Now showing 1 - 10 of 35
  • Publication
    Thermal Insulation and Mechanical Properties in the Presence of Glas Bubble in Fly Ash Geopolymer Paste
    The density, compressive strength, and thermal insulation properties of fly ash geopolymer paste are reported. Novel insulation material of glass bubble was used as a replacement of fly ash binder to significantly enhance the mechanical and thermal properties compared to the geopolymer paste. The results showed that the density and compressive strength of 50% glass bubble was 1.45 g/ cm3 and 42.5 MPa, respectively, meeting the standard requirement for structural concrete. Meanwhile, the compatibility of 50% glass bubbles tested showed that the thermal conductivity (0.898 W/mK), specific heat (2.141 MJ/m3K), and thermal diffusivity (0.572 mm2/s) in meeting the same requirement. The improvement of thermal insulation properties revealed the potential use of glass bubbles as an insulation material in construction material.
  • Publication
    Optimisation of warpage on plastic injection moulding part using response surface methodology (RSM) and genetic algorithm method (GA)
    In this study, Computer Aided Engineering was used for injection moulding simulation. The method of Design of experiment (DOE) was utilize according to the Latin Square orthogonal array. The relationship between the injection moulding parameters and warpage were identify based on the experimental data that used. Response Surface Methodology (RSM) was used as to validate the model accuracy. Then, the RSM and GA method were combine as to examine the optimum injection moulding process parameter. Therefore the optimisation of injection moulding is largely improve and the result shown an increasing accuracy and also reliability. The propose method by combining RSM and GA method also contribute in minimising the warpage from occur.
  • Publication
    Optimisation of shrinkage and strength on thick plate part using recycled LDPE materials
    ( 2021)
    Norshahira Roslan
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    Abdellah El-hadj Abdellah
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    Katarzyna Błoch
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    Paweł Pietrusiewicz
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    Marcin Nabiałek
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    Janusz Szmidla
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    Dariusz Kwiatkowski
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    Joel Oliveira Correia Vasco
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    Achieving good quality of products from plastic injection moulding processes is very challenging, since the process comprises many affecting parameters. Common defects such as warpage are hard to avoid, and the defective parts will eventually go to waste, leading to unnecessary costs to the manufacturer. The use of recycled material from postindustrial waste has been studied by a few researchers. However, the application of an optimisation method by which to optimise processing parameters to mould parts using recycled materials remains lacking. In this study, Response Surface Methodology (RSM) and Particle Swarm Optimisation (PSO) methods were conducted on thick plate parts moulded using virgin and recycled low-density polyethylene (LDPE) materials (100:0, 70:30, 60:40 and 50:50; virgin to recycle material ratios) to find the optimal input parameters for each of the material ratios. Shrinkage in the x and y directions increased in correlation with the recycled ratio, compared to virgin material. Meanwhile, the tensile strength of the thick plate part continued to decrease when the recycled ratio increased. R30 (70:30) had the optimum shrinkage in the x direction with respect to R0 (100:0) material where the shrinkage increased by 24.49% (RSM) and 33.20% (PSO). On the other hand, the shrinkage in the y direction for R30 material increased by 4.48% (RSM) and decreased by 2.67% (PSO), while the tensile strength of R30 (70:30) material decreased by 0.51% (RSM) and 2.68% (PSO) as compared to R0 (100:0) material. Validation tests indicated that the optimal setting of processing parameter suggested by PSO and RSM for R0 (100:0), R30 (70:30), R40 (60:40) and R50 (50:50) was less than 10%.
  • Publication
    Warpage optimisation using recycled Polycar-bonates (PC) on front panel housing
    ( 2021)
    Nur Aisyah Miza Ahmad Tamizi
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    Abdellah El-hadj Abdellah
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    Marcin Nabiałek
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    Jerzy J. Wysłocki
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    Bartłomiej Jeż
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    Paweł Palutkiewicz
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    Rozyanty Abdul Rahman
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    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.
  • Publication
    Tool wear and surface evaluation in drilling fly ash geopolymer using HSS, HSS-Co, and HSS-TiN cutting tools
    ( 2021) ; ; ;
    Joanna Gondro
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    Paweł Pietrusiewicz
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    Sebastian Garus
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    Tomasz Stachowiak
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    Andrei Victor Sandu
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    Mehmet Erdi Korkmaz
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    Mohamed Syazwan Osman
    This paper reports on the potential use of geopolymer in the drilling process, with respect to tool wear and surface roughness. The objectives of this research are to analyze the tool life of three different economy-grade drill bit uncoated; high-speed steel (HSS), HSS coated with TiN (HSS-TiN), and HSS-cobalt (HSS-Co) in the drilling of geopolymer and to investigate the effect of spindle speed towards the tool life and surface roughness. It was found that, based on the range of parameters set in this experiment, the spindle speed is directly proportional to the tool wear and inversely proportional to surface roughness. It was also observed that HSS-Co produced the lowest value of surface roughness compared to HSS-TiN and uncoated HSS and therefore is the most favorable tool to be used for drilling the material. For HSS, HSS coated with TiN, and HSS-Co, only the drilling with the spindle speed of 100 rpm was able to drill 15 holes without surpassing the maximum tool wear of 0.10 mm. HSS-Co exhibits the greatest tool life by showing the lowest value of flank wear and produce a better surface finish to the sample by a low value of surface roughness value (Ra). This finding explains that geopolymer is possible to be drilled, and therefore, ranges of cutting tools and parameters suggested can be a guideline for researchers and manufacturers to drill geopolymer for further applications.
