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The current work presents the reformulation of a composite based on high-density polyethylene obtained through the recycling of blow-molded containers (rHDPE) with natural fiber residues (wood sawdust). This material is technically and industrially known as WPC (wood plastic composite). The original formulation of this material contains 34% high-density polyethylene and 60% sawdust by weight fraction, while the remaining components include additives and coupling agents such as wax (Coupling Agent TPW 813 for plastic woods), stearic acid, and color pigment. The composite material was processed using the profile extrusion method, from which samples were obtained to conduct various experimental tests. The mechanical analysis revealed that both the strength and Young's modulus of the tensile and flexural properties slightly increased with the addition of sawdust to the composite. Additionally, the stiffness was higher compared to high-density polyethylene, indicating a direct relationship between these properties and the amount of sawdust incorporated. Besides this, other characterization methods were performed on the material, including density, hardness, and compression tests, as well as differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), natural and accelerated aging tests, Vicat softening temperature, and heat deflection temperature analysis (HDT). The initial evaluation provides a guide to enhance the most important properties with the aim of using the extruded profiles as pergolas in the real estate sector. Therefore, new formulations are developed with the assistance of Minitab 21 software, maintaining a constant proportion of materials that do not affect the mechanical properties, such as wax, stearic acid, and color pigment. Once the formulations are made, each one is characterized through tensile tests to determine which has the best performance. The formulation with the highest strength is re-characterized using the techniques mentioned in the starting material to obtain a material with the most optimal characteristics. [ABSTRACT FROM AUTHOR]

The preparation of wood‐plastic composites (WPCs) with high filling fibers and excellent physical properties remained a great challenge. This study used Camellia oleifera shell (COS, agroforestry product waste) as raw material, and prepared 60 wt% COS/high‐density polyethylene (HDPE) WPCs using profile extrusion method through pretreating fibers including hot water, hot steam, alkali, acid, extraction, and fine fiber screening. After pretreatments, the relative contents of cellulose and lignin increased, the relative contents of hemicellulose and extract decreased significantly, and the length‐diameter ratio was improved. The flexural strength, tensile strength and impact strength of hot water and steam heat treated composites reached 31.4, 17.1 MPa and 6.9 kJ/m2, 31.8, 16.8 MPa and 6.7 kJ/m2, respectively. Compared with untreated 28.8, 14.7 MPa and 5.5 kJ/m2, the advantages were more obvious. Alkali treatment and acid treatment improved the thermal stability and residue rate of the material. Extraction treatment and alkali treatment significantly reduced the processing torque force, which was conducive to processing, while acid treatment was the opposite. The highest water absorption and thickness expansion rate were 13.75% and 3.60% respectively at 7 days after alkali treatment, which were considerably higher than 5.60% and 0.78% without treatment, while other pretreatments improved the dimensional stability of the material. Highlights: High filling Camellia oleifera shell waste/HDPE composites were prepared.Physical and chemical pretreatments improved interfacial adhesion of the composites.Heat treatments significantly improved mechanical performance of the composites. [ABSTRACT FROM AUTHOR]

The inclusion of process variables in mixture experimental design is crucial for optimizing final products with precision. Unlike standard response surface designs, which are limited by the requirement that proportions must sum to 100%, mixture-process experiments enable a thorough evaluation of how operational factors, such as particle size and mixing time, interact with mixture components. This approach enhances the understanding of how processing conditions affect product properties and leads to more accurate predictive models, thereby improving production consistency and reliability. Regression analysis reveals that interactions between PET and both particle size and mixing time significantly impact the response variable. The model demonstrates strong predictive accuracy, with R-squared and adjusted R-squared values of 92% and 86%, respectively, and a low root mean square error (S) of 0.2818. The PRESS value of 3.38 confirms the model’s ability to accurately predict new data. The absence of high multicollinearity, as indicated by variance inflation factor (VIF) values below 5, further supports the model's stability and interpretability. Contour plots illustrate the effect of varying mixture proportions on the response, such as tensile strength, showing a positive impact of both particle size and mixing time. The highest tensile strength is achieved at maximum levels of these variables, indicating a synergistic effect. Response variable optimization identifies the optimal mixture composition as 90% PET, 10% wood, and no coupling agent. To maximize tensile strength, the largest particle size and longest mixing time should be used, though extrapolating beyond the studied parameters should be done with caution.

The mass loss calorimeter provides a robust method for evaluating flammability of very sooty materials such as wood plastic composites as a lower cost and rugged alternative to the reliable and effective cone calorimeter. The high amounts of smoke and carbon monoxide associated with these materials resulted in a much-reduced heat release rate, resulting in incomplete combustion of the diffusion flame, which required modifications to the standards in measuring heat release rate via oxygen consumption or carbon dioxide production or thermopiles. In addition to liquid fuels of ethylene glycol and methanol, the solids polystyrene and polymethyl methacrylate were used as calibration materials for the mass loss calorimeter and the instrumented heat release rate hood. Because of concerns about the flue gas thermopile methodology for heat release rate measurements, a second thermopile was attached to the exterior of the metal pipe chimney typically used for heat release rate calculations in the mass loss calorimeter. A heat balance analysis indicated that this is an effective design compared with alternative designs. Estimates of flaming heat release rate are reported using both signals from the thermopiles for calculation of heat release rates and confirmed with the updated oxygen consumption analysis under an instrumented hood. This special fire test arrangement was used to assess the flammability of four different wood plastic composites, some with fire-retardant treatments, such as ammonium polyphosphate and brominated, all of which tended to have high smoke production leading to high-radiant energy losses. The reduction of heat release rate with 10% by content of fire-retardant treatment was confirmed by both heat release rate measures. The average heat release rate decreased 19% to 39% when fire retardants were added, relative to this wood flour–polyethylene composite. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the impact of including teak wood in recycled high-density polyethylene wood plastic composites (WPC) with pine wood on their resistance to degradation caused by termite attack and accelerated weathering. A 23 factorial experimental design was conducted with three repetitions in the center to analyze the weight loss and termite mortality during the experiments. The factors studied were the days of exposure to accelerated weathering, days of exposure to termite attack, and the concentration of teak wood in the composite. Surface characterizations (SEM and FTIR) were carried out to analyze the exposed surfaces and determine the chemical modification of the composite components. The results showed that the WPC manufacturing process promotes a heterogeneous distribution of the wood particles, being greater within the center of the samples than on the surface. Specimens exposed to both accelerated weathering and termite attack resulted in a certain weight loss and termite mortality, depending on the material, conditions of exposure, and the content of teak wood in the WPC. When those compounds were subjected to accelerated weathering followed by termite attack they exhibited a higher termite attack. The presence of teak wood in the WPC produced a reduction in the effects of termite attack and accelerated weathering on weight loss and an increase in termite mortality compared to the WPC with only pine wood, as teak wood contains extractables with termiticidal action. The lowest value of weight loss (0.06%) was observed for the WPC with the highest amount of teak wood with termite attack, resulting in a termite mortality rate of 100% after 17 days of exposure. [ABSTRACT FROM AUTHOR]

