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Structural properties of recycled plastic/sawdust lumber decking planks
Abstract
Plastic lumber is being used to replace wooden lumber in some construction applications, especially in outdoor applications where the plastic lumber is presumed to weather better than the wood. However, the structural properties of the plastic lumber are not well understood, and the use of plastic lumber in structural applications is not authorized in the common building codes. In this research effort, standard 2×6 plastic lumber planks were tested for many different structural properties. The plastic lumber tested was a blend of recycled plastic and sawdust. The tests were conducted at −23.3°C to simulate winter conditions, and at 40.6°C to simulate summer conditions. In all cases the high temperature strength and stiffness was lower than at low temperature, so the high temperature values would determine the allowable strength and stiffness for design. The high temperature modulus of the plastic lumber was 5.79, 1.03, and 1.12 GPa in compression, flexure and tension respectively. High temperature strength values were 16.8, 12.0, and 1.45 MPa in compression, flexure and tension respectively. The high temperature shear strength of the plastic lumber was 5.31 MPa. Strength tests were also performed for nail and screw connections typically used with lumber, and the pull-out and lateral load were comparable to wooden lumber. The plastic lumber performed well under sustained load tests at high temperature. Slip resistance tests were performed, and it was found that the plastic lumber is more slippery than wooden lumber, but probably does not represent a safety hazard. The conclusion was that the plastic lumber is a good structural material, but it is not appropriate to simply substitute plastic lumber for wooden lumber pieces of the same dimension in structural applications. Plastic lumber structures must be designed using the structural properties of the plastic lumber.
... These differences mean plastic lumber is generally unsuitable as a direct replacement for natural wood of a similar shape and size, since the resulting structures may exhibit unacceptable deformation under load or buckle over time due to their own weight [17,43]. ...
... Wood fillers also increase the stiffness of composites, improve their machinability and are less expensive than polymer resin. Given the increasing use and importance of WPC, different authors have studied the effects of adding wood fiber on the mechanical properties of plastic lumber [7,9,43,[45][46][47]. Table 2 shows flexural modulus results of three composites made with the same filler, however in three different polymer matrices. ...
... Research by Solís and Lisperguer [48] indicates that adding wood waste reduced the impact strength of WPC ( Table 3). Processing Carroll et al. [43] evaluated the shear strength of Duraboard ® plastic lumber planks made from a compound of recycled plastic and sawdust under load and high temperatures. Mechanical tests were also conducted simulating winter (−23.3°C) and summer conditions (40.6°C). ...
... The manufacture of RPL allows making the most of large quantities of plastic wastes and converting them into useful and durable products [2]. This material has shown be rot resistant and not be susceptible to the corrosion or insect attacks, assuring the durability [3]. Structural elements made of RPL have a nonhomogeneous cross-section due to the cooling process during extrusion; this feature together with the nonlinear nature of the material makes different its tension and compression behavior, and some mechanical properties are difficult to determine [4]. ...
... As a consequence, in order to characterize this material and to enable the market acceptance of RPL in structural and building applications, ASTM International has developed specifications and test methods standards [5][6][7][8][9]. In addition, from materials engineering, RPL has been studied to know its mechanical properties, such as density, elasticity modulus, compressive, flexural, shear and tensile strength [3,10,4,11], creep behavior [4,12], among others, that are important for the structural design. ...
... Structural designs based on fragility analysis aim at increasing the safety of structural elements and avoiding the sudden failure of the material, controlling of damage of the structure when it is subjected to severe loads due to earthquakes. The damage is related to the ability of the structural system to dissipate the energy transmitted by external cyclic loads by means of the hysteretic behavior; this dissipated energy can be computed by the area enclosed by the hysteresis loops (see Figs. [3][4][5]. ...
Recycled Plastic Lumber (RPL) is a wood-like material made from recycled plastics that aims to diminish the environmental pollution resulting from plastic wastes. This material is used in different kinds of nonstructural and structural applications. Recently, RPL has been proposed as a suitable material to develop structural walls that comprise the seismic resistant system of housings, in order to lessen the housing deficiency. This article presents the results drawn from an experimental campaign carried out over three full-scale RPL walls, which were tested under cycling loading conditions to determine structural parameters such as strength, hysteretic behavior, ductility, energy dissipation, equivalent damping and characteristic failure modes of the RPL walls, which are necessary to design and to assess seismically the housings. Finally, a multilinear hysteretic model capable of simulating the nonlinear dynamic behavior exhibited by RPL walls was implemented, in order to simulate and to assess the seismic behavior of them under strong and destructive real earthquakes.
... The utilization of wood and natural fibers as a substitute to synthetic fillers such as carbon, glass or aramids for the production of particle boards is an ethically sound way of reducing the use of nonbiodegradable and nonrenewable resources. Woods and natural fibers because of their weight results in the formation of boards with low density and high toughness, applicable in the industrial production of window and door frames, furniture, railroad sleepers, automotive panels and upholstery, gardening items, packaging, shelves and general applications that does not require very high mechanical resistance but, low purchasing and maintenance costs [1][2][3][4][5]. Furthermore, the problem associated with the wearing and tearing of process equipment will be reduced as they are less abrasive than their inorganic counterpart. ...
... The central composite factorial design was employed to evaluate and quantify the effect of the operational variables on the pulp yields and residual lignin. The effect of the variables were quantified more precisely by choosing part of the experimental results and grouping them to form a first order full factorial design, with variables at two levels (2 3 ). Using this design, some of the experimental data were fitted to a first order polynomial regression equation as implemented in the "SPSS" statistical package. ...
... The independent variables X1, X2 and X3 correspond to the BD, MR and PS respectively. The ranges of values for each independent variable were: BD, 450, 550 and 650 kg/m 3 The values of the independent variables were normalized from -1 to +1 by using the equation: ...
Particle boards were prepared from saw dust wastes obtained from Gmelina aborea using polyethylene as binder. The boards were produced under three different compositional variables, namely: particles sizes (1 µm, 1.5 µm and 2 µm), densities (450kg/m3, 550 kg/m3 and 650 kg/m3) and mixing ratios ofsaw dust to polyethylene (30:70, 40:60 and 50:50). Part of the saw dust samples were chemically modified by pulping with caustic soda at 110oC and the effect of modification was examined on the physical and mechanical properties of the particle boards. The results showed that the chemically modified particle boards showed improved resistance to swelling and water absorption while a decrease was observed in the values of the modulus of rupture and elasticity.
... The product commercially known as plastic lumber can be exclusively made of plastics or can be a plastic composite (CARROLL et al., 2001). In both cases, it is manufactured with the dimensions (BOLIN; SMITH, 2011;BAJRACHARYA et al., 2014) of and for similar uses as wood lumber (CARROLL et al., 2001;BENTHIEN;THOEMEN, 2012;BAJRACHARYA et al., 2014). ...
... The product commercially known as plastic lumber can be exclusively made of plastics or can be a plastic composite (CARROLL et al., 2001). In both cases, it is manufactured with the dimensions (BOLIN; SMITH, 2011;BAJRACHARYA et al., 2014) of and for similar uses as wood lumber (CARROLL et al., 2001;BENTHIEN;THOEMEN, 2012;BAJRACHARYA et al., 2014). Currently, plastic lumber is primarily produced based on thermoplastic matrices (NAJAFI; ...
... However, these three studies did not measure the composite densities. (CARROLL et al., 2001) presents the composites' densities and compressive strength values, but the latter were measured only for extreme situations, such as very cold (-23.3 °C) or hot days (40.6 °C). Therefore, they were not considered in this analysis. ...
