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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 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 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]

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.

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]

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]

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 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]

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]

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.

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]

The long-term deformation of a geodesic spherical frame structure with a diameter of 20 m made from wood plastic composite (WPC) lumber (struts) is described using the Norton-Bailey power law model to predict the service life creep behavior (the creep strain ( ε c r )) of the WPC. The Norton-Bailey power law model parameters, A the power law multiplier, n the stress order, and m the time order, were obtained from experimental four-point bending flexural creep measurements of WPC lumber subjected to three levels of flexural stress: 7, 14, and 29% of the ultimate flexural strength for 200 days. The parameters obtained from the experiments showed good agreement to the model of the WPC lumber in flexure. The Norton-Bailey power law parameters were then implemented to describe the long-term deformation of the spherical frame structure. The limit of failure was considered when the WPC creep strain reaches the value of 1%. However, the FEA predicted the maximum creep strain to be 20% of the failure strain. This modeling approach is considered useful to describe and predict the long-term deformation of aquacultural structures made from viscoelastic materials during the envisioned service life (10 years) based on experimental creep data for the members that form the structure. [ABSTRACT FROM AUTHOR]

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.

Bu çalışmada, lignoselülozik dolgu maddesi türü, kullanım oranı ve erime akış indeksinin odun plastik kompozitlerin (OPK) özelliklerine etkisinin belirlenmesi hedeflenmiştir. Lignoselülozik dolgu maddesi olarak zeytin pirinası ve kızılçam odun unu %20 ve %40 oranlarında kullanılmıştır. Kızılçam odun unu veya zeytin pirinası, vaks ve maleik anhidrit graftlanmış polipropilen (MAPP)ve yüksek veya düşük erime akış indeksine sahip polipropilen üretim reçetesine göre yüksek devirli mikser yardımıyla homojen bir şekilde karıştırılmıştır. Homojen karışım öncelikle tek vidalı eksturuder de karıştırılarak odun plastik kompozit karışımları oluşturulmuş ve bu karışımlar kırıcı yardımıyla pelletler haline dönüştürülmüştür. Üretilen pelletler kullanılarak enjeksiyon kalıplama makinesinde deney numuneleri üretilmiştir. Kontrol numuneleri dolgu maddesi katılmadan üretimler gerçekleştirilmiştir. Üretilen deney numunelerinin fiziksel ve mekanik özellikleri belirlenmiştir. Erime akış indeksinin OPK'lerin özelliklerine önemli bir etkisinin olmadığı buna karşın dolgu maddesi türü ve oranına göre değişkenlik göstermesine rağmen mekanik özelliklerin ASTM D 6662 standardında belirlenen değerleri karşıladığı tespit edilmiştir.

In this study, wood plastic composite (WPC) materials were produced using high density polyethylene (HDPE) and wood fiber at various ratios ranging from 40% to 70%. The effects of fiber content on mechanical properties such as tensile strength, bending strength, elasticity modulus and shock resistance of these materials were investigated. In addition, maleic anhydride grafted polyethylene (MAPE) was also added to the materials, which had lowest and highest wood fiber additive, to investigate the effect of the binding agent effect. Composite samples were produced via a laboratory type twin screw extruder and test panels were prepared using hot press molding method. According to the results, the bending, tensile and shock resistances generally decreased with the increasing ratio of wood fiber in the composite material content while modulus of elasticity increased for the sample groups without coupling agent. However, the addition of the coupling agent MAPE into the material content significantly improved the mechanical properties. Especially, the addition of MAPE provided better resistance values than all sample groups without MAPE even for the samples containing 70% wood fiber. As a result, with this study, it has been shown that WPC materials with low cost, light weight, aesthetic appearance and good mechanical properties as well could be produced with high fiber ratio.

In this study, the thermal properties and fire resistances of the wood plastic composites produced with waste lignocellulosic materials were investigated. For this purpose, lignocellulosic waste, high density polyethylene, (HDPE) sodium borate (borax) and boric acid was used to produce the wood-plastic composites. A twin-screw extruder was used during the production of the wood plastic composites. The produced composite granule was pressed at 175 °C hot press. The effects of boric acid and borax added to wood plastic composites were investigated with the thermal gravimetric analysis (TGA), the horizontal burning rate and the limiting oxygen index (LOI). According to the results, it was understood that as the amount of the boron compounds was increased, the burning degree (°C) of the composite material increased. Furthermore, the using of the boric acid and sodium borate in the production of the wood plastic composite decreased burning speed.

