Vacuum Infusion Technique Research Articles

Mechanical properties of polyester/corn husk fibre composite produced using vacuum infusion technique

Issues pertaining to deforestation, environmental pollution and natural wastes are increasing day by day. These issues can be resolved by introducing a new composite material, in which natural waste is used as fibre and as a replacement of wood plastic composite. The different lengths (3, 6 and 9 cm) of corn husk fibre filled polyester composites were produced using the vacuum infusion method. Several mechanical properties of these polyester composites, such as tensile and flexural properties, were evaluated. The results revealed that both the tensile and flexural properties of polyester composites increased with increment of corn husk fibre length from 3 to 6 cm. However, the results decreased for 9 cm of fibre length filled composites. Similar trends were recorded after alkali treatment of the corn husk fibre filled polyester composites. The alkali treatment with sodium hydroxide had improved the tensile strength (33%), Young’s modulus (23%), elongation (14%), flexural strength (42%) and flexural modulus (8.5%) of the polyester/corn husk fibre composites with 6 cm of fibre length by enhancing the mechanical interlocking bonding between treated corn husk fibres and polyester.

Design of an Impact Absorbing Composite Panel from Denim Wastes and Acrylated Epoxidized Soybean Oil based Epoxy Resins

The focus of this work is to make a significant contribution to solid waste management by designing impact-absorbing bio-composite panels using bio-resin and denim wastes. In this context, composite panels are produced by vacuum infusion technique using both epoxy and acrylated epoxidized soybean oil (AESO) based hybrid resins while denim wastes are utilized as reinforcement materials in fiber and fabric forms. Both physical (fiber density and fiber weight ratio) and mechanical analyses (drop-weight impact resistance and dynamic mechanical analysis (DMA)) of the composites are performed. The outcomes of the study prove that the increase in the AESO ratio of the resin system improves the ductility of the composite and consequently the impact resistance. On the other hand, dynamic mechanical analysis results indicate that the AESO plug-in reduces the storage module and increases the damping factor.

Experimental investigation of the flexural fatigue performance of plain woven basalt fiber/epoxy.

Fatigue of composite materials is a very complex phenomenon, to date a numerous research effort is being spent on it. Because of deficiencies in study of flexural fatigue performance basalt fiber reinforced polymer (BFRP), the main objective of this work is to investigate the flexural fatigue performance of BFRP. The laminates of 4.0 mm average thickness were fabricated using the vacuum infusion technique. Three different stress levels of (162.90, 122.24, and 81.44) MPa were considered. A failure criterion was considered to be a 20% stiffness reduction of flexural fatigue test. Also, the stiffness reduction zones in the history of fatigue specimen were investigated. The failure mode of specimen at 20% reduction stiffness was inspected. The Weibull distribution function was used to obtain the failure probabilities and scatter. The S-N curve of composite laminates was constructed using five specimens at each number of cycles. This study indicated that under fatigue loading, the stiffness degradation process of composite materials was divided into three stages: the first is the high rate of stiffness degradation at the first few thousand cycles. The second stage then takes place with slow gradual stiffness degradation, which covers a sizeable portion of the component life. Finally, more grave types of damage occur, like fiber fracture, and induce complete material failure.

Mechanical Properties of Layered-Carbon Fiber Reinforced with Vacuum Infusion Process

Research on material engineering is widely developed in the precursors, composition of the material, and technique to create a composite. The layering and vacuum infusion resin are the developing technology to create the composites with the new characteristics and properties. This experiment is intended to find out the characteristics of layering carbon fiber reinforced by resin and is molded with vacuum infusion technique. The specimens of this experiment is layered-carbon fiber composites determined in three, four, five, six, and seven layers. The precursors of 220 and 240 carbon fibers are the main material of the composites. The tests conducted to the specimens are bending and tensile tests. The both tests are treated to reveal the mechanical properties of the composites. The least layers of 220 and 240 carbon fiber result the highest value of bending test, but the most number of carbon fiber layers show the opposite value. The results are reverse in the tensile test. The highest value of the tensile test is achieved by the most layers of carbon fiber, while the lowest value is in the least layers. This result is almost the same with the strain-stress, but overall the graphic is similarly increase to the most layers. Deduction achieved in this experiment is that the number of layers in the carbon fiber composites is significantly influencing the mechanical properties of the composite.

