Glass Fiber Polyester Composites Research Articles

Ceramic matrix composite reinforced with glass and walnut shell filler: Influence of mesh size on its mechanical properties

Fillers are added in the composite in order to not only enhances the properties enhancement but also reduces the fabrication cost. In this regard, various fillers are added in polymers to achieve optimized properties of composite. Walnut shell in the form of powder is now being utilizes as a filler reinforcement in the polymer matrix. The size of the walnut shell filler is one of the vital factors that influences greatly the mechanical properties of the composite. The present study thus shed lights on the reinforcement of walnut shell filler (WSF) of two categories of mesh size viz: 160–180 µm and 280–300 µm in the glass fiber-polyester composite. The weight fraction of WSF was varied from 0 to 15 % with a difference of 5 % in every reinforcement. Samples were fabricated as per ASTM standards and a comparison was made for mechanical properties. It was found that WSF with mesh size 160–180 µm performed well for tensile, flexural and impact behavior whereas WSF with mesh size 280–300 µm showed better improvement in hardness.

Role of discontinuous fiber core material on the mechanical behavior of hybrid sandwich polyester composites

This study investigated the potential for improving the mechanical behavior of glass fiber polyester composites by using symmetric hybrid sandwich configurations that combine continuous woven composite and different discontinuous reinforcements used as a core. The discontinuous reinforcements included sheet molding compound (SMC), bulk molding compound (BMC), and the discontinuous prepreg based platelets that were chopped from the woven trim scrap. Hybrid sandwich configurations using different core materials exhibited improvements in flexural mechanical properties, while providing more progressive failure under both flexural and compressive loading. Compressive strength in polyester SMC and woven laminate was significantly lower than flexural strength, while BMC and chopped platelets exhibited similar levels of strength in flexure and compression. Overall, hybridized compression molding produced sandwich structures can be used to control the failure progression and to improve the structural characteristics of composite, especially under flexural loads. The trim scrap core sandwich configuration had mechanical properties comparable with the BMC core hybrid. Therefore, trim scrap upcycling can be an efficient approach to reducing the amount of material waste during the manufacturing.

Characterization and numerical simulation of laminated glass fiber–polyester composites for a prosthetic running blade

The objective of this work was to explore different types of deformations (buckling, bending, and relaxation) on the properties of laminated composites based on polyester as the matrix and glass fiber in two forms: woven and chopped strand mat. The specimens were produced with the same thickness but with different number of ply. Also, a thin gelcoat based on clay particles was applied on the chopped strand mat samples to get a third series. The results showed that using the same thickness, the mechanical properties, especially in terms of bending and buckling, are influenced by the layers’ number. Furthermore, a sports application, which is the main objective of this work, is presented as an applied investigation for a leg prosthesis. Three different running blades “Flex-foot Cheetah” were manufactured to be experimentally and numerically (ANSYS ACP software) characterized to simulate real conditions. The results showed a good agreement between the experimental and numerical values in terms of total displacement, which is around 50 mm, the produced blade has been tested in quasi-static and dynamic compression, and results showed that the relaxation behavior depends on the structure design and the used materials.

Vibration and damping characteristics of sisal and glass fiber reinforced polyester composite

This study aims to evaluate the result of experimental investigation carried out on free vibration characteristics and damping factors of short sisal & glass fiber polyester composite. Composites specimen is fabricated in random fiber orientation using to hand lay-up method by Influence of fiber length (10mm) and weight percentage (5, 10, 15, 20 wt. %) . Studies revealed that increase in the fiber content will in-crease the natural frequency (Hz) and decrease the damping factor is given by the composites having a fiber loading of 20 wt. percentage ranges. The properties were compared with neat polyester. In this work, increasing fiber content increases the natural frequency (Hz) and decrease the damping factors of the composite.

Comparative Evaluation on Mechanical Properties of Jute, Pineapple leaf fiber and Glass fiber Reinforced Composites with Polyester and Epoxy Resin Matrices

Environmental consciousness and an increasing concern with the greenhouse effect have stimulated the construction, automotive, and packing industries to seem for sustainable materials that can replace conventional synthetic polymeric fibers. Natural fibers seem to be a good alternative since they are readily available in fibrous form and can be extracted from plant leaves at very low costs. In this work we have studied the mechanical properties of the composites made by reinforcing Jute, Pineapple leaf fiber and Glass fiber as 1:1:1 ratio into a polyester and epoxy resin. The fiber content in the composite was varied from 0.18 to 0.42 by volume fraction and the variation of mechanical properties such as tensile, flexural and impact properties in each case were studied. The results show that the Jute, Pineapple leaf fiber and Glass fiber reinforced epoxy composite exhibited better mechanical properties than Jute, Pineapple leaf fiber and Glass fiber polyester composite.

