Now showing 1 - 4 of 4
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Warpage optimisation using recycled polycar-bonates (PC) on front panel housing

2021-03-02 , Tamizi N.A.M.A. , Shayfull Zamree Abd. Rahim , Abdellah A.E.H. , Mohd. Mustafa Al Bakri Abdullah , Nabiałek M. , Wysłocki J.J. , Jeż B. , Palutkiewicz P. , Rozyanty Rahman , Mohd. Nasir Mat Saad , Mohd Fathullah Ghazli@Ghazali

Many studies have been done using recycled waste materials to minimise environmental problems. It is a great opportunity to explore mechanical recycling and the use of recycled and virgin blend as a material to produce new products with minimum defects. In this study, appropriate processing parameters were considered to mould the front panel housing part using R0% (virgin), R30% (30% virgin: 70% recycled), R40% (40% virgin: 60% recycled) and R50% (50% virgin: 50% recycled) of Polycarbonate (PC). The manufacturing ability and quality during preliminary stage can be predicted through simulation analysis using Autodesk Moldflow Insight 2012 software. The recommended processing parameters and values of warpage in x and y directions can also be obtained using this software. No value of warpage was obtained from simulation studies for x direction on the front panel housing. Therefore, this study only focused on reducing the warpage in the y direction. Response Surface Methodology (RSM) and Genetic Algorithm (GA) optimisation methods were used to find the optimal processing parameters. As the results, the optimal ratio of recycled PC material was found to be R30%, followed by R40% and R50% materials using RSM and GA methods as compared to the average value of warpage on the moulded part using R0%. The most influential processing parameter that contributed to warpage defect was packing pressure for all materials used in this study.

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Extraction of silica content from the Cymbopogan citratus (lemon grass) and its performance as reinforcement for polymers

2017-07-21 , Nur Firdaus Mohamed Yusof , Hakimah Osman , Hendrik Simon Cornelis Metselaar , Rozyanty Rahman

Silica is widely used as sources for adsorption materials, medical additives and fillers in composite and rubber industries. The manufacturing process of commercial silica use in various industries is very expensive and energy extensive. Therefore, agricultural waste material such as lemon grass is seen as a potential alternative silica sources for replacement of commercial silica which is currently available in the industry. In this research, a simple method based on the acid leaching treatment with hydrochloric acid (HCl) was developed to produce purified silica from lemon grass, followed by thermal combustion at 600°C. Acid leaching temperatures of 33, 50, 80 and 110°C were used. The silica content, shape and texture of the lemon grass ash was characterized using scanning electron microcopy -energy-dispersive X-ray (SEM-EDX) analysis. The SEM analysis indicated the presence of tubular-shaped porous aggregates, spherical and fibrous shapes of untreated and treated lemon grass at 33°C to 110°C. The highest silica content recorded was 73.46% for lemon grass treated at the highest leaching temperature of 110°C. The thermal stability of lemon grass ash was examined by using a thermogravimetric analysis (TGA) instrument. The TGA analysis shows that the untreated and treated lemon grass ash start to decompose at lower temperature (90 to 100°C). Lemon grass treated at the highest leaching temperature 110°C exhibit the highest thermal stability.

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A review on the potential of polylactic acid based thermoplastic elastomer as filament material for fused deposition modelling

2022-09-01 , Luqman Musa , Krishna Kumar N. , Shayfull Zamree Abd. Rahim , Mohamad Syahmie Mohamad Rasidi , Watson Rennie A.E. , Rozyanty Rahman , Yousefi Kanani A. , Ahmad Azrem Azmi

Currently, a range of sectors are implementing three-dimensional (3D) printing, which is a part of additive manufacturing (AM) technology via the fused deposition modelling (FDM) approach. As of now, various filament materials are available in the market and have their limitations. Thermoplastic elastomer (TPE) blend as a filament material in 3D printing should be implemented to overcome the weakness of available filaments. TPE blend stands out due to its flexibility, thermoplastic-like processability, and renewability. Based on the findings, TPE blend filament can be made with polylactic acid (PLA) thermoplastic and elastomers such as natural rubber (NR) and epoxidized natural rubber (ENR). The TPE printed components will be flexible; tough with excellent thermal and mechanical properties. In this paper, the characteristics of TPE are being reviewed to show the potential of TPE material as filament.

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The role of zinc chloride in enhancing mechanical, thermal and electrical performance of ethylene vinyl acetate/carbonized wood fiber conductive composite

2021-02-02 , Mohd Hanif Mohd Pisal , Azlin Fazlina Osman , Tan Soo Jin , Rozyanty Rahman , Alrashdi A.A. , Masa A.

Carbonized natural filler can offer the production of low cost composites with an eco-friendliness value. The evolving field of electronics encourages the exploration of more functions and potential for carbonized natural filler, such as by modifying its surface chemistry. In this work, we have performed surface modification on carbonized wood fiber (CWF) prior to it being used as filler in the ethylene vinyl acetate (EVA) composite system. Zinc chloride (ZnCl2) with various contents (2 to 8 wt%) was used to surface modify the CWF and the effects of ZnCl2 composition on the surface morphology and chemistry of the CWF filler were investigated. Furthermore, the absorptive, mechanical, thermal, and electrical properties of the EVA composites containing CWF-ZnCl2 were also analyzed. SEM images indicated changes in the morphology of the CWF while FTIR analysis proved the presence of ZnCl2 functional groups in the CWF. EVA composites incorporating the CWF-ZnCl2 showed superior mechanical, thermal and electrical properties compared to the ones containing the CWF. The optimum content of ZnCl2 was found to be 6 wt%. Surface modification raised the electrical conductivity of the EVA/CWF composite through the development of conductive deposits in the porous structure of the CWF as a channel for ionic and electronic transfer between the CWF and EVA matrix.