Development of hybrid layered structures based on natural fabric reinforced composites and warp knitted spacer fabric for acoustic applications

This study deals with the development of hybrid layered structures combining natural fabric reinforced composite plates and warp knitted spacer fabric for acoustic applications, and the evaluation of the sound absorption performances. Vacuum infusion technique was used to produce the composite plates. Jute and linen woven fabrics were used as reinforcing materials, and they were impregnated with epoxy resin. The composite plates were combined with warp knitted spacer fabric in different stacking sequences in three-layer structures. All samples were subjected to the measurement of sound absorption property using impedance tube method. The combinations of a single layer and double layers of warp knitted spacer fabric with natural fabric reinforced composite in the appropriate sequences were found to provide superior sound absorption coefficients (SAC) compared to non-hybrid layered structures. Based on the overall evaluation regarding SAC, noise reduction coefficient (NRC), and weight of the structure, the sample with the best performance was regarded as the double layers of spacer fabric backed with a jute fabric reinforced composite plate. The integration of natural fabric reinforced composites with warp knitted spacer fabric had better sound absorption performance compared to the glass fabric reinforced composites, and they were considered to have the potential of being used in interior noise control mainly in vehicles and buildings.

The Effect of Stacking Sequence and Ply Orientation on the Mechanical Properties of Pineapple Leaf Fibre (PALF)/Carbon Hybrid Laminate Composites.

In this paper, the effects of stacking sequence and ply orientation on the mechanical properties of pineapple leaf fibre (PALF)/carbon hybrid laminate composites were investigated. The hybrid laminates were fabricated using a vacuum infusion technique in which the stacking sequences and ply orientations were varied, which were divided into the categories of cross-ply symmetric, angle-ply symmetric, and symmetric quasi-isotropic. The results of tensile and flexural tests showed that the laminate with interior carbon plies and ply orientation [0°, 90°] exhibited the highest tensile strength (187.67 MPa) and modulus (5.23 GPa). However, the highest flexural strength (289.46 MPa) and modulus (4.82 GPa) were recorded for the laminate with exterior carbon plies and the same ply orientation. The fracture behaviour of the laminates was determined by using scanning electron microscopy, and the results showed that failure usually initiated at the weakest PALF layer. The failure modes included fibre pull-out, fibre breaking, matrix crack, debonding, and delamination.

Properties and characterization of novel 3D jute reinforced natural fibre aluminium laminates

Fibre metal laminates (FML) are being used in automotive, aerospace and naval applications due to their light weight and superior performance. The FMLs are made by sandwiching composite with metal. The environmental concerns due to non-biodegradability of such structures, lead to the development of FML containing natural fibre composites. Natural fibres composite, despite having good damping properties have overall poor mechanical properties. However, this aspect can be improved by weaving the fibres in 3 D pattern. In literature, FML made using 3 D woven jute composites is never reported. Furthermore, no literature is found on adhesion of natural fibre composite-metal bonding. In this paper, development of novel 3 D Jute Reinforced natural fibre Aluminium Laminates (JuRALs) is reported. Furthermore, the effect of 3 D weaving pattern and metal-composite bonding on mechanical properties and failure mechanism of the developed samples is also discussed in detail. The four-layered 3 D woven Jute fabric reinforcement was made using four interlocking patterns. The composites and JuRALs were fabricated using epoxy resin by vacuum infusion technique. The surface of aluminium was treated using phosphoric acid anodizing. Tensile, flexural and T-peel tests were performed according to ASTM testing method using Z100 All-round, Zwick Roell. The results showed that out of four types of used reinforcements, the through-thickness composites had better tensile properties while layer-to-layer composite had better flexural properties. The tensile and flexural properties of JuRALs made with through-thickness interlock reinforcement were better as compared to layer-to-layer interlock reinforcement. The T-peel results depicted that the constituent materials influenced the metal-composite adhesion properties, rather the type of 3 D structure.

Mechanical Properties of Carbon/Basalt Fabric Hybrid Composites Doped with Hexagonal Boron Nitride Nanopowders

The effect of various amounts (1, 2, and 4 wt%) of hexagonal nano boron nitride on the mechanical properties of carbon/basalt fabric reinforced epoxy hybrid composite laminates has been investigated through experimental methods. The hybrid composites were fabricated using hand lay-up and vacuum infusion techniques. The produced hybrid nanocomposites were characterized by SEM-EDS Mapping, XRD, and FT-IR analyses. In order to find the strength of the composites under the influence of uniaxial tensile, tensile experiments were conducted in ASTM D3039 standard, bending experiments in ASTM 7264, and impact experiments in ASTM D256 standard. The fracture morphologies were investigated after the tensile test using a stereomicroscope. The results of this study showed that the mechanical properties of hybrid composites were substantially improved by the addition of h-nBNs fillers at 1 wt% because of the high adhesion strength in the interphase between h-nBNs epoxy-fiber interactions.

