Wood Plastic Composite Panels Research Articles

Study on flexural property of glass fiber-reinforced polymer reinforced wood–plastic composite panels

ABSTRACT Fiber-reinforced polymers (FRPs) and wood–plastic composites (WPCs) have broad application prospects with the advantages of recyclability, lightweight, and corrosion resistance. However, WPCs cannot be used for bearing structures because of their poor mechanical properties. In order to improve the mechanical properties of WPCs, this study proposed a glass fiber-reinforced polymer (GFRP) to reinforce the tensile zone of WPCs. The failure mode, ultimate bearing capacity, and deformation of the panels were studied by four-point bending tests and finite-element simulations. The results showed that the failure modes of the panels were a mainly flexural failure, flexural shear failure, and interface debonding, and the optimal thickness of GFRP improved the ultimate bearing capacity of the WPC panel by 205% and the deflection by 55%. Finite-element simulations of WPC reinforced with GFRP were carried out, and the densities of WPC and the angles of glass fiber layup were considered. The results showed that the higher the density of WPC, the better the strengthening effect of the structure, and the fiber layup angles had less effect.

Study on Bending Creep Performance of GFRP-Reinforced PVC-Based Wood-Plastic Composite Panels.

Wood-plastic composites (WPCs) are environment-friendly materials, which have broad application prospects in structures. They cannot be used for bearing structures because of poor mechanical performance and creep deformation. In order to enhance the mechanical behavior and decrease the long-term creep deformation, glass fiber reinforced plastics (GFRP) sheets and rebar reinforcement design methods are proposed. The bending static tests and creep performance tests of WPCs were conducted. The results showed that GFRP sheets and rebars improved the ultimate flexural loading capacity and deformation capacity by 257% and 165%, respectively, decreased the creep deflection effectively, and avoided shear failure. When the load level was very low, the creep deformation of WPC panels unreinforced, or reinforcement developed stably with time, and the damage did not occur within 1100 h. When the load increased to 80% of the ultimate load level, all specimens were damaged in the compression zone, the creep deformation increased quickly and unstably, bending shear failure of the unreinforced specimen occurred after 7 h, shear failure of the GFRP-sheets-reinforced specimen occurred after 1100 h, and the rebar-reinforced specimen failed after 720 h with excessive deflection deformation in the span. The reinforced effect of GFRP sheets is better. The creep strain growth rate of all specimens increased quickly at the first stage and gradually decreased at the second stage and tended to be stable. The creep calculation model was built based on the four-element model, which is simple and efficient and can make scientific and reasonable predictions of the two phases of structural transient creep and deceleration creep.

Characterization and Vibro-Acoustic Modeling of Wood Composite Panels.

Natural fiber-filled polymers offer good mechanical properties and economic competitiveness compared to traditional materials. Wood flour is one of the most widely used fillers, and the resulting material, known as wood plastic composite (WPC), has already found a wide applicability in many industrial sectors including automotive and building construction. This paper, as a followup of a previous study on a numerical-based approach to optimize the sound transmission loss of WPC panels, presents an extensive numerical and experimental vibro-acoustic analysis of an orthotropic panel made out of WPC boards. Both structural and acoustical excitations were considered. The panel radiation efficiency and its transmission loss were modeled using analytic and semi-analytic approaches. The mechanical properties of the structure, required as input data in the prediction models, were numerically determined in terms of wavenumbers by means of finite element simulations, and experimentally verified. The accuracy of the predicted acoustic performances was assessed by comparing the numerical results with the measured data. The comparisons highlighted a significant influence of the junctions between the WPC boards, especially on the panel’s transmission loss. The radiation efficiency results were mostly influenced by the boundary conditions of the plate-like structure. This latter aspect was further investigated through a finite element analysis.

Structural Performance of HDPE and WPC Lumber Components Used in Aquacultural Geodesic Spherical Cages.