Mechanical Properties of Pineapple Leaf Fibre Reinforced Polymer Composites for Application as Prosthetic Socket

Biodegradable fibers derived from natural plants are abundantly available and are currently considered as waste. This study aims at investigating the mechanical properties of pineapple leaf fiber reinforced thermoset composites as possible alternatives to the above-knee glass fiber reinforced prosthetic socket. This study was carried out according to ASTM (2004) standards at temperature and relative humidity of 26 ± 3 °C and 51 ± 2%, respectively. Continuous pineapple leaf fibers are treated with sodium hydroxide and acetic acid, and then added to epoxy and polyester at varying fiber loadings of 0, 20, 30, 40 and 50% to produce fiber reinforced composites using the hand lay-up method. The mechanical properties of glass fiber polyester composite (GFPC) were compared with pineapple leaf fiber polyester composites (PLPC) and pineapple leaf epoxy composites (PLEC). The results showed that PLEC, particularly at 40% fiber loading, had superior mechanical properties than GFPC and PLPC. The tensile, flexural and impact strengths of PLEC are 76.47 ± 3.85 MPa, 81.27 ± 1.77 MPa and 59.03 ± 0.99 k/Jm2 , respectively. These values are higher than those of PLPC with tensile, flexural and impact strengths of 62.09 ± 4.47 MPa, 53.02 ± 1.20 MPa 45.22 ± 1.10 k/Jm2 , respectively. The tensile, flexural and impact strengths of GFPC are also lower and are respectively 59.03 ± 0.99 MPa, 66.10 ± 1.88 MPa and 52.48 ± 1.77 k/Jm2 . Thus, PLEC has the potential to be further developed as a replacement for glass fiber in above-knee prosthetic sockets.

The Effect Of Sulphuric Acid on The Properties of Random Glass Fiber Polyester Composite

Many supplementary investigations are necessary to accomplish the central demand for a chemical resistance test method of glass fiber reinforced resins. The effect of sulfuric acid (H 2 SO 4 - concentration 10%) on mechanical and chemical properties of malti layers random glass fiber reinforced with polyester resin composite were studied. The samples were immersed on the chemicals for six weeks. The effect of the sulfuric acid on the mechanical properties (tensile, bending, hardness) and physical properties (absorbility) has been studied on the random glass fiber polyester composite. The results showed the mechanical properties in most cases decreased such as the tensile, bending and hardness and the absorbility 5.3%.

Mechanical properties of natural fibers reinforced polyester hybrid composite

In this investigation, the mechanical properties of natural fibers reinforced polyester hybrid fiber reinforced polyester composite were analysed based on the wt % and length of the fibers. The glass fiber polyester composites were also prepared to compare the properties. The fractured surfaces of the composite specimens were investigated using scanning electron microscopy. The tensile and the flexural strength increases with the fiber length and content. On the other hand, the impact strength decreases with the fiber length and content. The experimental results were compared with predicted results using regression model.

Analysis of the Film-stacking Processing Parameters for PLLA/Flax Fiber Biocomposites

Nowadays, the market demand for environmentally friendly materials is rapidly increasing. Biodegradable fibers and biodegradable polymers, mainly extracted from renewable resources, are expected to be a major contribution to the production of new industrial high performance biodegradable composites, partially solving the problem of waste management. At the end of its lifetime, a structural biodegradable composite can be crushed and recycled through a controlled industrial composting process. Bodros et al. [1] showed that biodegradable L-polylactide acid (PLLA)/flax fibers mat composites exhibiting specific tensile properties equivalent to glass fiber polyester composites can be manufactured by an un-optimized film-stacking process. In our study, the process has been investigated more extensively. Indeed, the compaction of flax mats requires a higher load than for glass mats of similar areal weight. The transverse permeability of flax mats has also been shown to be lower than for glass mats. In both cases, this is due to a higher degree of entanglement of the flax fibers within the mat. However, the range of permeability and compressibility values of the flax mats are well within the values that allow a good through-the-thickness impregnation. Flax fibers cannot sustain long exposures at the impregnation temperature of the mats by PLLA resin. Through-the-thickness impregnation of flax mats processes such as film stacking are more suitable than in-plane impregnation processes such as resin transfer molding because the flow of resin is limited on short distances and allows short times of impregnation.