Plastic lumber and thermoplastic composites are sold as alternatives to wood products. However, many technical standards and scientific studies state that the two materials cannot be considered to have the same structural behaviour and strength. Moreover, there are many compositions of thermoplastic-based products and plenty of wood species. How different are their mechanical properties? This study compares the modulus of elasticity and the flexural, compressive, tensile and shear strengths of such materials, as well as the materials' specific mechanical properties. It analyses the properties of wood from the coniferae and dicotyledon species and those of commercialized and experimental thermoplastic-based product formulations. The data were collected from books, scientific papers and manufacturers' websites and technical data sheets, and subsequently compiled and presented in Ashby plots and bar graphs. The high values of the compressive strength and specific compressive and tensile strengths perpendicular to the grain (width direction) shown by the experimental thermoplastic composites compared to wood reveal their great potential for use in compressed elements and in functions where components are compressed or tensioned perpendicularly to the grain. However, the low specific flexural modulus and high density of thermoplastic materials limit their usage in certain civil engineering and building applications.
... One example of this is the creation of a wood-like material known as Recycled Plastic Lumber (RPL). The manufacture of this material requires a few chemical and industrial processes and allows the conversion of large quantities of plastic wastes into useful and durable products [10,11]. Additionally, several specifications and test methods standards have been developed by ASTM International to determine its mechanical properties (see e.g. ...
... [12][13][14][15][16]), which enable the market acceptance of this material for structural and non-structural applications. In this sense, the material has been studied to obtain its density, elasticity modulus, compressive, flexural, shear and tensile strength [11,[17][18][19], creep behavior [18,20], among others. ...
... Then, by an extrusion process, the flakes are homogenized and rapidly melt; finally, the molten mixture is discharged into a mold and cooled, shaping the finished product. This material has shown be rot resistant and not be susceptible to the corrosion or insect attacks, assuring the durability (Carroll et al., 2001). ...
... As a consequence, in order to characterize this material and to enable the market acceptance of RPL in structural and building applications, ASTM International has developed specifications and test method standards (ASTM D6108-13, 2013;ASTM D6109-13, 2013;ASTM D6111-13a, 2013;ASTM D6112-13, 2013;ASTM D6117-16, 2016). Additionally, RPL has been studied from materials engineering to know its mechanical properties which are important for the structural design, such as density, elasticity modulus, compressive, flexural, shear and tensile strength (Carroll et al., 2001;Li et al., 1994;MacBain and Saadeghvaziri, 1999;Gulhane andGulhane, 2017), creep behavior (MacBain andSaadeghvaziri, 1999;Chen et al., 2007), among others. ...
In recent years, innovative structural systems based on recycled plastic lumber walls (RPLW), precast ferrocement walls (PFW), and hollow reinforced concrete walls (HRCW) have been proposed for one and two-story housing so as to lessen the housing deficiency. This thesis presents the results drawn from cycling loading tests carried out over these three types of structural walls, in order to determine their strength, hysteretic behavior, ductility, energy dissipation capacity, equivalent viscous damping, and damage limit states. With the aim to assess their performances for the Design Basic Earthquake (DBE) and the Maximum Considered Earthquake (MCE), it was developed a nonlinear dynamic analysis methodology focused on the Performance-Based Seismic Design philosophy, which uses the Mostaghel's multilinear hysteretic model to represent and describe accurately the actual inelastic behavior and energy dissipation capacity of the structural walls; for the parameter identification of this hysteretic model, a novel procedure that uses the simple Particle Swarm Optimization (PSO) algorithm was proposed, which estimated in a good way the experimental hysteretic behavior of the walls, so the models were good enough for simulation purposes. Additionally, the IO, LS, and CP structural performance levels were related to the damage limit states and several assumptions were made to obtain performance-based seismic assessments as realistic as possible. Also, sets of actual recorded and artificial ground motions were employed to validate the use of the methodology, which were scaled to achieve the spectral matching with the NSR-10 target spectrum. Using the median of the Incremental Dynamic Analysis (IDA) results, the performance points of the RPLW fell within the LS and CP ranges for the DBE and the MCE, respectively, which evidences that this structural system meets exactly the basic safety performance objective established in the design philosophy of the NSR-10 building code. On the other hand, the performance points of the PFW and HRCW fell within the IO range for both earthquake hazard levels, which demonstrates their excellent seismic behavior. The obtained results approve the use of these structural systems for one and two-story housing.
... This environmentally friendly thermoplastic material was first used in railroad crossties and its application has recently been extended to bridge and structural members (Chandra et al., 2012). For example, recycled plastic lumber has been used to replace wood in some construction applications, especially outdoors, but the structural properties of these materials have not been well-studied yet (Krishnaswamy and Lampo, 2001;Carroll et al., 2001). ...
... Moreover, most of the companies do not have adequate quality control programs in order to certify that their products meet the minimum requirements for structural uses (Lampo, 1995;Krishnaswamy and Lampo, 2001). Several producers studied mixtures of two or more polymer types added with different materials (i.e., sawdust, glass fibers, resins) in order to improve some physical or mechanical properties (Carroll et al., 2001;Bajracharya et al., 2014). The challenge for the XXI century is to develop a sustainable and easy technology to improve the production of a structural RTT made of 100% of plastics. ...
... Due to their structural applications, WPCs are the largest and fastest-growing market (Pilarski and Matuana, 2005). Indeed, WPCs have been gaining popularity in several applications, including decking, cladding, and fencing in construction (Bajwa et al. 2011; Carroll et al., 2011). Building sector is very price sensitive and reducing production costs can be achieved by using recycled polymers. ...
... The material is much less hygroscopic than wood used as a control. This result is not surprising and can explain why softwood lumber is increasingly replaced by WPCs and plastic lumber in building applications (Carroll et al., 2011; Ganguly and Eastin, 2009). In general, wood polymer composites were known to be very resistant to biological decay as the required moisture content for fungal growth is significantly reduced by the polymer matrix. ...
This study evaluates the durability of wood-polymer composites (WPCs) elaborated for use in cladding application from recycled polypropylene (rPP) and wood flour. Local Maritime pine wood flour derived from regional sawmills was used in the study to reduce the environmental impact associated with transport. Different wood-plastic ratios with and without UV stabilizers and biocide were tested. One biocide and two UV stabilizers were tested and their impact on the performances of the elaborated composites was assessed by artificial weathering and fungal decay tests. Results showed that formulation with biocide exhibited low masse losses. Compared with the formulations without UV stabilizers, accelerated weathering resulted in discoloration (E ) and slight reduction of the maximum strain, which was enhanced by the addition of 1 wt% UV stabilizers to WPCs formulations. The study showed that the performances of WPCs elaborated from maritime pine wood flour and recycled PP could significantly be improved by using biocide and UV stabilizers..
... This task can be made easier by the fact that many of the typical applications of these composites do not require high mechanical properties of advanced composites made using high strength fi bers such as carbon, aramid and glass. Such applications include secondary and tertiary structures, panels, packaging, gardening items, housing panels, etc. [1, 14]. The most widely known and used natural organic fi llers are wood fl our and fi bers. ...
... Wood fl our and short fi bers are of great interest because of their low cost, dimensional stability and high elastic modulus. While tensile properties do not improve with wood fl our, the main shortcomings are poor fi ller particle/ polymeric resin adhesion, low impact strength and high thermal decomposition at temperatures over 200 °C [1, 14] . Flax, sisal, hemp and kenaf fi bers are relatively similar and are available in long lengths extracted from the stem (bast) of the plants; they can be used as fi llers by cutting them into short (staple) fi bers. ...
This manuscript reviews various aspects of fiber/resin interface in fiber reinforced composites, with special emphasis on green composites that use plant based fibers and sustainable resins. In this chapter we describe the importance of fiber/resin interface, factors affecting it, various modifications of fiber and resin that can be employed to improve the interfacial property and the experimental techniques to characterize the interface. The nature of the bonding between the fiber and resin and the mechanism of fiber/resin interaction are also discussed. Improving the fiber/resin interface is critical in the case of green composites since the hydrophilic plant fibers and some of the hydrophobic resins have very poor bonding. Strong adhesion at the fiber/resin interface is desirable for effective transfer of stress from broken fibers to intact fibers and, thus, to obtain good mechanical properties of the composites. However, weak bonding can provide energy absorbing modes through interface failure, making the composites tough. Thus, from the same set of fibers and resin it is possible to obtain composites with different properties simply through the control of fiber/resin interface.