Due to the high cost of transportation and the lack of established, affordable recycling routes, the rate of recycling of previously used polystyrene foam is extremely low. In this study, a novel treatment technique will be used to examine the feasibility of using waste polystyrene foam as a raw material to produce wood plastic composite (WPC). Where, the recycled polystyrene (rPS) foam waste was first dissolved in methylene chloride and compounded directly with flax fiber (FF) and additives forming a composite paste. The composite paste was then passes through vacuum distillation process for drying the composite paste and also for solvent recovery to reuse it in a further process. The dried composite was processed through thermal mixer extruding and compression molding processes to form the final WPC. The study discovered that WPC with 60 parts per hundred parts of resins (phr) of FF and 2 phr of dioctylphthalate (DOP) may be used to create rPS/FF composite with a proper tensile strength of 19.3 MPa, flexural strength of 78 MPa and compressive strength of 173 MPa compared to another WPS,s based on PVC, HDPE and PP. In addition of that the resulted composite possesses a great potential in manufacturing WPC with environmental and economical demanding application as wooden furniture and as a wooden panels for cladding the exterior building faces. [ABSTRACT FROM AUTHOR]

The excessive use of wood plastic composites (WPCs) at construction sites owing to their outstanding properties has caused serious disposal problems recently. Thermochemical conversions, such as pyrolysis and gasification, provide a solution for WPC disposal as a means of biofuel generation in an environmentally friendly manner. In this study, air gasification of WPCs was performed over activated bio-char-based catalysts for green valorization with the aim of achieving higher H 2 generation. The KOH activation resulted in a significant increase in the Brunauer-Emmett-Teller surface area (14 times) and total pore volume (∼6.7 times), and KOH activated char was an excellent adsorbent for trapping tar, resulting in higher tar conversion into lighter hydrocarbons and H 2. In addition, KOH-activated biochar showed the highest gas yield (69 wt%) and highest H 2 selectivity (29.76 vol.%) compared to non-catalytic and non-activated bio-char catalysts. In contrast, an equivalence ratio of 0.20 was considered optimal over KOH-activated biochar for obtaining a higher H 2 selectivity (29.76%) and minimum CO 2 (17.08%). The increased catalyst/feedstock ratio from 0.1 to 0.2 also enhanced the conversion of WPC toward H 2 generation (29.76%–35.93%). Finally, the Ni loading over KOH-activated biochar provided the highest H 2 selectivity of 43% owing to the synergy of tar cracking, water gas shift reaction, and steam and dry reforming reactions. The increase in the H 2 content of the product gas was significant because it increased the overall heating value and quality of the obtained gas. Largely, this study will be a stepping stone toward sustainable valorization of WPC over activated biochar-based catalysts for higher H 2 generation. • WPC air gasification over KOH activated biohcar and Ni/KAC was performed. • KOH activation resulted in 14 times increase in BET surface area. • KOH activated biochar resulted in significant increase in H 2 generation. • Synergistic effect of added Ni and inherent AAEMs increased H 2 generation. • The biochar seems to be green and economical solution for enhanced H 2 generation. [ABSTRACT FROM AUTHOR]

This research work is focused on the development of an alternative method for manufacturing Wood Plastic Composite (WPC) panels based on Wood Veneers (WVs) and High-Density Polyethylene (HDPE) through compression molding, which enhances the physical properties, particularly, water absorption and moisture content. The aim of the present research was to develop alternative panels to replace commercial ones, which are heavily affected by hot, humid climates. In this context, the study began with the design process, which consisted of the collection and processing of primary material, production of the additional components necessary for the manufacturing process, determination of the WV ratio, and preparation of the samples. Thereafter, physical and mechanical tests were carried out on WPC, HDPE (control), commercial gypsum boards (GBs), plywood (PW), and medium density fiberboard (MDF) samples. The results indicate that the method applied to manufacture the WPC samples improved physical properties, achieving a water uptake of less than 4% in both proportions of replacement tested, in contrast to commercial panels, which reached values between 10% and 40%. In addition, a greater load capacity was achieved for lower thick elements. [ABSTRACT FROM AUTHOR]

