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Wood-Plastic composites in the United States: The interfacing of two industries
Abstract
Wood-plastic composites (WPC) industry in the US is discussed. The WPC market was 320,000 metric tons in the year 2001, and the volume is expected to double by the year 2005. Growth of the WPC market may be accelerated by the phase out of chromated copper arsenate wood for residential uses such as decks, playgrounds and fencing. Future of WPC will depend on new product identification, product quality, consumer reaction/perceptions, and success of research and development.
... Diante dessas problemáticas, a adoção da madeira plástica em substituição à madeira natural emerge como uma estratégia significativa para enfrentar esses desafios ambientais. A madeira plástica, um material compósito formado por uma matriz polimérica e uma carga de preenchimento e/ou reforço, oferece benefícios estéticos, resistência à umidade e mofo, além de maior resistência a pragas e fungos comparativamente à madeira natural (Clemons, 2002;Cabral et al., 2016). Embora possa ser empregada em tapumes e hastes para cercas, a madeira plástica destaca-se principalmente na construção de decks (Carus et al., 2015), espaços que desempenham funções sociais, estéticas e de lazer no ambiente construído (Freda;Ferreira, 2021). ...
... Diante desse cenário, a escolha de empregar o homogeneizador termocinético para a mistura dos materiais se mostra estratégica, assegurando uma mistura eficiente e homogênea das matérias-primas, mesmo diante das disparidades de densidade, em contraposição à extrusão. No estudo conduzido por Clemons (2002), foram delineadas as propriedades mecânicas previstas para compósitos à base de polipropileno, incorporando 40% em peso de farinha de madeira, conforme os padrões ASTM para plásticos. ...
Resumo A exploração comercial de madeira natural na construção civil gera impactos ambientais significativos, especialmente pelo desmatamento. Uma alternativa sustentável é a produção de madeira plástica, um compósito formado pela incorporação de cargas de reforço em matrizes poliméricas, amplamente utilizado na construção de decks. Este estudo tem como objetivo avaliar a viabilidade do uso de polipropileno virgem e resíduos de beneficiamento de madeira na produção de madeira plástica, buscando reduzir os impactos ambientais da exploração de madeira natural. Foram produzidas amostras com diferentes proporções de carga, utilizando processos de homogeneização, extrusão e compressão a quente. A adição de até 30% de farinha de madeira ao polipropileno resultou em melhorias substanciais nas propriedades mecânicas, especialmente em flexão, com aumento da rigidez e redução da deformação. Esses resultados são promissores, considerando que a principal aplicação da madeira plástica, os decks, está sujeita a esforços de flexão. Além das vantagens mecânicas, o compósito desenvolvido apresenta uma aparência visual semelhante à da madeira natural, em termos de textura e tonalidade, facilitando sua aceitação no mercado como uma alternativa estética e ecologicamente sustentável.
... They typically are based on polyethylene (PE), polypropylene (PP), or polyvinyl chloride (PVC). Other lignocellulosic materials are sometimes used instead of wood include jute, flax, hemp, or plant residues of other agricultural crops (Youngquist et al. 1995;Schut 1999;Clemons 2002;Klyosov 2007). ...
... Wood raw material is the main component for the production of WPC products and is most often a by-product of an industrial process. (Youngquist et al. 1995;Schut 1999;Clemons 2002;Klyosov 2007). The EU Waste Framework Directive 2008/98/EC aimed for 70% of construction and demolition waste to be recycled by 2020 and a future recycling rate of 90%. ...
Currently, there is a big issue with waste, its processing and subsequent use. While there are many initiatives to replace materials that are poorly biodegradable, it is necessary to process and ideally use the waste that is already produced. In this study, the properties of composite boards made of waste materials and biodegradable polymer were investigated. The composite boards were made from wood and plastic waste using high-energy milling technology. This technology for material preparation is promising, as it includes controlling the morphology of particles, homogenizing the mixture, and drying the material during the milling process. The results showed higher flexural strength of high-density fiberboard (HDF) boards compared with tested composites with one exception. Wood/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [PHBV] composite exhibited 30% higher modulus of elasticity (MOE) than HDF due to the higher modulus of PHBV. The lowest thickness swelling (3%) and water absorption (12%) were measured for wood/recycled high density polythene (rHDPE) composite. The HDF boards recorded the lowest dimensional stability. The highest water absorption of tested composites was measured for wood/PHBV composite. The resistance to wood-rotting fungi was greatest for wood/PHBV composite containing marble powder, which corresponded to the results of scanning electron microscopy.
... There is a mixture of wood, thermoplastics, and some additives in WPCs with a wood content between 50 wt% to 80 wt% (Clemons 2002). Recently, wood fiber reinforced polyvinyl chloride (PVC) has become more popular due to its acceptable mechanical properties, long lifetime, moisture and fungus resistance, recyclability, and wood-like surface performance (Clemons 2002). ...
... There is a mixture of wood, thermoplastics, and some additives in WPCs with a wood content between 50 wt% to 80 wt% (Clemons 2002). Recently, wood fiber reinforced polyvinyl chloride (PVC) has become more popular due to its acceptable mechanical properties, long lifetime, moisture and fungus resistance, recyclability, and wood-like surface performance (Clemons 2002). PVC is suggested as a thermoplastic resin to urea-formaldehyde due to the adhesive properties (Song et al. 2017). ...
Adhesives, flame-retardant chemicals, and paints are used in engineered wood products (EWPs) to increase some of the properties of wood. Most of the engineered wood composites, including plywood, particleboard, and fiberboard, used as furniture components contain formaldehyde resins as an adhesive. The International Agency for Research on Cancer (IARC) added formaldehyde to the list of human carcinogens (Group 1) in 2004. Flame-retardant chemicals are semi-volatile organic compounds that can migrate from the products to the air. There are developmental neurotoxic effects from flame-retardant additives, among which polybrominated diphenyl ethers (PBDEs) are commonly used in EWPs. The flexibility and durability of plastics are increased using phthalates, which are a class of synthetic chemicals, by adding them to the polyvinyl chloride (PVC) that is used in the wood-plastic composites (WPC). Formaldehyde, PBDEs, and phthalates are toxicants that are commonly present in value-added furniture products. This review summarized the toxic effects of these chemicals from the aspect of human health and from the perspective of green products.
... Currently, WPC materials most often consist of 60% wood our and 40% plastic and are based on polyethylene (PE), polypropylene (PP) or polyvinyl chloride (PVC). Other lignocellulosic materials are sometimes used instead of wood -jute, ax, hemp or plant residues of other agricultural crops (Youngquist 1995, Schut 1999, Clemons 2002, Klyosov 2007. ...
... Wood raw material is therefore the main component for the production of WPC products and is most often a by-product of an industrial process. (Youngquist 1995, Schut 1999, Clemons 2002, Klyosov 2007). The EU Waste Framework Directive 2008/98/EC aimed for 70% of construction and demolition waste to be recycled by 2020 and a future recycling rate of 90%. ...
Currently, there is a big issue with waste, its processing and subsequent use. On the one hand, there are many initiatives to replace materials that are poorly biodegradable, but on the other, it is necessary to process and ideally use the waste that we have already produced. In this study, the properties of composite boards made of waste materials and biodegradable polymer were investigated. The composite boards were made from wood and plastic waste using high-energy milling technology. This technology for material preparation is promising as it includes controlling the morphology of particles, homogenising the mixture and drying the material during the milling process. Results show higher flexural strength of HDF boards compared to tested composites with one exception. Wood/PHBV composite exhibits 30% higher MOE than HDF due to its higher modulus of PHBV. The lowest thickness swelling (3%) and water absorption (12%) were measured for wood/HDPE composite. HDF boards recorded the lowest dimensional stability. The highest water absorption of tested composites was measured for wood/PHBV composite. Resistance to wood-rotting fungi was greatest for wood/PHBV composite containing marble powder, which corresponds to the results of scanning electron microscopy. The effects of both fungi (Coniophora puteana and Pleurotus ostreatus) in the decay test were similar.