... This strategy allowed to increase the mechanical properties, in particular the stiffness, of the lumber decks [7,8] while reducing the cost and the environmental impact of the composite by replacing plastics with a biodegradable scrap material. The push deriving from the development of this new class of composite encouraged the investigation of suitable ways to improve wood/polymer interface [9,10], to optimize decks geometry [11], and promoted the evaluation of in-service parameters effects such as temperature [12] and moisture content [13]. Despite all these efforts, plastic and WPCs lumber decks still display an environmental impact significantly higher than wood one [14]. ...
... These products are not biodegradable, and they can stay in our environment for hundreds of years without experiencing significant degradation, posing a risk of contamination of the air, soil, and water. As a result, there has been a growing interest in the development of sustainable alternatives to traditional petrochemical-based epoxy resins [11,12]. ...
Epoxy is the most prevalent thermosetting resin in the field of polymer composite materials. There has been a growing interest in the development of bio-based epoxy resins as a sustainable alternative to conventional petrochemical epoxy resins. Advances in this field in recent years have included the use of various renewable resources, such as vegetable oils, lignin, and sugars, as direct precursors to produce bio-based epoxy resins. In the meantime, bio-oils have been produced via the decomposition of biomass through thermochemical conversion and mainly being used as renewable liquid fuels. It is noteworthy that bio-oils can be used as a sustainable resource to produce epoxy resins. This review addresses research progress in producing bio-oil-based epoxy resins from thermochemical processing techniques including organic solvent liquefaction, fast pyrolysis, and hydrothermal liquefaction. The production of bio-oil from thermochemical processing and its use to inject sustainability into epoxy resins are discussed. Herein, we intend to provide an overall picture of current attempts in the research area of bio-oil-based epoxy resins, reveal their potential for sustainable epoxy resins, and stimulate research interests in green/renewable materials.
... +us, these are ecofriendly as well as cost-effective [33]. Natural fibers have various advantages in comparison to synthetic fibers which include less abrasion, not being harmful to the employees during their production process and their composites can easily be disposed of after completing their life cycle [34,35]. Natural fiber-based composites can also be used to recover the energy after the completion of their life cycle by incinerating them in a furnace [36]. ...
Natural fibers have emerged as an effective replacement for synthetic fibers in the fabrication of green composites to be used for producing various components in automotive, aerospace, and other applications. In this proposed study, the mechanical properties of banana and coir fiber-based green composites have been optimized by using a hybrid AHP-TOPSIS approach. Corn starch along with glycerol has been used as the matrix material for fabricating the green composites. The mechanical properties such as tensile strength, flexural strength, and impact strength of the developed green composite have been optimized with a focus on the utilization of this composite in automotive and aerospace applications. Three different weight percentages (0%, 5%, and 10%) of banana and coir fibers was considered for the fabrication of green composites. The constituents of the green composite have been taken as the input variables whereas the mechanical properties of the green composite are considered as the output variables for designing the experiment. The design of the experiment consisted of nine different combinations of input and output variables. Results of the study revealed that 5 wt.% of banana fiber, 10 wt.% of coir fiber, and 85 wt.% of corn starch provide the optimum mechanical performance of the developed green composites.
... Although plastic lumber is not used for structural applications (W1, W2), there are other uses in civil construction such as decks and paneling (Carroll et al., 2001;Friedrich & Luible, 2016), and university studies aim at expanding these applications (O8) (Martins et al., 2017). The low demand for WPC for structural purposes (W1) indicates the need to improve the mechanical properties of the product so that it can have structural applications in civil construction. ...
This review aimed to analyze plastic lumber manufacturing in Brazil, a country with a large amount of natural wood, and devise strategies to boost production. No studies were found on the development and application of plastic wood in a natural wood producing country that has been significantly affected by deforestation. Wood-plastic composite lumber was used in the present study. The methodology consisted of a bibliographic review, questionnaire, SWOT and TOWS analyses. The questionnaire was completed by plastic lumber manufacturers in order to better understand the positive and negative points of the plastic wood market and production. Information on environmental, economic and technical aspects was collected to support analyses. Brazil has 11 plastic lumber producers with a production capacity of 11 × 103 metric tons, a very small amount when compared to the natural wood market. Established companies are seeking to expand domestic and foreign markets for plastic lumber, which is largely composed of polyethylene with several lignocellulosic fibers, especially wood residue for civil construction applications. According to SWOT analysis, Brazil is developing plastic lumber with several strengths (opportunities). TOWS analysis showed that in order to boost plastic lumber production, make it more competitive and reach international markets, wood and plastic residue should be aimed at manufacturing WPC. Brazil produced around 37 × 106 metric tons of wood residue and discarded approximately 16 × 106 metric tons of plastic waste in landfills, materials that could potentially be used to produce plastic lumber. There are other raw material alternatives for plastic lumber production in the agricultural sector, such as straws and grain husks. However, the country urgently needs to develop a reverse a logistics network and residue collection, as well as conduct research to channel residues to plastic lumber production. Thus, there is a greater likelihood of continued development and, consequently, attracting new markets. There is an attempt to overcome weaknesses (plastic lumber is not used for structural applications), demonstrating the need for strategies that foster technical development for structural applications. Threats (high prices and lack of fiscal incentives) require coping strategies to increase production, thereby reducing its cost. These measures could increase plastic lumber production, making it competitive enough to replace natural wood, and lead to a decline in deforestation.
... Geosynthetic reinforcement had little tensile strength for n values less than 80, which is lower than the creep limit strength. University researchers Carroll et al. (2001) found that the modulus of plastic lumber is smaller than that of wooden lumber. As a tensile member, it has a low tensile strength, which makes it an unsuitable material. ...
Mechanically Stabilized Earth (MSE) walls constructed on unsuitable foundation soil are prone to large deformation and bearing capacity failure. A variety of techniques can be applied to address this issue, such as removal and replacement of existing soil with competent soil, staged construction, dynamic compaction, stone columns, geosynthetic reinforcement. One common traditional approach followed by Texas Department of Transportation (TxDOT) for the improvement of unsuitable foundation soil is removal of the in-situ soil and replacement with suitable fill material. However, this method can be time-consuming and expensive. A pile-supported system in combination with geosynthetic reinforcement can provide a sustainable solution for ground improvement. The use of Recycled Plastic Pins (RPPs) can be a viable alternative to other conventionally used piles. So, to minimize construction time and cost, the use of RPPs for ground improvement needs to be evaluated as an effective and sustainable technique. The objective of this study is to assess the effectiveness of RPPs for improving unsuitable foundation soil. An extensive field-testing program was conducted on RPP reinforced soil. Four identical test sections were constructed; among which three were reinforced with RPPs having different sizes and spacings, and the fourth one was left unreinforced to use as a control section. Performance monitoring for all four test sections was conducted using inclinometer and pressure plates for more than two years. The field monitoring data indicated that the settlement of the reinforced section was reduced up to 84%, and RPPs were carrying 78% of the total surcharge load. Based on the available field data, RPPs show a promising potential for improving the unsuitable foundation soil.
The performance of the test sections was further evaluated in numerical modeling using finite element software PLAXIS 2D. A parametric study was conducted using the calibrated model to evaluate the effect of foundation and backfill soil strength, RPP size, and spacing on settlement and pressure distribution of the RPP reinforced system. Finite element studies showed that larger cross-sections and closer spacing of RPPs provided better resistance. Settlement, stress reduction ratio, and stress concentration ratio prediction models were developed using the modeling results will help determining the settlement and pressure distribution of RPP reinforced foundation. Based on the performance monitoring results and further analyses, it can be concluded that the RPPs can be effectively used to increase the bearing capacity of MSE wall foundation.