Lowering processing temperature of poly(ethylene terephthalate) waste (rPET) and ultra-high molecular weight polyethylene (UHMWPE) by blending to avoid decomposition of rice husk fiber (RHF) during the manufacturing of wood plastic composite (WPC) was one of the main goals of the research study. (rPET/LDPE)-g-MA and (HDPE/LDPE/UHMWPE)-g-MA blends were prepared with good flowability at 240°C. The MA grafted chain in the blends were verified by FTIR. Good miscibility and compatibility of the blends were revealed by SEM. The effect of blends ratios employed as blended matrices on performance properties of the manufactured WPC were explored. MFI and HDT were increased with decreasing (rPET/LDPE)-g-MA ratio. The reversed domain phase between rPET and blended PE mixture was pronounced at 50:50 ratio. Mechanical performances were generally reduced upon decreasing the (rPET/LDPE)-g-MA ratios. The reduction of high strength rPET fraction in the blended matrices was taken as the main cause. Exceeding the reversed phase ratio, the declining of the toughness was retarded due to rising on the interfacial strength and UHMWPE toughener fraction. The effect of DCP/VTMS crosslinker on the properties of the macro crosslinked WPC (XWPC) was investigated. The elastomeric bridges on the sauna cured WPC samples were revealed by SEM. High crosslink density upon increasing the crosslinker fraction had an obvious effect on MFI, HDT, toughness and ductility of the macro crosslinked XWPC. However, the flexible characteristic of the elastomeric amorphous PE chains in the blended matrices at high DCP/VTMS usage was manifested as brittleness retardant for the macro crosslinked XWPC. [ABSTRACT FROM AUTHOR]

In this study, it is aimed to produce wood plastic composite material with eggshell additives and to investigate the mechanical properties of these materials. Mechanical properties such as tensile strength and modulus of elasticity, elongation at break, flexural strength and modulus of elasticity and impact resistance of new materials produced by adding eggshell to wood plastic composite at different rates were investigated. It was determined that tensile strength values gradually decreased due to the increase in the amount of eggshell in the composites produced. The modulus of elasticity of the composite material in tensile strength increases with the increase in the amount of eggshell in the mixture. With the increase of the eggshell ratio used, the elongation values of the plastic composite at break are reduced. The eggshell material used in wood plastic composite reduces the bending strength of the material. The eggshell reduces the modulus of elasticity of the composite material in bending. The eggshell composite material did not cause a significant change in impact resistance. [ABSTRACT FROM AUTHOR]

Copyright of Gozdarski Vestnik is the property of Federation of Forestry Associations of Slovenia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fabricating wood‐plastic composites (WPCs) using recycled plastic and wasted biomass materials is one of the effective approaches to alleviate the global energy crisis and reduce carbon emission. However, the unsatisfactory mechanical properties and fire safety hazards significantly limit the application of WPCs. Herein, recycled high density polyethylene (R‐PE), bean dregs and intumesce flame retardant (IFR) were melt‐blended into flame‐retardant WPC by mechanochemical crosslinking. The results show that the as‐prepared WPC within 22 wt% IFR achieves a satisfactory UL‐94 V‐0 rating and a limiting oxygen index of 31.0%, exhibiting a 40%, 27.6%, and 16.4% reduction in peak heat release rate, total heat release and total smoke production respectively compared to controlled WPC. The results also revealed an unexpected improvement in the mechanical performance of WPCs using the strategy (elevation of 73.6% in the elastic modulus and 75.9% in the breaking elongation, respectively), which can be attributed to the improved interfacial compatibility between R‐PE, bean dregs and IFR. This work offers an innovative and feasible approach for fabrication of high‐performance fire‐retardant WPC based on recycling waste plastics and agriculture wastes, and contributing to the circular economy and sustainability in accordance with the greening strategy in the world. [ABSTRACT FROM AUTHOR]

The present work studies the positive or negative effect of zeolite mineral on the tensile and flexural mechanical behavior of a wood-plastic composite. Eight different blends were developed, the components used were wood flour (WF), polypropylene (PP), zeolite (Z) and maleic anhydride modified polypropylene (MAPP) as coupling agent. The eight blends were made using a counter-rotating twinscrew extruder, while the specimens were produced on a plastic injection molding machine with a 60ton clamping capacity. The standards used to determine the tensile and flexural mechanical properties were ASTM 638 and ASTM 790, respectively. Ten repetitions of each mixture were carried out. In addition, a reference (100% polypropylene) was used to compare the results obtained to determine whether the effect of using the zeolite mineral generated positive or negative results in the compounds obtained. Both studies showed that as the proportion of zeolite increases in the blend, the tensile and flexural properties are affected. However, the mixture (M7) with proportions in its components of, 34.375% WF, 55.875% PP, 6.75 % Z and 3% MAPP, showed an increase in the tensile and flexural mechanical properties, indicating a strong relationship between the components that integrate the wood-plastic composite (WPC), mainly between wood and mineral. [ABSTRACT FROM AUTHOR]

In the present work, the ability of wood-plastic composite containing high density polyethylene and wood powder as a recycled material to remove methylene blue cation pigment was studied. The effect of some important parameters such as pH, adsorbent amount and contact time was investigated. Adsorption efficiencies for methylene blue were maximized at alkaline pH. Adsorption capacity increased with increasing adsorbent amount and contact time. The value of R2 in Langmuir model was equal to 1 and the separation factor for 0.5 and 1 g of adsorbent was 0.09 and 0.1, respectively. Given that the methylene blue adsorption data were more consistent with the Langmuir isotherm model, it can be stated that the wood-plastic composite probably has uniform adsorption surfaces and the adsorption process occurred in a homogeneous system on the adsorbent surface. Based on the results of this study, it was observed that this composite is a suitable adsorbent for removing methylene blue from aqueous solutions and used as a purifying agent in the decolorization of effluents containing pigments. This adsorbent is recyclable and cost-effective for dye removal from textile industry wastewater.

