Search Results (102)

The integration of acoustic emission (AE) signals into adaptive control systems for CNC wood milling represents a promising advancement in intelligent manufacturing. This study investigated the feasibility of using AE signals for the real-time monitoring and control of CNC milling processes, focusing on medium-density fiberboard (MDF) as the workpiece material. AE signals were captured using dual-channel sensors during side milling on a five-axis CNC machine, and their characteristics were analyzed across varying spindle speeds and feed rates. The results showed that AE signals were sensitive to changes in machining parameters, with higher spindle speeds and feed rates producing increased signal amplitudes and distinct frequency peaks, indicating enhanced cutting efficiency. The statistical analysis confirmed a significant relationship between AE signal magnitude and cutting conditions. However, limitations related to material variability, sensor configuration, and the narrow range of process parameters restrict the broader applicability of the findings. Despite these constraints, the results support the use of AE signals for adaptive control in wood milling, offering potential benefits such as improved machining efficiency, extended tool life, and predictive maintenance capabilities. Future research should address signal variability, tool wear, and sensor integration to enhance the reliability of AE-based control systems in industrial applications. Full article

In this study, a flame-retardant wood-polymer composite was produced using huntite-hydromagnesite mineral, recognized for its non- flammability properties. In this context, wood-polymer composites were produced with the co-rotating twin-screw extrusion technique, while polypropylene was applied as the composite matrix, medium density fiberboard waste and inorganic huntite-hydromagnesite mineral were used as the reinforcement material. The proportion of wood powder additives was changed to 10% and 20%, and the huntite and hydromagnesite ratio was changed to 30%, 40%, 50% and 60%. Maleic anhydride grafted polypropylene, i.e., MAPP, was applied as a binder at a rate of 3%. Polypropylene, wood fibers, mineral powders, and MAPP blended in the mixer were processed in the extruder and turned into granules. Structural, morphological, thermal, mechanical, and flame-retardant properties of the composites were analyzed using XRD, SEM, FTIR, TGA, tensile testing, and the UL-94 vertical flammability test. Test samples were prepared to evaluate the physical and mechanical properties with a compression molding machine. It was concluded that the composites gained significant flame retardancy with the addition of huntite hydromagnesite. The potential for using this material in various fields and its compliance with the principles of circular economy and the Sustainable Development Goals (SDG 12) were noted. Full article

Current wood waste recycling processes need to be improved to prioritize material recovery over energy recovery by cascading the use of wood waste and limiting as much as possible non-recyclable batches that may contain even partially highly contaminated grade C wood and/or Medium Density Fiberboard. In the presented research, a life cycle assessment has been carried out for a new product recovered from bulky waste. The Environmental Footprint 3.1 (adapted) method has been used to assess the potential environmental impact. The results may support a quality assessment of new products undertaken from the perspective of the circular economy and environmental management in the waste sector. The study aimed at the identification of environmental hotspots in the life cycle of the secondary wooden blocks (from cradle to market analysis). Bulky waste was subjected to recovery and recycling processes (a laboratory scale), and by adding starch and water a new product was obtained. The study has demonstrated that the production of blocks has the greatest impact on the life cycle in the following categories: Resource use, fossils (24%), Climate change (23.9%), Eutrophication, freshwater (13.3%), and Resource use, minerals and metals (11.8%). This is due to the high electricity consumption of electricity by equipment and machinery used for the processing of waste and the fabrication of the blocks. Full article

