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To reduce dependence on wood and deforestation, alternative materials have been considered. This research evaluated particleboards panels of Pinus elliotti mixed with residues of polyethylene terephthalate (PET) in flakes with 50% of each material, glued with 10% of castor oil-based polyurethane resin (PUR). The temperature during board production was varied to evaluate its influence on the physical and mechanical properties of the boards. The study concludes that the increase in temperature did not result in a significant improvement in the particleboard properties, but their results showed application potential according to the normative standards.

Formaldehyde-based resins are commonly used in the particleboard industry due to their high bonding strength and excellent water resistance. Nowadays, the healthy and sustainable issues lead to the development of bio-based wood adhesives. In the last past decade, soybeans were the most prominent crop for the production of environmentally friendly adhesive with no formaldehyde in its composition. This review covers the strengths, weaknesses, opportunities and threats of soy-based adhesives as a replacement of conventional resins. Moreover, this work details the different techniques used to improve the performance of soy protein adhesives in order to encourage their use in the wood industry.

The effective recovery of wood waste generated in wood processing and also at the end of wood product life is important from environmental and economic points of view. In a laboratory, 16 mm-thick three-layer urea–formaldehyde (UF)-bonded particleboards (PBs) were produced at 5.8 MPa and 240 °C and with an 8 s/mm pressing factor, using wood particles prepared from (1) fresh spruce wood (C), (2) a mixture of several recycled wood products (R1), and (3) recycled faulty PBs bonded with UF resin (R2). Particles from spruce wood were combined with particles from R1 or R2 recyclates in weight ratios of 100:0, 80:20, 50:50 and 0:100. In comparison to the control spruce PB, the PBs containing the R1 recyclate from old wood products were characterized by lower thickness swelling after 2 and 24 h (TS-2h and TS-24h), lower by 18 and 31%; water absorption after 2 and 24 h (WA-2h and WA-24h), lower by 33 and 28%; modulus of rupture in bending (MOR), lower by 28%; modulus of elasticity in bending (MOE), lower by 18%; internal bond (IB), lower by 33%; and resistance to decay determined by the mass loss under the action of the brown-rot fungus Coniophora puteana (Δm), lower by 32%. The PBs containing the R2 recyclate from faulty PBs were also characterized by a lower TS-2h and TS-24h, lower by 45% and 59%; WA-2h and WA-24h, lower by 61% and 51%; MOR, lower by 37%; MOE, lower by 17%; and IB, lower by 33%; however, their biological resistance to C. puteana was more effective, with a decreased Δm in the decay test, lower by 44%.

The application of citric acid and glycerol as natural binder was investigated for the manufacturing of jute stick particleboard in this study. The effects of citric acid content (0–30 wt%), citric acid and glycerol mixture (ratio of CA–G), and pressing temperatures on the properties of jute stick particleboard were investigated. Citric acid-bonded jute stick particleboard had good mechanical properties and dimensional stability when citric acid concentration was 20 wt% at pressing temperature of 200 °C. By addition of glycerol concentration (40/60), the properties were further increased. The modulus of rupture (MOR) and thickness swelling (TS) values of CA–G (40/60) bonded jute stick particleboard were 19.67 N/mm 2 and 9%, respectively, which satisfy the minimum requirement for type-18 of particleboard JIS A 5908 (2003). FTIR analysis confirmed the formation of ester linkage by polymerization reaction between carboxyl groups and alcohol groups. Citric acid and glycerol polymer reacted with jute stick particles and produced cross-linked networks with enhanced properties, hence improved the adhesiveness during particleboard production. It could be concluded that citric acid and glycerol mixture can be a potential natural binder for the production of jute stick particleboard.

The effects of waste pulp fiber on the mechanical, physical, and technological properties of particleboard were investigated. For this purpose, 1.5%, 3%, 4.5%, and 6% were added to the middle layer of the chip blank. As an adhesive, 7% urea-formaldehyde (UF) resin was used in the middle layer and 12% in the top layer, in proportion to the dry chip weight. Chip blanks were pressed in a hydraulic press at 195 ± 5 °C, 30 kg/cm² pressure, and for 300 s, whereby test samples with dimensions of 550 x 550 x 19 mm3 and a density of 630 kg/m³ were produced. The 3% waste pulp fiber utilization provided optimum values, such as 7.3% and 27.2% improvements in bending strength and elastic modulus, respectively. However, 6.6% and 9.7% increases in thickness swelling (24 h) and water absorption (24 h) were observed. Moreover, there was a 24.6% increase in formaldehyde emissions. According to the results, it can be said that waste paper pulp fiber could be an alternative to wood raw material in particleboard production at low levels of addition.

Aiming at the problems of low classification accuracy and overfitting caused by the limited number of particleboard image samples, a Capsule Network algorithm based on the improved CBAM (Convolutional Block Attention Module) attention model is proposed. The improved algorithm utilizes the GELU equation to improve the CBAM attention model and incorporates it into the convolutional layer of the Capsule Network. In this way, the improved algorithm optimizes the feature maps of surface defects and, meanwhile, improves the training efficiency and stability of the model. The improved algorithm alleviates the overfitting problem by adding a dropout layer, which makes the model more suitable for small sample classification. The effectiveness of the method proposed in this paper is verified by classification experiments on the dataset of particleboard surface defect images.