The processing temperature of poly(ethylene terephthalate) waste (rPET) and ultra-high molecular weight polyethylene (UHMWPE) was lowered by blending to avoid decomposition of rice husk fiber (RHF) during the manufacturing of wood plastic composite (WPC). Maleic anhydride (MA) grafted blends of HDPE/LDPE/UHMWPE-g-MA and rPET/LDPE-MA were prepared. Those blends were flowable at 240 °C. They were employed as blended matrices to make HDPE/LDPE/UHMWPE-g-MA/rPET/LDPE-MA/RHF wood composite at processing temperatures not exceeding 240 °C. The study of RHF loading on the WPC performance revealed that melt flow index (MFI) and mechanical performances measured by impact, flexural, and tensile properties were weakened, but heat distortion temperature (HDT) was enhanced at high RHF loading. When the stabilizer content did not exceed 2 phf, the toughness and ductility were improved. Surface treatment of RHF by MA and dicumyl peroxide (DCP) enhanced the interfacial surface adhesion, but the toughness and ductility of the WPC were reduced at high MA/DCP dosing. The formation of crosslink structure via peroxide free radical initiated reaction at the MA grafted branch chains was the prime suspect for the inferiority of the mechanical performances.

In this study, it was aimed to determine the stress and relaxation behavior of wood plastic composites produced by using magnesiumoxysulphate and lignocellulosic filler. For this purpose, test specimens were produced by using 10% and 20% magnesiumoxysulfate, lignocellulosic filler (Pinus brutia Ten.), 3% wax and maleic anhydride grafted polypropylene (MAPP) into the polymer matrix. Extrusion and injection molding methods were used in the manufacturing of test specimens. In order to determine the stress relaxation behavior of wood plastic composites in tensile, a total of 15 test samples, 3 for each variable parameter of each production code, were prepared in depend on the ASTM D 638 (2004) standard. The stress-relaxation behaviors of test samples were determined at 600 Newton force, tensile speed of 5mm/min and tensile for 2 hours. The experiments were carried out in room conditions and the temperature of the room where the experiment was conducted was adjusted with air conditioning. According to the test results; It has been determined that the ratio and type of filler materials have a significant effect on the stress relaxation values. It has been determined that the Synthetic and lignocellulosic filler participation rates are effective on the stress relaxation values of the test samples and the stress relaxation values decrease significantly as the participation rate increases. It has been determined that the filler ratio reduces the mobility of the polymer chains between them, this delays the relaxation and as the amount of filler increases, the relaxation decreases. In applications where stress relaxation behaviour it is important, specific care should be paid on the selection of filler amount.

Nowadays, great emphasis is placed on environmental aspects of production processes with focus to lower carbon footprint. Natural fibre-reinforced plastics (NFRP) show potential for application in many fields of industry due their specific properties. Machining of NFRP-based materials is meeting several problems arising from non-homogenous structure as well as plastic-based matrix. Machining of NFRP using conventional technologies meets limitations due to the properties and geometry of the tools. Abrasive water jet (AWJ) machining can solve some of the problems machining NFRP materials. The presented article focused on surface topography evaluation of one kind of NFRP composite material after cutting by AWJ. Optical profilometry and 3D microscopy were applied for measurement of surface roughness parameters of surfaces created by AWJ with variable cutting parameters. Maximal height of profile Rz was measured in 20 lines perpendicular to the jet direction form upper to lower cut line. Structure of cut surface was observed and evaluated for different technologic parameters. The obtained results show promising presuppositions for application of AWJ technology for cutting of NFRP based materials. [ABSTRACT FROM AUTHOR]

As the products made from wood–plastic composites (WPCs) become more sophisticated and required more detail profiles, the injection moulding processing method with wood pulp as the reinforcing material is the answer to cater to the rapid change and demands of composite products. The general objective of this study was to study the effects of the material formulation, as well as the injection moulding process parameters, on the properties of a polypropylene composite reinforced with chemi-thermomechanical pulp from oil palm trunks (PP/OPTP composite) via the injection moulding process. The PP/OPTP composite with a material formulation of 70% pulp/26% PP/4% Exxelor PO produced using injection moulding at 80 °C as the mould temperature and with 50 tonnes of injection pressure exhibited the highest physical and mechanical properties. The increment loading of pulp increased the water absorption capacity of the composite. Higher loading of the coupling agent effectively reduced the water absorption capacity and increased the flexural strength of the composite. The increase in mould temperature from unheated to 80 °C prevented excessive heat loss of the flowing material, which enabled the molten material to flow better and filled up all cavities in the mould. The increased injection pressure slightly improved the physical properties of the composite, but the effect on the mechanical properties was insignificant. For the future development of WPCs, further studies should be focused on the viscosity behaviour, as a greater understanding of the processing parameters' effects on the PP/OPTP's viscosity behaviour will lead to improved product design and enable great potential usage of WPCs. [ABSTRACT FROM AUTHOR]

This research work is focused on the development of an alternative method for manufacturing Wood Plastic Composite (WPC) panels based on Wood Veneers (WVs) and High-Density Polyethylene (HDPE) through compression molding, which enhances the physical properties, particularly, water absorption and moisture content. The aim of the present research was to develop alternative panels to replace commercial ones, which are heavily affected by hot, humid climates. In this context, the study began with the design process, which consisted of the collection and processing of primary material, production of the additional components necessary for the manufacturing process, determination of the WV ratio, and preparation of the samples. Thereafter, physical and mechanical tests were carried out on WPC, HDPE (control), commercial gypsum boards (GBs), plywood (PW), and medium density fiberboard (MDF) samples. The results indicate that the method applied to manufacture the WPC samples improved physical properties, achieving a water uptake of less than 4% in both proportions of replacement tested, in contrast to commercial panels, which reached values between 10% and 40%. In addition, a greater load capacity was achieved for lower thick elements.