Recycling wood-based panels is essential for promoting the cascading use of wood, advancing the transition to a circular economy, and maximizing the efficient use of natural resources. While recycling particleboard has become a well-established industrial practice, recycling medium density fiberboard (MDF) panels presents challenges, particularly in preserving material quality. The aim of this research work was to investigate and evaluate the combined effect of recycled MDF fibers and urea–formaldehyde (UF) resin content on the performance characteristics of the panels. MDF recycling was conducted using hydrothermal hydrolysis and hammer mill refinement. Preliminary experiments revealed that the degradation of properties in recycled MDF panels is not uniform with the addition of recycled fibers. The panels retained their properties significantly with up to 20% recycled fiber content, while formaldehyde emissions decreased by 1.2%. Based on these findings, the optimization of recycled fiber and UF resin content was performed, revealing that the maximum allowable recycled fiber content through hydrothermal hydrolysis and hammer mill refinement is 24%, with a minimum UF resin content of 12%. This study highlights the potential for integrating recycled MDF fibers into new panels, contributing to more sustainable production practices. By optimizing the balance between recycled fiber content and UF resin, it is possible to produce MDF panels that meet industry standards while reducing the environmental impact. Full article

Wood-based panels (WBPs) have versatile structural applications and are a suitable alternative to plastic panels and metallic materials. They have appropriate strength parameters that provide the required stiffness and strength for furniture products and construction applications. WBPs are usually processed by cutting, milling and drilling. Especially in the furniture industry, the accuracy of processing is crucial for aesthetic reasons. Ensuring the WBP surface’s high quality in the production cycle is associated with the appropriate selection of processing parameters and tools adapted to the specificity of the processed material (properties of wood, glue, type of resin and possible contamination). Therefore, expert assessment of the durability of WBPs is difficult. The interest in the automatic monitoring of cutting tools in sustainable production, according to the concept of Industry 4.0, is constantly growing. The use of flexible automation in the machining of WBPs is related to the provision of tools monitoring the state of tool wear and surface quality. Drilling is the most common machining process that prepares panels for assembly operations and directly affects the surface quality of holes and the aesthetic appearance of products. This paper aimed to synthesize research findings across Medium-Density Fiberboards (MDFs), particleboards and oriented strand boards (OSBs), highlighting the impact of processing parameters and identifying areas for future investigation. This article presents the research trend in the adoption of the new general methodological assumptions that allow one to define both the drill condition and delamination monitoring in the drilling of the most commonly used wood-based boards, i.e., particleboards, MDFs and OSBs. Full article

Many countries widely use biomass for household heating and heat production in district heating systems. Unfortunately, the steady increase in annual plastic waste production has a negative impact on the quality of solid biofuels. This is due to the increasing contamination of these fuels with wastes from plastic and wastes from furniture production, such as laminates and medium-density fiberboard made from wood fibers, among others. The design of specialized biomass combustion systems does not allow for the burning of waste fuel, or the reduction in hazardous organic compounds emitted when burning contaminated biofuels. The study demonstrated the detection of polymeric impurities in solid biofuels through analytical pyrolysis (Py-GC-MS). The study was conducted on model samples that contained increasing proportions of plastic waste, ranging from 0.1 to 10.0% w/w to biomass. Markers were identified and described to indicate contaminated fuel, and the interactions between the sample matrix and plastic were studied. Unique markers were detected that indicate the presence of contamination, even at low concentrations like 0.1% w/w of plastic waste in solid biofuel. These results suggest that direct analytical pyrolysis of solid biofuels, which are already on the market but not covered by the relevant regulatory system and are contaminated with polymeric ingredients, is a method that is not only possible but also gives quick confirmation. Full article

Sanding in medium-density fiberboard (MDF) often encounters unstable quality and premature failure, primarily because there is currently no abrasive belt specifically suitable for MDF sanding characteristics. We designed two precision-shaped abrasive belts (PSAs) for MDF and herein report on the characteristics. The material removal process for PSA was divided into three phases; the most stable, phase II, represents the effective working period. Compared to the contrast accumulated abrasive belt, PSAs achieve 16.12 and 11.10 times higher surface quality based on the mean value of roughness parameter S_a, achieving 1.34- and 2.0-, and 15.61- and 8.54-times-higher stability in material removal and surface quality based on the mean deviation. Wear patterns on PSAs include large abrasive wear, micro-abrasive fall-off, fracture, and wear, avoiding premature failure due to blockage and promoting long-term and efficient sanding. The uniform shape, height, and distribution of particles in PSAs results in excellent sanding performance. This study provides the foundation for further research on sanding mechanisms and PSA design for MDF. Full article

