Compression Moulding Method Research Articles

Effect of comingling techniques on mechanical properties of natural fibre reinforced cross-ply thermoplastic composites

Continuous natural fibre reinforced thermoplastic composite materials not only offer low weight and better strength than short fibre reinforced composites but are also biodegradable and eco-friendly. The impregnation of resin into the reinforcement is considered as a major concern during the fabrication of thermoplastic composites. Therefore, intermediate materials known as comingled fabrics were developed to assist the fabrication of continuous fibre reinforced thermoplastic composites by aligning the polypropylene fibres alongside the reinforcement natural fibres (jute, hemp and flax) using weaving and knitting techniques. Cross-ply composite panels were fabricated using hot press compression moulding method. The novelty of this work is the simplified methodology to develop the comingled fabrics and the effects of comingling on the mechanical properties of composites. The effect of the comingling technique on the tensile, flexural and impact properties of composites is explained in this research work. Knitted comingled composite specimens exhibit superior mechanical properties than woven comingled composite specimens. The experimental results have shown 14%, 7% and 3% increase in tensile strength, 25%, 20% and 13% increase in flexural strength and 37%, 54% and 44% increase in impact strength of knitted comingled specimens of jute, hemp and flax respectively.

Effect of water absorption on the mechanical properties of cross-ply hybrid pseudo- stem banana/glass fibre reinforced polypropylene composite

The initiative to reduce the consumption of non-renewable resources increases the awareness of being green in composites. The synthetic fibres are currently substituted by natural fibres applicable in various industries such as automotive and building. In this study, the effects of water absorption on the tensile and flexural properties of cross-ply hybrid pseudo-stem banana/glass fibre reinforced polypropylene composites are investigated. The hybrid banana (B)/glass (G) polypropylene composites and the reference specimens of the non-hybrid composites of the plain banana and glass fibres termed the BBB and GGG specimens were fabricated using hot compression moulding method. Water absorption test was conducted according to ASTM D570 until the specimens reached saturation. Tensile (ASTM D3039) and flexural (ASTM D790) test were carried out on the dry specimens as well as the wetted specimens. It can be observed that non-hybrid GGG has the best water absorption properties and hybrid specimen with glass as outermost skin shows a comparable result. However, water absorption reduced the mechanical properties of the composites. The incorporation of glass fibre in the composites improved overall properties of the composites. The hybrid GBG dry specimen tensile strength and wet specimen flexural strength is 136.28 and 73.86 MPa respectively. The hybrid composite GBG shows comparable flexural properties to GGG composite.

Development and investigation of Pongamia pinnata epoxy composites

Abstract In the modern developments to increase the concerns in the natural fibers and its applications in different fields. In this paper, the development and investigation of Pongamia pinnata epoxy composites by compression moulding method. The 20 wt% composites have more mechanical strength as compared to other composites because of the uniform distribution of load. The scanning electron microscopy (SEM) shows the morphology of composites and ensures the presence of fiber reinforcement.

A comparison study on the mechanical properties of composites based on kenaf and pineapple leaf fibres

The arising trend of using natural fibres in the composite materials has stimulated the continuous exploration of their mechanical properties. The positive environmental behaviours of natural fibres are the driving factor that allows them to gain their wide acceptance in industries. However, the mechanical behaviour of natural fibre-based composites is still not fully explored. In this research study, the mechanical properties of composite materials with different types of natural fibre and various fibre compositions were investigated. The polypropylene-based composite materials were fabricated through hot press compression moulding method using a hydraulic hot press machine. The composites were then subjected to mechanical tests to study the tensile, flexural and impact properties of such materials. The results demonstrated that the tensile strength and flexural strength of pineapple leaf fibre (PALF)-based composites were 7.83% and 54.23% higher than kenaf-based composites at a fibre content of 30 wt%. Moreover, the impact strength of PALF-reinforced composites was 3.08% and 5.56% higher than kenaf fibre-reinforced composites in the flatwise and edgewise impact orientations. Overall, composites with 30 wt% evidenced the top most mechanical properties irrespective of types of plant fibre.