Innovative products, including wood plastic composite, point to the potential of using the principles of the circular economy. The increasing share of plastic waste combined with wood raw material creates great potential for meeting the environmental criteria of wood plastic composite products. The aim of the paper is to present a proposal for modifications of the standard methodological overhead cost calculation with the subsequent comparison of the results of the innovative methodological calculation, based on the investment plan for the production using recycled wood-plastic raw materials. The application of the Calculation of Machine Hours Rates requires precise identification of the production capacity in terms of machinery hours and composition of the calculation formula. Although the results of the comparison of price differentiation did not reveal a fundamental change in the cost allocation, it may differ for variations in other surface and volume product dimensions, changed wood-plastic component proportions or subsequent final surface treatment. [ABSTRACT FROM AUTHOR]

In the present work, the ability of wood-plastic composite containing high density polyethylene and wood powder as a recycled material to remove methylene blue cation pigment was studied. The effect of some important parameters such as pH, adsorbent amount and contact time was investigated. Adsorption efficiencies for methylene blue were maximized at alkaline pH. Adsorption capacity increased with increasing adsorbent amount and contact time. The value of R2 in Langmuir model was equal to 1 and the separation factor for 0.5 and 1 g of adsorbent was 0.09 and 0.1, respectively. Given that the methylene blue adsorption data were more consistent with the Langmuir isotherm model, it can be stated that the wood-plastic composite probably has uniform adsorption surfaces and the adsorption process occurred in a homogeneous system on the adsorbent surface. Based on the results of this study, it was observed that this composite is a suitable adsorbent for removing methylene blue from aqueous solutions and used as a purifying agent in the decolorization of effluents containing pigments. This adsorbent is recyclable and cost-effective for dye removal from textile industry wastewater. [ABSTRACT FROM AUTHOR]

Copyright of China Forest Products Industry is the property of China Forest Products Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Application of out-of-service rubber from a variety of sources is of both environment-protecting and resource-saving importance. To that end, recycled tire rubber was utilized as a filler to fabricate wood-high density polyethylene (HDPE) composite with enhanced toughening performance using the injection procedure in this work. Dosages of rubber powders were 0, 5, 10, and 15wt% based on the overall weight of poplar wood flour and HDPE (HDPE: wood flour = 70꞉30). The injection-fabricated composites were subjected to a four-cycle repetitive compressing loadings (0–3 kN) and dynamical mechanical analysis (DMA, room temperature to 150 °C, in the dual cantilever mode). It was found that the rubber-filled materials exhibit advantageous energy absorption performance compared to wood-HDPE composites under repetitive compressions. The rubber-filled wood-HDPE composites are thermomechanically labile in an environment with raised temperature. The HDPE matrix substance occupies the predominant role in thermally yielding of the overall composite, typically in the temperature range of 50–75 °C resulting in a loss modulus peak. Up to 130–150 °C, all the composites fully loses their moduli with loss factor (Tan δ) reaching its peak values of 0.30–0.38. To conclude, rubber-filled wood-HDPE is a qualified material applicable in proper temperature range.

Nowadays, great emphasis is placed on environmental aspects of production processes with focus to lower carbon footprint. Natural fibre-reinforced plastics (NFRP) show potential for application in many fields of industry due their specific properties. Machining of NFRP-based materials is meeting several problems arising from non-homogenous structure as well as plastic-based matrix. Machining of NFRP using conventional technologies meets limitations due to the properties and geometry of the tools. Abrasive water jet (AWJ) machining can solve some of the problems machining NFRP materials. The presented article focused on surface topography evaluation of one kind of NFRP composite material after cutting by AWJ. Optical profilometry and 3D microscopy were applied for measurement of surface roughness parameters of surfaces created by AWJ with variable cutting parameters. Maximal height of profile Rz was measured in 20 lines perpendicular to the jet direction form upper to lower cut line. Structure of cut surface was observed and evaluated for different technologic parameters. The obtained results show promising presuppositions for application of AWJ technology for cutting of NFRP based materials.

The paper deals with the application of abrasive water-jet cutting to composite material containing natural reinforcement—wood plastic composite. The specimens were cut through the application of four flows of different abrasive mass: 150, 200, 250, and 300 g·min−1, respectively, and under different traverse speeds required to achieve the (expected) quality level Q1–Q5 (according to the SN 214001: 2010 standard). The output quality of Q1–Q5 was set in the CNC cutting programs and the real traverse speed values were calculated by machine control system according to change in the flow of the abrasive mass. The quality of surface topography was assessed using a tester (contact roughness) and an Inspectis digital zoom microscope. The results of topography–surface roughness parameters Ra presented here are compared with the values normalized for individual samples sets. The applied technology, i.e., the AWJ, eliminated the problem of tool wear and adhesion of the thermoplastic matrix to tool surfaces (compared to standard machining). [ABSTRACT FROM AUTHOR]

In this study, the effect of walnut shell and charcoal flour on the applied characteristics of the resulting plastic composites was investigated. For this purpose, walnut shell and charcoal flour in three levels of 20, 30 and 40% were mixed with high density polyethylene using Brabender internal mixer during the melt mixing process, then standard test samples were made by injection molding method. Mechanical properties including tensile and flexural strength, tensile and flexural modulus and impact strength were measured. Physical properties including water absorption and thickness swelling after 24 hours immersion were evaluated and scanning electron microscopy images were also examined. The results showed that the flexural strength and impact strength of the wood plastic composite containing 40% walnut shell flour were higher than the samples containing 40% charcoal flour. Also, by increasing the walnut shell and charcoal flour from 20 to 30%, the flexural strength increased by 3.3% and 6.1%, respectively, and by increasing the walnut shell and charcoal flour from 20 to 40%, the flexural modulus increased by 51.9% and 63.8%, respectively. Other results of mechanical strength indicate that with increasing walnut shell charcoal from 20 to 40%, tensile strength and modulus increased to 22.9 and 109.7%, respectively, and with increasing walnut shell and charcoal flour from 20 to 40%, the impact strength decreased by 6.6 and 5.4%, respectively. The results of physical properties showed that with increasing walnut shell and charcoal flour from 20 to 40%, water absorption for 24 hours decreased by 19.2 and 8.4%, respectively, and thickness swelling by 24 hours decreased by 53.6 and 46.7%, respectively. [ABSTRACT FROM AUTHOR]