Many factors (material properties, drill bit type and size, drill bit wear, drilling parameters used, and machine-tool characteristics) affect the efficiency of the drilling process, which could be quantified through the delamination factor, thrust force, and drilling torque. To find the optimal combination among the factors that affect the desired responses during drilling of wood-based composites, various modelling techniques could be applied. In this work, an artificial neural network (ANN) and response surface methodology (RSM) were applied to predict and optimize the delamination factor at the inlet and outlet, thrust force, and drilling torque during drilling of prelaminated particleboards, medium- density fiberboard (MDF), and plywood. The artificial neural networks were used to design four models—one for each analyzed response. The coefficient of determination (R²) during the validation phase of designed ANN models was among 0.39 and 0.96. The response surface methodology was involved to reveal the individual influence of analyzed factors on the drilling process and also to figure out the optimum combination of factors. The regression equations obtained an R² among 0.88 and 0.99. The material type affects mostly the delamination factor. The thrust force is mostly influenced by the drill type. The chipload has a significant effect on the drilling torque. A twist drill with a tip angle equal to 30° and a chipload of 0.1 mm/rev. could be used to efficiently drill the analyzed wood-based composites. Full article

Over the past decade, distributed acoustic sensing has been utilized for structural health monitoring in various applications, owing to its continuous measurement capability in both time and space and its ability to deliver extensive data on the conditions of large structures using just a single optical cable. This work aims to evaluate the performance of distributed acoustic sensing for monitoring a multilayer structure on a laboratory scale. The proposed structure comprises four layers: a medium-density fiberboard and three rigid polyurethane foam slabs. Three different damages were emulated in the structure: two in the first layer of rigid polyurethane foam and another in the medium-density fiberboard layer. The results include the detection of the mechanical wave, comparing the response with point sensors used for reference, and evaluating how the measured signal behaves in time and frequency in the face of different damages in the multilayer structure. The tests demonstrate that evaluating signals in both time and frequency domains presents different characteristics for each condition analyzed. The supervised support vector machine classifier was used to automate the classification of these damages, achieving an accuracy of 93%. The combination of distributed acoustic sensing with this learning algorithm creates the condition for developing a smart tool for monitoring multilayer structures. Full article

This study investigates the influence of various tool coatings, cutting speeds, and feed per tooth values on cutting forces during the CNC milling of Medium Density Fiberboard (MDF). The coatings tested include reference, TripleSi, Hyperlox, DLC, and lapped coatings. Experiments were conducted using an SCM Morbidelli m100 CNC milling machine under controlled conditions. Cutting speeds were set at 8, 10, and 12 m/s, while feed per tooth values were varied at 0.1, 0.2, and 0.3 mm. Cutting forces were measured using a three-axis piezoelectric dynamometer Kistler, and the data were analyzed to determine the impact of these variables on cutting performance. The results revealed that while cutting speed had a minimal effect on cutting forces, feed per tooth significantly influenced them, with higher values of feed per tooth leading to increased forces. Among the coatings, lapped and TripleSi exhibited the lowest cutting forces, whereas DLC showed the highest. Statistical analysis, including ANOVA and Scheffé tests, confirmed the significant differences between the coatings and highlighted the superior performance of the lapped and TripleSi coatings in reducing cutting forces. Full article