Based on previous research, a novel wood–plastic composite (WPC) lumber has shown potential to replace high-density polyethylene (HDPE) lumber in the construction of aquacultural geodesic spherical cage structures. Six HDPE and six WPC assemblies, which are representative of typical full-size cage dimensions, were fabricated by bolting pairs of triangular panel components made with connected struts. Half of the panel assemblies had a plastic-coated steel wire mesh to simulate the actual restraint in field applications of the cages. The objective of the research was to characterize the structural performance of the panel assemblies under compressive loading. To determine the critical buckling load for the panel assemblies made from WPC and HDPE struts with and without wire mesh, Southwell’s method was implemented. A two-dimensional (2D) linear finite element analysis model was developed to determine axial forces in the struts of the panel assembly for the applied load and boundary conditions. This model was used to determine strut compressive forces corresponding to the Southwell’s method buckling load and the experimental failure load. It was found that the wire mesh increased the load capacity of both HDPE and WPC panel assemblies by a factor of two. The typical failure mode of the panels made from HDPE lumber struts, with and without wire mesh, was buckling of the struts, whereas the failure mode of the WPC panels, with and without wire mesh, was fracture at the notched section corresponding to the location of the bolts. The load capacity of the panel assemblies made from WPC lumber struts was three times and 2.5 times higher than the load capacity of the panel assemblies made from HDPE lumber struts with and without wire mesh, respectively.

Manufacturing Wood–Plastic Composites from Waste Lignocellulose Plus Haloxylon Species and Recycled Plastics

Abstract The aim of this research is to show useful utilization of agricultural residues such as cotton stalks and branches of pistachio, pomegranate, and Haloxylon species with recycled plastic in manufacturing wood–plastic composite (WPC) panels. Wood–plastic panels were made from a combination of agricultural residues (as natural fiber) and recycled plastic (as resin) at 50 percent, and 60 percent by weight fiber loading. Density and dimensions of the panels were 0.61 g/cm3 and 350 by 350 by 14 mm, respectively. Physical and mechanical properties of the panels including thickness swelling, water absorption, static bending (modulus of rupture and modulus of elasticity ), and internal bond were investigated. Physical and mechanical properties of the WPC panels decreased with an increase in fiber content from 50 percent to 60 percent. Physical and mechanical properties of samples made with 50 percent plastic were higher than samples with 40 percent plastic. The best values of physical and mechanical properties of the WPC panels were found at 10 percent and 5 percent Haloxylon particle loading, respectively. The highest values of mechanical properties of WPC panels were found at 50 percent plastic and 5 percent Haloxylon particle loading.

Waste glass powder – Innovative value-adding resource for hybrid wood-based products

Abstract This paper reports on a novel and cost-effective means of enhancing the porosity, stiffness and resistance to moisture/water, swelling and fire of wood plastic composite panels (WPCs); an increasingly important family of engineered materials that can be produced entirely from waste. This solution opens a new opportunity for transferring 100% wastes into resources. In this study, waste polypropylene container and saw dust was used to produce WPC and mixed waste glass was selected as secondary filler. Effect of particle size and coupling agent on mechanical properties of WPCs were investigated. A series of specimens were prepared with powder filler (saw dust and glass)/polypropylene binder with weight percent ratio of 60/40 respectively. Secondary glass powder filler was incorporated to the blend, replacing 5–30% of wood powder content. The glass-reinforced-WPCs were stiffer (higher MOE) with an increment of around 0.5 GPa per 5 wt% addition of glass powder achieved, less porous and exhibited better resistance to moisture/water absorption, thickness swelling and fire. Although the improvement in flexural strength (MOR) was less significant, this study confirms incorporating glass powder in WPCs can be a solution to create enhanced performance of thermoplastic-wood composite for high moisture environment application out of 100% wastes.

Властивості личкованих деревинно-полімерних матеріалів плоского способу пресування

Досліджено процес личкування деревинно-полімерних матеріалів (ДПМ) плоского способу пресування. Личкування ДПМ здійснено одночасно з їх пресуванням. Для личкування використано декоративний ламінат високого тиску (HPL) товщиною 0,5 мм. Як клей для приклеювання HPL використано поліетиленову (ПЕ) плівку або вторинний поліетилен низької щільності (ВПЕ). Для порівняння виготовлено личковані ДПМ без використання клею для приклеювання HPL. Встановлено, що тип клею не має істотного впливу на механічні показники ДПМ. Межа міцності під час статичного згинання у разі використання ВПЕ зростає на 14%, а у разі використання ПЕ плівки – на 24%, порівняно із личкованими ДПМ без використання клею для приклеювання HPL. Аналогічні залежності спостережено і для модуля пружності під час статичного згинання. Тип клею для приклеювання HPL також не має визначального впливу на межу міцності під час розтягування перпендикулярно до площини плити. Набрякання за товщиною значно зменшується із використанням клею, особливо це проявляється під час занурення взірців у воду на 24 год. У разі використання ПЕ плівки та ВПЕ отримано практично однакові результати набрякання за товщиною, як за 2, так і за 24 год занурення.