... Some researchers currently use natural fiber as a reinforcing/filler in the polymer matrix [31,32,186]. At the same time, natural fibers can be added to a polymer matrix at a very high rate at process temperatures where they will not degrade [33,34]. Natural fibers are biodegradable and recyclable, and they can easily be converted into thermal energy during combustion, without leaving residues, causing lesser pollution [35]. ...
... The tendency of natural fibers to cluster during production, their low operating temperature requirement (<200°), and being affected by moisture limit the use of natural fibers as polymer reinforcement [38]. The fact that natural fibers contain moisture causes some problems during the production process [33]. It is possible to minimize these problems with some reinforcements and pretreatments, such as the use of additives (anti-aggregation agents) and drying of natural fibers before production. ...
This chapter summarizes the recent studies on natural and synthetic short fiber-filled thermoplastic-based hybrid composites. This review will provide information on the manufacturing processes and the structure, and the properties of hybrid thermoplastic composites, in separate sections. It supplies data on physical, mechanical, morphological, rheological properties, and thermal and flammability characterizations of select hybrid composites. This chapter underlines the importance of hybrid thermoplastic composite in achieving predetermined material performances. Recent studies have proven that the hybridizations of natural fiber and inorganic filler might provide exceptional and promising features.
... Aunque la madera es la fibra más usada en los WPC (Caulfield et al., 2005), otras fuentes de biomasa también son usadas con PP y PE (Clemons et al., 2013). De hecho, Clemons (2002) refiere que puede usarse tanto madera (en cualquiera de sus formas) como otras fibras vegetales en los WPC. ...
... Estos materiales compuestos pueden ser producidos por diversos métodos: extrusión, moldeo por inyección y moldeo por compresión. Cada uno de estos métodos produce compuestos con diferentes propiedades mecánicas dependiendo del tamaño de fibra y, principalmente, de la proporción utilizada (Clemons, 2002). ...
La industria forestal en el país es compleja y, generalmente, los niveles de eficiencia son bajos. En el aprovechamiento de muchas de nuestras especies maderables más valiosas se produce una gran cantidad de residuos. Esto repercute no solo a nivel económico y social, sino también ambiental. Lo mismo se repite para productos alternativos a la madera, como el bambú. Situaciones como estas nos llevan a reflexionar sobre la importancia de promover alternativas que logren un aprove�chamiento integral y sostenible de nuestros recursos.
En este contexto, la producción de materiales compuestos puede contribuir a la utilización de residuos de manufacturas y al reciclaje de otros materiales. Así, los
materiales compuestos de bambú y plástico se convierten en una opción con el
potencial de disminuir el impacto ambiental generado por la acumulación y manejo
inadecuado de residuos del bambú y restos plásticos. Además, su producción favo�recería la cadena productiva del bambú al generar un mayor valor agregado y crear
una fuente adicional de ingreso para las poblaciones locales.
Aunque los materiales compuestos se usan desde la antigüedad (Pérez, 2012) y
desde 1939 ya se emplean fibras naturales para el refuerzo de matrices plásticas (Lucintel, 2011), en el Perú esta línea de investigación no ha sido extensamente
desarrollada. Es así que, siendo la Guadua angustifolia Kunth la especie de bambú más utilizada a nivel comercial en el país (Takahashi, 2010), se propuso la ejecución de un proyecto que investigara la elaboración de materiales compuestos de dicha especie y plástico.
... Briefly, the compounding process of wood and other additives is performed to produce a homogeneous composite material by incorporating into a molten thermoplastic. The composite material is then formed into a product, and profile extrusion, injection moulding, and compression moulding are used as the common forming processes (Yadav et al., 2021;Clemons, 2002). Fillers can be used in order to enhance the physical and mechanical properties of WPC. ...
Composites of High Density Polythene, HDPE, and wood sawdust were harnessed in the formulation of wicking agents that could be employed in cleaning oil spills. The method used in compounding the composite of HDPE and various wood sawdust {Uvwero (Buchholzia coriacea), Akomu (Pycnanthus angolensis), Obeche (Triplochiton scleroxylon), Ugbarugba (Copaifera species), and Bombar (Bombax buonopozense)} was an extrusion method which was done at 200°C. The composite of High Density polythene (HDPE)/Akomu/Sand with a ratio of 4:4:1 gave the highest crude oil absorption of 82.16% while the composite of High Density Polythene/Akomu/Sand with a ratio of 5:1:3 gave the lowest oil absorption of 1.67%. The water test of the composite of High Density Polythene (HDPE)/Ugbarugba/Sand with a ratio of 2:6:1 gave the highest water absorption of 60.78% while the composite of High Density Polythene (HDPE)/Bombar/Sand with a ratio of 2:6:1 gave the lowest water absorption of 0.14%. Thus, the composite of High Density Polythene (HDPE)/Akomu/Sand with a ratio of 4:4:1 can serve as an effective medium for crude oil spill clean-up as it would absorb more crude oil than water.
... Wood-plastic composites (WPCs) represent a relatively new class of composite materials compared to conventional particleboards and have emerged as a growing and promising sector in both the wood and plastic industries [5]. WPCs typically consist of a mixture of wood components, mostly wood flour, and thermoplastic polymers, which are processed into boards under heat and pressure [6]. The dominant manufacturing technologies for WPCs are extrusion and injection molding [7]. ...
... The method of mixing affects the properties of WPCs (Migneault et al. 2009;Azeez 2017;Yadav et al. 2021). There are techniques for mixing the composite material constituents; these are by a single screw, Twin screw (co-rotating, counter-rotating), and the Woodtruder method (Santulli et al. 2017;Bouvier and Campanella 2014;Selvasankar 2017;Kim and Pal 2010). Wood plastic composite properties differ when using one of the earlier methods used in mixing and producing plastic wood, which shows us the significant impact that the mixing method has on the quality and efficiency of manufactured wood (Nunez et al. 2003;Yang et al. 2003). ...
This work introduces a new mixing technique for producing wood-plastic composites. The main constituents of the wood-plastic composites are recycled low-density polyethylene and residual dust from routing medium-density fiberboard. The new mixing technique depends on separating the fibers and the polymer during the melting stage of the polymer to avoid the degradation of the fibers due to heat. Physical tests including a water absorption test and a thickness swelling test were applied on specimens produced with the single screw extruder and a new mixing technique, with different fiber-polymer weight ratios (50–50%, 55–45%, 60–40%, 65–35%, and 70–30%). It was found that at a (70–30%) mixing ratio, a reduction in water absorption of about 70% and 67% for densities of 1100 and 1250 kg/m ³ , respectively was reached. While at a (50–50%) mixing ratio, a reduction of about 24% and 14% for densities of 1100 and 1250 kg/m ³ , respectively was accomplished. In general, the resistance to water absorption and thickness swelling was observed to be improved for the new mixing technique for all mixing ratios compared to the single-screw extruder.
... 26 Résultats de l'analyse EDX de l'échantillon…………………………………………75 ...
... The micro-mechanical analysis of TS and YM of both extruded and injection-molded wood-plastic biocomposites was reported in the literature [53,54]. In both cases either extruded [55] or injection-molded [56] composites, theoretically predicted values of TS through Kelly and Tyson's model were close to the experimentally investigated values. ...
This article provides a comprehensive review of the suitability of the various micro-mechanical models for accurately predicting the tensile properties, namely, tensile strength (TS) and Young’s modulus (YM) of the biocomposites. A brief overview of the developed conventional micro-mechanical models based on the assumption of unidirectional long fibers has been discussed initially. It further examines how these models have evolved to account for the complexities introduced by different fiber orientations and geometries and the approaches to enhance the accuracy of the different micro-mechanical models that have been proposed over the years. This article also highlights other key parameters such as fiber geometry, fiber length, fiber packing, fiber-matrix interfacial bonding, and fiber orientation which have to be accounted for reducing the discrepancies between the predicted values and experimental data. Models developed for composites reinforced with continuous long fibers and those with randomly oriented short fibers are explored. This article also evaluates the accuracy of these models and identifies key parameters influencing their predictions.