No matter where we reside, the issue of greenhouse gas emissions impacts us all. Their influence has a disastrous effect on the earth’s climate, producing global warming and many other irreversible environmental impacts, even though it is occasionally invisible to the independent eye. Phase change materials (PCMs) can store and release heat when it is abundant during the day (e.g., from solar radiation), for use at night, or on chilly days when buildings need to be heated. As a consequence, buildings use less energy to heat and cool, which lowers greenhouse gas emissions. Consequently, research on thermally active medium-density fiberboard (MDF) with PCMs is presented in this work. MDF is useful for interior design and furniture manufacturing. The boards were created using pine (Pinus sylvestris L.) and spruce (Picea abies L.) fibers, urea–formaldehyde resin, and PCM powder, with a phase transition temperature of 22 °C, a density of 785 kg m⁻³, a latent heat capacity of 160 kJ kg⁻¹, a volumetric heat capacity of 126 MJ m⁻³, a specific heat capacity of 2.2 kJ kgK⁻¹, a thermal conductivity of 0.18 W mK⁻¹, and a maximum operating temperature of 200 °C. Before resination, the wood fibers were divided into two outer layers (16%) and an interior layer (68% by weight). Throughout the resination process, the PCM particles were solely integrated into the inner layer fibers. The mats were created by hand. A hydraulic press (AKE, Mariannelund, Sweden) was used to press the boards, and its operating parameters were 180 °C, 20 s/mm of nominal thickness, and 2.5 MPa for the maximum unit pressing pressure. Five variants of MDF with a PCM additive were developed: 0%, 5%, 10%, 30%, and 50%. According to the study, scores at the MOR, MOE, IB, and screw withdrawal resistance (SWR) tests decreased when PCM content was added, for example, MOE from 3176 to 1057 N mm⁻², MOR from 41.2 to 11.5 N mm⁻², and IB from 0.78 to 0.27 N mm⁻². However, the results of the thickness swelling and water absorption tests indicate that the PCM particles do not exhibit a substantial capacity to absorb water, retaining the dimensional stability of the MDF boards. The thickness swelling positively decreased with the PCM content increase from 15.1 to 7.38% after 24 h of soaking. The panel’s thermal characteristics improved with the increasing PCM concentration, according to the data. The density profiles of all the variations under consideration had a somewhat U-shaped appearance; however, the version with a 50% PCM content had a flatter form and no obvious layer compaction on the panel surface. Therefore, certain mechanical and physical characteristics of the manufactured panels can be enhanced by a well-chosen PCM addition. Full article

Medium-density fiberboard (MDF) waste generation has increased steadily over the past decades, and therefore, the investigation of novel methods to recycle this waste is very important. The potential of repurposing MDF waste as an adsorbent for the treatment of Cd(II), Cu(II), Pb(II), and Zn(II) ions in water was investigated using MDF offcuts. The highest adsorption potential in single-metal ion solution systems was observed for Pb(II) ions. The experimental data of Pb(II) ions fit well with the Freundlich isotherm and pseudo-second-order kinetic models. Complexation and electrostatic interactions were identified as the adsorption mechanisms. The adsorption behavior of multi-metal ion adsorption systems was investigated by introducing Cd(II) ions as a competitive metal ion. The presence of the Cd(II) ions reduced the adsorption potential of Pb(II) ions, yet the preference for the Pb(II) ions remained. Regeneration studies were performed by using 0.1 M HCl as a regeneration agent for both systems. Even though a significant amount of adsorbed metal ions were recovered, the adsorption potential of the MDF was reduced in the subsequent adsorption cycles. Based on these results, MDF fines have the potential to be used as an economical adsorbent for remediation of wastewater containing heavy metal ions. Full article