Some Mechanical Properties of Nylon Composite Plywood Produced from Different Wood Species

Aim of study: Investigation of some mechanical properties of panels produced using polyethylene waste as adhesive instead of formaldehyde-based resins used in plywood was aimed and polyethylene amount was tried to determine for plywood produced from different wood species. Area of study: This study was conducted at the Pilot Facility of Department of Forest Industry Engineering, Karadeniz Technical University in Trabzon, Turkey. Material and Methods: Beech ( Fagus Orientalis Lipsky ), alder ( Alnus glutinosa subsp. barbata ) and Scots pine ( Pinus sylvestris L.) veneers were used to produce polyethylene plywood. Three different polyethylene amounts was used (160, 200 and 240 gr/m 2 ). Density, shear strength, bending strength and modulus of elasticity of plywood panels were determined according to TS EN 323-1, TS EN 314-1 and TS EN 310, respectively. Main results: The best mechanical strength values for beech and alder were obtained from panels produced using 200 gr/m 2 polyethylene amounts. Moreover, these values for Scots pine were found in panels produced using 160 gr/m 2 polyethylene amounts. Research highlights: When this study applies in the plywood industry, can provide to both recycle polyethylene waste and prevent formaldehyde release. Polyethylene plywood waste can be used production of wood plastic composite panels.

WPC 방음판의 수직하중에 대한 내하성능 평가

The weight of soundproof panels is an important consideration in the design of panels, especially used in high noise barriers. The panels located at the lower section of the high noise barrier are likely to be deformed or broken by the weight of the upper panels. Korean road construction specifications and standards for soundproof panels still don’t provide specific requirements for load carrying capacity of panels. In order to determine the maximum vertical load which a wood plastic composites (WPC) panel can bear, a compression test and a flexural test were performed. In addition, the maximum loading number and height of WPC panels in a noise barrier were calculated for full, simple, and continuous support conditions.

Composite panels obtained from automotive waste plastics and agricultural macadamia shell waste

Disposal of waste has become a serious environmental issue, and problem continues to increase with increase in population and development of industries. Efficient and environmental solution is critically required to address the solid and hazardous waste streams. In this study, waste automotive plastics and macadamia shell is used to produce wood plastic composite (WPC) panel. The density, mechanical, microstructure and thermal properties of produced WPC panels are assessed and compared with 100% automotive plastic panel. Density of produced WPC panels increased linearly with increase in content of macadamia shell. The mechanical tests indicate that the addition of macadamia shell increased the comprehensive modulus 548 MPa for 75% macadamia shell WPC panel. Microstructure analysis of fractured surfaces in compression manner reveals that addition of macadamia shell partially transforms the brittle failure of waste automotive plastic into ductile failure that could be a result of mechanical bonding between plastic and macadamia shell powder. Thermal property also indicates that the WPC panel has good flame retardant property compare to 100% plastic panel. This approach of using automotive waste plastics and macadamia empty shells to eco-friendly WPC panels could be a solution to serious environmental pollution, resource recovery and also for economy benefit.

Coupling effect of waste automotive engine oil in the preparation of wood reinforced LDPE plastic composites for panels

We demonstrated the formulation of wood plastic composite (WPC) materials with flexural strength of 13.69 ± 0.09 MPa for applications in outdoor fencing using municipal waste precursors like low density polyethylene (LDPE) plastics (54.0 wt. %), sawn wood dust with particle size between 64 and 500 μm derived from variable hardwood species (36.0 wt. %) and used automotive engine oil (10 wt. %). The WPC panels were prepared by pre-compounding, extruding at a screw auger torque of 79.8 Nm and pressing through a rectangular mould of dimension 132 mm × 37 mm × 5 mm at temperature 150 °C. The efficacy of black waste oil, as a coupling agent, was demonstrated by the absence of voids and pull-outs on microscopic examination using scanning electron microscopy. No hazardous substances were exhaled during thermo-gravimetric mass spectrometry analysis. The percentage crystallinity of the LDPE in the as-prepared material determined by differential scanning calorimetry was 11.3%.