... BPC is a polymer composite from a mixture of bark powder (reinforcing material) combined with a matrix thermoplastic polymer, such as polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), and others. Such composites can additionall include fillers from wood fibers, wood, and other organic materials (Clemons 2002). The use of raw materials that can be made into composite products does not have to come from high-quality materials but can also utilize waste. ...
The effects of pressing time were evaluated relative to the physical, mechanical, and morphological properties of flat-pressed composites made from Gmelina arborea bark and recycled polypropylene (RPP). Bark powder (5% moisture content) was mixed with RPP pellets in a weight ratio of 40:60 with added maleic anhydride (MAH) as compatibilizer. The materials were mixed in a rotary blender for 15 min at speed 80 rpm until homogeneous. The mixture was heated from 175 to 200 °C until RPP pellets were completely melted and then cooled to room temperature. Afterwards, the mixture was made into powder and molded using a steel plate mold at 175 to 200 °C and pressure of 30 kg/cm2 for 2, 4, and 6 min to a targeted density of 1.0 g/cm3. The tested physical properties were covered density, moisture content, water absorption, and thickness swelling. The mechanical properties modulus of elasticity (MOE) and modulus of rupture (MOR), tensile strength parallel to length of panel were also examined. Research results showed that the properties were significantly affected by pressing time and it can be concluded that the optimum condition was obtained at 4 min of pressing.
... This problem could be improved by searching applications where solid fillers or reinforcements are intentionally added to the polymer, such as natural fillers. Thus, the use of recycled plastic to obtain Wood Plastic Composite is, therefore, ideal since natural fibres or fillers can attenuate and even improve the variations in the properties of the base polymer (Clemons, 2002;Yeh, Agarwal, & Gupta., 2009;Leu, Yang, Lo, & Yang, 2012). In the same strength ...
... To overcome the deficiencies of polymers and the call for new products makes this research on polymeric materials for human usage important, and following new environmental regulations guiding materials okay, with the strong conviction to save the ecosystem very important work (Nwanonenyi et al., 2013). Note that for rigidity and temperature resistance, the inorganic materials if used as fillers provide all, but are costly and abrasive to the processing equipment (Cletus, 2002;La Mantia et al., 2005). Organic waste fillers from farms have gained attention enormously as several industries want to use them and the plastic industry is one of them. ...
The Periwinkle shell (Tympanotonus fuscatus) is one of the most abundant wastes in the Calabar coastal region of Nigeria and needs to be put into proper use. The great need to shift attention towards waste materials with good mechanical properties to replace some materials used in the Automobile industries for Automobile products is paramount. This research focused on the Mechanical characterization of several composites developed from Periwinkle Shell Powder (PSP) as filler and four selected polymeric materials as the matrix. Recycled high-density polyethylene (rHDPE), Recycled linear low-density polyethylene (rLLDPE), Recycled polystyrene (rPP) and recycled polystyrene (rPS) from waste dumps were selected as the Matrix for the composites. The crushed periwinkle shell (CPSP) was subjected to a calcination (ashing) process. Ashed Periwinkle Shell Powder (APSP) was used to reinforce the rHDPE, rLLDPE, rPP and rPS at 0 to 40% filler loading. Mechanical tests carried out resulted in the 30%PSP and 70%PP composite having better tensile and flexural strengths, good flexural modulus, hardness, impact and moisture absorption results. Results obtained from the mechanical tests were comparable with values obtained from a tested existing vehicle bumper. The APSP-filled recycled polymer composites can serve as a suitable green alternative to existing vehicle bumpers.
... The research for polymeric materials to overcome their deficiencies, especially during usage by humans and new environmental regulations guiding materials that are not okay with the ecosystem, call for this research work (Nwanonenyi et al., 2013). Note that these in-organic materials if used as fillers provide rigidity and temperature resistance but are costly and abrasive to the processing equipment (Cletus, 2002;La Mantia et al., 2005). On the other hand, organic fillers especially from wastes gathered at farms have gained enormous attention from several industries and the plastic industry is one of them. ...
The automobile industry principally in bumper production, strive to meet the target of saving passenger lives, reducing impact and energy absorbed while improving the economy. The need to have an eco-friendly material make the characterization and utilization of the periwinkle shell (Tympanotonus fuscatus) found as waste in the coastal region paramount and to incorporate these waste materials with excellent comparable mechanical properties as fillers is most important. In this research, composites were developed using Periwinkle shell Powder (PsP) as the reinforcement and five different polymeric materials as the matrix. The selected polymeric materials are recycled low-density polyethene (rLDPE), recycled high-density polyethylene (rHDPE), recycled linear low-density polyethylene (rLLDPE), recycled polystyrene (rPP) and recycled polystyrene (rPS) obtained from waste dumps. The periwinkle shells of two separate samples, Ash periwinkle shell powder (APsP) and an Un-ash periwinkle shell powder (UAPsP) were characterized using Xray Fluorescence (XRF). Results obtained from the mechanical tests of the control sample gave a tensile strength of 6.42 MPa, hardness of 73.67Hv, flexural strength of 143.62MPa, impact energy of 0.641J, Flexural Modulus of 2177.55 MPa, density value 0.915 g/cm 3 and a moisture absorption of 0.24%. The physical and mechanical properties from this research proved the extent at which the ashed periwinkle will add value positively to the composite for the car bumper.
... WPC polymer constitutes wood waste, plastic, and chemical additives such as lubricants, coupling agents, nucleating agents, pigments, and UV stabilizers. Compared with pure plastics, the incorporation of wood fiber into the plastics led to improved flexural and tensile stiffness [10]. ...
The aggregation of carbon nanotubes (CNTs) in thermoplastic polymers in the process of mixing is challenging, leading to inappropriate distribution of CNTs in the composites, thus limiting the performance of mixed CNT–polymer matrix. Therefore, this study proposes a strategy to strengthen the performance of wood–plastic composites (WPCs) using the functional CNTs. For this purpose, the raw CNTs with 0, 1, and 2 wt% contents as a reinforcement, and Maleic Anhydride grafted Polyethylene (MAPE) with 0 and 3 wt% as a coupling agent were used. Besides, 2 wt% of functionalized CNTs were separately applied. Materials were compounded in an internal mixer (Haake), and then the samples were prepared by the injection molding machine. Mechanical properties of the composite, including tensile strength and modulus and physical properties, including water absorption and thickness swelling, were tested. We found that increasing the contents of raw CNTs from 0 to 2 wt% led to the increase in the tensile strength and modulus of sample up to 36.7% and 12%, and decrease in water absorption and thickness swelling up to 54.5% and 19.4%, respectively. The physical and mechanical properties of samples were improved by adding MAPE up to 3 wt%. The dispersion of CNTs in HDPE was increased using the functional CNT nanoparticles, with an improvement in the morphological properties of WPCs. The main finding is that the adhesion of WPCs fiber matrix was highly improved in the presence of 2 wt% of functionalized CNTs.
... The benefits of wood flour include its low cost, lightweight, and accessibility, making it an economically friendly material that can be used in composites [5][6][7][8]. The construction and automotive industries are where WPCs are most commonly used, but they are also employed in packaging, the creation of different home furnishings, office equipment, and other goods [5,6,9]. ...
Due to environmental and financial concerns, there is a growing demand for composite materials in a wide range of industries, including construction and automotive industries. In 2020, the market for wood plastic composites was estimated to be worth 12.6 billion, with a compound annual growth rate of 8.9% between 2021 and 2030. The fundamental disadvantage of reinforced composites by natural fibers is the different nature of the hydro-philic lignocellulosic and the hydrophobic thermoplastic polymers, although natural fibers would lower total costs. These composites typically fail mechanically as a result of fiber debonding, breaking, and pull-out. In a fiber-reinforced composite, the matrix's function could be described as distributing the force to the added fibers using interfa-cial shear stresses. A strong connection between the poly-meric matrix and the fibers is necessary for this procedure. Weak adhesion at the interface prevents the composite from being used to its maximum potential and leaves it open to attacks from the environment that could damage it and shorten its lifespan. Poor mechanical performance is caused by insufficient adhesion between hydrophobic polymers and hydrophilic fibers in natural fiber-reinforced polymer composites. Consequently, during the past 20 years, a variety of chemical, thermal, and physical methods have been employed to address these issues. These methods largely concentrated on the grafting of chemical groups that could enhance the interfacial contacts between the matrix and natural fibers. This review article aimed to give information on several types of fiber treatments and natural fiber-treated composites with a specific focus on their physical and mechanical properties.