Hardness, wear behavior and processing time of diluent and non-diluent nanocomposite laminates manufactured by vacuum infusion technique

The manufacturing of nanocomposites using the Vacuum Resin Infusion (VRI) technique can be considered a challenging task. The reason for this challenge is the high viscosity of the nanofilled resin. For large composite laminates, the nanofilled resin may be cured before complete mold filling, and thus can be considered as a waste of money. In this study, different weight fractions of TiO2 nanoparticles (0.25 wt. % and 0.5 wt. %) were added to epoxy resin. Also, different weight fractions of ethanol (0.5 wt. % and 1 wt. %) were added to both unfilled and nanofilled epoxy. The processing time, hardness, and wear behavior of the composite laminates were investigated. It was found that the addition of TiO2 nanoparticles improved the hardness and wear behavior of composite laminates but the processing time was high. Also, results showed that adding a small amount of ethanol (0.5 wt. %) and 0.25 wt. % of TiO2 nanoparticles to epoxy reinforced with chopped/woven glass fiber not only reduced the processing time but also improved the hardness and wear resistance as compared to neat composite laminates. Moreover, adding 0.5 wt. % of ethanol and 0.25 wt. % of TiO2 nanoparticles to woven E-glass/epoxy (WN0.25E0.5) gives hardness and wear resistance close to that obtained with woven E-glass/epoxy filled with 0.5 wt. % of TiO2 nanoparticles (WN0.5). It is economical to manufacture WN0.25E0.5 rather than WN0.5 as the cost and processing time of WN0.25E0.5 is lower than WN0.5.

Effect of Stacking Sequences on Mechanical Properties of Kenaf Hybrid Composites

In the current project, Kenaf fiber (K) and carbon fiber (C) with epoxy resin were utilized to form carbon-kenaf hybrid composites using a vacuum infusion technique. The volume fraction of fiber and thickness of a hybrid composite was fixed at 40 vol.% and 3mm, respectively. Four different sequences were introduced in the current project including CCCCC, KKKKK, KCKCK, and CKCKC. Mechanical testing such as tensile and flexural tests were performed according to ASTM D3039 and ASTM D790, respectively. Scanning Electron Microscope (SEM) and Optical Microscope (OM) were used to identify modes of failures in both tensile and flexural tests of carbon/kenaf hybrid composites. The hybrid CKCKC sample displayed a higher value in tensile strength (264.23 MPa), tensile modulus (11.06 GPa), flexural strength (438.51 MPa) and flexural modulus (25.13 GPa) as compared than KCKCK hybrid sample.

Investigation of the mechanical, thermal, and acoustical behaviors of cotton, polyester, and cotton/polyester nonwoven wastes reinforced epoxy composites

The aim of this paper is to develop a textile waste-based composite material with adequate mechanical, acoustical, and thermal properties for automotive or construction fields. For this purpose, three recycled nonwoven wastes including cotton, polyester, and cotton/polyester blend are employed and blended in epoxy resin. The manufacturing of the composite panels is performed by vacuum infusion technique. Mechanical, thermal and acoustical tests are conducted to characterize the performances of both nonwoven fabrics and composite panels. Theoretical Young’s moduli of different composites are calculated based on the rule of mixtures in two ways and compared with practical results. Results show that mechanical properties of the manufactured panels are significantly improved compared to pure resin without a notable change in the thermal behavior of the epoxy resin, where composite reinforced cotton nonwoven shows a specific Young’s modulus of 3500 MPa/g·cm−3 and a specific tensile strength of 38 MPa/g·cm−3. These panels have been found to be promising materials to decrease the noise emission and good alternatives to pure epoxy products due to their contribution to reducing the textile wastes in landfills as well as the production costs.

Effect of fibre loading on tensile strength of kenaf/glass fibre epoxy hybrid composite for insulator application

This paper discussed the tensile behaviour of epoxy reinforced with kenaf and glass fibre. The non-woven kenaf fibre mat and glass fibre mat were reinforced with epoxy matrix with different stacking sequence viz. neat Epoxy (E), Kenaf/Epoxy(K/E), Kenaf/Glass/Kenaf/Epoxy (K/G/K/E), Glass/Kenaf/Glass/Epoxy (G/K/G/E), Kenaf/Glass/Kenaf/Glass/Epoxy (K/G/K/G/E) and Glass/Epoxy(G/E). The laminate composite samples were prepared using vacuum infusion technique. Tensile strength and modulus evaluation of fibre mat reinforced polymer composite are key study in any structural application, thus the tensile properties of Kenaf/Glass fibre hybrid epoxy composites were characterized followed by Scanning Electron Microscopy (SEM) studies on the fractured surface of the composites. The results show that G/K/G/E composite has the highest tensile strength of 49.0 MPa compared to K/G/K/E composite and pure epoxy. The modulus of G/K/G/E composite was 165 MPa and K/G/K/E composite was 122 MPa. The percentage strain of G/K/G/E composite is recorded at 6.6%, whereas K/G/K/E was only 6.2%. The SEM studies show that the fracture surface has a uniform fibre distribution. Scanning electron microscopy fractography showed fibre cracking, debonding and fibre pulled-out as the main fracture mode of composites and G/K/G/E composite exhibited better interfacial bonding between the matrix and reinforcement compared to other compositions.

