis of wood-based panel production and foreign trade situation in the process of globalization

Küreselleşme genel olarak teknoloji, haberleşme ve ulaşım gibi alanlarda hızlı gelişme neticesinde ülkelerin ekonomik, siyasi ve sosyal ilişkilerinin gelişmesi ile sonuçlanan bir uluslararası bütünleşme süreci olarak ifade edilebilir. Bu süreçten orman ürünleri sektörü de payını almış ve odun esaslı levha üretim dengeleri değişmiştir. Bu çalışma kapsamında küreselleşme sürecinden geçen ülke ekonomileri içerisinde önemli bir üretim hacmine ulaşan odun esaslı levha üretim ve dış ticaretinin değişim süreci incelenmiştir. Bu amaçla dünya ölçeğinde 2020 yılı itibariyle odun esaslı levha üretim miktarının en yüksek olduğu on ülke (Çin, Amerika Birleşik Devletleri, Rusya, Almanya, Kanada, Hindistan, Brezilya, Polonya, Türkiye, Tayland) belirlenmiştir. Bu ülkelere ait son 25 yıllık toplam üretim ve dış ticaret değerleri ile odun esaslı levha olarak tanımlanan kontrplak, yongalevha, OSB, MDF/HDF’nin üretim ve dış ticaret değerleri ayrı ayrı değerlendirilmiştir. Sonuçlar incelendiğinde 2020 yılı itibariyle üretim miktarı bakımından Türkiye’nin dünya genelinde dokuzuncu sırada yer aldığı en yüksek üretimin ise Çin tarafından yapıldığı belirlenmiştir. Ülkeler düzeyinde üretim ve ihracat miktarının yıllar itibariyle artış içinde olduğu görülmüştür.

The evaluation of the efficiency of different waxes on some physical and surface properties of fiberboard

Bilindiği üzere odun esaslı levha ürünlerinin özellikle kullanım yerlerinde suya ve rutubete maruz kaldıklarında dayanımlarının az olması bu ürünlerin dezavantajlı olarak kabul edilen ve iyileştirilmesi gereken özelliklerinden biridir. Bu nedenle odun esaslı levhaların suya, rutubete karşı dayanımlarını artırabilmek adına üretimleri esnasında su itici maddeler kullanılmaktadır. Bu çalışmada, levha üretiminde yaygın olarak kullanılan su itici maddelerden biri olan parafine alternatif olarak iki farklı vaks-mum türü seçilmiş ve etkinlikleri değerlendirilmiştir. Levha örneklerinin 2-24 saat süre için kalınlığına şişme (KŞ) ve su alma (SA) değerleri, yüzey pürüzlülük parametreleri ile yüzey sertlik değerleri belirlenmiştir. Ölçümler sonucunda, kontrol grubuna kıyasla diğer grupların KŞ ve SA oranlarında belirgin derecede iyileşme olduğu belirlenmiştir. Özellikle sadece parafin, parafin-balmumu ve parafin-soya vaksı karışımlarının tutkala ilave edildiği grupların oldukça düşük SA ve KŞ değerleri verdiği görülmüştür. Yüzey pürüzlülük parametreleri ise vaks türüne, uygulama yöntemine bağlı olarak değişim göstermiştir. En yüksek yüzey sertlik değeri balmumu ve parafinin karışım halinde yüzeye uygulandığı grupta elde edilmiştir. Buna göre, kullanılan bitkisel ve hayvansal vaks türlerinin de su itici etki gösterebilecekleri, özellikle uygun yöntem ve farklı kombinasyonlarla uygulanmaları durumunda etkinliklerinin artırılabileceği düşünülmektedir.

Better insights into wood-based panel production

Abstract Dieffenbacher has developed a completely new software platform for the digitalization of wood-based panel production plants. The name of the Platform is EVORIS. This article explains how smart data processing in production, with the help of artificial intelligence and machine learning, delivers transparency to production processes and helps operators and technologists to produce smarter. Furthermore, experiences in working methods, the development process, AI engineering and, above all, lessons learnt from theory vs. practice are illustrated.

Preparation and characterization of birch plywood prepared by hot-pressed peanut meal adhesive

The preparation of birch plywood by hot-pressed peanut meal (HPM) adhesive was studied using response surface methodology. The effects of hot-pressing temperature, hot-pressing time, and hot-pressing pressure on the boiling water strength (BWS) were investigated. The BWS of birch plywood was significantly affected by hot-pressing temperature and hot-pressing time. The optimal preparation conditions for maximizing the BWS were: hot-pressing temperature of 120 °C, hot-pressing time of 80 s mm −1 and hot-pressing pressure of 1.2 MPa. Under these conditions, the BWS was 1.21 ± 0.02 MPa. The thickness expansion rate of water absorption (TS) and the wood compressibility were 6.39% and 15.8% respectively. Characterization of birch plywood showed the chemical reactions between hydroxyl of plywood, and the amino, carboxyl and azacyclobutane structures of peanut protein, forming a dense bonding surface and resulting in the higher BWS of birch plywood. This work provided an important reference for the application of HPM adhesive in the production of wood-based panels. • High value utilization of hot-pressed peanut meal was improved. • Chemical reaction between hot-pressed peanut meal adhesive and birch veneer. • The hot processing has strong universality and birch plywood has no formaldehyde. • The boiling water strength of birch plywood reached the national class I standard.

The Possibility of Using Pine Bark Particles in the Chipboard Manufacturing Process

This research evaluated the possibility of using sawmill by-products from the roundwood-processing line in the production of wood-based panels. Due to its number of favorable properties, interesting chemical composition and large reserves resulting from the lack of industrial applications, the research focused particularly on the use of bark. Manufactured variants of boards differed in the proportions of wood chips to bark (70:30, 60:40, 50:50). Moreover, the boards containing only wood chips and a mixture of chips and sawdust were used as references. Urea-formaldehyde adhesive mixed with ammonium nitrate as a hardener was applied as a binding agent for the boards. Based on the mechanical properties (modulus of elasticity, modulus of rupture, internal bonding), physical properties (density, thickness swelling, water absorption) and content and emission of formaldehyde, it was found that it is possible to produce boards characterized by good properties from sawmill by-products without advanced processing. Moreover, the use of bark instead of sawdust in order to increase the homogeneity of the cross-section allows one to obtain panels with significantly lower formaldehyde emission and water uptake.