... Insufficient surface treatment of the fibers causes an unbonded structure around the fiber. For this reason, surface treatment of natural fibers is critical [83]. ...
... The use of TiO2 also slightly reduced the EatB values of the WPCs before weathering. In the literature, it has been stated that an increase in the WPCs hardness values causes a decrease in the EatB values (Yam et al. 1990;Clemons 2002;Sain and Panthapulakkal 2006;Çavuş 2017). Similar to tensile strength, it has been observed that weathering has a significant effect on EatB values. ...
This study investigated the effects of Iroko wood flour (WF) and nano-titanium dioxide (TiO2) concentration on the properties of polypropylene (PP)-based composites, including accelerated weathering resistance, tribological behavior, thermal stability, physical characteristics, mechanical strength, morphological features, color changes, and surface roughness. The results showed that the presence of WF and TiO2 significantly influenced the density, hardness, thermal stability, crystallinity, coefficient of friction, and wear rate of the composites. Both fillers positively impacted the tensile strength, flexural strength, and flexural modulus of the composites, although the elongation at break values decreased. TiO2 addition enhanced thermal stability and protection against UV radiation, whereas using wood flour negatively affected color properties. Moreover, the surface roughness of the composites was affected by weathering time and wood flour content. These findings highlight the potential of WF and TiO2 as effective fillers for enhancing PP-based composites’ properties and weathering resistance.
... Wood fiber/plastic composites (WPCs) can be a cost-effective alternative to many plastic composites or metals in terms of bending, stiffness or weight (Raj 1992;Raj et al. 1989). WPCs are becoming increasingly acceptable to consumers as a replacement for natural wood due to advantages such as durability, permanent color, and reduced maintenance, in spite of their high price (Clemons 2002). ...
Date Palm Fiber (DPF) is one of the most available natural fibers in the Middle East, especially in Iran and the Persian Gulf region. This research provides a new insight into DPF, with consideration of morphological, chemical characteristics, and bulk density, as well as morphological and mechanical properties of DPF/HDPE wood plastic composite. There are three parts of date palm that are used for producing fiber, the trunk, rachis, and petiole. Results indicated that there is significant difference between trunk and petiole on fiber length but rachis has no significant differences relative to the other parts. The aspect ratios have significant differences among of three parts, with the highest and lowest values measured for the petiole and trunk, respectively. The chemical composition of various parts of the date palm tree differed significantly; with the highest amounts of cellulose and lignin content belong to rachis. Bulk density was measured for three parts of date palm, and the lowest amount was 0.082 g/cm3. The highest strengths were achieved in composites with 30 and 40% fiber content, depended on which original parts of the tree were used.
... The wood-plastic composites (WPCs) market size is USD 5.6 billion globally in 2021 with about a 10% compounded growth [1]. WPCs have relied on a steady stream of sawmill and secondary manufacturing residues for wood fiber [2]. In geographical locations where wood residues are not available, alternative natural fibers can be used in WPC applications [3]. ...
The aim of this study was to evaluate the use of waste natural fibers from milled hop bines and hemp stalks, without chemical treatment, and compare them to a commercial wood fiber for use in wood–plastic composite (WPC) materials. The fibers were characterized (density, fiber size and chemical composition). WPCs were produced by the extrusion of a blend of fibers (50%), high-density polyethylene (HDPE) and coupling agent (2%). The WPCs were characterized for their mechanical, rheological, thermal, viscoelastic and water resistance properties. Pine fiber was about half the size of hemp and hop fibers and thus had a higher surface area. The pine WPC melts had a higher viscosity than the other two WPCs. Additionally, the tensile and flexural strengths of the pine WPC were higher than those of hop and hemp WPCs. The pine WPC was also shown to have the least water absorption followed by hop and hemp WPCs. This study highlights that different lignocellulosic fibers influence their WPC properties. The properties of the hop- and hemp-based WPCs were comparable to commercial WPCs and can be improved by further milling/screening the fibers to a smaller particle size (volumetric mean of ~88 μm) to increase their surface area, fiber–matrix interactions and improve stress-transfer.
... This problem could be improved by searching applications where solid fillers or reinforcements are intentionally added to the polymer, such as natural fillers. Thus, the use of recycled plastic to obtain Wood Plastic Composite is, therefore, ideal since natural fibres or fillers can attenuate and even improve the variations in the properties of the base polymer (Clemons, 2002;Yeh, Agarwal, & Gupta., 2009;Leu, Yang, Lo, & Yang, 2012). In the same strength ...
Due to its geographic extent, Algeria is characterized by its great climatic variability ranging from the Mediterranean climate in the north to the Saharan climate in the south, making its flora and fauna rich and diverse. This biodiversity is at the origin of typical dietary practices for each region. In the northern part of the country, we will find mainly olive oil, figs, bovine, goat and sheep milk against dates such as “Deglet Nour” as well as camel breeding in the southern regions with a production of milk and meat, essential for the food security of local populations. Other traditional food products made from cereals and also cheeses and fats are typical of each region and are found throughout Algeria. Algerian local products have long assured food security for local populations, hence the need to enhance and develop them in order to ensure sustainability in their use for a growing population.
... PE-based WPCs are typically used in exterior building components such as decking, fencing, and siding, while those with PP are used more in automotive applications. Wood/PVC composites are primarily used in window frame manufacturing and in decking applications [11]. WPCs building products typically have a 15-years warranty and are competitive in cost with treated wood. ...
Wood-plastic composites (WPCs) have shown exceptional promise as a building material, especially for outdoor uses. Using renewable wood fiber as the reinforcing filler in WPCs increases the material’s environmental sustainability. While virgin commodity thermoplastics are primarily used in these composites, using post-consumer plastic further contributes to their sustainability. While they are beginning to be used in the Gulf countries, information on their performance, especially durability under harsh desert climates, is sparse. The present investigation on WPCs is based on the two most popularly used thermoplastics in WPCs, virgin high-density polyethylene (HDPE) and polypropylene (PP), with the wood content varying between 0 and 36 wt. %. These were prepared with melt processing from a masterbatch and characterized primarily using thermal methods and tensile properties of their injection molded test pieces. Variations in tensile properties, especially the tensile modulus (MPa), the tensile strength (MPa), and the ultimate extensibility (%) of the composite samples were investigated to determine an optimal wood-fiber loading. For either polymer type, exceeding 27 weight percent of wood fiber resulted in unacceptably low ultimate extensibility of the material.
... The tensile and flexural moduli of the composites are affected by the moduli of its components. Using natural fibers in the matrix increases these moduli (Clemons 2002;Febrianto et al. 2006;Razavi-Nouri et al. 2006). Because cellulosic materials have relatively large tensile moduli, they improve the tensile modulus of the composites into which they are incorporated (Oksman and Clemons 1998). ...
The effects of nanoclay content were investigated vs. the mechanical, thermal, and morphological characteristics of a nanocomposite made from poplar wood flour and polypropylene. The wood flour, polypropylene, nanoclay, and the maleic anhydride grafted polypropylene (MAPP) were mixed in an extruder, and the test specimens were made via injection casting. Then, the mechanical and thermal properties were examined. The results showed that the tensile strength, flexural strength, and flexural modulus were improved when the wood flour content increased from 40% to 50%. Additionally, increasing the wood flour content from 40% to 60% enhanced the tensile modulus. The addition of nanoclay at dosages up to 2 wt% enhanced the tensile strength and the tensile modulus, whereas these properties were degraded with the addition of nanoclay at up to 4 wt%. The tensile strength and flexural modulus improved when the nanoclay content increased up to 4 wt%. The crystallinity enthalpy decreased when the wood flour content increased.