A Comparative Study on Mechanical Properties of Carbon and Kenaf Composites via Vacuum Infusion Technique

The growth of polymer-based composites from either synthetic or natural fibres, especially carbon and kenaf fibres as reinforcement, has gained major interest in many pieces of research. However, only a little attention has been made that compared the mechanical performances of these developed composites based on previous studies. In fact, this comparative study is essential to identify the mechanical gaps between synthetic and natural fibres. Thus, the current work is aiming to provide a comparative study on mechanical properties of manufactured composite materials from both synthetic and natural fibres in which carbon and kenaf fibres were used as reinforcing agents, whereas epoxy resin acts as a matrix phase that fabricated via vacuum infusion method. The thickness and fibre loadings of fabricated composite materials were fixed at 3 mm and 40 vol. %, respectively. The investigations focused on the mechanical performances of carbon and kenaf composites under tensile and flexural tests. The result shows that tensile and flexural strengths for carbon composite were attained at 399.05 MPa and 362.29 MPa, respectively. Meanwhile, for kenaf composite, the tensile strength was gained at 77.28 MPa, whereas, the flexural strength was obtained at 61.24 MPa.

AWJM Performance Measurement of Sandwich Composites

Sandwich composites, wherein the skin and core fulfills the requirement of different properties, like in foam sandwich structure, foam is providing damping and skin provides rigidity to the structure. In this work a sandwich panels with foam core and glass/polyester skin is fabricated by vacuum infusion technique. Abrasive water-jet drilling of these materials is performed to study the effect of standoff distance (SOD), Water Jet Pressure (JP) and Traverse Rate (TR) on kerf taper and surface roughness and Material Removal Rate (MRR). The experiment is designed using Taguchi’s L9 orthogonal array. The ANOVA is done to study the influence of input parameters on output. It is found that SOD is the most influencing parameter on the kerf taper and surface roughness..

Evaluation of Mechanical and Free Vibrational Analysis of Vegetable Fiber Reinforced Polyester Sandwich Composites with Polyvinyl Chloride Core

The present work addresses the vibrational behavior of sandwich structures made up of three different fibers such as woven sisal (S), woven banana (B) and woven glass fiber (G) with polyevinyl chloride core (PVC). The sandwich structures contain two external faces with polyevinyl chloride (C) as core. In this research work nine different layering patterns are fabricated such as SCS, BCB, GCG, SCG, BCG, BGCGB, BGCBG, SGCGS and SGCSG. Catalyzed unsaturated isothalic polyester resin is injected to the sandwich core using vacuum infusion technique. All the fabricated sandwich composites were subjected to study the tensile and vibration properties. Results reported that the BGCGB and SGCGS exhibited better tensile properties than the other composites. Further, the combination of BGCBG, and SGCGS provides the highest natural frequency in mode I, and the other sandwich composite combinations show the highest in the mode II and mode III. In damping, SCS has provided highest one among the other types.

Adhesively- and hybrid- bonded joining of basalt and carbon fibre reinforced polybenzoxazine-based composites

Polybenzoxazines-based composites are an excellent alternative in lightweight design due to their outstanding properties in terms of chemical stability, inherent flame resistance, as well as mechanical performance. The present work provides an investigation of different joining techniques for polybenzoxazine-based composites, namely adhesively - and hybrid bonded joining. The effects of fibre reinforcement (carbon or basalt), and substrate thickness (2 or 3 mm) on the lap-shear strength of joints are taken into consideration. Here, basalt (BFRP) and carbon fibre reinforced plastics (CFRP) were manufactured by vacuum infusion technique followed by a convection oven curing. Mechanical characterisation of substrates included tensile and interlaminar shear strength testing. Hybrid joints were fabricated by rivet insertion in cured joints bonded with a structural adhesive. Adhesive bonding showed to be a proper joining technique presenting a good adhesion with substrates, and adequate cohesive strength. Hybrid bonded joints had a fail-safe fracture and higher energy absorption prior to failure than their adhesively bonded counterparts. No effect of substrate thickness on lap-shear strength was observed. The dominating failure mechanism for the joints was the delamination of the topmost-layer due to peel stresses. CFRP joints exhibited higher lap-shear strength than BFRP joints, which was consistent with interlaminar shear strength results.

