Mohd Hilmi Othman

The Effects of Parameter Settings on Shrinkage and Warpage in Injection Molding through Cadmould 3D-F Simulation and Taguchi Method

This study is focused on the effects of process parameters in plastic injection molding towards shrinkage and warpage problem of High Density Polyethylene (HDPE) specimen. The aim was to identify the main effects of different process parameters on warpage and shrinkage defects via numerical simulation software and experimental validation. Series of simulations were carried out using Cadmould 3D-F in order to utilize the combination of process parameters based on three level of L9 Taguchi orthogonal design. The Signal to Noise (S/N) ratio and the Analysis of Variance (ANOVA) were used to optimize the levels and to point out the impact of the process parameters on warpage and shrinkage. From the results, it showed that the most affected parameter on the warpage and shrinkage is packing time, with the P value of 48.93%, followed by melting temperature with 40.58%. The filling time and packing pressure were not a significant factor because they only contribute 7.30% and 3.19% of P value, respectively.

The Effects of Injection Moulding Processing Parameters and Mould Gate Size towards Weld Line Strength

Plastic moulded parts should have good mechanical properties and free from defects. Tensile behaviour of plastics plays an important role in defining the quality of injection-moulded products. In this study, numerical simulation (Cadmould) was employed to investigate the influence of gate sizes as well as the injection moulding parameters towards the occurrences of weld lines at Acrylonitrile Butadiene Styrene (ABS) specimens. This research begins from the simulation, fabrication of mould, practical injection process and tensile test. The double gates mould was used to present the weld line defects. The result shows that the smaller gate size produces less weld line in plastic parts, which was verified through simulation process. The optimal parameter setting that produced good tensile strength specimens was also validated experimentally in this research

Dumbbell shape EBG structure — Worth to EBG assisted microwave filter designing

Novel designs of dumbbell shape EBGS have been reported with distinguished filtering features that include larger stopband, dual-band, multi-band and low-pass performance. None but dumbbell shape EBG structure alone can show all mentioned different performances with minor modification and change in dimensions. Beyond the conventional ideas a special idea has been incorporated by restructuring the size and dimension of EBG pattern to amend the result. Proposed designs showed excellent performances that obtained for much smaller etched area; hence ripple heights that mostly depend on etching area get reduced greatly.

Soda Anthraquinone Pulping of Oil Palm Male Flower Spikes

This study was carried out to investigate the characteristics of pulp and paper produced from oil palm oil male flower spikes (OPMFS). The evaluation of the pulping process was studied based on the chemical Soda Anthraquinone pulping process. 60 gsm papersheet of oil palm male flower spikes were prepared from unbeaten and unbleached OPMFS Soda-AQ pulp. All optical, physical and mechanical characteristics were investigated according to TAPPI and MS ISO standards. OPMFS pulp recorded value of 6.42 s, 353 ml, 76.5 %, 36.7 % and 9.35 for drainage time, freeness, moisture content, screened yield percentage and Kappa number respectively. OPMFS paper sheet recorded value of 56.99 g/m2, 131.11 µm and 0.43 g/m3 for grammage, bulking thickness and apparent bulk density respectively. Unbleached OPMFS paper also recorded 26.49 % and 43.50 % for brightness and opacity. For mechanical characteristics, OPMFS paper recorded 39.10 N.m/g, 8.32 mN.m2/g, 3.15 kPa.m2/g and 38.50 for tensile index, tear index, burst index and folding endurance (no.) respectively. This research demonstrate some potential characteristics of oil palm male flower spikes (OPMFS) paper to be investigated as a newly explored non-wood based raw material for papermaking.

Optimisation of Processing Condition Using Taguchi Method on Strength of HDPE-Natural Fibres Micro Composite

Injection molding usually uses to produce part from plastic. Other than it is cheap, it also can produce part in large quantity. In this paper, Taguchi Methods was used to define the optimization of process parameter for an injection molding machine to produce a dumbbell product from High-density Polyethylene (HDPE) + natural fiber (Kenaf). Taguchi Methods with L9-34 approaches will be used in this work. Four different formulation of material will be tested to find the best formulation and its parameter setting. Here, an orthogonal array (OA), signal-to-noise (S/N) ratio and analysis of variance (ANOVA) are employed to analyze the effect of injection molding parameter. The significant of formulation and parameter setting from injection molding through the hardness and the strength value of the specimen. Furthermore, test will be conducted through hardness test and tensile test. Changes in the parameter setting will give different hardness and tensile strength value. The optimum parameter setting was set base on the S/N ratio. For each formulation, it has their optimum parameter setting for hardness and for tensile strength. The optimum parameter setting was predicting their S/N ratio using Minitab software.