... MAPP, one of the most efficient compatibilizing agents in the wood plastic composites industry, was utilized in the manufacturing of composites to enhance the interfacial adhesion between wood flour and polymer matrix. [31][32][33] The WA of composites is limited by the strong interfacial adhesion between fiber and polymer matrix brought on by compatibilizing agents (MAPP chemically binds with OH groups in the cell wall). Compatibilizing agents improve the adhesion quality between plastics and wood flour to reduce voids in the interface region and block hydrophilic groups. ...
In this study, wood plastic nanocomposites (WPNC) reinforced with nano magnesium oxide (MgO) were produced in a flat press using the dry blending method. It is aimed to investigate the technological properties of the produced WPNC panels. To achieve this aim, scots pine wood flour, waste polypropylene (PP), maleic anhydride grafted PP (MAPP) and nano MgO were mixed and combined in eight different formulations by dry blending method. The densities, water absorption and thickness swelling, tensile strength, bending strength, modulus of elasticity (MOE), surface roughness and Shore D hardness properties of the obtained WPNC panels were determined. On the other hand, scanning electron microscope (SEM) micrographs were obtained to determine the morphological properties of WPNCs. Nano MgO and MAPP reinforcement positively affected the technological properties of flat-pressed WPNC panels. It was determined that increasing nano MgO ratio and MAPP reinforcement increased the water resistance of WPNC panels. It has been determined that the use of MAPP and nano MgO significantly improves the mechanical properties of WPNC panels. When the SEM micrographs of WPNC panels were examined, it was observed that large voids were formed especially in WPNC panels that without MAPP and nano MgO, and these voids were largely eliminated with the increase of MAPP reinforcement and nano MgO ratio. Following the technological results obtained within the scope of this study, it is recommended to conduct new studies to investigate the biological resistance of nano MgO reinforced WPNCs due to the known antibacterial, catalytic and photocatalytic properties of nano MgO.
... Wood plastics composites are materials made from a combination of wood flour, thermoplastic resin and chemical additives (Clemons, 2002). WPCs belong to one of the most dynamic sector in the plastic industries (Rothlin, 2007). ...
This study evaluates the effects of densities and mixing ratio on the physical and mechanical properties of wood plastic composites boards at mixing ratio of 1:1 to 1:1.4 and nominal densities of 700kg/mm3 and 800kg/mm3. The quantity of High Density Polyethylene (HDPE) and saw dust used in the production of Wood Plastic Composites (WPCs) was weighed to a nominal density of 700kg/mm3 and 800kg/mm3. The materials were thoroughly mixed and fed into a neatly primed oil mould with a dimension of 300 x 300 x 10 mm. Test samples used for physical and mechanical properties determination were collected from each board produced from the mould. The results showed that WPCs board produced from mixing ratio 1:1 had the highest Modulus of Rupture (MOR) and Modulus of Elasticity (MOE) values of 6.52 mm N-2 and 564.95 mm N-2 respectively. Water absorption, thickness swelling and linear expansion of WPCs produced from wood/plastic ratio of 1:1.4 had the lowest mean values of 6.67, 0.83, 0.68% and 21.61, 1.33, 5.35% respectively after 2 hours and 24 hours of water immersion test. Analysis of variance carried out at 0.05% probability level showed that the effect of density and mixing ratio were significant on the physical and mechanical properties of wood plastic composites boards.
... PVC polimerinin, poliolefin (polietilen ve polipropilen gibi) polimerlerine kıyasla daha ucuz olması, farklı direnç isteklerine cevap verecek türlere sahip olması ve çeşitli katkı maddeleriyle özelliklerinin geliştirilebilir olması gibi birtakım avantajlarından dolayı çoğu plastik ve polimer kompozit üreticileri PVC'yi diğer polimerlere tercih etmektedirler. Son zamanlarda, odun lifi takviyeli PVC kompozitler, makul mekanik özellikleri yanı sıra düşük rutubet, biyolojik direnç, uzun ömür, ahşap benzeri yüzey performansı ve geri dönüştürülebilirlik nedenleriyle oldukça ilgi çekicidirler (Clemons, 2002;Clemons ve Ibach, 2004). ...
Bu çalışma, modifiye edilmiş odun ununun termoplastik kompozitler üzerindeki etkisini belirlemek amacıyla yapılmıştır. Bu amaçla, farklı konsantrasyonlarda (%0-3-6-12) alkali (sodyum hidroksit (NaOH)) ile muamele edilmiş odun unu, polivinil klorür (PVC) polimerine ilave edilerek odun-PVC kompozitleri üretilmiştir. Alkali muamelesinin odun-PVC kompozitlerin mekanik özelliklerine etkisini tespit etmek için çekme direnci, çekmede elastikiyet modülü, eğilme direnci, eğilmede elastikiyet modülü ve sertlik değerleri belirlenmiştir. Alkali ile muamele edilmiş odun unu içeren kompozit numunelerin çekme direnci, eğilme direnci ve elastikiyet modülü değerleri muamele edilmemiş odun unu içerenlerinkine kıyasla daha yüksek tespit edilmiştir. En yüksek çekme ve eğilme direnci değerleri %6 NaOH muameleli odun unu içeren kompozit numunesinde tespit edilmiştir. Ayrıca, kompozitlerin sertlik değerlerinin, alkali muamelesinden çok fazla etkilenmediği görülmüştür. Bunlara ek olarak, termogravimetrik analiz (TGA) sonuçları, alkali muamelesinin kompozit malzemelerin termal kararlılığında artışa sebep olduğunu göstermiştir..
... WPC'ler, hem ahşap hem de plastiğin uygun performans ve maliyet özelliklerini birleştiren gelişmekte olan bir malzeme sınıfını temsil eder. Bu nitelikler nedeniyle, orman ürünleri şirketleri, WPC'leri atık odun ve düşük ticari değeri olan ahşabın katma değerli kullanımını artırmanın bir yolu olarak görmektedir (Clemons, 2002;Stark ve ark., 2010). Ana bileşenlerin kimyasal ve fiziksel özellikleri çok farklı olduğundan dolayı, bu tip kompozitler genellikle polimerik matris ve lifler arasındaki uyumluluğu artırmak için katkı maddeleri içerir (Martins ve ark., 2017). ...
Günümüzde çeşitli odunsu ve plastik bazlı materyaller ile farklı üretim metotları ve karışım oranları kullanılarak odun plastik kompozitleri üretilmektedir. Üretimin çeşitlendirilmesi, farklı oranlarda renk ve parlaklık özelliklerine ait ürünlerin oluşmasına imkan sağlamaktadır. Bu araştırmada, yüksek yoğunluklu polietilen (YYPE) ve ceviz meyvesi kabuk (CMK) unundan hazırlanarak farklı oranlarda üretilen (1 no’lu grup = %100 YYPE + %0 CMK, 2 no’lu grup = %80 YYPE + %20 CMK, 3 no’lu grup = %70 YYPE + %30 CMK ve 4 no’lu grup = %60 YYPE + %40 CMK) odun plastik kompozitlerinde renk, parlaklık ve beyazlık indeksi özellikleri araştırılmıştır. Elde edilen laboratuvar sonuçlara göre, varyans analizi sonuçları için parlaklık, renk ve beyazlık indeksi testlerinde karışım oranı faktörlerinin anlamlı sonuçlar verdiği belirlenmiştir. Ceviz kabuğu unu oranının %20’dan %40’a doğru artması ve plastik oranının %80’den %60’a azalması ile üretilen odun plastik kompozitlerin sahip oldukları yüzey alana göre paralel (║) ve dik (⊥) yönlerde olacak şekilde yapılan ölçümler sonrasında beyazlık indekslerinin azaldığı, buna ek olarak, ho açısı değerlerinin arttığı, L*, a*, b* ve C* değerlerinin azaldığı belirlenmiştir. Çalışmada kullanılan ceviz meyvesi kabuğu ununun farklı karışım oranlarında kullanılması ile üretilen odun plastik kompozitlerinde farklı beyazlık indeksi, parlaklık ve renk sonuçlarının oluşmasına imkân sağladığı görülmüştür.
... Examples of these are PE and PVC. Thermoplastics are used in many different commercial products such as milk cartons, grocery bags and siding (Clemons, 2002). ...