Properties of Veneered Flat Pressed Wood Plastic Composites by One-Step Process Pressing

The aim of this study was to develop, manufacture and determine properties of veneer overlaid flat pressed wood plastic composite (WPC) panels from recycled low density polyethylene (rLDPE), wood particles and different kinds of veneer (rotary-cut birch veneer and sliced oak veneer) using various adhesives by one-step hot pressing. Food packaging polyethylene film (PE film) as recycled stretch wraps, recycled low density polyethylene (rLDPE) particles and phenol formaldehyde (PF) resin were applied as adhesive for the bonding of veneer to the surface of WPC. No modification additives were used for the manufacture of WPC. It was found that compared with non-veneered WPC, the panels sandwiched with natural veneers greatly improved their properties. The bending strength was improved in 1.9–2.6 and 7.9–10 times across and along veneer fibers respectively for both types of investigated veneer. The highest values of bending strength were observed in WPC panels veneered with rotary-cut birch veneer. However, the water resistance of veneered WPC panels was reduced in comparison with non-veneered. The WPC specimens veneered with both types of veneer using PE film had better mechanical properties and water resistance than those of the specimens made with other two types of adhesives. The veneering of WPC panels enables to significantly improve adhesion properties of these veneered surfaces for their further finishing. In addition, the veneering of WPC panels hides the surface defects and provides a uniform application of different paints, varnishes and films to the surface of such materials. Overlaying WPC panels with wood veneers improves their appearance and properties resulting in eco-friendly value-added products.

Biological Characterization of Panels Manufactured from Recycled Particleboards using Different Adhesives

Transforming waste or recycled materials into value-added products is of high priority today. Wood plastic composites (WPCs) show high potential for the use of recycled materials in making durable composites. The applicability of WPC panels produced from recycled materials (ultralight foam core particleboards) for exterior building application was tested using wood-destroying basidiomycetes. The results showed that the panels were fully resistant against Coniophora puteana (Cp) and Gloeophyllum trabeum (Gt), but not very resistant against Pleurotus ostreatus (Po). The decay susceptibility index of Po-exposed specimens showed that the polystyrene-bonded (PS) samples were more resistant than solid beech wood samples that were used as references, followed by melamine-urea formaldehyde-bonded samples. A comparison with the reference samples also showed that the panel density had a significant influence on the panel’s resistance against basidiomycetes. The higher the panel density, the more resistance will be achieved in the panel.

Effect of Wood-derived Charcoal Content on Properties of Wood Plastic Composites

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

Wood Plastic Composite Panels: Influence of the Species, Formulation Variables and Blending Process on the Density and Withdrawal Strength of Fasteners

In this work, the influence of four variable parameters including fiber types (poplar and rice straw), fiber contents (45, 60, and 75 wt%), fiber sizes (20–40 and 40–60 mesh), and blending methods (hot-pressing and extrusion) on the physico-mechanical properties of wood plastic composite panels were studied. Generally, the results showed that each of the above-mentioned parameters had significant effect on the nail and screw withdrawal strength (pull-out load) and density, whereas their interactions did not have highly impressive effects on the properties. All tested properties vary significantly with fiber origin. Composites filled with larger fiber size, produced panels with higher withdrawal strength and density. The effect of blending method on density was maximal. Withdrawal strength values of each sample decreased with increase in fiber loading. The lowest withdrawal strength values of nail and screw were obtained from the samples filled with rice straw. It was found that strength properties of the composites can be improved moderately by adding 45 wt% fiber, 20–40 mesh particle and poplar flour. According to the results, the blending method is a significant variable in the determination of withdrawal strength. Therefore, the blending method can be recommended based on the end product applications.