... Material scientists used the term "ecocomposites" or "green composites". These materials are based on the fact that many of the typical applications do not require excellent mechanical behavior; while fulfills the needs for some secondary applications like panels, packaging, cases, gardening items [3,4]. Based on the above statements, it is necessary to discuss here some materials. ...
... In addition, plastic wastes are harmful since their pigments contain many highly toxic trace elements 1 . However, post-consumer plastic waste can be used in many plastic lumber products, reducing the amount of material that must be discarded in landfills 2,3 . ...
Composites based on recycled high-density polyethylene (rHDPE) and muscovite mica, with different rHDE/mica ratios (100/0, 95/5, 90/10, 85/15 and 80/20, weight percentage) were prepared in an internal mixer with roller-type rotors at temperature of 170 ºC for 10 minutes. The materials obtained were characterized by tests of density, Shore hardness D and melt-flow index, along with infrared spectroscopy, thermogravimetry, differential scanning calorimetry and scanning electron microscopy. The hardness analysis confirmed the action of mica as a reinforcing load in the matrix, but this effect stabilized at around 15%. The TG analysis showed that the 85/15 composite presented slightly better performance than the 80/20, indicating that mica, up to 15%, caused disorganization of the polymer structure instead of reinforcing it. The DSC results revealed that the composites had slightly lower melting temperatures than the matrix. The FTIR spectrum indicated there was no chemical interaction between the rHDPE and mica.
... Material scientists used the term "ecocomposites" or "green composites". These materials are based on the fact that many of the typical applications do not require excellent mechanical behavior; while fulfills the needs for some secondary applications like panels, packaging, cases, gardening items [3,4]. Based on the above statements, it is necessary to discuss here some materials. ...
In the modernworld, natural fiber reinforced polymer composites (NFRP) are gaining too much attention due to thelower manufacturing cost and favorable effects on the environment after use. Besides this, the processing problems ofsuch materials always remain a challenge. The bio/natural fiber has some protective layers and coatings causing hindrance for good interactions with polymer for good performance characteristics. Although numerous processes are already developed for overcoming the processing parameters but the desired goals are still not achieved. This short review focus on some useful properties and pre-treatment of fibers used for the manufacturing NFRP along with problems associated with effective remedial solutions. The viewers of this paper will get the basic knowledge and may select the area to study further in this field.
... The interest in WFs is because they provide dimensional stability and can enhance the elastic modulus. The main drawback of WF is that their poor adhesion with the polymer matrix and lower decomposition temperatures [46,47]. • Lignocellulosic fillers also include wood, naturals fibres and trashes of variety of plants. ...
The mounting interests on the development of materials with superior performance has induced the expansion of filler reinforced composites market around the globe. The use of fillers in the polymeric materials helps the enhancement of the functional properties of the resulting composites. The primary concerns of the polymeric industry are poor material properties, degradability, and cost factors. Hence, embedding the polymer matrix with the fillers becomes inevitable. The polymeric materials with an appropriate filler, better filler/matrix interaction, along with advanced techniques, leads to the formation of superior performing composites for potential applications in various industries. Dedicated efforts have been made to understand the relationship between the filler particles in the polymers and their properties. Reports in the past conclude that the fillers play a vital role in the enhancement in the properties of the composites. This review article presents the influence of fillers on the thermal and mechanical properties of biocomposites.
... An extensive study on lignocellulosic fibers such as sisal, jute, banana and oil palm empty fruit bunch fibers has shown that lignocellulosic fibers have the potential to be used as an effective reinforcement for thermoplastics and thermosetting materials [14][15][16]. The mechanical performance of epoxy composites reinforced with betel/areca nut short fiber at different compositions was studied using the extrusion and hot press molding technique. ...
An experimental processing for optimizing mechanical properties of micro-scaled areca nut powder (ANP)-reinforced epoxy composites has been reported. The ANP is a specific combination of different areca nut particulate sizes by weight percentage. The samples of ANP-reinforced epoxy composites with different filler weight percents (10%, 20%, 30%, 40% and 50%) were processed into laminates by casting method. The experimental results showed optimum mechanical strength for 30% ANP-reinforced epoxy composite while higher dielectric constant for 40% and 50% ANP-reinforced epoxy composites which can become alternative engineering materials. Additionally, the exploration of mechanical properties prediction models for ANP-reinforced epoxy composites has been performed by comparing the obtained experimental values of mechanical properties and the existing theoretical prediction models via constitutive modeling parameters for nonlinear regression using GraphPad Prism 6 software. Novel modeled equations named as SAS prediction models for density, thermal conductivity and mechanical strength for micro-scaled ANP-reinforced epoxy composites have been developed. The genesis theory of variation in mechanical strength and thermal conductivity of the developed ANP-reinforced epoxy composites has been investigated by Raman spectroscopy and fractographic methods.
... In addition, being the fastest growing and largest market make the demand on WPC to be high [3,4]. Besides, WPC have many applications ranging from industrial products to commercial building and home construction, such as fencing in construction, cladding and decking [5,6]. Previously, WPC was made from wood fiber and plastic materials but now WPC can be made from natural fiber obtained from agricultural waste and recycled plastic materials. ...
This research is a preliminary study on the preparation of wood plastic composites (WPC) from corn husk fiber (CHF) and recycled polystyrene foam (rPS). The effects of fiber content and alkaline treatment on tensile, thermal, water absorption and morphological properties of the composites were investigated. The rPS/CHF composites were prepared using melt compounding and compression moulding processes. The results showed that an increase of fiber content increased the tensile strength, modulus, and thermal stability (Td50%) of composites. However, the water absorption of composites increased vastly as the fiber content increases. The addition of more fiber also caused an earlier thermal degradation to composites. Alkaline treatment has improved the tensile strength, modulus, thermal stability (Td10%), and also reduced water absorption of rPS/CHF composites. The WPS prepared from rPS and treated CHF shows better tensile and thermal properties with lower water absorption.
... Since the wood of the Moroccan maritime pine is rich at the national level, and needs to be regenerated at the age of maturation, and since this wood has no relevant application on an industrial scale, and that the current world production of plastic is around 100 million tonnes per year [4], which threatens the ecosystems of our planet, it is expected to value them in composite materials called wood-plastic composites (WPC), these composites represent an emerging class of materials that have gained increasing degrees of acceptance because of their favorable performance characteristics such as improved stiffness, density, lower abrasiveness, better processing capacity, favorable cost of wood and plastic and a significant reduction in environmental impact [5][6][7][8][9]. The field of application of (WPC) is diverse; it is used in furniture, floor covering, on walls and ceilings, stair treads, sliding doors, bulletin boards and other Industrial Products [10][11][12][13]. ...
In this paper, we have investigated the stability, mechanical properties, and the microstructure of wood–plastic
composites, which were fabricated using recycled high-density polyethylene (HDPE) with pine wood flour used as
fillers. Composite panels were obtained using hot-press molding. The tensile and flexural properties of the composites
based on recycled HDPE revealed the strength properties of the composites can be improved by increasing the
polymer content, also the composite formulation significantly improved the morphology and the stability. Scanning
Electron Microscope (SEM) was used to characterize the morphology of the wood particulate/HDPE interface. It
was clearly proved from the results that wood-plastic composite (WPC) based on recycled high density polyethylene
(HDPE) can be successfully utilized to fabricate stable and strong WPCs.
... However, there is increasing demand for more complex product shapes and geometries, which need post-extrusion processing after the material fabrication stage. The tightening of environmental legislation in the European Union, with its demands for greater utilization of different waste segments and reduction in landfill waste, means that WPCs that can utilize and recycle municipal and building waste (Carroll et al. 2001;Cruz-Estrada et al. 2010). Thus, the area of WPCs are an increasingly interesting research area. ...
Wood plastic composites are an interesting development in composite materials. They have gained wide market interest recently because of their sustainable material sources and beneficial material properties. Because thermosets or thermoplastics are involved in the composites, the material is temperature-dependent and susceptible to considerable dimensional changes with the variation of temperature. To minimize waste generation and enable reheated material post-processing, the distortion and displacement of the composite material has to be controlled precisely in different temperature ranges. This article studies ways to control this displacement and proposes a solution with an odometer and polynomial curve fit.