This study investigated the interaction between particle size and mixing ratio on the porosity of particleboard and in consequence its effect on the physical and mechanical properties of panels. Tea Oil Camellia Shell (TOCS), which could provide 1.8 million tons of lignocellulose raw material annually, can be a useful resource for particleboard production. In that regard, particleboards with different particle sizes (coarse and fine) and mixing ratios (wood and TOCS) bonded with Polymethylene polyphenyl polyisocyanate (pMDI) were investigated. The results showed that particleboard made with TOCS particles had higher densities than those of commercial wood particles. Furthermore, particleboards made with fine particles had lower porosity. The average values for physical and mechanical properties have shown that except for thickness swelling (TS), most properties were better with coarse particles. In terms of all properties, results showed that adding 50% of commercial wood in conjunction with TOCS particles regardless of particle size can offer acceptable results, which qualified all requirements of EN 312:2010 standard for P2-type particleboard (boards for interior fitments (including furniture) for use in dry conditions). In addition, due to the porous structure of the shells, TOCS-based particleboards have better thermal conductivity compared to wood-based particleboards.

Cellulose nanomaterials (CNs) are of increasing interest due to their appealing inherent properties such as bio-degradability, high surface area, light weight, chirality and the ability to form effective hydrogen bonds across the cellulose chains or within other polymeric matrices. Extending CN self-assembly into multiphase polymer structures has led to useful end-results in a wide spectrum of products and countless innovative applications, for example, as reinforcing agent, emulsion stabilizer, barrier membrane and binder. In the current contribution, after a brief description of salient nanocellulose chemical structure features, its types and production methods, we move to recent advances in CN utilization as an ecofriendly binder in several disparate areas, namely formaldehyde-free hybrid composites and wood-based panels, papermaking/coating processes, and energy storage devices, as well as their potential applications in biomedical fields as a cost-effective and tissue-friendly binder for cartilage regeneration, wound healing and dental repair. The prospects of a wide range of hybrid materials that may be produced via nanocellulose is introduced in light of the unique behavior of cellulose once in nano dimensions. Furthermore, we implement some principles of colloidal and interfacial science to discuss the critical role of cellulose binding in the aforesaid fields. Even though the CN facets covered in this study by no means encompass the great amount of literature available, they may be regarded as the basis for future developments in the binder applications of these highly desirable materials.

PurposeGreen manufacturing (GM) is the environmental benign manufacturing of products with a minimal negative impact on the natural environment. Research studies on GM have increased in the last years with attention to the application of life cycle assessment (LCA). However, the manufacturing industry still faces some barriers and challenges that hinder a proper practical integration of GM using LCA. Accordingly, this paper performs an LCA-based GM case study of a wood-based industry that produces particleboards to investigate environmental hotspots and suggests GM indicators and solutions for a hot-pressing machine tool.MethodsA case study of a wood-based industry that produces particleboards in Brazil was designed. A LCA-based GM framework was developed and applied according to its three phases: pre-assessment, environmental assessment and monitoring, and post-assessment. Each phase is composed of specific stages and each stage has its own activities and goals. To quantify the environmental life cycle impacts, the ILCD midpoint method with 13 impact categories was selected. Based on these environmental impacts, a set of indicators and solutions was designed to improve the product life cycle impacts through a greener manufacturing process of particleboards. A cradle-to-grave approach was used to model the particleboard life cycle and the manufacturing phase was modeled based on the unit process life cycle inventory (UPLCI) methodology.Results and discussionThe particleboard manufacture was designed into five unit processes and results of the pre-assessment showed that the hot-pressing unit was the most relevant process because of its direct and indirect impacts mainly to human toxicity cancer effects, global warming, and photochemical ozone formation. During the environmental assessment and monitoring phase, the hot-pressing machine was then investigated based on the main contributors to the caused environmental impacts, i.e., electricity consumption and air emissions of free formaldehyde, as well as in terms of its most relevant process parameters: pressure (P) and temperature (T). Opportunities to reduce up to 21% upstream impacts and up to 41% downstream impacts were identified from making simple changes to the hot-pressing parameters. Further investigation in the post-assessment revealed that environmental impacts can be estimated based on the applied P and T values and GM indicators were suggested.ConclusionsThe proposed GM framework can be used in other case studies to integrate GM + LCA in practice. Results of the case study application showed that the hot-pressing machine was a hotspot into the cradle-to-grave life cycle impacts of particleboards and the proposed GM indicators can be used to predict life cycle impacts at manufacturing level.

This study investigated the material characterization with the fuzzy theory of particleboards bonded by urea formaldehyde with nanofillers including nanofibrillated cellulose (NFC) and titanium dioxide (TiO2). The density, water absorption, thickness swelling, and mechanical tests (which included flexure and internal bonding strength tests) were considered. The fuzzy sets theory addressed the ambiguity and subjectivity of language using triangular fuzzy numbers to assess the interests of decision maker’s (DMs). The addition of nanofillers slightly decreased water absorption values due to possible good interactions between nanofillers and urea formaldehyde. Thickness swelling ranged from 0.4 to 17.5%, and water absorption ranged from 0.4 to 10.7% compared to the control sample. The physical properties of the samples were generally improved by urea formaldehyde with NFC/TiO2, and the densities of the test panels were found to be similar. The modulus of rupture of the panels with urea formaldehyde with nanofillers were under the EN 312 standard’s requirements, and the highest flexural strength and flexural modulus of elasticity were 11.1 and 1.3 GPa, respectively. Internal bond values were between 0.55 and 0.89 MPa. According to EDAS method rankings, 2C2T-8 was the best material, followed by 2C1T-8 and 2C-8. The samples coded with Control-4 and Control-8 were the lowest-performing materials.