Effects of nano ZnO on strength and stability of unsaturated polyester composites

AbstractZnO–glass fiber–unsaturated polyester composites have been prepared. On exposure to the metal halide lamp, their resistance to ultraviolet (UV) degradation is evaluated. Experimental results show that ZnO can reduce the UV degradation of the unsaturated polyester matrix. ZnO can significantly retard the UV degradation process of the matrix resin, and can also increase the impact strength of the composites under the experimental conditions. Differential scanning calorimetry (DSC) analyses also indicate that the addition of ZnO to unsaturated polyester may retard the crosslink process and catalyze the decomposition of the resin. However, after more than 40 hr of UV irradiation, it was crosslinked. SEM fracture morphology shows that nano ZnO could hinder crack growth and induce more cracks, and when the content of ZnO reaches 6 wt%, the impact fracture mechanism changes abruptly and plastic deformation appears, which indicates that 6 wt% for ZnO in unsaturated polyester could be considered as the critical content. Around the critical content, the particles are near enough to interact with each other and this results in the change of fracture mechanism. The results also indicate that the proper content of ZnO added into an unsaturated polyester could prolong the durability and lessen the reject rate of transparent glass fiber–polyester composites. Copyright © 2008 John Wiley & Sons, Ltd.

Micromechanical modelling and simulation of chopped random fiber reinforced polymer composites with progressive debonding damage

The aim of the present paper is to provide a quantitative prediction of the elastic-damage behaviour of randomly oriented fiber polymer composites. A constitutive model based on micromechanical considerations is presented. The nucleation and growth of voids induced by progressive fiber debonding is combined with the constitutive relationship. Failure resulting of excessive damage accumulation is captured by a critical void volume criterion and a vanishing element technique. Experimentally, damage accumulation in random glass fiber–polyester composites was monitored by a videoextensometry technique able to control the local strain rate. Good agreement of model predictions with experimental data is pointed out. The model was implemented into a finite element program and numerical applications on composite structures (a tensile specimen and a plate containing a central hole) are presented to illustrate the capability of the approach. Digital image correlation method was also used to measure the full-field strain in a notched specimen under tensile loading. The simulated results compared favourably with those obtained from experiments.

A study on the potential of sugarcane fibers/polyester composite for tribological applications

The tribo-potential of sugarcane fibre reinforcement in the thermoset polymers for enhancing the adhesive wear resistance has not been explored so far. Hence, the present work aims to explore the possibility of using this natural fibre to reinforce polyester and thus opens a new way to implement locally available inexpensive fibres and produce a new candidate tribo-material for bearing applications. Sugarcane fibre/polyester (SCRP) and glass fibre/polyester (GRP) composites (with chopped fibres of 1, 5, 10 mm length randomly distributed and unidirectional mat fibres) were prepared using compression mould and hand-lay-up techniques. Friction coefficients and wear rates of SCRP and GRP composites were determined under dry sliding contact conditions in parallel and anti-parallel orientations and subjected to different operating parameters such as load, speed and test duration. Results of friction and wear proved that SCRP composite is a promising composite which can be a competitive to GRP composite. In the case of chopped sugarcane/polyester (C-SCRP) composite, very smooth patches of polymer film (protective layer) due to plastic deformation shielded the surface of C-SCRP composite pin from damage by the metallic asperities and thereby contributed to the higher wear resistance. Furthermore, this layer provided enhancement to the bonding of SCFs fibre with matrix. In contrast C-GRP composite produced broken hard particles of GF at the interface which acted as a third body and restrained the formation of such protective layer. Wear resistance of C-SCRP composite increased significantly with increasing load but decreased drastically for C-GRP composite. In addition, wear rate of C-SCRP composite decreased by (20–50%) when the fibre length increased from 1 to 5 mm. With further increase in the fibre length to 10 mm, the wear rate was no longer decreased instead increased drastically by 40–70%. Besides C-SCRP composite gave friction coefficient of the same order as C-GRP composite. Unidirectional sugarcane/polyester (U-SCRP) composite showed lowest wear resistance when fibre was oriented parallel to sliding direction. But when this composite tested in AP-O, wear resistance was almost the same as the CM-GRP composite. Moreover, the U-SCRP composite exhibited lowest friction coefficient when tested in AP-O and highest when tested in P-O, suggesting that reinforcing polyester with sugarcane fibre (SCF) in AP-O can be a competitive to glass fibre. In conclusion, glass fibres have negative impact on the formation of polymer film and responsible for the observed discontinuous (ruptured) film for C-GRP composite. In other words, the back transfer polymer film formed at the interface managed to survive in the case of using SCF but in the case of GF, the effect of impact-type repeated loading caused by hard asperities and broken particles of glass fibre unstable the formation of such protective layers together with increased debonding and fractured fibre resulted in higher wear rate of C-GRP composite. Finally, microscopic observation evidenced that the SCF has the ability to have a fairly good bonding with the polyester matrix. This in turn made the separation of fibre from the composite more difficult and hence contributed to improvement of wear resistance for C-SCRP composite compared to C-GRP composite. In contrary, the bonding between GFs and the matrix for C-GRP composite was not that strong and the fibres were easily debonding.