Investigations on mechanical and morphological characterization of chitosan reinforced polymer nanocomposites

Epoxy(EP)/Chitosan(CTS) nanocomposites was successfully prepared by compression moulding method. The morphological characterization on EP/CTS nanocomposites was carried out using scanning electron microscopy, x-ray diffraction, Fourier transmission infrared spectroscopy. Mechanical properties were studied as per ASTM D638-91, ASTM D256 and thermal properties were examined by differential scanning calorimetry and thermogravimetric analysis. SEM micrographs displays good dispersion of CTS was exhibited in the composite structure. Functional groups and degree of crystallinity are identified using FTIR and XRD. The TGA and DSC study show that the CTS nanoparticles were thermally stable. The addition of up to four weight percentage of CTS nanoparticles showed moderate improvement in tensile (80%) and flexural strength (47%) compared to neat epoxy and on addition of more than four weight percentage, the mechanical properties started deteriorating. In vitro hemolytic assay confirms the hemocompatibility of CTS/EP composites and the hemolytic ratio was found to be less than 5%. This result suggests that the CTS/EP composites are favourable biomaterials for bone fracture fixation plates and orthopaedic applications.

Dielectric Properties of Ethylene Vinyl Acetate Copolymer Composites Filled with Carbon Nanotubes, Graphene Nanoplatelets and Iron Oxide Nanoparticles

Ethylene vinyl-acetate copolymer (EVA) composite materials containing multiwall carbon nanotubes (MWCNT), graphene (Gr) and iron (III, IV) oxide (Fe3O4) nanoparticles where processed by melt blending. Film specimens were prepared by using compression moulding method. All nanoparticles content in samples was chosen equal to 20 wt.%. The material dielectric spectroscopy was used in a range of 10-2 Hz to 107 Hz to investigate nanoparticle effect on the dielectric active (ε’) and passive components (ε’’), specific electrical conductivity (σ’) and dielectric loss (tg) for the characterization of the dissipation of electromagnetic energy.

Fracture analysis and mechanical properties of three phased glass/epoxy laminates reinforced with multiwalled carbon nanotubes

Abstract Herein, we report the use of Multi Wall Carbon Nano Tubes (MWCNTs) as nano-compatibilizers based on their astonishing mechanical properties and ease of processing. To fabricate laminate samples, pure MWCNTs were homogeneously dispersed in the fiber-reinforced plastic (FRP) composite with 0, 0.5, 1 and 1.5 wt. % loading. The laminates were prepared with eight plies (4.0 ± 0.1 mm thickness) using the hand layup technique assisted by the compression moulding method. It was found that the tensile, compressive and inter-laminar shear strength (ILSS) increase by 103.81%, 139.78% and 36.06%, respectively corresponding to 1 wt. % loading of MWCNTs as compared to neat GFRP specimen. However, a rapid decrease in strength beyond 1 wt. % loading of MWCNTs has been noted. Interestingly, the maximum of the tensile strength was higher than that of the compressive strength, and the maximum of the tensile modulus was larger than that of the compressive modulus in the case of 1 wt. % loading of MWCNTs. It was observed that after a certain loading, the mechanical properties of such laminates can only reach the best value with an optimum loading of MWCNTs. In addition, the micromechanical failure modes and effect of MWCNTs loading on internal morphologies of the composites were also intensively explored with the help of Field Emission Scanning Electron Microscopic (FESEM) analysis.

Copy paper as a source of reinforcement for biodegradable composites – Influence of fibre loading, processing method and layer arrangement – An overview

The study investigates the use of copy paper in poly (butylene adipate terephthalate)-PBAT and polylactide-PLA composites. The influence of paper volume fraction (21, 30 and 48%) on the void content and the composite properties was analysed by using two different compression moulding methods. An increasing fibre content lead to significantly improved tensile characteristics, while the Charpy impact strength showed a toughness decrease for PBAT and an increase for PLA composites. Additionally, layered composites, where either two stiff PLA composite layers enclosed a ductile PBAT composite core or vice versa, were produced with the aim to increase the toughness. Due to the high elongation of PBAT, the insufficient fibre/matrix adhesion and the low fibre length, this goal could not be reached. However, copy paper represents a good reinforcing component achieving a maximum strength of 120 MPa and a tensile modulus of 10.2 GPa at the highest paper volume fraction in PLA.