The Effect of Parameter Setting towards the Processing of Hinges Test Samples through Cadmould 3D-F Injection Moulding Simulation

The objective of this study is to analyze the main parameter setting in injection moulding that influenced the processing of selected thermoplastics components. The test sample used for this project was a hinge made from Polypropylene (PP). This sample was being utilised to analyse the parameters affecting the quality of plastic products, which were warpage and shrinkage. Computer-Aided Engineering (CAE) was applied through CadMould 3D-F simulation software. The processing parameters such as filling time, melt temperature, wall temperature and cooling time were selected to determine the quality of the product. By adopting Taguchi Method, the orthogonal array, Signal-to-Noise (S/N) ratio and Analysis of Variance (ANOVA) were used to find the optimum levels as well as to indicate the impact of the process parameters on warpage and shrinkage. The verification test was also performed to prove the effectiveness of Taguchi technique after the optimum levels of process parameters. The ANOVA results show that cooling time and wall temperature are found to be the most significant factors for shrinkage and warpage, with the contribution of 66.96% and 56.82% respectively. The verification test with the optimal settings shows that warpage were improved by about 0.4% and shrinkage with 4.2% improvement. These findings are useful for production engineer to determine optimal parameter during performing injection moulding on hinges products.

A Study of Injection Moulding Optimum Parameters to Control Shrinkage and Warpage of Polypropylene-Nanoclay Hinges Samples

Injection moulding is one of the most efficient processes in mass production that can easily attain up to complex geometry product within a very short cycle time. To choose a suitable setting of parameter was very crucial, in controlling the quality of product with regard to their function. The main propose of this research is to optimize the injection moulding parameter for controlling the shrinkage and warpage of thermoplastics sample through practical injection moulding. The additional study for this project is to investigate the effect of nanoclay contents towards the parameter setting. In this experiment, the selected parameters were packing pressure; melt temperature, screw speed and filling time. The material that was selected for this project was a mixture of polypropylene and nanoclay with the addition of polypropylene-grafted-maleic anhydride as the compatibilizer. Three formulations were chosen, which was 0 wt%, 3 wt% and 5 wt% of Nanoclay. Each formulation was added with 15 wt% of compatibilizer. The experiment design for this project shall adopt the L943 Orthogonal Array of Taguchi Method. By using the Signal to Noise Ratio responses, the optimum parameter for each formulation has been obtained. The findings of this experiment shall be useful for future manufacturing process in order to control shrinkage and warpage specifically for products made from polypropylene-nanoclay.

The effect of alkali treatment under various conditions on physical properties of kenaf fiber

Alkali treatment was known as one commonly used treatment for natural fiber and obtained a good fiber matrix adhesion, thermal and mechanical properties of composite. This paper reports the effect of alkali treatment conditions on the physical properties of kenaf fiber such as density, weight loss, diameter, cross sectional and fiber morphology. In this study, kenaf fiber were treated under various conditions alkali concentration at 2, 6 and 10 (w/v%), immersion duration at 30, 240 and 480 minute and immersion temperature at 27, 60 and 100°C. The effects of alkali treatment on kenaf fiber physical properties under various conditions were explored. Alkali treatment conditions setting have an impact on kenaf bast fiber physical characteristics. In kenaf fiber density, it was found that a small increase of kenaf density value after alkali treatment compared to untreated kenaf fiber. When each of alkali treatment parameters increased, kenaf fiber density also increased slightly. Kenaf fiber weight loss also exhibit a similar pattern of small increment with the increase of treatment parameters. Additionally, kenaf fiber diameter and cross sectional area show a decline pattern after treated with alkali. Furthermore, this decline pattern was corresponding with the increasing level of alkali treatment parameters. The maximum of kenaf diameter reduction was recorded at high level of each alkali treatment parameters.

Effect of beating process to soda anthraquinone pulp of oil palm male flower spikes fibre

This study was carried out to investigate the effect of beating process to the characteristics of pulp and paper produced from oil palm oil male flower spikes (OPMFS). OPMFS pulp was prepared according to chemical Soda-AQ pulping process. 60 gsm handsheet of oil palm male flower spikes paper were prepared from OPMFS pulp with four different beating times which are 0 revolution, 1000 revolutions, 2000 revolutions and 3000 revolutions. All physical and mechanical characteristics were investigated according to TAPPI and MS ISO standards. The results show that overall physical and mechanical characteristics of POMFS paper were influenced and enhanced by beating process between 0 until 3000 revolutions. This research demonstrate some potential characteristics of palm oil male flower spikes (OPMFS) paper to be investigated as a newly explored non-wood based raw material for papermaking raw material for papermaking.

Optimisation of Processing Condition Using Taguchi Method on Warpage for HDPE-Clay Composite

Injection molding is one of the most important processes in manufacturing nowadays. Thus, attention must be give towards the optimization of the product defects. Parameters have been chosen by screening tests to improve the process quality. The main purpose of this study is to optimize the processing condition using Taguchi Method on shrinkage for HDPE-Clay specimen. The experiment starts by preparing the mixture between HDPE and clay. Then, screening test is conducted to obtain the parameters. The parameters are melt temperature, injection speed, injection pressure and cooling time. By using the array orthogonal L9 (34), signal to noise ratio and ANOVA were conducted. Based on the S / N ratio analysis, best combination can be produced for warpage (melt temperature: 190°C, injection speed: 40%, injection pressure: 30% and cooling time: 3 seconds). While for ANOVA, melt temperature is most significant with 60.28% for warpage.