Selection of a material for their end use in engineering applications depends on the properties of materials. In this paper, physical and mechanical properties of teak sawdust-polypropylene composite are evaluated and most suitable composition for outdoor applications have been determined by using TOPSIS technique of optimization. Virgin and recycled polypropylene are mixed with teak sawdust to fabricate the composite with and without maleated polypropylene (MAPP) using compression molding method. TOPSIS technique of optimization involves prioritizing the performance indicators. Important properties such as tensile strength, flexural strength, impact strength, hardness, melt flow index, water absorption and thickness of swell are selected for the study. The composition 50% recycled polypropylene, 45% wood sawdust and 5% MAPP by weight is found to be most suitable for outdoor applications. [ABSTRACT FROM AUTHOR]

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Wood flour (WF) filled polymer composites are widely used in our daily life. Unfortunately, a wick effect of WF during burning seriously deteriorates the flame retardancy of wood-plastic composites. Traditional flame retardants cannot efficiently restrict the wick effect of WF due to their random distribution. In this work, amino glycerin decorated ammonium polyphosphate (APD-APP) was well designed and prepared through an ion exchange reaction to tailor the dispersion of flame retardant in WF-filled polymer composites. When the APD-APP was incorporated into the WF/polypropylene composite (WPC), it showed significantly different distribution compared to that of APP and mainly accumulated at the surface of WF, and then resulted in the formation of core-shell WF@APD-APP. More importantly, the flame retardancy of WPC/APD-APP is remarkably superior to that of WPC/APP. In vertical burning test, 25.0 wt% of APD-APP upgraded the UL-94 rating and limiting oxygen index (LOI) of WPC from no rating and 19.0% to the corresponding V-0 rating and 29.0%. Moreover, the melt dripping of WPC was completely eliminated by APD-APP. In the combustion test, the peak of heat release rate and total smoke production for WPC were respectively decreased by 70.0% and 76.6% in the presence of 30.0 wt% of APD-APP. In addition, mechanical properties of WPC/APD-APP are also superior to that of WPC/APP. The mechanism for the excellent flame retardancy of WPC/APD-APP revealed that the formed core-shell WF@APD-APP affected a residual network through the intergrowth charring of APD-APP and WF during thermally decomposing, and then the wick effect of WF was significantly weakened. Finally, the flame retardancy of WPC/APD-APP was enhanced through typical intumescent flame-retarding action via simultaneous interfacial and bulk charring. [ABSTRACT FROM AUTHOR]

This research aimed to investigate the effect of chemical treatment of wood flour on some of physical, mechanical and morphological properties of wood plastic composite. Chemical treatment of wood flour at 7 levels without treatment, acetylation, benzoylation, mercerization, magnesium hydroxide, calcium hydroxide and warm water treatment were considered as variable factors. For evaluate reaction of wood flour with chemical materials, weight percent gain (WPG) were calculated. After chemical treatment, Wood flour and polypropylene with weight ratio of 60 to 40 and 4 per hundred compound (phc) of coupling agent mixed in the extruder device and then the specimens were fabricated by injection molding method. Then mechanical tests Included tensile, flexural and impact strength and physical examination, including water absorption and thickness swelling was performed on specimens according to (ASTM) standard. Also to study the morphology of the composites, scanning electron microscopy (SEM) was used. The results showed that by chemical treatment the mechanical strength increased and physical properties such as water absorption and thickness swelling decreased. Also the highest chemical treatments of wood flour was related to the banzylation treatment. As well as obtained results of scanning electron microscopy was indicate improve in cross linking between fibers and polymeric matrix on effect of chemical treatment, so that in treatment samples exiting of fibers into the matrix not observed.

In this study, effect of nano-wollastonite on fire resistance characteristics of wood flour/polypropylene composite was investigated. The composites samples were manufactured using a dry blend/hot press method. In this study, the dried wood flour of beech as the filler in a 60%, poly propylene as the matrix in a 37% and polyethylene grafted with maleic anhydride as the coupling agent in a 3% total weight was used. Also, nano-wollastonite was used in four levels of dried wood flour loading (0, 1, 3 and 5%). Nominal density and dimensions of the composites were 1 g/cm3 and 1*20*25 cm, respectively.Bending strenght according to ASTM standard and Fire resistance characteristics such as, flammability duration, duration of flame after removing the burner, duration of glow after removing the burner and mass reduction were measured acceding to ISO 11925. Results indicated that by increasing the nano-wollastonite increases the bending strengh,MOE and flammability duration increased but mass reduction, duration of flame and duration of glow decreased. Also the dispersion of nano-wollastonite in composites was evaluated by Filed Emission Scanning Electron Microscopy (FE-SEM).