... Several studies have demonstrated that structural members made of post-consumer recycled polymers can be used in construction, but with some precautions [29]. First, Carroll et al. [7] found that the compressive, flexure, and tensile strength depended on temperature, and decrease during the summer. Second, Jayaraman and Bhattacharyya [25] found that addition of wood fiber generally improves the mechanical properties of the members. ...
Remanufacturing has achieved viability in a diversity of industrial markets as a means to both maintain the value of products and minimize waste. From carpet tiling to manufacturing robots, a wide range of goods have presently established supply and consumer networks that support remanufacturing, and thus offer a point of entry into a more circular industrial economy. Based on this performance, it is reasonable to expect that remanufacturing can in some cases be made an iterative endeavor; that existing networks may be leveraged to create additional lifecycles for previously remanufactured goods at net environmental and economic gain over virgin production. This case study identifies and explores factors of Davies Office, Inc. (Davies) remanufacturing processes for office furniture that affect the economic and environmental practicality of creating multiple remanufacturing cycles. Specifically, we use Life Cycle Assessment (LCA) to estimate the impacts of multiple remanufacturing cycles and how these are affected by “adaptive remanufacturing,” a neologism to describe the use of an end-of-life (EOL) product core to create a similar, but non-identical product. LCA results suggest that adaptive remanufacturing is both an environmentally preferable and economically viable business strategy. Specifically, the ability to update, reconfigure, and customize previously obsolete products to meet present market demands enables lifecycle extension beyond what is achievable with traditional remanufacturing. In this, the study posits that such adaptive remanufacturing techniques not only expand the potential environmental benefits of remanufacturing, but enhances the long-term economic viability of remanufacturing in durable product markets.
... However, incorporation of biological fillers like wood flour in polymers provide certain disadvantages, such as low thermal stability, tendency to uptake moisture, low bulk density, thermal degradation of wood flour (even for low melting point polymers), issues related to pushing wood flour in the tiny feeding openings of typical polymer processing machinery, limiting its potential to be employed as a reinforcement for polymers, and low chemical compatibility at the interface fiber-polymer matrix reducing the mechanical properties [8]. Thermoplastics like polypropylene (PP), polyethylene (PE), polystyrene (PS), and polyvinyl chloride (PVC) are the preferable NFRC matrix choices, due to the fact that processing temperature of NFRC should be kept below 200 • C to avoid the degradation of the lignocellulosic component of natural fibers [5,24]. ...
Research on additive manufacturing (AM) has
gained significant attention in recent years. In this study,
two different matrices of polypropylene and polylactic acid
materials filled with three different percentages of wood
flour were employed; namely 10, 20, and 30%. Biocomposite
filaments (developed by twin screw extrusion) were
further used in AM by fused deposition modeling (FDM) to
obtain testing samples for the characterization of the tensile
and flexural properties through mechanical testing. Tensile
and flexural mechanical properties of the composite material
obtained by AM-FDM were compared against those
obtained by injection molding. Experimental results showed
that samples obtained with a percentage of 20% ofwood flour
showed lower mechanical properties, while those obtained at
30% testing samples turned very brittle. Mechanical properties
like flexural stiffness were higher in the testing samples
obtained by injection molding compared to those by AMFDM.
To understand the thermal behavior of the composites,
specimens were subjected to TGA experimentation. Experimental
results show an analysis of the optimum temperatures
for processing the composites through AM, and provide evidence
that these composites could potentially be applied in
the design of auto parts due to their biodegradability and
mechanical strength.
... However, there is increasing demand for more complex product shapes and geometries, which demand post-extrusion processing after the material fabrication stage. Tightening environmental legislation in the European Union, with its demands for greater utilization of different waste segments and reduction in landfill waste, mean that WPCs, which can utilize and recycle municipal and building waste (Carroll et al. 2001;Cruz-Estrada et al. 2010), are an increasingly interesting research area. For example, an interesting research topic recently has been combining WPCs with other composite materials such as fibre reinforced plastic (Lale Arefi et al. 2014) or pure polymer (Moritzer and Martin 2016) to increase the usability of the WPCs. ...
Wood plastic composites (WPCs) have recently gained increased market share as a result of their beneficial properties and use of sustainable material sources. Currently, however, WPC products are limited to extruded profiles. More complex product shapes and geometries will increase market potential, but they demand additional post-processing after extrusion. Post-processing machinery coupled online with an extruder necessitates material handling, which is commonly achieved using belt conveyors. This paper considers transport of WPC material through a post-extrusion process using a belt conveyor system. Special emphasis is placed on studying the friction and surface energy properties of the belt conveyor. Friction at the interface of the raw material and belt cover was tested using a standard incline-plane method, and adhesion and stickiness were evaluated by determining the surface free energies of the belt cover and WPC material at 23 and 100 °C. On the basis of these measurements, this paper investigates key aspects of belt cover material selection and proposes a conveyor belt configuration for a prototype post-extrusion process line that can be utilized in commercial mass production of WPC products.
... Several studies have demonstrated that structural members made of post-consumer recycled polymers can be used in construction, but with some precautions. First, Carroll et al. [10] found that the compressive, flexure, and tensile strength depend on temperature and decrease during the summer. Second, Jayraman and Bhattacharyya [11] found that addition of wood fiber generally improves the mechanical properties of the members. ...
... Several studies have demonstrated that structural members made of post-consumer recycled polymers can be used in construction, but with some precautions. First, Carroll et al. [10] found that the compressive, flexure, and tensile strength depend on temperature and decrease during the summer. Second, Jayraman and Bhattacharyya [11] found that addition of wood fiber generally improves the mechanical properties of the members. ...
There has been increasing interest in the use of recycled polymer composites as a replacement for timber piling in coastal and waterfront environments. This trend is expected to grow because polymeric piling is more attractive than timber when life cycle costs are factored in, and also because polymeric piling is a creative method for the recycling and reuse of tons of plastic waste. However, composites face obstacles because they do not have a long track record of use in civil engineering structures. Polymeric piling is typically made of high density polyethylene (HDPE) and reinforced with fiber reinforced polymer E-glass (FRP) or steel. This paper summarizes the current state of the art in polymeric piling practice, including (1) the mechanical properties of piling made of recycled polymers; (2) the durability of recycled polymers in aggressive soils; (3) the compressive creep of recycled HDPE and FRP; (4) drivability; (5) design considerations such as skin friction, end bearing, and buckling; and (6) load testing of polymeric piles.
The effects of iron oxide red pigment, organic red 254 pigment, titanium white pigment, and carbon black pigment on the properties of wood fiber (WF)reinforced high‐density polyethylene (HDPE) composites under outdoor aging conditions were investigated. The results indicate the addition of pigments in the outdoor aging process has a certain physical protection effect on the composites, effectively preventing the damage of ultraviolet rays on the WF/HDPE composites, and the mechanical experiments show that the pigments protect the composites more obviously in the first 3 months. Among them, the carbon black pigment had the best color‐fixing effect on the composites, with the ∆ E * value is only 4.1, and the protective effect on the composites was relatively good due to its special structure. The quality change also verified again that the carbon black pigment has a certain protective effect on the plant fiber composites in the pre‐aging period outdoors, in which the mass of the composites with added carbon black pigment increased by 0.14%. Comprehensively, it shows that the addition of pigment cannot completely prevent the photo‐oxidation reaction of the composites from occurring, but it can effectively slow down the aging process of the composites and prolong the service life.
Highlights
WF/HDPE‐modified composites were prepared by injection molding.
The surface color of composites with pigment additions was analyzed.
The addition of pigments effectively protects the composites.
Mechanical and thermal properties have also been investigated.