The physical and mechanical properties of particleboard bonded with different cooking percentages of seaweed (Kappaphycus alvarezii), with different percentages of starch and different percentages of adhesives, and wood plastic composite (WPC) from High-Density Polyethlene (HDPE) with Acacia mangium wood powder were determined in this study. Seaweed mixed with different percentages of sulfuric acid (30%, 50%, 70%) and Sodium Hydroxide (70%, 50%, 30%) were prepared as a binder for particleboard. For a starch-based binder, different percentages of starch (10%, 15%, 20%) were prepared, before producing particleboard with different amounts of binder (20%, 25%, 30%). As for WPC, wood powders were bonded with different percentages of HDPE content (70%, 80%, 90%). Results indicated that WPC at 90% HDPE shows the best performance in the water absorption (0.07%) and thickness swelling test (2.54%). Starch-based particleboard recorded the highest Modulus of Elasticity (MOE) value (1115.07 N/mm2 at 15% starch with 30% amount of binder), while WPC (90% HDPE) and starch-based particleboard (10% starch with 20% amount of binder) both recorded the highest Modulus of Rupture (MOR) at the same value, which is 7.84 N/mm2. Starch-based particleboard has a better internal bond, which is 0.05 N/mm2. However, seaweed-based particleboard has a higher density value, which is 0.6 g/cm3. [ABSTRACT FROM AUTHOR]

With its market demand expansion and increased application areas, products of wood-plastic composite (WPC) have been developing and growing rapidly in many countries over the last decades. This paper attempts to investigate the effect of wood species that are waste from the furniture industries on the performance of wood-plastic composites (WPCs). The samples were prepared by varying the wood flour species at 30wt% mixed with 70wt% HDPE (High Density polyethylene). The wood species used for samples preparation are Cordia africana's /wanza/ wood flour, Austria pine's wood flour, and the mixture of both wood species flour in 15wt% of each wood species and the resulted composites tensile and impact properties determined. Morphological and water absorption characteristics of these composites were also determined. The composite from the mixture of wood species exhibited best interfacial bonding between matrix and reinforcement that resulted in providing the best water absorption property, and the maximum tensile strength of the composite which is, 15.465 MPa. Compared with the pure HDPE, the reduction of impact strength with the addition of wood was also observed. Wood species in wood-plastic composites are an essential factor for the performance of WPCs. [ABSTRACT FROM AUTHOR]

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Forest Products Industry is the property of China Forest Products Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wood-plastic composites (WPCs) have shown promising domestic and industrial applications. Both virgin and waste materials have been used as matrix and reinforcement materials in WPCs manufacturing which enhances the eco-efficiency of WPCs products. This study presents a comprehensive review on the WPCs manufacturing techniques including pre-processing of the composite ingredients and post-processing of the WPCs products. Three main types of pre-processing techniques have been discussed; chemical, mechanical, and thermal treatments. Conventional manufacturing techniques of WPCs such as extrusion molding, injection molding, compression molding, stir casting, and hot-press method have been presented. In addition, advanced manufacturing techniques such as selective laser sintering have been briefly discussed. The recycling of WPC is also discussed. Eco-friendly assessment of WPCs has been also introduced. Important conclusions and the future research trends have been mentioned in the end of the article.

The transition from fossil-based to bio-based materials requires in-depth environmental durability analysis for material engineering and construction applications. We report the hydrothermal aging and biodegradation effect on 6 types of compatibilized microcrystalline cellulose (MCC) and poly(butylene succinate) (PBS) composites. The prepared highly loaded systems with 70 wt% of MCC showed a strong positive impact on the composites' mechanical and thermomechanical properties concerning applied modifications. MCC was modified with different coupling agents, namely polyhydroxy amides (PHA), alkyl ester (EST), (3-Aminopropyl)trimethoxysilane (APTMS), maleic acid anhydride, and polymeric diphenylmethane diisocyanate (PMDI). In addition, cross-linking agent carbodiimide (CDI) was used as an alternative to MCC modification. Modification of MCC compared to unmodified composite induced the enhanced rigidity, creep properties, and thermal stability of the materials due to the cross-linking in the interface by proposed chemical treatment. PMDI and CDI chemical modification resulted in the highest elastic modulus while keeping high strength values. A significant 2.5-fold reduction of the coefficient of linear thermal expansion and decreased thermal strains for modified biocomposites were obtained. Due to the hydrophilic nature of MCC, the hydrothermal aging of the composites revealed a dramatic decrease in the elastic modulus and strength characteristics compared to neat PBS. The hydrophilicity depends on the applied surface modification as indicated by contact angle measurements and water absorption and swelling tests. EST facilitated water wetting and enhanced water penetration, and reduced material biodegradation to 30 days, a 2.5-fold improvement compared to the neat PBS polymer. In contrast, PHA, APTMS, PMDI, and CDI improved biocomposites durability while suppressing biodegradation. The obtained results could be useful for selecting an optimal MCC surface modification route to design novel and perspective biocomposites with tailored durability and biodegradation and to replace polyolefin composites for wood polymer composite applications. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate some of the properties of experimental wood plastic composite (WPC) panels manufactured from a low percentage of rubberwood (Hevea brasiliensis Muell. Arg), waste polyethylene terephthalate (PET) and silica at three different ratios. It was determined that water absorption values of the samples decreased with the increasing amount of PET in the panels. The lowest absorption value of 0.34% was determined for the samples having 40% PET in their content as a result of 24-h soaking. The highest hardness value of 4492 N was found for the samples made with the combination of rubberwood, PET and silica at 10%, 40% and 50%, respectively. The compressive strength of WPC specimens also followed a similar trend with the hardness characteristics of the panel and improved with increasing PET percentage. Statistical analyses revealed that values of compression strength, hardness, 2-h and 24-h water absorption of the specimens made with 20, 30, and 40% PET content resulted in significant difference from each other (p ≤ 0.0001). Based on the findings in this study it appears that increasing silica content in the samples adversely influenced their mechanical properties while creating a certain level of enhancement of water absorption of the specimens. It seems that using a combination of waste PET and a limited amount of silica with a low percentage of wood particles could have the potential to produce value-added environmentally friendly composites to be used for different applications. [ABSTRACT FROM AUTHOR]