In this study, the effect of nanoclay particles and coupling agent on the physical and mechanical properties of polypropylene / waste paper composites was studied. To meet this objectives, waste paper fibers with polypropylene in 50% by weight, nanoclay (0, 2 and 4%) and coupling agent (0 and 3%) were compounded in an internal mixer at 155°C and 60rmp and the samples were prepared by injection molding. The results showed that the physical and mechanical strength of composite improved in the presence of coupling agent. As well as water absorption, thickness swelling, flexural and tensile strength and flexural and tensile modulus, were improved by increasing of nanoclay particles content, however notched impact strength was reduced. Also, study on structural behavior of composite with x-ray diffraction showed that nanoclay distributed as intercalation structure in polymer matrix, and distance between layers were increased with increasing of nanoclay particles content.

To achieve value-added utilizations of plantation timbers, eucalyptus veneer/high-density polyethylene film composites were prepared, with process-factors (PF) (hot-pressing temperature, HT; hot-pressing duration, HD; hot-pressing pressure, HP; HDPE-film content, HC) and composite-properties (CP) (water-resistant bonding-strength, BS; modulus of rupture, MOR; modulus of elasticity, MOE) investigated. According to thermal analyses, 140 to 180 °C was appropriate for HT. Based on statistical analyses, HD was easier to affect CP, while MOE was easier to be affected by PF. Quantitative relationships between PF and CP were determined by the neural-network (ANN) modeling. In ANN simulation surveys, CP displayed Gaussian distributions (R2 > 0.9) when PF changed in current ranges, with positive correlations between BS and MOR (R2 ≈ 0.5). Combining ANN and the genetic-algorithm, optimal processes (HT, 160 °C; HD, 50 s/mm; HP, 1.3 MPa; HC, 6 layers) were found, and optimal results (BS, 1.30 MPa; MOR, 86.94 MPa; MOE, 8.33 GPa) were comparable to various reported poplar-plywoods. Microscopic images demonstrated that composite interfaces were formed by the mechanical interlocking. The optimal BS attained Chinese standards for water-resistant plywoods, so proposed composites can serve as water-resistant and formaldehyde-free building materials for furniture and interior design.

The effect of different content (0–20 wt%) Acrylonitrile-styrene-acrylic (ASA) on mechanical, thermal and three-body wear behaviors of eucalyptus fiber/polyvinyl chloride (EF/PVC) composites were studied in this research. The results show that the mechanical properties of the composites such as impact strength, tensile strength, flexural strength and flexural modulus increased with increasing ASA content lower than 15 wt%. The addition of 15 wt% and 20 wt% ASA can improve thermal stability of the EF/PVC composites in the early period of the heating, and the effect weakened on later stage due to the thermal degradation of ASA, which occurred in the temperature range 416°C–442°C. The three-body wear resistance of the EF/PVC composites can be improved by ASA, and the abrasive wear mechanism of the composites was predominated by linear travel, sand particle plough and cut action, ASA and PVC plastic deformation, and fibers debonding.

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.

The long-term deformation of a geodesic spherical frame structure with a diameter of 20 m made from wood plastic composite (WPC) lumber (struts) is described using the Norton-Bailey power law model to predict the service life creep behavior (the creep strain ( ε c r )) of the WPC. The Norton-Bailey power law model parameters, A the power law multiplier, n the stress order, and m the time order, were obtained from experimental four-point bending flexural creep measurements of WPC lumber subjected to three levels of flexural stress: 7, 14, and 29% of the ultimate flexural strength for 200 days. The parameters obtained from the experiments showed good agreement to the model of the WPC lumber in flexure. The Norton-Bailey power law parameters were then implemented to describe the long-term deformation of the spherical frame structure. The limit of failure was considered when the WPC creep strain reaches the value of 1%. However, the FEA predicted the maximum creep strain to be 20% of the failure strain. This modeling approach is considered useful to describe and predict the long-term deformation of aquacultural structures made from viscoelastic materials during the envisioned service life (10 years) based on experimental creep data for the members that form the structure.

The effect of wood-derived charcoal flour on the water resistance and mechanical properties of wood plastic composite (WPC) panels was investigated. The hot press molded WPC panels were produced from polypropylene (37 wt%) with maleic anhydride-grafted polypropylene (MAPP, 3 wt%) and different mixtures of wood flour and charcoal flour. The amount of charcoal flour was gradually increased up to 60 wt%. The thickness swelling and water absorption of WPC panels considerably decreased with increasing charcoal flour content. The internal bond strength and bending properties of the WPC panels significantly improved with increasing charcoal flour content. This was mainly attributed to the high amount of pores and gaps in the charcoal flour. Melted polypropylene could get into the pores and gaps during the hot press molding, which lead to a better interfacial adhesion between polymer matrix and wood filler. The results showed that the charcoal flour could be partially substituted for the wood flour in the production of WPC panels having higher dimensional stability and internal bond strength.