Severe burdening of landfills due to non-degradable plastic waste deposition is a major environmental hazard. Although there have been initiatives to use recycled plastic as a building material, it has been successful only as a non-structural material or as a partial replacement of aggregate in concrete. Further, as far as the use of recycled plastic as construction materials is concerned, the present design standards do not mention anything regarding the matter. In the present study, an experimental program is developed to evaluate the mechanical properties of recycled plastic lumbers (RPL) developed using mixed multi-layered plastic (MLP). First, the specific density and coefficient of thermal expansion of RPL-MLP are evaluated. Compression, tension, flexure, and shear tests are also carried out on the RPL-MLP using displacement-controlled and load-controlled testing machine. All tests are carried out using pertinent ASTM standards. It is observed that the material exhibits a compressive strength of about 25 MPa. The flexural modulus is determined to be about 6 MPa and 12 MPa for the specimen kept in plank position and joist position respectively. The initial compression modulus was found to be only about 325 MPa. MLP exhibits excellent deformation capability, although the ultimate failure is a brittle mode. The paper also discusses the challenges involved in testing such a material and ideas to improve its structural performance. It can be concluded that RPL-MLP lumber can be used in low stress building applications.
Wood plastic composites as a substitution for HDF. As part of the research, industrial HDF boards were used and WPC composites were produced, differentiated in terms of matrix (PLA and HDPE) and filler content (40%, 50% and 60%). The density and density profile was measured to compare HDF and WPC structure. In addition, the manufactured boards were tested for strength (MOR, MOE), screw holding, thickness swelling and water absorption after immersion in water for 2 and 24 hours. WPC were characterized by a higher density than HDF boards and a uniform density profile. In addition, WPC composites were characterized by lower MOR and MOE values than HDF boards. Compared to HDF boards, WPC composites were characterized by higher values of screw holding and better resistance to moisture.
Bu çalışmada TS 9215’e göre ahşap ve plastik olmak üzere 2 farklı malzemeden üretilmiş elbise askılarında mukavemet deneyi yapılarak, hangi malzemeli elbise askısının daha iyi mukavemet değerlerinin olduğu, deformasyon miktarları ve deformasyon noktalarının değerlendirilmesi amaçlanmıştır. Ahşap elbise askıları, plastiklere göre geri dönüştürülebilmesi ve sürdürülebilirlik oranları yüksek olan bir malzeme olmaktadır. Mukavemetlerini ölçmek için de TS 9215 standardından yararlanılmıştır. Araştırmanın ve deneylerin modelini TS 9215 standardına göre oluşturulan deney düzeneği oluşturmuştur. Deneyde 8’i ahşap ve 8’i plastikten olan toplamda 16 tane elbise askısı uygulnan anket sonuçlarına göre seçilerek kullanılmıştır. Her bir elbise askı standarda uygun olarak, 3 noktadan asılabilir 5 kilogramlık kütleler ile 8’er saat boyunca deney düzeneğinde asılmış ve her 2 saatte bir kontrol edilmiştir. Deney sonucunda oluşan deformasyonlar gözlemlenmiştir. Gözlemlenen deformasyonlar ilk olarak fotoğraflanmıştır ardından milimetrik cetvel ile hassas bir şekilde ölçülüp not alınmıştır. Elde edilen metrik veriler M. Excel programında çözümlenmiş, tablo ve grafik haline getirilmiştir. Her iki türden yapılmış elbise askılarında kanca kısımlarındaki deformasyonun, elbise askılarının mukavemet deformasyonlarından çok daha fazla olduğu tespit edilmiştir. Bu araştırmada elde edilen bulgular, ahşap elbise askılarının plastik elbise askılarından daha fazla mukavemetli, deformasyon indeksinin daha az olduğunu göstermiştir. Bunun yanı sıra ahşap elbise askılarında kullanılan ağaç malzemenin de mukavemet özelliklerine büyük etki ettiği tespit edilmiştir. Araştırmada da ahşap elbise askıları üretici tercihli kızılağaç ve okaliptüs cinslerinden yapılmıştır. Bu iki cins arasındaki karşılaştırmada da kızılağacın daha mukavemetli olduğu bulunmuştur.
Over the last 70 years, pultrusion has matured into an industry-leading process when it comes to providing high throughput and automated composite manufacture at a competitive price point. In this paper, we review recent innovations that have advanced pultrusion to a versatile manufacturing technology and thereby allowed composite materials to penetrate markets in, e.g., the automotive, construction, aerospace, and wind turbine industries. We accompany our review with discussions on how pultrusion has enabled technological advancements within additive manufacturing and sustainable composite manufacturing, and finally, we provide an outlook and suggestions for where we see the potential for research and new industrial applications of pultrusion technology.
Plastic waste management represents a significant problem worldwide, but also, an opportunity for construction materials development. This manuscript explores plastic composite trends, emphasizing thermal and mechanical features. Data obtained from literature over 88 plastic composites were classified into six filler-based categories, 78% presented mechanical data, whereas only 40% provided thermal characterization. The explored features summarize thermal conductivity range values from 0.02 to 2.23 W/(m·K) and Compression Strength between 0.1 and 158 MPa within the recycled plastic composites repository with densities from 50 to 2100 kg/m3, similar to those considered conventionally a feasible possibility to reduce energy demand through low-energy architectural envelopes.
This work aimed to investigate the effects of wood waste types (twigs, leaves, and palm fronds) and contents (ranging from 40 to 60 wt%) on the physical and mechanical properties of plastic bag composites under sea coast climate conditions. Wood-plastic composite (WPC) pellets were blended with a twin screw extruder, and sample panels were compressed using a compression molding machine. Statistical analysis indicated that exposure time led to significantly deteriorating changes in all the physical and mechanical properties of WPCs. The lightness and total color change values altered with an increase in exposure time. An increase of wood waste content from 40 to 60 wt% in plastic bag composites increased the percentage loss for modulus of rupture (MOR), modulus of elasticity (MOE), screw withdrawal strength (SWS), and hardness, which is relative to micro-cracks on the surface of the WPCs. Overall, the mechanical properties of the plastic bag composites based on twigs had less loss and superior MOR, MOE, SWS, and hardness compared to those based on leaves and palm fronds, at equal plastic to wood ratios. Thus, plastic bag composites based on twigs are recommended for the manufacture of WPC materials in applications for construction and building products.
Screw holding performance in WPC composites. In this research effort, the impact of fillers’ composition on wood-plastic composites (WPC) made of poly (lactic acid) PLA was tested. The composites varied in filler type (bark, sawdust) and its content in the boards (40, 50, 60%). The composites were manufactured in a two-stage process consisting of extrusion and flat pressing. Analogically prepared HDPE boards were a reference. Composites were tested for density, density profile, and screw-holding ability. Boards based on PLA performed better screw-holding ability than HDPE. The greatest influence was exerted by the share of matrix/filler. An increase in the content of lignocellulosic particles from 40 to 60% (regardless of the type of matrix: PLA or HDPE) generally reduced screw-holding ability. The type of filler (sawdust, bark) was almost 3 times more important in the case of HDPE boards compared to PLA boards.
Green composites are materials having eco-friendly attributes that are technically and economically feasible while minimizing the generation of pollution. In this context, it refers to the combination of fully degradable fibers mostly cellulosic materials and natural resins to develop green composite materials. In the past decade, overdependence on petroleum products (synthetic polymers, resins, etc.) has consistently increased, and on account of this the researchers are now focusing more on green materials specially cellulosic. Green composites do not harm the environment much and could be satisfactory alternatives to petroleum-based polymers and polymer composites. The developing anxiety toward prevention of ecological destruction and the unfilled requirement for more adaptable environmental friendly materials has prompted expanding interest about polymer composites, originating from sustainable sources and biodegradable plant materials, particularly from forests. These have widened the utilization of plant fibers as reinforcements and have increased the possibility for sustainable and “biodegradable” composites, which can be called “green” composites as they satisfy the criteria of “green materials.” Thus the challenge to obtain “green” composite involves obtaining “green” polymers functioning as matrices in the production of composite materials. This chapter considers the materials and methods utilized for the fabrication and particularly the utilization of green composites in different technological fields.