Thermal Properties of Woven Kenaf/Carbon Fibre-Reinforced Epoxy Hybrid Composite Panels

The effects of carbon fibre hybridisation on the thermal properties of woven kenaf-reinforced epoxy composites were studied. Woven kenaf hybrid composites of different weave designs of plain and satin and fabric counts of5×5and6×6were manually prepared by a vacuum infusion technique. A composite made from 100% carbon fibre was served for a comparison purpose. Thermal properties of pure carbon fibre and hybrid composites were determined by using a thermogravimetric analyser (TGA) and differential scanning calorimeter (DSC). It was found that a hybrid composite with higher kenaf fibre content (fabric count6×6) showed better thermal stability while the highest thermal stability was found in the pure carbon fibre composite. The TG and DTG results showed that the amount of residue decreased in the plain-designed hybrid composite compared to the satin-designed hybrid composite. The DSC data revealed that the presence of woven kenaf increased the decomposition temperature.

Influence of sodium bicarbonate treatment on the aging resistance of natural fiber reinforced polymer composites under marine environment

Aim of the current study is to investigate how an innovative and eco-friendly chemical treatment based on sodium bicarbonate solution (10 wt%) can improve the aging resistance in marine environment of epoxy based composites, reinforced with flax and jute fibers. To this scope, treated and untreated fiber reinforced composites were manufactured through vacuum infusion technique. The resulting composites were then exposed to salt-fog spray conditions up to 60 days, according to ASTM B117 standard. The assessment of their durability was made by means of tensile, flexural quasi-static tests and Charpy impact tests. Furthermore, the water uptake evolution of each composite was monitored during the whole aging exposition.The experimental campaign evidenced that the beneficial effect of the sodium bicarbonate treatment on adhesion between flax fibers and epoxy matrix allows treated laminates to better retain their flexural properties during the salt-fog-exposition, in comparison to untreated laminates. Conversely, the proposed treatment leads to a slight worsening effect on the durability of jute fiber reinforced composites.

Effect of Stacking Sequence and Sodium Bicarbonate Treatment on Quasi-Static and Dynamic Mechanical Properties of Flax/Jute Epoxy-Based Composites.

The present paper deals with the investigation of quasi-static and dynamic mechanical response of epoxy-based composites reinforced with flax and/or jute plain weave fabrics. In order to evaluate the influence of the stacking sequence, two monolithic laminates reinforced with flax or jute fibers and two hybrid flax/jute laminates were manufactured through the vacuum infusion technique. Furthermore, an eco-friendly and cost-effective surface treatment based on fiber soaking in a sodium bicarbonate solution was employed to improve the fiber-matrix adhesion. The mechanical characterization (by means of quasi-static flexural, dynamic mechanical thermal analysis and Charpy impact tests) allowed to evidence that the sodium bicarbonate treatment leads to noticeable improvement of the mechanical performances of flax reinforced composites, whereas jute composites experience a slight decrease of their mechanical properties. Overall, the hybridization allows to achieve intermediate mechanical properties among those of monolithic composites. Furthermore, the coupled action of hybridization and surface treatment does not lead to a beneficial and reliable effect on the mechanical response of the resulting composites.

Effects of Fabric Counts and Weave Designs on the Properties of Laminated Woven Kenaf/Carbon Fibre Reinforced Epoxy Hybrid Composites

The effects of different fabric materials namely weave designs (plain and satin) and fabric counts (5 × 5 and 6 × 6) on the properties of laminated woven kenaf/carbon fibre reinforced epoxy hybrid composites were evaluated. The hybrid composites were fabricated from two types of fabric, i.e., woven kenaf that was made from a yarn of 500tex and carbon fibre, by using vacuum infusion technique and epoxy resin as matrix. The panels were tested for tensile, flexural, and impact strengths. The results have revealed that plain fabric is more suitable than satin fabric for obtaining high tensile and impact strengths. Using a fabric count of 5 × 5 has generated composites that are significantly higher in flexural modulus as compared to 6 × 6 which may be attributed to their structure and design. The scanned electron micrographs of the fractured surfaces of the composites demonstrated that plain woven fabric composites had better adhesion properties than satin woven fabric composites, as indicated by the presence of notably lower amount of fibre pull out.