Presented article with machining (specifically drilling technology) of composite materials is based on Wood-Plastic Composite, in short WPC (as a minimum substitute for wood in interior / exterior applications). Experiment is focusing on selected technological parameters of machining (spindle speed and tool feed rate) on the characteristics of created surface. Surface cut zone quality -- surface topography is examined by contact profilometry (as commonly available methods) and optical methods. The results of the experiments point to the disadvantages of these composite materials and the basic aspects influencing the quality of surfaces after machining is the inhomogeneity of the material. [ABSTRACT FROM AUTHOR]

Abstract The development of wooden joints possessing high resistance performance has become an important issue for the construction of newer buildings. This study attempts to strengthen the lateral resistance of bolted joints using the previously reported plasticizing technique. This technique consists of two processing stages: incising the surface of the wood using an ultraviolet wavelength short-pulse laser and impregnating the resin into the incised area. This technique makes it possible to plasticize only a local part of the wood surface. Bolted joint specimens were assembled using plasticized wood around the bolt hole, and the lateral tests were conducted. Acrylic monomer and urethane prepolymer were used as the impregnating resins and their incision depths were set as 4 and 10 mm. When the lateral load acted parallel to the grain, changes in the lateral resistance characteristics were observed, especially for the stiffness and yield load. For example, when acryl was used, and the incision depth was 10 mm, an increment of 73% in the yield load was observed, as compared to the non-impregnated specimens. The specimen groups impregnated with acryl exhibited greater changes in their properties than those using urethane. When loaded perpendicular to the grain, an increase in properties were observed; however, these increments were lower than those of the groups loaded parallel to the grain.

The properties of wood plastic composites (WPCs) depend on their microstructure, particularly the level and geometry of wood reinforcement in the composite. We hypothesize that impregnating a WPC with a radiocontrast agent will increase the contrast between wood and plastic, allowing better visualization of its microstructure and numerical analysis of the geometry of its wood reinforcement. A commercial WPC was scanned using X-ray micro-CT, impregnated with aqueous sodium iodide, and then rescanned. CT data from both scans were visualized, and we analyzed the geometry of wood reinforcement and levels of wood, plastic, zinc borate (ZB), and voids in the WPC. ZB occurred mainly as discrete particles between wood flakes, and interfacial voids formed a network of cracks within the WPC. Sodium iodide labeling made it possible to clearly visualize wood and plastic in the WPC and quantify levels of different phases and the geometry of wood particles. However, sodium iodide was not an ideal contrast agent because it swelled wood particles, closed interfacial voids, and partially dissolved ZB particles. We suggest methods of overcoming these limitations and conclude that advances in labeling are necessary to improve our understanding of the relationship between the microstructure of WPCs and their properties. [ABSTRACT FROM AUTHOR]

Mechanical strength of multiphase material depends on mechanical properties of components and interface bonding states, which has always been a research hot spot. In this work, a hyperbranched polyethyleneimine‐grafted nano SiO2 (pSiO2)‐decorated ammonium polyphosphate (APP) was applied to synergistically improve the flame retardancy and toughness of wood plastic composite (WPC). With nonpolar carbon skeleton and polar amine groups on it, pSiO2 could successfully coated on APP via ionic bonding and improve the compatibility between wood fiber and high‐density polyethylene (HDPE). According to digital image correlation (DIC), pSiO2 improved the strain transfer from HDPE molecular to wood fiber, thus an increased high‐deformation region was observed in WPC/pSiO2 and WPC/APP‐pSiO2. pSiO2 provided numerous of stress concentration area,to induce the formation and inhibit the convergence of craze. As a result, WPC/APP with 30% pSiO2 addition showed a 47.9% increment in impact strength compared to WPC/APP. Besides, pSiO2 also showed a synergistic effect with APP and further improved the flame retardancy of flame retardant WPC. This work provides a route for interface design and internal stress–strain study of multiphase composites. [ABSTRACT FROM AUTHOR]

The sound insulation performance is an important technical index for evaluating the physical property of the building wall. Three kinds of structural wood walls integrated with wood plastic composite (WPC) were designed. And the sound insulation performance of the walls was studied. The results showed that for the wall that constructed by the WPC as the wall studs, compared with the one that constructed by the pine wood as the wall studs, the deviation of their sound insulation was lower than ±3 dB. The wall's external panel material had significant effect on the wall's sound insulation property, and the contribution of the wood-plastic panel to the sound insulation was much higher than that of the polyvinyl chloride (PVC) plastic hanging board. The surrounding sealing quality of the wall's external panel material had an important influence on the sound insulation effect of the building wall, and the panel of the wood plastic interior wall had less influence on the sound insulation performance of the wall. Taking the sound-absorbing cotton or non-woven fabric as elastic strips was an effective technical measure to improve the sound insulation performance of the walls. The sound insulation was improved by 2.4 dB and 3.1dB respectively after the correction of pink noise spectrum, and increased by 2.8 dB and 3.6 dB respectively after the correction of traffic noise spectrum.