Impact of ZnO nanoparticle morphology on relaxation and transport properties of PLA nanocomposites

In this work we study the effect of zinc oxide (ZnO) nanoparticle morphology and concentration on the resulting relaxation and transport properties of polylactide (PLA) nanocomposites. Films containing spherical and rod-shaped ZnO nanoparticles were incorporated into an amorphous polylactide (PLA) matrix through a solvent-precipitation and compression moulding method. Morphological analyses carried out by scanning electron microscopy (SEM) together with ultraviolet–visible (UV-Vis) spectroscopy and thermogravimetric analysis (TGA). Results indicate a much better distribution of rod-shaped ZnO within PLA matrix. Relaxation experiments reveal faster physical aging kinetics of PLA in presence ZnO nanoparticles notwithstanding their shape, suggesting the presence of non-interacting surfaces between the amorphous PLA matrix and the ZnO nanoparticles. Interestingly, both helium and oxygen permeability remained stable or increase upon nanoparticle addition, and anisole sorption kinetics showed faster mass transport in the nanocomposites, suggesting that the low interfacial adhesion between PLA and ZnO brings supplementary voids to the material increasing mass transport. Overall, the experimental findings here reported provide a deeper understanding on the influence of metal oxide nanoparticle morphology on the resulting relaxation and gas transport properties of amorphous polymeric nanocomposites.

Investigation of the Impact, Hardness, Density and Water absorption of Polypropylene Filled Doum Palm Shell Particles Composite

Particulate fillers are used to improve the physical and mechanical properties of polymers to make it more suitable for engineering application. This study determined the impact, hardness and physical properties of polypropylene reinforced Doum palm shell particles composite; the effect of particles loading and particle size on the impact, hardness, density and water absorption properties of the composite were studied. The composites were prepared by compounding polypropylene and Doum palm shell particles using compression moulding method. The particles loading in the matrix (polypropylene) were varied from 0 - 40 wt. % at 5 wt. % intervals, after which the composites were characterized. SEM analysis was also conducted on the composites. The results showed that the addition of Doum palm shell particles stiffened the flexibility of the polymer and improved its ability to absorb and dissipate energy. Composite of 150 µm has the maximum impact strength of 4.1 kJ/m 2 at 35 wt. % particles loading and 3.9 kJ/m 2 at 30 wt. % particles loading for 300 µm. The hardness of the composite was improved with increase in particle loading of the composites. The hardness increases from 6.53 HRF to 9.1HRF at 35 wt. % for 150 µm particle size and 8.6 HRF for 300 µm. Density and water uptake of the composite increases with increase in particles loading and size in the composites. The SEM images of the composites reveal a good interfacial bonding between Doum palm shell particles and the matrix. These account for the good impact and hardness properties of the composites obtained. Keywords: Impact strength, Hardness, polypropylene, Doum palm shell particles, Microstructural analysis, water absorption DOI : 10.7176/JIEA/8-1-04

Development and evaluation of water absorption, compression and impact properties of okra Nanofibrillated cellulose reinforcement in epoxy resin composites

Abstract Nanofibrillated cellulose were extracted from natural fibre of Okra plant by a chemical, Acid hydrolysis and mechanical method to study their potential for use as reinforcement fibrils in bio composite applications. The okra Nanofibrillated cellulose composites were prepared by Compression moulding and VARTM method. The Present work was to investigate water absorption, compression and impact properties of okra Nanofibrillated cellulose reinforced epoxy composites. The water absorption compression and impact of okra Nanofibers Reinforced Epoxy composites were studied and the effects of okra Nanofiber (0, 1, 2, 4 and 6 wt%) are also examined. The water absorption, compression and impact properties of Nanofibre reinforcement has improved when compared with the virgin composite. Water Absorption capacity is less for okra Nanofibrillated cellulose reinforced epoxy resin composites sample when compared to other composite samples but it is high when compared to pure epoxy resin sample. The compression strength of 4 wt% okra Nanofibrillated cellulose composites shows improve quality result among other composites and it gives 4 wt% improved strength of the pure epoxy resin composites. Whereas 4 wt% okra Nanofibrillated cellulose composites (OKCNFs) shows improve impact strength as compared to Epoxy resin composites. The okra Nanofibrillated cellulose composites are tested by means water absorption, compression and impact test based on ASTM standard. Effect of Fibril surface Treatment on water absorption, compression and impact properties are also observed.