Due to the environmental and sustainability issues, the interest in biobased composite materials is rapidly growing, both in terms of their industrial applications and fundamental research. However, in addition to numerous advantages, natural composites have some serious drawbacks when compared to synthetic composites. Higher moisture absorption, inferior fire resistance, lower mechanical properties, and durability are some of them. The properties of biocomposites are influenced by a number of variables, including the fiber type, environmental conditions, processing methods, and the type of fiber modifications. Due to the positive economic and environmental outlook of biocomposites, there are numerous studies dedicated to the surface treatment of fibers and improvement of the fiber/matrix interface. This chapter focuses on the characteristic idea of biocomposites, discussing the role of their components, biomatrix and biofillers, as well as challenges impeding their advancement into wider applications.
Raising global attention towards environmental problems has gained a drastic emergence of environmentally friendly and sustainable green materials based on renewable resources and tends to be biodegradable and recyclable. Such green materials may be either cement-based or polymer-based. The cement-based ones require new addition of binders which includes the recycled and geo-polymer aggregators. The effective application of renewable/recycled resources assures the reduction in consumption of various minerals and also petrochemical products which certainly leads to depletion of natural resources, whereas, in polymer-based materials, the selected natural fibres like jute, hemp, kenaf, sisal and flax have been recommended to replace/substitute the synthetic fibres. Whereas bio-resins have grown up to a large extent and these are absolutely derived from vegetable oil, protein as well as starch to overcome the use of petroleum-based products. Hence, commercial products along with its sophisticated applications are emerging nowadays for such green composites. The tremendous development of green composites must be a competitive alternate for glass fibre reinforced composite material which is a broad focus of research in the present era.
Materials called biodegradable green composites consisting of matrices and reinforcers made entirely from natural resources are macro-, micro-, or nano-sized materials that can fulfill desired mechanical and thermal properties as well as being light. Producing natural polymers with good mechanical properties and thermal stability has attracted the attention of many researchers. The use of this material through a variety of mixtures and composites has become more and more popular as raw materials are limited and there is more concern about greener material that is environmentally friendly. Therefore, materials made from renewable sources such as biocompatible/biodegradable polymers can dominate the future by replacing the petroleum raw material. However, more efforts are needed to achieve better properties of the renewable polymer blend and composites and also to address the deficiencies of this new material. To do this, a basic understanding of renewable material types, structures, properties, and potential applications as needed. The study covers the application areas of biodegradable green composites. The stated application areas can be literature support for the rapid development of biodegradable composites at the request of researchers, manufacturers, and consumers for environmentally friendly products.
The high availability and low cost, added to its renewable, biobased and biodegradable nature, make TPS a promising alternative to the non-biodegradable plastics produced from fossil resources. However, in order to be competitive, its mechanical and water vapor barrier properties, as well as its stability in high moisture environments, must be improved. In this chapter, strategies for the development of TPS matrix composites such as those obtained from starch/biodegradable polyester blends are developed. In particular, two systems are deeply described: PBAT/starch and PHB/starch. The chosen polyesters have the important advantage of being biodegradable in soil, very stable in water due to their hydrophobic character and mechanically good enough to improve starch’s properties. The inclusion of fillers and strategies to improve polymer compatibility, including the use of compatibilizers, polymer modifications and special processing conditions, are reported. The properties of these materials are studied from three key points for their application: thermal, barrier and mechanical. The results show that the combination of the two strategies, making a blend and including fillers, leads to the best results. However, there is still much to improve, especially regarding the compatibility between the involved phases.
The utilization of waste plastic bag, especially as a matrix for wood plastic composites, is expected to reduce the environmental problems throughout the world caused by its use. Wood plastic composites were manufactured via melt mixing of chopped or pelleted waste plastic bags, sawdust and polyethylene grafting maleic anhydrate (MAPE) according to Extreme Lattice Mixture - Design of Experiment (DoE). The effects of concentrations and reprocessing of waste plastic bags on flexural modulus of elasticity and strength of composites were analyzed. In general, flexural modulus of composites from chopped and pelleted waste are increased but still below the value of SNI 8154–2015. Moreover, the flexural strength of the resulted composites from chopped waste also increased than that of the pelleted one. Some of the formulas of composites from chopped waste met the value required by SNI 8154 – 2015. On the contrary, the flexural strengths of composites from pelleted waste are decreased than that of the virgin one. This is probably due to the existence of interaction between pelleted waste and sawdust that prevented the waste plastic to perfectly melted, hence acted as stress concentration sites. Furthermore, the resulted composites were optimized for flexural modulus using response optimizer plot in order to achieve modulus 2000 MPa that required by the standard. However, the optimized flexural modulus of composites from chopped and pelleted waste was in the range of 1500 MPa, which is far below the standard. Therefore, reprocessing of chopped waste into pellets is not necessary due to inferior properties of composites from pelleted waste than that of the chopped one.
In this research work, dynamic, mechanical, and thermophysical properties of untreated and 5, 7, and 10 wt % styrene treated tea dust (TD):polypropylene (PP) composites prepared by injection-molding machine were elaborated. There were distinctive and significant improvement observed in mechanical properties (tensile strength, tensile modulus, and elongation at break), physical analysis (water swelling), dynamic mechanical properties (storage modulus, loss modulus, and tan δ), and thermal behavior and surface morphological properties of styrene treated TD:PP (40:60) composites as compared to that of untreated one. The tensile strength (from 7.00 to 9.95 MPa), tensile modulus (from 350 to 715 MPa), storage modulus (from 8500 to ∼10,500 MPa), and loss modulus (from ∼150 to ∼200 MPa) increased on 10 wt % styrene treatment of TD over the untreated TD:PP (40:60) composites. The styrene treated TD:PP (40:60) composites behaved as more elastic than their pure counterpart. Styrene treated TD:PP (40:60) composites were more thermally more stable (85 °C difference) as compared to virgin PP. Overall, this research also indicates the use of TD waste. An improvement in dispersion of styrene treated TD particles in PP was also observed in the preparation of the PP composites due to good compatibility of styrene with PP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44750.
A review of research on injection-moulded wood fibre-filled thermoplastic composites is presented in this chapter. Brief description of injection-moulding compounding process (including drying and mixing and extrusion) as well as injection-moulding process itself is also presented. A review on wood fibre-reinforced thermoplastic composites is also reported. An in-depth discussion is presented on thin-part moulding and the formation of residual stresses, volumetric shrinkage and warpage using injection moulding for composite products. Simulation work and statistical analysis related to the topic are also reviewed. Finally, some ideas about further research on wood-filled thermoplastic composite are proposed.
In the olive oil-producing countries, large quantities of olive solid waste are dumped in nature causing several environmental problems. Therefore, the use of this by-product as filler in (ethylene–propylene) matrix could be an effective way to reduce significantly the quantities of the disposed biomass and elaborate a cost-effective material. However, the hydrophilic nature of this natural filler decreases the compatibility with the hydrophobic matrix. To improve the interfacial adhesion, maleated polypropylene was added as a compatibilizing agent. In a first step, the influence of the filler loading on the rheological, thermal, and mechanical properties was investigated. Composites with various filler contents were prepared by melt blending using a twin-screw extruder and injection molding. The filler addition led to an increase of the viscoelastic properties and the crystallinity degree. Then, the coupling agent (MAPP) was reported to enhance the rheological, thermal, and mechanical properties of the composites up to a critical amount beyond which the plasticizing effect becomes more predominant than the reinforcing effect, a fact that could be responsible for the decrease of viscoelastic properties, crystallinity, and mechanical properties. POLYM. ENG. SCI., 2015. © 2015 Society of Plastics Engineers
This study aims to investigate the effects of two types of wood flour; oil palm mesocarp flour (OMF) and rubberwood flour (RWF), and their particle sizes on mechanical, physical, and thermal properties of wood flour reinforced recycled polypropylene (rPP) composites. The composite materials were manufactured into panels by using a twin-screw extruder. The rPP composites based on RWF significantly showed higher flexural, tensile, and compressive properties (both strength and modulus) as well as hardness and thermal stability than those composites based on OMF for the same particle sizes. However, distribution of RWF in the rPP matrix was less homogeneous than that of the rPP/OMF composites. Furthermore, a decrease of the particle sizes of filler for the rPP/OMF or RWF composites increased the flexural, tensile, compressive, and hardness properties. Likewise, the thermal stability of both OMF and RWF composites were insignificantly affected by the particle sizes.