This study was conducted to investigate the feasibility of using waste textile fibers and the effect of nanoclay content on the physical and mechanical properties of a composite made from wood flour and polypropylene. Therefore, wood flour and polypropylene with a weight ratio of 50 to 50 with the textile waste fibers in two levels (0 and 15%), nanoclay in three levels (0, 2 and 4%) and 3% compatibilizer were mixed in an extruder at temperature of 160°C. Afterwards, the specimens were made with injection molding thechnology. Mechanical properties including tensile and flexural strength, impact strength and physical properties such as water absorption and thickness swelling were measured. The overall results showed that addition of textile fibers significantly improves the mechanical and and weakens the physical properties of the studied composite. The results indicated that the physical and mechanical properties of wood plastic composites except impact resistance, improved with increasing nanoclay content. The results of morphological studies to study the distribution of nanoclay using a range of X-ray diffraction (XRD) showed that the distribution of particles in the polymer matrix is the type of intercalation and by increasing the amount of nanoclay particles, layer to layer distance was increased.

Abstract This study investigated the mechanical, chemical structure and thermal properties of hot press molded wood plastic composite (WPC) panels produced from different amounts (30, 40, or 50% weight) of decayed Pinus massoniana Lamb. and polypropylene with chitosan (3 wt%) and different kind of carbon (2 wt%). The results were compared with the properties of WPC produced without carbon. The mechanical, chemical structure and thermal data showed that WPC with carbon was better than WPC without carbon, and the best condition to produce decayed wood plastic composite was hot pressing temperature at 170 °C for12 min, Carbon Nanotubes (CNT) and chitosan (CS) accounting for 2% and 3% of total mass, and the proportion of decayed wood and PVC is 40% and 60%. [ABSTRACT FROM AUTHOR]

This paper presents the development of wood plastic composite manufactured from recycled polypropylene/polyethylene (r-PP/PE) blend reinforced with kenaf fibre. The r-PP/PE were sourced from rejected-unused diapers, which the plastic and absorbent gel were separated. The composite was prepared by varying the fibre loadings, at 0, 30, 40, 50, and 60 wt%. The composite was tested for flexural and impact tests followed by thermal and morphological analyses. The thermal analysis was performed by using differential scanning calorimetry technique, while the scanning electron microscopy was used for morphological analysis. It was found that the maximum flexural strength of the composite was at 30 wt% of kenaf fibre, meanwhile the maximum modulus was at 60 wt%. SEM morphology showed the failure mode from the impact fractures such as voids, fibre breakage and matrix cracking. From thermal analysis, the addition of kenaf fibre reduced the degree of crystallinity of the r-PP/PE but an improvement can be observed after the second step of heating and cooling. [ABSTRACT FROM AUTHOR]

This study was carried out to investigate the effect of weathering time on the physical and mechanical properties and color change in composite made of wood flour and high density polyethylene (HDPE). For this purpose, wood flour and polyethylene at a weight ratio of 60:40 with coupling agent were compounded in an internal mixer, and the samples were made in injection molding. Then, the weathering process by ultraviolet irradiation and water spray was done on the samples at different times of 250, 500, 1000 and 2000 hours in accelerated weathering apparatus. Finally, the physical and mechanical properties and color measurement of samples were tested, and compared with control samples. Results indicated that the flexural strength, flexural modulus, tensile strength and tensile modulus decreased with an increase in weathering time; however, the water absorption increased. Also, the yellowness of wood plastic samples decreased with an increase in weathering time and due to the lightness and color change increased.

This study investigates the feasibility of using recycled high density polyethylene (HDPE) and wood fiber from species Eucalyptus grandis (EU) to manufacture experimental composite panels. The use of maleated polyethylene as coupling agent (CA) improved the compatibility between the fiber and plastic matrix. The mechanical properties of the resultant composites were compared with polymer with and without compatibilizer. The influence of the coupling agent (CA) in the polymer matrices and composites were evaluated at different concentrations, checking the physical, mechanical and thermal properties of wood plastic composites (WPC). Results of mechanical, physical and thermal properties showed that concentration of 3% w/w CA in the polymer matrices was that which showed the best results, but in the composites properties were very similar in all formulations. Based on the findings in this work, it appears that recycled materials can be used to manufacture value-added panels without having any significant adverse influence on material properties.