Role of laminate fracture energy on ballistic performance of glass composite laminates

In the present study varying thickness of (5-25mm) E-glass composite laminates have been prepared through hot compression moulding method using different matrix systems such as phenolic and epoxy with E-glass fiber as a common reinforcement. The laminates were initially evaluated for their mechanical and mode-I inter laminar fracture energy as per ASTM test methods. It is observed that the laminate having epoxy matrix has shown higher mechanical and fracture energy than the laminate made using phenolic matrix. This is due to the strong adhesion bond between the epoxy matrix and glass fiber reinforcement. Further, the laminates were subjected to ballistic impact tests against 7.62X 39 mild steel projectiles. It is observed that the laminate having lower fracture energy (E-glass/phenolic) has shown better energy absorption under ballistic impact. Failure analysis on post impacted laminates have been studied using C-scan analysis and observed that E-glass/epoxy composite laminate has shown limited damage area, whereas E-glass/phenolic composite laminate has shown more damage area. This study reveals that the laminate having lower fracture energy for delamination is more suitable for higher energy absorption due to dissipation of energy in lateral directions under ballistic impact conditions.

Comparative study of physical, mechanical, and thermal properties on sugar palm fiber (Arenga pinnata (Wurmb) Merr.) reinforced vinyl ester composites obtained from different geographical locations

Sugar palm fibers (SPF) reinforced vinyl ester (VE) composites were prepared in this study. The SPFs were obtained from three different geographical locations: Kuala Jempol (Peninsular Malaysia), Tawau (West Malaysia), and Tasik Malaya (Indonesia). The SPFs were utilized as reinforcement material with a fixed loading of 10 wt.%. The reinforced VE composites were prepared using a wet lay-up compression moulding method. The physical properties examined were water absorption, thickness swelling, and moisture content. To determine the strength of the SPF composites, tests on the tensile, flexural, and impact strength related to mechanical properties were completed. A thermogravimetric analysis (TGA) was completed to observe the thermal properties. This study confirmed that the properties of the composites were affected by the strength of the fiber. The SPF/VE composites obtained from Kuala Jempol had the highest tensile, flexural, and impact strength compared to the SPF/VE composites from Indonesia and Tawua. In addition, SPF Jempol/VE also recorded the highest percentage of water absorption, thickness swelling, and moisture content. A comparison of thermal properties showed that SPF Tawau/VE had highest percentage of mass loss between fibers from the three geographic locations.

Mechanical and abrasive wear behavior of cenosphere filled carbon reinforced epoxy composites using Taguchi-Grey relational analysis

Carbon fabric reinforced Epoxy (C-E) composites filled with different weight percentage of silane treated flyash cenosphere (CSP) particles were synthesized using hand layup process followed by compression moulding method. The fabricated samples were subjected to mechanical tests and two body multipass abrasive wear test (2BMAW) in accordance with American society for testing and materials (ASTM). Mechanical results showed addition of CSP particles in C-E composites tends to improve property such as density, hardness, flexural and impact strength. Meanwhile Taguchi method with Grey relational analysis (GRA) was implemented for 2BMAW test to optimize the wear process parameters with multi-response characteristics. Filler wt% (Filler content), Grit size of abrasive (emery paper), sliding distance (m) and Load (N) were selected as wear process parameters for which responses were coefficient of friction (COF), specific wear rate (SWR) and hardness (BH) of the composites. Analysis of variance (ANOVA) result based on grey relational grade (GRG) revealed that filler wt% (filler content) and sliding distance were found as most significant process parameter influencing the wear performance of the composites by 55% and 19% respectively followed by Grit size of emery paper and applied load. Finally microstructure analysis of the fractured and worn sample has been studied using scanning electron microscope to understand the mode of failure mechanism.

Impact Resistance of Bamboo Fabric Reinforced Polypropylene Composites and Their Hybrids

Bamboo in woven fabric form embedded in the polymer results in easier material handling during production and reduction in the manufacturing cost of the composites. In the current study, the effect of hybridization of bamboo fabric with glass fibres on the impact properties of the composites made from them has been studied. The composites were fabricated using a compression moulding method. Bamboo fibres were in the form of twill-weave fabric. Impact tests were conducted using an instrumented drop weight impact test system. It can be seen that the peak load and energy absorbed increase with the increase in the applied impact energy. For the BPP composites, the applied energy of the impact was increased until penetration was occurred at 55 J. While for the BGPP hybrid composites, they were penetrated at the applied energy of only 35 J. However, The hybrid composites exhibit a greater peak load resistance than the BPP composites. The crack damage in the composites was also reduced with the presence of fabric reinforcement. These preliminary results indicate that bamboo fabric is truly a new contender for developing excellent and balanced properties of composites such as for the interior components.