Processing and flexural properties of surface reinforced flat pressed WPC panels

While extrusion and injection molding are the common technologies to produce wood-plastic composites (WPC), pressing may be an alternative, particularly when flat products are striven for. In this study, flat pressed WPC panels were surface-reinforced by two different types of thermoplastic face layers to improve flexural properties. The two face materials applied were a commingled fabric made of glass and polypropylene filaments (TWINTEX®) and a glass fabric reinforced polypropylene laminate (S-TEX®). Combination of face layers and WPC panels was achieved in a single and a two stage flat pressing process. Besides studying the effects of reinforcing material and number of process stages, the influence on flexural properties of the reinforced panels was identified. Unreinforced WPC panels were tested for comparison. The reinforced WPC panels exhibited greatly improved flexural properties, with MOE (MOR) values up to nearly 10,000 N/mm² (90 N/mm²).

Properties of wood plastic composite panels made from waste sanding dusts and nanoclay

This article presents the application of waste sanding dusts in order to evaluate its suitability as reinforcement for thermoplastics as an alternative to wood fibers. The effects of sanding dust loading and nanoclay content on the physical and mechanical properties were also studied. Overall trend showed that with addition of sanding dusts, tensile and flexural properties of the composites were significantly decreased, due to the reduction of interface bond between the fiber and matrix. It was found that flexural, tensile and withdrawal strength of fasteners were moderately enhanced by the addition of 2 wt% nanoclay in the matrix. However, with increase in the nanoclay content (4 and 6 wt%), the flexural and tensile properties decreased significantly. The results also showed that the withdrawal strengths of screws are much higher than those of nails. At certain amount of sanding dust, with increasing nanoclay loading the withdrawal strengths of fasteners (screws and nails) were considerably decreased. The thickness swelling and water absorption of the composites dramatically decreased with the increase in nanoclay loading. Except thickness swelling, both variable parameters (sanding dust and nanoclay contents) showed significant influence on physico-mechanical properties.

Thickness swelling and water absorption of WPC after immersion in cold and boiling water

Thickness swelling (TS), water absorption (WA) and edge swelling (ES) of 20 mm flat-pressed wood–plastic composites (WPC) panels with a wood flour (WF) content of 50 and 70 % manufactured using an industrial single-daylight press and samples of a high pressure laminate (HPL) compact panel were determined after immersion in cold water according to EN 317 and boiling water according to EN 438 in order to propose, describe and verify a method to (1) measure TS, WA and ES more quickly than by applying EN 317 and (2) to make the properties of WPC and HPL comparable to each other. TS, WA and ES of WPC panels determined after immersion in cold and boiling water were found to correlate with a correlation coefficient of 95–99 % equating 24 h (EN 317) and 0.5 h (EN 438) to factor x. Properties of WPC panels with WF content of 50 % were found to be comparable, respectively superior to those of HPL.

Effects of agglomeration and pressing process on the properties of flat pressed WPC panels

This study discusses the influence of agglomeration process, press type and press parameters, on the physical and mechanical properties (water absorption (WA), thickness swelling (TS), internal bond strength, module of elasticity, and module of rupture) of flat pressed wood–plastic composite panels. Additionally, the effects of coupling agent and polymer's melt flow rate on panel properties are investigated. The compounding of the raw materials is done using a heating cooling mixer and a die ring agglomerator (DRA). Test panels are made using a laboratory scale single-daylight press, an industrial single-daylight press, and an industrial scale continuous double belt press (DBP). The best results were obtained using the DRA and the continuous DBP, with 24 h WA and TS values of below 1%, and a modulus of elasticity of more than 4500 N mm−2. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Effects of formulation variables on surface properties of wood plastic composites

Degree of surface quality of wood plastic composites (WPCs) is a function of both raw material characteristics and the manufacturing variables. The WPC panels comprised of different panel densities (800, 950, 1000, and 1080kg/m3), wood flour contents (50, 60, 70, and 80wt.%), wood flour sizes (<0.5, ⩾0.5 to <0.8, 0.8–1, and >1mm), and hot-pressing temperatures (190 and 210°C) were manufactured using a dry blend/flat-pressing method under laboratory conditions. The surface smoothness of the WPC panels improved with increasing WPC density, plastic content, and hot-pressing temperature while it deteriorated with increasing wood flour size. The reduction in the particle size of the WF resulted in a more compact structure on the WPC surface. In general, the wettability of the samples increased by increasing surface roughness.