Mimi Azlina Abu Bakar

Mechanical properties of hybrid glass/kenaf fibre-reinforced epoxy composite with matrix modification using liquid epoxidised natural rubber

The hybridisation of natural fibre with glass fibre provides a method to improve the mechanical properties instead of using the natural fibres alone. This research is focused on the hybridisation of glass/kenaf fibre with the addition of liquid epoxidised natural rubber to enhance the desired mechanical properties of the composite by reducing the synthetic fibre usage and encourage the natural fibre consumption. Liquid epoxidised natural rubber was added to the epoxy matrix in order to improve its mechanical properties whilst E-glass fibre and kenaf bast fibre were used as the reinforcement in the composite. Liquid epoxidised natural rubber (3%) was added as a toughening agent. Two types of kenaf fibre were prepared – untreated and treated with 6% NaOH – whilst the glass fibre was treated using a silane coupling agent. The flexural test, Izod impact test, environmental stress cracking resistance analysis and scanning electron microscopy analysis were performed to determine the effect of fibre treatment and liquid epoxidised natural rubber addition on the mechanical properties of the hybrid fibre-reinforced composite. It was found that the treatment and the addition of liquid epoxidised natural rubber contribute to the increment of the impact strength by 40% whilst the flexural properties recorded a 13% and 15% increment for both flexural strength and flexural modulus, respectively. The environmental stress cracking resistance analysis showed that the composites are more affected in acid medium followed by base medium and then with the control medium (air). The addition of liquid epoxidised natural rubber seems to improve the stability of the samples in the medium initially but tends to decrease rapidly over time due to debonding of the rubber particles.

Mechanical Properties of Oil Palm Fibre Reinforced Epoxy for Building Short Span Bridge

Oil palm industries generate at least 30 million tonnes of lignocellulosic biomass annually in the form of oil palm trunks (OPT), empty fruit bunches (EFB), oil palm fronds (OPF) and palm pressed fibres (PPF). At present, the biomass is either left to rot in the plantations to provide organic nutrients to the oil palm trees (mulching) or used as solid fuel in the boilers to generate steam and electricity at the mills. An oil palm plantation produces about 55 tonnes ha-1 yr-1 of total dry matter in the form of fibrous biomass as compared to only about 5.5 tonnes ha-1 yr-1 of palm oil and palm kernel oil.1 The fibrous biomass is yet to be commercially exploited. Technology development in the industry is still focused on process development and improvement rather than creating and inventing newer products for value-added application. The need for materials not harmful to the body but having appropriate properties has increased due to a lack of resources and increasing environmental pollution. Thus, composites prepared from recycled materials are actively being sought after. Many synthetic polymeric materials are produced by combining with various reinforcing fillers to improve their mechanical properties and obtain the desired properties. Among these reinforcing fillers, active research is under way concerning the use of lignocellulosic materials, which are among the most environmentally friendly agrowastes, as a substitute for synthetic materials. 3 Lignocellulosic materials offer many environmental benefits when used as reinforcing fillers for plastics, including their making the final product lightweight, decreasing the erosion of the manufacturing machinery, low cost, biodegradability, and absence of production of residue or toxic by-products when burnt.

Effect of Carbon Fibre Ratio to the Impact Properties of Hybrid Kenaf/Carbon Fibre Reinforced Epoxy Composites

Effects of the incorporation of untreated and treated hybrid kenaf/carbon fibre reinforced epoxy composites on the impact properties were studied. Hybrid kenaf/carbon fibres and thermoset matrices were hand-laid up and characterized in terms of its mechanical properties. The kenaf fibres were alkali treated whilst the carbon fibres were gamma radiation treated before use as reinforcement in the epoxy resin matrix. The reinforcing effects of kenaf hybridized with carbon fibre in epoxy composites were evaluated at various fibre loadings with overall fibre contents 20 wt%. Hybrid composites with different ratios of kenaf fibre : carbon fibre ; 0.9:0.1, 0.8:0.2, 0.7:0.3 and 0.6:0.4 were prepared. Impact tests of untreated and treated hybrid kenaf/carbon fibres were performed. The fractured surfaces of these composites were investigated by using scanning electron microscopic technique (SEM) to determine the interfacial bonding between the matrix and the fibre reinforcement. It was found that the treated hybrid composites increased the impact strength by 26% compared to the untreated ones.

Effect of Single Based Binder Palm Stearin on Sintered Properties of Hydroxyapatite Scaffold

This paper reports on the compatibility of hydroxyapatite (HAP) combined with single based binder, palm stearin for ceramic injection molding in order to obtain the best properties. The feedstock was prepared at a powder loading of 62 Vol % using 5μm fine ceramic powder of hydroxyapatite and the binders consisting of 100% of palm stearin. The specimens underwent thermal de-binding and then sintered in an electrical furnace within a temperature range from 500°C to 1000°C. The resulting exhibit promising properties which the final product produced after the sintering process was successfully tested by mechanical testing. It is proven that even the specimen only consists of single based binder can form a complex shape without collapse just like the specimen obtained by the conventional binder system. Therefore, the fabrication also is more towards green processing technology and energy conservation due to the binder used was from natural local resources and used lower processing temperature at 50°C to 70°C for mixing and injection molding.