A modeling approach for prediction of erosion behavior of glass fiber–polyester composites

In recent years, a fairly good number of articles dealing in characterization of solid particle erosion of glass fiber reinforced composites are available but exhaustive study on this vital aspect leading to understand erosion phenomenon is hardly found in the literature. Therefore, in the present work, a theoretical model based on principle of conservation of particle kinetic energy is developed to de- termine wear rate of glass-polyester composites due to multiple impact erosion. Room temperature erosion tests are then carried out to study the effect of various control factors in an interacting environment on the erosion be- havior of these composites. For this purpose, design of experiments approach utilizing Taguchi's orthogonal arrays is adopted to test the specimens on air jet type erosion test configuration. The results indicate that erodent size, fiber loading, impingement angle and impact velocity are the significant factors in the order of their influence on wear rate. Taguchi approach enables to determine optimal param- eter settings that lead to minimization of erosion rate. Artificial neural network (ANN) approach is applied to the erosive wear data to reach at acceptable predictive models. Scanning electron microscopy of the eroded surface of the composites is performed for observation of the features such as crack formation, fiber fragmentation and matrix body deformation. Finally, popular evolutionary approach known genetic algorithm (GA) is used to generalize the method of finding out optimal factor settings for minimum wear rate.

Could biopolymers reinforced by randomly scattered flax fibre be used in structural applications?

Thermoplastics reinforced by natural fibres are mainly used for fitting-up products in the automotive industry. The aim of this work is to study the tensile properties of natural fibre-biopolymer composites in order to determine whether or not, biocomposites may replace glass fibre reinforced unsaturated polyester resins. The materials used are flax fibre, polylactic acid (PLA), l-polylactide acid (PLLA), poly(3-hydroxylbutyrate) (PHB), polycaprolactone and starch thermoplastic (MaterBi® Z), poly(butylene succianate) (PBS) and poly(butylene adipate-co-terephtalate) (PBAT). The tensile properties of the flax fibres have already been determined [C. Baley, Analysis of the flax fibres tensile behaviour and analysis of the tensile stiffness increase, Comp Part A 2002;33:939–948]. The composites are manufactured using a film stacking technique. After studying the processing parameters, these are then adapted to each thermoplastic composites. Test samples are cut out from the composites to test their mechanical properties under tensile loading conditions. These tensile properties are then compared to those of similar polypropylene flax composites. Preliminary results show that the tensile properties are improved with the fibre volume fraction. The tensile strength and Young’s modulus of PLLA and PLA flax composites are greater than those of similar PP/flax fibre composites. The specific tensile strength and modulus of flax fibre/PLLA composite have proved to be very close to those of glass fibre polyester composites.

Axial compressive failure of glass-fibre polyester composites under superposed hydrostatic pressure: influence of fibre bundle size

The axial compressive strengths of three 0·52 V f glass-fibre/polyester pultrusions were determined under superposed hydrostatic pressures extending to 300 MPa. Atmospheric strengths were in the range 380–790 MPa, and all materials showed a strong, about 3, pressure-dependence. Kinking of fibre bundles or sub-bundles preceded fracture in all materials at all pressures, but failure to detect non-propagating transverse cracks, which allow such groups of fibres to act in unison, indicates that bundle-debonding controlled the critical mechanism of failure. The effects of shape, size, and eccentricity of the bundles on buckling and debonding are considered. It is tentatively concluded that the critical parameter is the transverse tensile strain of the resin, ϵ 1 , causing bundles (rather than individual fibres) to debond. The pressure-dependence of the compressive strength is well predicted by the ϵ 1 criterion. To obtain fair correlations with the measured values, the bundle-bundle decohesion strengths would have to be to the order of 223 MPa, rather than approximately 50–100 MPa estimated for the fibre-fibre debond strengths.