In this study, some mechanical properties of wood-plastic composite material produced from bamboo (Bambusoideae) were investigated. Wood-plastic composite materials were produced by mixing Low Density Polyethylene (LDPE) material and bamboo fibers at the rates of 5% and 10%. The produced wood composite samples were subjected to tensile strength and bending strength tests and the results were examined. The results showed that the tensile strength decreased by 6% as the bamboo ratio increased from 5% to 10%. In addition, increasing the bamboo ratio from 5% to 10% increased the average bending strength of each test group by 44.75%. Öz Bu çalışmada, bambu liflerinden üretilen ahşap-plastik kom-pozit malzemenin bazı mekanik özellikleri araştırılmıştır. LDPE malzeme ile bambu liflerinin %5 ve %10 oranlarında karıştırılmasıyla ahşap plastik kompozit malzemeler üretilmiştir. Üretilen ahşap-kompozit örnekler çekme mu-kavemeti ve eğilme mukavemeti testlerine tabi tutulmuş ve sonuçları incelenmiştir. Sonuçlar, bambu oranı %5'ten %10'a yükseldikçe çekme mukavemeti % 6 oranında azaldığı göstermiştir. Ayrıca, bambu oranının %5'ten %10'a yük-seltilmesi, her bir test grubunun ortalama eğilme mukavem-etini % 44,75 oranında artırmıştır. Anahtar Kelimeler: Bambu, Lif, LDPE, Ahşap-plastik kompozit. Creative Commons Atıf-Türetilemez 4.0 Uluslararası Lisansı ile lisanslanmıştır.
... Odun plastik kompozitler (OPK) terimi, un veya lif formundaki lignoselülozik dolgu malzemeleri (LDM), termoset ya da termoplastikleri içeren kompozitlerin ifade etmektedir (Clemons, 2002). Bir diğer bir deyişle, OPK; LDM, plastik malzeme ve katkı maddelerinin birbiriyle uygun şartlarda karıştırılarak üretilen kompozitlerin genel bir isimlendirilmesidir (Matuana ve Heiden, 2004). ...
Abstract: 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.
... WPCs are currently being tremendously used in exterior building applications for residential construction, the introduction of WPCs for decking and ooring is mainly responsible for the growth. WPCs exhibited greater durability, less maintenance, absorb less moisture and have better fungal resistance when compared to timber (Clemons, 2002). Recent ndings show that WPC products are currently developed for railings, fencing, roo ng and siding (Gardner et al., 2015). ...
Polyethylene composites reinforced with wood dust from Ceiba pentandra were produced at one proportional variable of wood to polymer ratio. The polymers employed for the study were derived from recycled polyethylene embalmed dihydrogene monoxide bags. Derived homogenous particlesize of 1.00 mm of w ood and polyethylene particles were used for production at ascending varying percentage of 40, 50, and 60 for wood and at descending varying percentages of 60, 50, and 40 for polyethylene. The effects of Coptotermes curvignathus attack on weight and mechanical properties of wood polyethylene composites were investigated while the extent of damages was examined. The properties which include weight, density, flexural modulus, flexural strength, compressive strength were determined before and after field exposure. The percentage weight changes were also determined after 12 weeks of graveyard field exposure. The mechanical values obtained before and after termite attacks ranged from 781.03 Kg/cm ³ to 810.60 Kg/cm ³ for density, 1087.76 Nmm − 2 to 4320.02 Nmm − 2 for flexural modulus, 43.68 Nmm − 2 to 59.14 Nmm − 2 for flexural strength and 18.43 Nmm − 2 to 32.55 Nmm − 2 for compressive strength. The density of the wood polyethylene composites was found to be at peak values when the wood content was at 40% while polyethylene content was at 60%. The wood polyethylene composites made at equal percentage of 50/50 was found to be at lowest values for all properties accessed both before and after termite exposures. The proportional percentage of wood/ polyethylene significantly affects the outcome of weight, density, flexural modulus and compressive strength of the composites after exposure to graveyard under tropical climate. This study revealed that the WPC products can be classified as very durable and durable while WPC at proportional ratio of 40/60 can be adopted for house application in Nigeria.
... When the first (terrace) decking made of WPCs appeared on the market in the 1990s, it was considered a low-maintenance product with a long service life [6]. The polymer matrix was initially thought to fully encapsulate the wood particles. ...
Knowledge about the resistance of wood–polymer composites (WPCs) to biological attack is of high importance for purpose-oriented use in outdoor applications. To gain this knowledge, uniform test methods are essential. EN 15534-1 (2018) provides a general framework, including the recommendation of applying a pre-weathering procedure before the biological laboratory tests. However, the procedure’s manner is not specified, and its necessity assumes that a durability test without such pre-weathering will not produce the structural changes that occur during outdoor use. To verify this assumption, this study examined the influence of natural, ground-level pre-weathering on the material properties of different WPC variants, which were tested at intervals of six months in four durability tests under laboratory conditions in accordance with EN 15534-1 (2018). Weathering factors were calculated from determined characteristic values such as mass loss, and loss in moduli of elasticity (MOE) and rupture (MOR). The weathering factors based on mechanical properties tended to decrease with increasing weathering duration. The expected negative influence of pre-weathering on these material properties was thus not confirmed. The weathering factors based on mass loss were subject to high variation. No significant effect of pre-weathering on mass loss due to fungal attack became evident. Overall, the necessity of a pre-weathering step in biological durability tests shall be questioned based on the presented results.
... Wood flour is made by grinding post-industrial material, such as planer shavings, chips, and sawdust, into a fine, flour-like consistency (Stark 1997). Wood fibre is available from both virgin and recycled sources, including pallets, demolition lumbers, and old newsprint (Hwang 1997;Lu et al. 2000;Clemons 2002). Wood from small-diameter trees and underutilized species can also be used. ...
Outbreaks of mountain pine beetle are evaluated as a generic disturbance agent, and comparisons are made with other forest disturbances such as wildfire, windthrow, and logging. A useful basis for comparison is the degree of disruption to the overstorey, understorey, and forest floor layers. Clear differences are observed in the impacts of bark beetles, fire, and windthrow, but there is overlap with various harvesting systems. Insects are selective in terms of the species or size of tree that is killed; this selectivity varies with stand composition, stand structure, and outbreak stage. The mountain pine beetle functions as part of larger natural disturbance regimes in western North America, which vary with climate and forest type. Outbreaks of many different insects occur throughout western Canada, with the relative role of fire and insects differing among ecoregions and over time. Beetle-killed stands may facilitate extreme fire behaviour and may be more susceptible to future burning. Large expanses of dead or removed trees also result in altered soil water balance and stream flows, disposing some sites to mass movement or flooding. All disturbances generate heterogeneity, with much of the value to biodiversity and ecosystem recovery depending on residual structure and biological legacies. The capacity for unassisted recovery and the value of each stand to timber supply, carbon balance, and habitat needs in a landscape context are relevant when considering salvage logging or forest rehabilitation. The future role of forest pests is expected to fluctuate in response to changes in climate and the altered composition and structure of western forests.
... Examples of these are PE and PVC. Thermoplastics are used in many different commercial products such as milk cartons, grocery bags and siding (Clemons, 2002). ...
Bu çalışmada, bambu liflerinden üretilen ahşap-plastik kompozit malzemenin bazı mekanik özellikleri araştırılmıştır. LDPE malzeme ile bambu liflerinin %5 ve %10 oranlarında karıştırılmasıyla ahşap plastik kompozit malzemeler üretilmiştir. Üretilen ahşap-kompozit örnekler çekme mukavemeti ve eğilme mukavemeti testlerine tabi tutulmuş ve sonuçları incelenmiştir. Sonuçlar, bambu oranı %5’ten %10’a yükseldikçe çekme mukavemeti % 6 oranında azaldığı göstermiştir. Ayrıca, bambu oranının %5’ten %10’a yükseltilmesi, her bir test grubunun ortalama eğilme mukavemetini % 44,75 oranında artırmıştır.