This study aims to fabricate an Eco-friendly wood-plastic composite (WPC) with poly (lactic acid) (PLA) biodegradable matrix reinforced by wood flour (WF) of Fir and Pulp fibers (PF). PLA samples were compared to the samples made from one of the most commonly used synthetic plastics, i.e., Low density polyethylene (LDPE) to evaluate the results of this study. In addition to the physical and mechanical properties, the morphological properties of the new product were also studied by electron scanning (SEM). According to the results of the mechanical properties of the PLA samples, the highest resistance was related to the samples containing PF filler and the strength of the samples was also improved by increasing the percentage of PF. In the case of physical properties, the best result was for those samples containing WF fillers, and these physical properties improved by reducing wood flour content. According to the results and the general comparison of the two polymers, the best resistance was related to the samples made with LDPE. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper deals with the application of abrasive water-jet cutting to composite material containing natural reinforcement—wood plastic composite. The specimens were cut through the application of four flows of different abrasive mass: 150, 200, 250, and 300 g·min−1, respectively, and under different traverse speeds required to achieve the (expected) quality level Q1–Q5 (according to the SN 214001: 2010 standard). The output quality of Q1–Q5 was set in the CNC cutting programs and the real traverse speed values were calculated by machine control system according to change in the flow of the abrasive mass. The quality of surface topography was assessed using a tester (contact roughness) and an Inspectis digital zoom microscope. The results of topography–surface roughness parameters Ra presented here are compared with the values normalized for individual samples sets. The applied technology, i.e., the AWJ, eliminated the problem of tool wear and adhesion of the thermoplastic matrix to tool surfaces (compared to standard machining).

Abstract A Bio composite comprising Prosopis Juliflora Fiber (PJF) and Poly Lactic Acid (PLA) was processed considering two particulate sized reinforcements, coarse PJF (avg. 15 µm) and fine PJF (10-50 nm). They were added individually at ratios of 10, 15, 20 and 25 wt% into PLA matrix. The composites were extruded and tested for mechanical properties. The addition of PJF resulted with an increase in the tensile, flexural and impact strengths of the polymer. Adding PJF to PLA showed a decrease in the hardness of the polymer. Water Absorption test showed an increase in water uptake with increasing fiber content. The most optimum ratio of PLA to PJF was found to be 80:20. The fine PJF reinforced composites proved to be superior over the coarse PJF reinforced composites at all stages of the research. FESEM and TGA were used to study morphology and thermal characteristics respectively.

The aim of this study is to investigate the effect of sepiolite mineral used in the production of polypropylene based wood plastic composite (OPK) materials on thermal properties and thermal conductivity. The pellets obtained from the mixture of wood flour, polypropylene and sepiolite minerals with double-screw extruder were milled and pressed to produce OPK boards. Thermal properties such as Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) as well as the thermal conductivity properties of the produced boards (ASTM C 1113-09) have been determined. It has been determined that the addition of the sepiolite mineral used as fire retardant in OPK materials increases the thermal and thermal conductivity properties, while the crystallization degree decreases.

Since invasive alien species are one of the main causes of biodiversity loss in the region and thus of changes in ecosystem services, it is important to find the best possible solution for their removal from nature and the best practice for their usability. The aim of the study was to investigate their properties as components of wood-plastic composites and to investigate the properties of the wood-plastic composites produced. The overall objective was to test the potential of available alien plant species as raw material for the manufacture of products. This would contribute to sustainability and give them a better chance of ending their life cycle. One of the possible solutions on a large scale is to use alien wood species for the production of wood plastic composites (WPC). Five invasive alien hardwood species have been used in combination with polyethylene powder (PE) and maleic anhydride grafted polyethylene (MAPE) to produce various flat pressed WPC boards. Microstructural analyses (confocal laser scanning microscopy and scanning electron microscopy) and mechanical tests (flexural strength, tensile strength) were performed. Furthermore, measurements of density, thickness swelling, water absorption and dimensional stability during heating and cooling were carried out. Comparisons were made between the properties of six WPC boards (five alien wood species and mixed boards). The results showed that the differences between different invasive alien wood species were less obvious in mechanical properties, while the differences in sorption properties and dimensional stability were more significant. The analyses of the WPC structure showed a good penetration of the polymer into the lumens of the wood cells and a fine internal structure without voids. These are crucial conditions to obtain a good, mechanically strong and water-resistant material. [ABSTRACT FROM AUTHOR]

In this study, Wood Plastic Composites (WPCs) were produced from post-consumer bulky wastes of recycled plastic and wood in order to minimize waste, decrease environmental effects of plastics, reserve natural resources, and support circular economy for sustainable production and consumption. Five different types of polypropylene (PP) or polyethylene (PE) based recycled plastics and wood obtained from urban household bulky wastes were used in the production of recycled WPC composites, r-WPCs. Virgin WPC (v-WPC) and r-WPC compounds were prepared with wood flour (WF) and maleic anhydride grafted compatibilizer (MAPP or MAPE) to evaluate the effect of recycled polymer type and compatibilizer on the mechanical properties. It was found that tensile strength properties of r-WPCs produced from recycled PP (r-PP) were higher than that of the r-WPCs produced from mixed polyolefins and recycled PE. r-WPCs containing anti-oxidants, UV stabilizers, and compatibilizer with different WF compositions were produced from only recycled garden fraction PP (PPFGF) to determine the optimum composition and processing temperature for pilot scale manufacturing of r-WPCs. Based on tensile, impact, flexural, and water sorption properties of r-WPC compounds with different formulations, the optimum conditions of r-WPC compounds for industrial manufacturing process were determined. Surface morphology of fractured surfaces as well as tensile, flexural and density results of r-WPC compounds revealed the enhancement effect of MAPP on interfacial adhesion in r-WPCs. r-WPC products (crates and table/chair legs) based on bulky wastes were produced using an injection molding process at industrial scale by using 30 wt% WF-filled r-WPC compound. This study demonstrated that r-WPC compounds from recycled bulky plastic and wood wastes can be used as a potential raw material in plastic as well as WPC industry, contributing to circular economy. [ABSTRACT FROM AUTHOR]