The effective and comprehensive utilization of forest resources has become the theme of the global “dual-carbon strategy”. Forestry restructured wood is a kind of wood-based panel made of wood-based fiber composite material by high-temperature and high-pressure restructuring–molding, and has become an important material in the field of construction, furniture manufacturing, as well as derivative processing for its excellent physical and mechanical properties, decorative properties, and processing performance. Taking Medium Density Fiberboard (MDF) as the recombinant material as the research object, an event-triggered synergetic control mechanism based on interventional three-way decision making is proposed for the viscoelastic multi-field coupling-distributed agile control of the “fixed thickness section” in the MDF continuous flat-pressing process, where some typical quality control problems of complex plate shape deviations including thickness, slope, depression, and bump tend to occur. Firstly, the idea of constructing the industrial event information of continuous hot pressing based on information granulation is proposed, and the information granulation model of the viscoelastic plate shape process mechanism is established by combining the multi-field coupling effect. Secondly, an FMEA-based cyber granular method for diagnosing and controlling the plate thickness diagnosis and control failure information expression of continuous flat pressing is proposed for the problems of plate thickness control failure and plate thickness deviation defect elimination that are prone to occur in the continuous flat-pressing process. The precise control of the plate thickness in the production process is realized based on event-triggered control to achieve the intelligent identification and processing of the various types of faults. The application test is conducted in the international mainstream production line of a certain type of continuous hot-pressing equipment for the production of 18 mm plate thickness; the synergistic effect is basically synchronized after 3 s, the control accuracy reaches 30%, and the average value of the internal bond strength is 1.40, which ensures the integrity of the slab. Practical tests show that the method in the actual production is feasible and effective, with detection and control accuracy of up to ±0.05 mm, indicating that in the production of E0- and E1-level products, the rate of superior products can reach more than 95%. Full article

Ultrasonic detection is currently used in the industry of medium-density fiberboard to detect blister defects. Due to the small detection area of a single sensor, multiple sensors need to be used, which results in high costs. Starting from elastic thin plate vibration theory, this paper builds a vibration dynamic model to detect blisters. The size and depth of the blister area can be established by determining the natural frequency of the thin plate vibration in the blister area. In this model, if the elastic modulus and density are known, the natural frequency of the thin plate vibration at the blister place is directly proportional to the blister depth and inversely proportional to the square of the blister radius. The size and depth of the blister can be determined by measuring the first third-order natural frequency of this area of research. A total of 25 specimens with blister sizes and depths were simulated, and the natural frequencies of the specimens were measured. Subsequently, the detection model was verified by comparing its experimental data with theoretical values. The theoretical value was highly consistent with the measured data. The measured values of the first, second, and third-order natural frequencies were slightly smaller than the theoretical calculated values, with average relative deviations of −1.6%, −1.34%, and −1.03%, respectively. As the order progressed, the deviation exhibited a downward trend, and the third-order natural frequency displayed the smallest deviation and highest accuracy. The proposed vibration dynamic model can detect larger blister areas by measuring the natural frequency, which can overcome the shortcomings of small ultrasonic detection areas in current actual industries. Thus, the practical online blister detection device is expected to be further developed. Full article

A novel pretreatment strategy utilizing a combination of NaOH and 1-Butyl-3-methylimidazolium chloride ([Bmim]Cl) was proposed to enhance the enzymatic hydrolysis of abandoned Medium-density fiberboard (MDF). The synergistic effect of NaOH and [Bmim]Cl pretreatment significantly improved the glucose yield, reaching 445.8 mg/g within 72 h, which was 5.04 times higher than that of the untreated samples. The working mechanism was elucidated according to chemical composition, as well as FTIR, ¹³C NMR, XRD, and SEM analyses. The combined effects of NaOH and [Bmim]Cl led to lignin degradation, hemicellulose removal, the destruction and erosion of crystalline regions, pores, and an irregular microscopic morphology. In addition, by comparing the enzymatic hydrolysis sugar yield and elemental nitrogen content of untreated MDF samples, eucalyptus, and hot mill fibers (HMF), it was demonstrated that the presence of adhesives and additives in waste MDF significantly influences its hydrolysis process. The sugar yield of untreated MDF samples (88.5 mg/g) was compared with those subjected to hydrothermal pretreatment (183.2 mg/g), Ionic liquid (IL) pretreatment (406.1 mg/g), and microwave-assisted ionic liquid pretreatment (MWI) (281.3 mg/g). A long water bath pretreatment can reduce the effect of adhesives and additives on the enzymatic hydrolysis of waste MDF. The sugar yield produced by the combined pretreatment proposed in this study and the removal ability of adhesives and additives highlight the great potential of our pretreatment technology in the recycling of waste fiberboard. Full article