... Como base fundamental de los procesos de diseño esta la necesidad de predecir el comportamiento de materiales bajo ciertas condiciones; a lo largo de la historia, investigaciones, científicos y descubrimientos accidentales han definido y documentado todo tipo de comportamientos y propiedades presentes en los materiales; propiedades mecánicas, químicas, ópticas, eléctricas, térmicas, magnéticas entre muchas más han servido como herramienta para el desarrollo de productos y de nuevas tecnologías. Los materiales WPC existen desde los años 70, pero desde entonces, ha sido poco su desarrollo, debido a la poca relevancia que le dieron los países productores de materia prima y el área de la construcción a la utilización de productos ecológicos (3,14) . ...
El uso de fibras naturales como material de refuerzo en materiales compuestos se ha convertido en tendencia mundial, sin embargo, es muy limitado el uso, y aun menor la producción de estos materiales a escala local. En el presente trabajo se realiza un análisis experimental para determinar el comportamiento de las propiedades mecánicas de la mezcla de polietileno de baja densidad con materia vegetal, en específico la resistencia máxima real a tensión, compresión y flexión, además se evalúa la influencia de la variación de los elementos constituyentes del compuesto y la procedencia de la madera vegetal.
... Como base fundamental de los procesos de diseño esta la necesidad de predecir el comportamiento de materiales bajo ciertas condiciones; a lo largo de la historia, investigaciones, científicos y descubrimientos accidentales han definido y documentado todo tipo de comportamientos y propiedades presentes en los materiales; propiedades mecánicas, químicas, ópticas, eléctricas, térmicas, magnéticas entre muchas más han servido como herramienta para el desarrollo de productos y de nuevas tecnologías. Los materiales WPC existen desde los años 70, pero desde entonces, ha sido poco su desarrollo, debido a la poca relevancia que le dieron los países productores de materia prima y el área de la construcción a la utilización de productos ecológicos (3,14) . ...
El uso de fibras naturales como material de refuerzo en materiales compuestos se ha convertido en tendencia mundial, sin embargo, es muy limitado el uso, y aun menor la producción de estos materiales a escala local. En el presente trabajo se realiza un análisis experimental para determinar el comportamiento de las propiedades mecánicas de la mezcla de polietileno de baja densidad con materia vegetal, en específico la resistencia máxima real a tensión, compresión y flexión, además se evalúa la influencia de la variación de los elementos constituyentes del compuesto y la procedencia de la madera vegetal
Polymeric materials, both thermoplastics and thermosets, have wide ranging applications in the building construction industry. Modern building construction, for both residential and commercial purposes, is subject to diverse constraints and objectives. Besides the basic concerns of durability, comfort, and cost-effectiveness, building designs also need to take account energy efficiency and ecological and environmental concerns.
In this chapter, some of the major applications in the building and construction industry such as sidings, insulation, piping, roofing, glazing, decking, and fencing are presented. Novel ideas to mitigate plastics waste issues have been identified while research efforts toward passive cooling have been documented.
Wood–plastic composites (WPCs) are some of the most common modern composite materials for interior and exterior design that combine natural waste wood properties and the molding possibility of a thermoplastic polymer binder. The addition of reinforcing elements, binding agents, pigments, and coatings, as well as changes to the microstructure and composition, can all affect the quality of WPCs for particular purposes. To improve the properties, hybrid composite panels of WPCs with 30 wt. % and 40 wt. % of wood content and reinforced with one or three metal grid layers were prepared sequentially by extrusion and hot pressure molding. The results show an average 20% higher moisture absorption for composites with higher wood content. A high impact test (HIT) revealed that the absorbed energy of deformation increased with the number of metal grid layers, regardless of the wood content, around two times for all samples before water immersion and around ten times after water absorption. Also, absorbed energy increases with raised wood content, which is most pronounced in three-metal-grid samples, from 21 J to 26 J (before swelling) and from 15 J to 24 J (after swelling). Flexural tests follow the trends observed by HIT, indicating around 65% higher strength for samples with three metal grid layers vs. samples without a metal grid before water immersion and around 80% higher strength for samples with three metal grid layers vs. samples without a grid after water absorption. The synthesis route, double reinforcing (wood and metal), applied methods of characterization, and optimization according to the obtained results provide a WPC with improved mechanical properties ready for an outdoor purpose.
During the examination and analysis of the physical and mechanical properties of wood polymer composites (WPC), researchers have consistently observed alterations in the strength and durability of the material. These changes have been found to correlate with variations in the wood content of the composite as well as its sensitivity to different climatic conditions. This dynamic relationship between composition, environmental factors, and material performance is a critical aspect of scientific research in this field. Moreover, the manufacturing processes and technologies employed in the production of WPC materials are intricately linked to these factors. Researchers carefully tailor production methods and select appropriate fillers based on the specific characteristics mentioned above. The inclusion of wood fillers in the composite composition is an important area of investigation, as it significantly impacts the resulting material properties. This systematic exploration of how different wood fillers influence the properties of the composite material is an integral part of the scientific research conducted in this domain. By comprehensively understanding these relationships, researchers can optimize the composition and production methods of WPC materials to enhance their strength, durability, and overall performance in varying climatic conditions.
This chapter presents an extensive review of the scientific literature associated with various microwave treatments on wood waste products. First, the basic concepts of microwave radiation and its applications in wood waste product fabrication are reviewed. Then, an extensive literature review of the most significant experimental research papers is provided, divided into two microwave heating treatment uses: wood drying and wood waste products performance improvement. Next, the post-treatment of wood-plastic composites (WPCs) by microwave irradiation as a case study was reviewed and a real example of WPCs samples was discussed. Finally, the chapter concludes with a proposal of doing future research studies concerning the impact of microwave technology on some important properties of wood waste products, i.e., resistance to biological agents, fire, environmental conditions, and so on.
Abstract
Researchers have done a lot of work in the recent past on lignocellulosic biomass-reinforced composites. Nowadays, these reinforcements have gained importance and are offering new opportunities in various automobile and industrial applications. A review of literature related to alkali-treated lignocellulosic fibers is reported in this work, which helps in understanding the important role of alkali treatment in improving the interfacial bonding between the filler and the matrix, which definitely enhances the properties of the composites. The lignocellulose-based biomass needs to be chemically modified in order to get the surface roughness that improves the mechanical and chemical interlocking between the reinforcement and the matrix. The potential of such chemically treated biomass has been reviewed as reinforcement for the polymer composites. It is necessary to understand the nature and quantity of work, which has been conducted recently to characterize such lignocellulosic fillers in polymer composites, for gaining in-depth knowledge. There is ample scope for the underutilized but abundantly available biomass to be used as reinforcement for certain application in industrial as well as household composites.