Tensile Properties of Untreated and Treated Long Kenaf Fiber/Polyester Composites

The interest in using fibers as reinforcement in composites has increased in recent years due to its lightweight, combustible, non-toxic, non-abrasive, low cost and biodegradable properties. In this study, two difference types of long kenaf fiber (LKF) used in fiber-reinforced composites which are untreated and treated with 1% sodium hydroxide (NaOH). The volume fraction of LKF used are 20%, 25% and 30% prepared by cold pressed hand lay-up technique were investigated. A series of tensile tests were performed to evaluate the effect of their modulus and ultimate tensile strength (UTS). The morphological and structural changes of the fibers were investigated by using scanning electron microscopy (SEM). It has found that the treated long kenaf fiber (TLKF) shows the higher value of tensile strength compared to untreated long kenaf fiber (ULKF).

Tribology study of hydroxyapatite (HAp) scaffold blended single based binder via rheology and mechanical properties

Purpose This paper aims to investigate the vital characteristic of an innovative ceramic injection molding (CIM) process for orthopedic application with controlled porosity and improved tribological and mechanical properties which were affected by complex tribological interactions, whether lubricated like hip implants and other artificial prostheses. The main objective is to maximize the usage of palm stearin as a single based binder as the function of flow properties during injection molding process. Design/methodology/approach The binder used in this present study consists of 100 per cent palm stearin manufactured by Kempas Oil Sdn Bhd and supplied by Vistec Technology Sdn Bhd. The feedstock was prepared by using a Z-blade mixer (Thermo Haake Rheomix OS) and Brabender mixer model R2400. The feedstock prepared was injection molded using a manually operated vertical benchtop machine with an average pressure of about 5-7 bars. The firing step included the temporary holds at intermediate temperatures to burn out organic binders. At this stage, the green molded specimen was de-bound using a single-step wick-debinding method. Findings The maximum content of ceramic material is applied to investigate the efficiencies of net formulation that can be achieved by ceramic materials. The longer the viscosity will change with shear rate, the higher the value of n obtained instead. From the slope of the curves obtained in Figure 3, the value of n for the feedstock was determined to be less than 1, which indicates a pseudoplastic behavior and suitability for the molding process. Moreover, high shear sensitivity is important in producing complex and intrinsic specimens which are leading products in the CIM industry. Originality/value The feedstock containing HAp powder and palm stearin binder was successfully prepared at very low temperature of 70°C, which promoting a required pseudo-plastic behavior during rheological test. The single binder palm stearin should be optimized in other research works carried out, as palm stearin is most preferred compared to other polymeric materials that provided high energy consumption when subjected to the sintering process. Besides the binder is widely available in Malaysia, low cost and harmless effect during debinding process.

The effect of fiber treatment on abrasive wear properties of palm fiber reinforced epoxy composite

Oil palm industries generate at least 30 million tons of lignocellulosic biomass annually in the form of oil palm trunks (OPT), empty fruit bunches (EFB), oil palm fronds (OPF) and palm pressed fibres (PPF). The palm fiber is one of the natural fibers used as reinforcement in composite materials in order to decrease environmental issues and promotes utilization of renewable resources. This paper presents a study on the effect of alkaline treatment on wear properties of palm fiber reinforced epoxy resin composite. Abrasive wear testing was deployed to investigate the wear profile of the composite surfaces. Testing was carried out which focused on the effect of alkaline treatment to the palm fiber under different amounts of fiber loading i.e. 1 wt%, 3 wt%, 5 wt% and 7 wt%. The palm fibers were soaked into 6 % of alkaline solution or natrium hydroxide (NaOH) for 12 hours. The fiber was treated in order to remove amorphous materials such as hemicelluloses, lignins and pectins of the fiber. The wear test sampl...

Analysis of Transmission Fluid in Manual Diesel Engine by Ferrographic Technique

Condition monitoring techniques have been developed in the past two decades in order to predict and overcome the wear related damage progression in gear transmission systems. Ferrographic Technique (FT) is a microscopic analysis to identify the presence of material composition by characterizing particles concentration, type, size, distribution, and morphology. This technique is part of a Predictive Maintenance (PdM) program to avoid a major failure in machine systems. In the present study, analysis of wear characterization in diesel engine by Ferrographic Technique was conducted. Transmission fluid samples were collected from intercity bus and analyzed using Ferrogram Maker (FM-III). Optical microscopy and Predict Chart were used to characterize and identify sample in where groups. It was observed that the corrosive and black oxide wear type were major findings in all samples tested.

The Effects of Oil Groove Position on Torque and Frictional Force in Hydrodynamic Journal Bearing

Axial groove is a common supply method of distributing lubricant within a journal bearing. Lubricant is generally fed at a specific supply pressure to ensure that the journal and the bearing surface are separated. Shearing action between lubricant and bearing parts creates frictions which contribute to power loss in journal bearing. In the present study, an experimental work was conducted to determine the effect of oil groove location on torque and frictional force in hydrodynamic journal bearing. A journal diameter of 100mm with a 12 length-to-diameter ratio was used. The oil supply pressure was set at 0.20 to 0.25 MPa. The groove was positioned at 3 different locations namely 00, +150and +300. Measurements of torque and frictional force were obtained for speed values of 300, 500 and 800 RPM at different radial loads. It was observed that the change in oil groove location has affected the fluid frictional force and friction coefficient to some extent.