Effects of Processing Methods on Mechanical Properties of Alkali Treated Bagasse Fibre Reinforced Epoxy Composite

Effects of the processing methods on the mechanical properties of treated bagasse fibre reinforced epoxy composite were evaluated. The composite materials were processed by employing hand lay-up and compression moulding methods and fibres were treated with NaOH solution. The composite samples were subjected to tensile, flexural and impact tests. Based on the findings, compression moulding method produced better mechanical properties compared to the composites manufactured by hand lay-up method. The results showed that the tensile strength and Young’s modulus of the samples produced by compression moulding method increased by 77 percent and 47 percent respectively (at optimal fibre loading) compared to those produced by the hand lay-up method. The results also showed noticeable improvements in the impact strength of the material produced by compression moulding method, with impact strength of 11.5 kJ/m2 against the samples produced by hand lay-up method, with impact strength of 7 kJ/m2.

Polyester-based redmud reinforced banana fibre composites: impact and flexural property studies

Redmud (RM)-based polymer composite is one of the most promising fillers to be used for composite preparation. In this work, redmud is used as a secondary reinforcement along with banana fibre combined with the polyester matrix. Redmud and banana fibre of varying weight percentage in the ratio 50:50 are taken for this study. Banana fibre of 30 mm optimal length is used for this study. Redmud of different weight percentages varying from 10 to 50% wt has been taken for this study. The composites are prepared by compression moulding method. Impact and flexural strength studies are carried out for different composite combinations subjected to dry and wet (moisture) conditions. The results showed that the addition of redmud filler of 10% wt and fibre of 40% wt increases the impact strength by 43% due to the more amount of energy absorption. It decreases the flexural strength by 34% respectively due to poor bonding and dispersion of filler. In the case of composites subjected to moisture study shows same phenomenon when compared with the virgin composites.

Mechanical Properties and Wear Properties of Kenaf – Aloe Vera – Jute Fiber Reinforced Natural Fiber Composites

A composite material is made up of two or more constituent materials. The constituent materials differ in their physical and chemical composition. Composite materials are widely used in the aerospace and automotive industry. Nowadays researchers and engineers have begun to show their research interest in the field of natural fiber composites. The reason is that natural fiber composites possess enhanced corrosion resistance, ease of manufacturing, environmental friendly, and last but not the least is the easy availability of the raw materials which are required for the fabrication of the natural fiber composites. In the present experimental work, Kenaf-Aloe Vera-Jute Reinforced Natural Fiber Composites are fabricated by Compression Molding Method and are tested for their mechanical properties such as Tensile Strength, Flexural Strength, and Impact Strength. Also, the fabricated composite materials are tested for its wear properties. The composite specimens for the testing of the above mentioned mechanical properties as well as for the wear properties are prepared as per the ASTM Standards.

Study on mechanical properties of glass wool/epoxy reinforced composite

Recently, composite materials have been used in various domains. The reasons for this are low weight and can withstand high strength. New developments of the conventional composites replacing the metal and metal matrix materials in addition to environmental effects are also very minimal. In this, work is undertaken to prepare the fibre reinforced composites and study their mechanical behaviour of combinations. To prepare the fibre reinforced composite (FRP), glass wool (GW) is incorporated into epoxy resin with the varying weight percentage of 0, 30, 40 and 50 by the way of compression moulding method. The composites were assessed on its properties such as tensile strength, flexural strength, impact strength, hardness and density of the composites and have been performed with ASTM standards at room temperature. The fracture regions were studied using scanning electron microscopy (SEM). From the experimental results, high strength was attained at 40 weight % addition of glass wool into epoxy matrix. It is found that the composites have a better strength, which makes this method more convenient and less costly.

Effect of fiber content on tensile retention properties of Cellulose Microfiber Reinforced Polymer Composites for Automobile Application

Today, the utilization of biodegradable materials has been hogging much attention throughout the world. Due to the disposal issues of petroleum based products, there is a focus towards developing biocomposites with superior mechanical properties and degradation rate. In this research work, Hibiscus Sabdariffa (HS) fibers were used as the reinforcement for making biocomposites. The HS fibers were reinforced in the polyester resin by compression moulding method. Water absorption studies of the composite at room temperature are carried out as per ASTM D 570. Also, degradation behavior of HS/Polyester was done by soil burial method. The HS/polyester biocomposites containing 7.5 wt% of HS fiber has shown higher value of tensile strength. The tensile strength retention of the HS/Polyester composites are higher than the neat polyester composites. This value increases with increase of HS fiber loading in the composites. The results indicated that HS/polyester biocomposites can be used for making automobile components such as bumper guards etc.