  • Publication
    Key features of additive manufacturing: A review
    This work reviews the key features and capabilities of additive manufacturing, which include the fundamental of additive manufacturing followed by types of additive manufacturing technologies. Advantages and limitation of additive manufacturing is discussed and the emergence of additive manufacturing in industrial revolution 4.0 is presented. Economy benefits through the additive manufacturing showing beneficial potential.
  • Publication
    Optimisation of warpage on thin shell plastic part using response surface methodology (RSM) and glowworm swarm optimisation (GSO)
    In manufacturing a variety of parts, plastic injection moulding is widely use. The injection moulding process parameters have played important role that affects the product's quality and productivity. There are many approaches in minimising the warpage ans shrinkage such as artificial neural network, genetic algorithm, glowworm swarm optimisation and hybrid approaches are addressed. In this paper, a systematic methodology for determining a warpage and shrinkage in injection moulding process especially in thin shell plastic parts are presented. To identify the effects of the machining parameters on the warpage and shrinkage value, response surface methodology is applied. In thos study, a part of electronic night lamp are chosen as the model. Firstly, experimental design were used to determine the injection parameters on warpage for different thickness value. The software used to analyse the warpage is Autodesk Moldflow Insight (AMI) 2012.
  • Publication
    Evaluation of shrinkage and weld line strength of thick flat part in injection moulding process
    ( 2021-10-01)
    Nasir S.M.
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    Sharif S.
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    Abdellah A.E.h.
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    This paper evaluates the shrinkage and strength of weld line using Design of Experiment and Response Surface Methodology in multi-objective optimisation utilising the injection moulding parameters. A simulation process was conducted to determine the recommended setting of injection moulding parameters and the range of the variable parameters. An experimental work was conducted according to the experimental design, where regression models were established to predict the shrinkage and weld line strength. A new set of process parameters setting was found to achieve the optimum shrinkage and weld line strength of the moulded part. The results of shrinkage and weld line strength using an optimal parameter setting after optimisation process were compared with the results obtained using the recommended setting from Autodesk Moldflow Insight software. It was found that the shrinkages in the normal to and parallel to the melt flow directions were reduced by 5.969% and 4.375%, respectively, through the predicted model generated using RSM. On the other hand, the weld line strength improved by 3.758% as compared to the weld line strength obtained from the recommended setting. The shrinkages in both parallel to and normal to the melt flow directions using multi-objective optimisation were reduced by 5.891% and 4.160%, respectively, while the weld line strength was improved by 3.756%, using the combination of the following parameters; 69.93 Â°C of coolant inlet temperature, 270 Â°C of melt temperature, 70 MPa of packing pressure and 8 s of cooling time. The predicted errors ranged between 0.2 and 14.5% during the validation experiments. The packing pressure was found to be the most significant parameter affecting the shrinkage in both parallel to and normal to melt flow directions. The coolant inlet temperature on the other hand was the most significant parameter affecting the weld line strength.
  • Publication
    Redesign of drone remote control using design for manufacturing and assembly (DFMA) method
    "The redesign of drone remote control using DFMA method" is a case study to analyze and redesigned the controller product through its assembly process in term of manual handling time, manual insertion time, total assembly time, design efficiency of the design and manufacturing method for the design. The components and manufacturing of the drone remote control were undergone alteration with design for manufacturing and assembly (DFMA) and redesigned methods. The main focuses of this research are to analyze the current design efficiency of drone remote control and improved the design efficiency. At the same time, the redesign was applied to existing model under the same platform. As a result, the assembly time for redesign showed an improvement of 24.93% where the assembly time was reduced from 480.56 s to 360.79 s and design efficiency was increased 1.66% from 4.99% to 6.65%. Therefore, the best design with optimal value is accomplished.
  • Publication
    Synthesis and Luminescent Properties of LiEu (0.50-x) Gd 0.50 (WO 4) 2 Sm x Red Phosphor
    Red phosphor is widely used in enhancing white light emitting diodes. Recent trends show there are several efforts in improving the efficiency of lighting particularly using Europium (III) as activators in Gadolinium tungstate phosphors. In this work, LiEu(0.50-x)Gd0.50(WO4)2Smx red phosphor was synthesized using solid-state reaction. The crystal structure, morphology and photoluminescence properties of the sample were analysed. The structure of the phosphor was found to be tetragonal with space group I41/a by characterizing the phosphor using the X-ray powder diffraction (XRPD) application. The morphologies present the angular-shaped particles. The highest emission peak occurred at 615 nm corresponding to the 5D0→7F2 transition under near-UV region. The optimum amount of Sm3+ that enhanced the intensity of the host lattice at x = 0.15 mol. The improvement on the photoluminescence properties of these phosphors without any changes on the structure and crystal symmetry shows a good potential of the red emitting phosphor to be used in the light emitting diodes (WLEDs) applications.