Composites such as Wood Polymer Composites (WPCs) comprised of polymer matrix and natural fiber is expected to increase in market growth due to its sustainable and environment-friendly nature. Polymers are widely utilized in the different types of fields and contributing the plastic waste in the atmosphere. The knowledge of this product regarding its long-term efficiency is still vague. Properties of recycled polymers, virgin polymers, and effects of weathering are aspects to be considered of WPCs in civil engineering study. Various weight percentage of fillers such as rice husk (RH) as well as recycled /waste polypropylene polymer (WPP) were incorporated together to influence its mechanical characteristics. The condition monitoring of the fabricated composites materials is treated through Ultra-Violet irradiation exposure to reveal its photodegradation. WPC specimens with several compositions of WPC pellets obtained from the industry were each mixed with 10%, 20% and 30% of homopolymer polypropylene (HPP) and later exposed to 1000, 2000, 3000, 4000, 5000 and 6000 h of UV irradiation under accelerated weathering. In this case of studies, WPP, RH and HPP are denoted by the letter A, B and C respectively. The specimens were then subjected tensile test, flexural test, FTIR analysis and morphological study of the fractured surface using Optical Microscope. The study revealed the WPC made from HPP recorded the highest tensile and flexural strength. On the other hand, the modulus of elasticity continued to increase alongside the decrease of HPP constituent. The Carbonyl Index (CI) value were calculated after FTIR to study the rate of photodegradation the specimens went through after UV irradiation exposure which give overall perspective for the civil engineering application. All the mechanical properties as well as decreased in values after they were being subjected to accelerate weathering which is important for building services interest. This is also in agreement with the CI value obtained after specimens were subjected to UV irradiation exposure. From the morphological study of fractured surface, it was observed that all WPC specimens experienced clean surface crack before UV irradiation. Formation of voids occurred after UV irradiation. Increased hours of UV irradiation and RH content caused larger voids formed which outcome in the reduce of mechanical characteristics of the specimens. However, for specimens made from WPC pellets, it was noticed that the tensile strength alongside the flexural strength fluctuates as the percentage of RH content raised. The total opposite however was observed for modulus of elasticity and flexural modulus. As RH content increased, these two properties also increased. The addition of HPP definitely helped to improves the mechanical properties and reduced the rate of photodegradation after the specimens were subjected to accelerated weathering. This is due to the RH fillers became less exposed to UV irradiation and humidity. Mixing HPP with WPP pellets helped in controlling the matrix pull outs. HPP also helped increase the interface bonding of RH and polymer matrix in the WPC pellet. In conclusion, adding optimum percentage of RH as fillers and HPP as additional reinforcements to WPP can improved the mechanical properties of WPC as well as reducing the rate of photodegradation when subjected to UV irradiation exposure.KeywordsWood polymer compositesWaste polypropyleneWeatheringUltra-violet irradiationPhotodegradation
Wood plastic composites (WPC) has been a rapidly growing industry and a new class of materials in the composite industry. Wood plastic composites are usually made in the extrusion process by mixing wood flour, thermoplastic and small amounts of process additives. The bond between wood and plastic is typically weak; there is a problem in tension transferring between timber and plastic phases due to water-absorbing properties of wood and water-repellent properties of plastics. As a solution to this problem, compatibilzer additives improve the stress transfer between plastic and wood and bridgeable between the surfaces are used. In this study, WPC was produced by using high density polyethylene (HDPE) and polypropylene (PP) which have the most usage area in the world. In the thesis study, coniferous (Pinus nigra) and (Fagus orientalis L., Populus nigra) tree species were used. In the WPC production, prosess maleic anhydride treated polyethylene (MAPE) and polypropylene (MAPP) were used to bonding between hydrophobic plastic and hydrophilic wood flour and EBS and AKROPAN 4590 PX were used to facilitate production. On the prepared experiment samples; Physicall test (density, thickness swelling, water absorption rate), mechanical tests (static bending resistance, modulus of elasticity, tensile strength), were performed accordance to the standards. All the results were evaluated by statistical analysis. Thus, the effects of compatibilzer additives on the physical, mechanical, technological characteristics of WPC samples are revealed at a certain level of confidence. When the obtained data were evaluated, it was observed that the use of % 3 additive material gave positive results on all WPC properties. It has been observed that the use of additive material in WPC production positively affects the physical and mechanical effects of the material.
Systematic Sustainable Design in Architecture and the Need to Mimic Nature
There are many industrial fields in mechanical engineering, namely, energy, power, space, automotive and transportation, etc., which need to be fed by materials equipped with superior properties such as high strength, high resistance to corrosion and oxidation and good thermal and electric conductivity. Moreover, rivalry metal industry demands high functionality in terms of surface integrity and dimensional accuracy for the components. Despite having many initiatives been launched for providing top quality parts from these heavy metals, their intriguing structures also bring challenging issues in machining. In order to meet the requirements, different cooling/lubricating strategies have been carried out from a great deal of researchers to date. The performances of dry, flood cooling, minimum quantity lubrication (MQL), high-pressure cooling and cryogenic cooling have been discussed under comparable perspectives for several materials before. Among them, a special and improved type of MQL, hybrid nanofluids attracted most attention recently, which is originated by combining the base fluids and nanomaterials in principle. This chapter focuses on the state of the art on hybrid nanofluids, including their preparation process, thermophysical behaviors and applications on machining operations. Accordingly, MoS2, hBN, Al2O3, SiO2, CNTs, TiO2, SiC, TiC, AlN, SiN, CuO, GnP and graphite seem to be the mostly preferred additives for improving the machining quality.
No contexto das comemorações dos 60 anos da Escola de Engenharia de
São Carlos (EESC), da Universidade de São Paulo (USP), estamos entregando aos
interessados no tema “Painéis Lignocelulósicos” esta publicação que reúne
diferentes subsídios ao assunto, desenvolvidos com apoio de Agências de Fomento
como a Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); o
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) e a
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).
Compósitos de partículas lignocelulósicas se constituem em alternativas
muito convenientes para a substituição de materiais e produtos tradicionalmente
empregados em diversos segmentos industriais: do mobiliário, das embalagens e
até dos componentes das edificações.
Nos últimos anos, observa-se o envolvimento de um número mais
expressivo de pesquisadores na busca de subsídios que venham a contribuir para
a melhor compreensão das possibilidades de produção dos painéis de partículas.
Insumos até então desconsiderados para tal finalidade (como os resíduos de
diferentes origens) passaram a integrar o rol das potenciais matérias primas para
a oportuna substituição das partículas oriundas de árvores inteiras, solução em
desuso nos países com tecnologia mais avançada.
A utilização dos citados insumos, além da influência positiva na redução do
consumo energético, também contribui para diminuir impactos ambientais e disseminar
a prática dos conceitos de sustentabilidade. Estes aspectos vão ao encontro dos
interesses contemporâneos de emprego adequado dos recursos naturais.
Muitos dos capítulos aqui apresentados resumem dissertações e teses
desenvolvidas no âmbito do Programa Ciência e Engenharia de Materiais,
recentemente assumido pela EESC-USP, que tem se empenhado para alcançar
reconhecimento mais efetivo nas avaliações institucionais, em especial tendo
como referência a grande expansão que esta área do conhecimento vem
experimentando nos últimos anos e a inequívoca inserção que docentes e
egressos do Programa têm alcançado em seus segmentos de atuação.
Também integram o livro, capítulos referentes a trabalhos desenvolvidos na
Universidade Estadual Paulista Júlio de Mesquita Filho, na Universidade Federal
de São João Del-Rei, na Universidade Estadual do Centro-Oeste (Irati, PR), na
Universidade FUMEC (Belo Horizonte, MG), no Centro Universitário do Leste de
Minas Gerais (Coronel Fabriciano, MG), na Universidade do Sagrado Coração
(Bauru, SP). Colaborações recebidas de docentes da Universidade de Coimbra,
Portugal, e da Universidade Nacional de Córdoba, Argentina, enriquecem o
conjunto de temas abordados.
Aos autores e às instituições, expressamos nossos agradecimentos pelas
contribuições disponibilizadas.
Waldek Wladimir Bose Filho
Coordenador do Programa Ciência e Engenharia de Materiais, Departamento de
Engenharia de Materiais, Escola de Engenharia de São Carlos
Universidade de São Paulo
Francisco Antonio Rocco Lahr
Departamento de Engenharia de Estruturas, Escola de Engenharia de São Carlos,
Universidade de São Paulo
André Luís Christoforo
Departamento de Engenharia Mecânica, Universidade Federal de São João del-Rei
São Carlos, junho de 2013.
Engineered wood materials, also known as wood-plastic composites (WPCs), are being investigated by the U.S. Navy for waterfront construction applications primarily because of their superior durability characteristics compared to wood. Durability, however, reaches beyond structural integrity and biodeterioration effects. Fire performance requirements are also critical issues in the acceptance of new combustible construction materials. To address fire performance issues in waterfront construction tests methods and protocols were investigated. The objectives of this study were to determine Navy requirements for waterfront component fire resistance, to identify or develop test protocol requirements, and to initiate small sample fire testing based on those requirements. Currently the Navy's criteria documents defer to NFPA 307, Construction and Fire Protection of Marine Terminals, Piers and Wharves, where component cross-sectional area is a determining factor. Because WPCs allow for hollow cross sections, these criteria will need to be modified. Standard test methods and modifications thereof were assessed for their relevance and potential application to WPCs. In particular, one test method (ASTM E108) was adapted and evaluated for wood-plastic composites, and found to provide good differentiation between various material types. ASTM D1929 was conducted to address building code acceptance criteria. Finally, it was suggested that a modified version of ASTM E119 could be used for further evaluation.