Evaluation of shrinkage and weld line strength on thick flat part in injection moulding process
Mechanical properties such as strength of moulded part is critical predominantly for parts that require a sufficient strength for the functionality of the product. One of the main concerns that affects the mechanical properties is weld line defect which occurs when two or more gates are used during...
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my-unimap-771762022-11-24T07:44:16Z Evaluation of shrinkage and weld line strength on thick flat part in injection moulding process Khairul Azwan, Ismail, Assoc. Prof. Dr. Mechanical properties such as strength of moulded part is critical predominantly for parts that require a sufficient strength for the functionality of the product. One of the main concerns that affects the mechanical properties is weld line defect which occurs when two or more gates are used during the injection moulding process. In addition, the dimensions of the part are also crucial in terms of precision of the product. Thus, the shrinkage of the moulded parts also needs to be controlled. Most of the previous studies focus on the weld line strength or the shrinkage of the moulded part separately and it is rare to find studies that incorporate both of these aspects. Therefore, the current study evaluates both shrinkage and strength of weld line using Design of Experiment (DOE) and Response Surface Methodology (RSM) in multi-objectives optimisation utilizing the injection moulding parameters. The mould was successfully designed and fabricated complete with gating system, cooling system, core and cavity of a thick flat part based on ISO standard. The variable parameters used in this study are coolant inlet temperature, melt temperature, packing pressure and cooling time. Simulation process was conducted to determine the recommended setting of injection moulding parameters and the range of the variable parameters. The acceptable range of coolant inlet temperature was set between 50°C and 70°C, while the melt temperature was between 250°C and 270°C. The range of packing pressure was set between 50 MPa to 70 MPa and cooling time between 8 s and 12 s. Experimental works were conducted according to the experimental design where regression models were established to predict the shrinkage and weld line strength. An optimal setting parameter of the process was established to achieve the optimum shrinkage and weld line strength of the moulded part. The results of shrinkage and weld line strength using an optimal setting after optimisation process were compared with the results obtained using the recommended setting. It was found that, the shrinkage in the normal and parallel directions to the melt flow were reduced by 5.97 % and 4.91 % by predicted model generated using RSM. On the other hand, the weld line strength was improved by 3.76 % as compared to the weld line strength obtained from the recommended setting. Universiti Malaysia Perlis (UniMAP) Thesis en http://dspace.unimap.edu.my:80/xmlui/handle/123456789/77176 http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77176/3/license.txt 8a4605be74aa9ea9d79846c1fba20a33 http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77176/1/Page%201-24.pdf e1736b6e7174246ff129d5c2d2e04284 http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77176/2/Full%20text.pdf ae1a3094d7502ed8f5e3dfe0141c1984 http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77176/4/Mohd%20Nasir%20M%20Saad.pdf e187bc57003b0718a294375c25eca3e9 Universiti Malaysia Perlis (UniMAP) Injection molding of plastics Concrete -- Expansion and contraction Materials -- Mechanical properties School of Manufacturing Engineering |
| institution |
Universiti Malaysia Perlis |
| collection |
UniMAP Institutional Repository |
| language |
English |
| advisor |
Khairul Azwan, Ismail, Assoc. Prof. Dr. |
| topic |
Injection molding of plastics Concrete -- Expansion and contraction Materials -- Mechanical properties |
| spellingShingle |
Injection molding of plastics Concrete -- Expansion and contraction Materials -- Mechanical properties Evaluation of shrinkage and weld line strength on thick flat part in injection moulding process |
| description |
Mechanical properties such as strength of moulded part is critical predominantly for parts that require a sufficient strength for the functionality of the product. One of the main concerns that affects the mechanical properties is weld line defect which occurs
when two or more gates are used during the injection moulding process. In addition, the dimensions of the part are also crucial in terms of precision of the product. Thus, the shrinkage of the moulded parts also needs to be controlled. Most of the previous studies focus on the weld line strength or the shrinkage of the moulded part separately and it is rare to find studies that incorporate both of these aspects. Therefore, the current study evaluates both shrinkage and strength of weld line using Design of Experiment (DOE) and Response Surface Methodology (RSM) in multi-objectives optimisation utilizing the injection moulding parameters. The mould was successfully designed and fabricated complete with gating system, cooling system, core and cavity of a thick flat part based on ISO standard. The variable parameters used in this study are coolant inlet temperature, melt temperature, packing pressure and cooling time. Simulation process was conducted to determine the recommended setting of injection moulding parameters and the range of the variable parameters. The acceptable range of coolant inlet temperature was set between 50°C and 70°C, while the melt temperature was between 250°C and 270°C. The range of packing pressure was set between 50 MPa to 70 MPa and cooling time between 8 s and 12 s. Experimental works were conducted according
to the experimental design where regression models were established to predict the shrinkage and weld line strength. An optimal setting parameter of the process was established to achieve the optimum shrinkage and weld line strength of the moulded
part. The results of shrinkage and weld line strength using an optimal setting after optimisation process were compared with the results obtained using the recommended setting. It was found that, the shrinkage in the normal and parallel directions to the melt
flow were reduced by 5.97 % and 4.91 % by predicted model generated using RSM. On the other hand, the weld line strength was improved by 3.76 % as compared to the weld line strength obtained from the recommended setting. |
| format |
Thesis |
| title |
Evaluation of shrinkage and weld line strength on thick flat part in injection moulding process |
| title_short |
Evaluation of shrinkage and weld line strength on thick flat part in injection moulding process |
| title_full |
Evaluation of shrinkage and weld line strength on thick flat part in injection moulding process |
| title_fullStr |
Evaluation of shrinkage and weld line strength on thick flat part in injection moulding process |
| title_full_unstemmed |
Evaluation of shrinkage and weld line strength on thick flat part in injection moulding process |
| title_sort |
evaluation of shrinkage and weld line strength on thick flat part in injection moulding process |
| granting_institution |
Universiti Malaysia Perlis (UniMAP) |
| granting_department |
School of Manufacturing Engineering |
| url |
http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77176/1/Page%201-24.pdf http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77176/2/Full%20text.pdf http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77176/4/Mohd%20Nasir%20M%20Saad.pdf |
| _version_ |
1776104245684076544 |