The search for alternative polymer composites prepared by renewable resources is gaining increasing attention in the industrial sector. Here we prepared new polyurethane (PU) composite foams with high percentages of the natural vegetable fibers Spartium Junceum in conjunction with biodegradable polyethylene glycols (PEGs). The density and mechanical properties of PU foams were investigated. Further characterization of the morphology of these materials was carried out by scanning electron microscopy. Here we show that these properties can be easily tuned by changing the molecular length of PEGs, the weight ratio between the two principal monomers, and the fraction of water added to the reacting mixtures. POLYM. COMPOS., 2015. © 2015 Society of Plastics Engineers
Composites of rubberwood flour (RWF) and recycled polypropylene (rPP) were produced into panel samples by using a twin-screw extruder. The effects on creep behavior of mixture fractions of rPP, RWF, maleic anhydride-grafted polypropylene (MAPP), and ultraviolet (UV) stabilizer were studied in a D-optimal mixture design. Creep was significantly affected by the composition. Increasing the fraction of RWF decreased creep, while MAPP and UV stabilizer increased it. The models fitted were used to optimize a desirability score that balanced multiple creep characteristics. The model-based optimal formulation 50.5 wt% rPP, 44.9 wt% RWF, 3.5 wt% MAPP, 0.1 wt% UV stabilizer, and 1.0 wt% lubricant was experimentally validated to have low creep closely matching the model predictions.
The mechanical properties of composites from recycled waste plastic and waste sawdust are of interest in trying to convert these waste streams to useful products. The development of these composites from natural fiber is therefore receiving widespread attention due to the growing environmental awareness. The effects of compositions were investigated including different grades of plastic (virgin and recycled) and amounts of wood flour, coupling agent, and ultraviolet (UV) stabilizer on mechanical and physical properties of polypropylene/rubberwood flour (RWF) composites. Virgin polypropylene gave better mechanical properties than recycled (recycled polypropylene (rPP)), both in composites and as unfilled plastic. RWF content exceeding 25 wt% enhanced the strength of RWF-reinforced rPP composites. The modulus and hardness of composites increased linearly with wood flour loadings. Maleic anhydride-grafted polypropylene (MAPP) as a coupling agent increased the strength, modulus, and hardness of the composites. However, addition of 1 wt% UV stabilizer degraded the mechanical properties. Therefore, 4 wt% MAPP content is recommended to achieve good mechanical properties of rPP/RWF composites, while the amount of UV stabilizer should be as small as possible to avoid its negative influence.
A recent addition to the list of composite building materials is plastic lumber. While utilizing recycled plastics as building materials promotes recycling, plastic lumber itself is a poor replacement for solid wood. Research is underway to improve the mechanical properties of wood/polymer composites. This report investigates the use of Willamette Valley rye grass straw as a filler in the commodity plastics polyethylene (pe) and polystyrene (ps). Since recycled plastics are often mixtures, blends of pe and ps were studied. A compatibilizer was used to improve the properties of the plastic blends. Composites of blends of plastics filled with straw showed a linear relationship in strength and stiffness. Straw performs similarly to wood as a filler in these systems. In composites containing only one plastic, the performance of straw as a filler seemed slightly superior to wood in polyethylene and slightly inferior in polystyrene. The properties observed here compare favourably to those of commercial products and suggest that improvements in these products are possible.
Samples of lumber manufactured from recycled plastics by four different companies were subjected to stress-strain tests at two rates of strain over relatively short intervals of time. A simple model uses data from the strain-rate tests to calculate long-term (-25 years) creep strain. Calculated long-term values range from approximately 25-80% greater than values extrapolated from short-term data. Results for the recycled products are compared with experimental creep data for virgin polyethylene. The findings are examined in terms of morphological features and sample composition.
An assessment was made of the chemical environmental impact of a new pier constructed of recycled postconsumer waste plastic in the East River, New York City. The waste plastic consists principally of polyethylene and polyethylene terephthalate. Plastic pilings are immune to the marine boring organisms that are destroying conventional wood structures. A variety of organic compounds and metal ions are leached from the plastic surface but in small quantities to produce river water concentrations far lower than those of compounds found to be already present. Many of the leached compounds seem to be characteristic of product residues in the plastic containers. In comparison, significant amounts of As, Cr, Cu, Mn and Se were leached from pressure-treated lumber, another material used in pier construction. In addition to its aesthetic and functional qualities, recycled plastic timber has the significant environmental advantage that it will not add appreciably to the pollutant load of the East River.
Plastic lumber manufactured using post consumer waste plastic has been proposed as an acceptable material for use in the construction of docks, piers and bulkheads and is touted to outlast conventional wood products due to its strength, durability and resistance to rot. This study examines the long-term engineering properties of plastic lumber manufactured using post consumer waste plastic (TRIMAX, Ronkonkoma, NY). Plastic lumber profiles were used in the decking of a pier built in West Meadow Creek, Old Field, NY during December 1995. Samples of plastic lumber were removed from the deck of the pier periodically over a two-year period and returned to the laboratory for testing. Results of engineering tests showed the in-plane compression modulus (260±30 MPa), dimensional stability and the Shore D surface hardness (60±2) of plastic lumber removed from the pier remained similar to or greater than their pre-placement values. In contrast, significant changes in the modulus of elasticity of plastic lumber were measured with prolonged weathering. The modulus of elasticity of plastic lumber initially decreased from 1370 Pa to 750 Pa following 12 months weathering, a decrease equal to 45% of its pre-placement value and then increased during the second year to close to its initial value. The high variability in the modulus of elasticity should restrict the use of plastic lumber profiles to non-load bearing structural applications.
Properties of refined reinforced compounded post-consumer plastics
- Applebaum
- Van Md
- Ke
- Renfree Rw Nosker Tj
- Morrow
Applebaum MD, Van Ness KE, Nosker TJ, Renfree RW, Morrow DR. Properties of refined reinforced compounded post-consumer plastics, SPE ANTEC '91: Conference Proceedings, Montreal, Canada, 5–9 May 1991, p. 2155–61.
Special Considerations in the Design of Connections for Recycled Wood/Plastic Composite Lumber, Structures Congress'94
- G H Kyanka
Kyanka, GH. Special Considerations in the Design of Connections for Recycled Wood/Plastic Com-posite Lumber, Structures Congress'94, Atlanta, GA, 24 – 28 April, 1994. p. 929 – 33.
Recycled plastic lumber and shapes design and specifications, restructuring - America and beyond
- M G Mclaren
McLaren MG. Recycled plastic lumber and shapes design and specifications, restructuring — America and beyond. Proceedings of Structures Congress XIII, Boston, MA 2 – 5 April, 1995. p. 819 – 33.
Morphological and rheological characteristics of commercially produced recycled plastic lumber
- Van Ke
- Hocking
- Sk
- Renfree Rd Nosker Tj
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Van Ness KE, Hocking SK, Nosker TJ, Renfree RD, Sachan RD. Morphological and rheological characteristics of commercially produced recycled plastic lumber. SPEANTEC'95: Conference Pro-ceedings, Boston, MA, 7–11 May 1995. p. 3704 – 09.
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Properties of refined reinforced compounded post-consumer plastics
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Composite recycled plastic marine piling and timber: an alternative to traditional wood products for marine use
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Morphological and rheological characteristics of commercially produced recycled plastic lumber
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