MODELLING, MANUFACTURING OF MOLD TOOL AND PLASTIC FLOW ANALYSIS OF AN AIR COOLER TANK

Transcription

1 International Journal of Mechanical and Production Engineering Research and Development (IJMPERD) ISSN Vol. 3, Issue 3, Aug 2013, TJPRC Pvt. Ltd. MODELLING, MANUFACTURING OF MOLD TOOL AND PLASTIC FLOW ANALYSIS OF AN AIR COOLER TANK VISWA MOHAN PEDAGOPU Assistant Professor, Department of Mechanical Engineering, School of Engineering and Technology, Shoolini University, Solan, Himachal Pradesh, India ABSTRACT The component Air Cooler Tank has been remodelled from the previous model in Pro-e WF2 software providing the additional features like stiffeners, decreasing the thickness and changing the material from ABS to polypropylene in order to reduce the component cost. The mold tools like core, cavity, core back plate, cavity back plate, ejector pin, etc., were also modelled. Core and cavity of the prototype components with aluminium material were manufactured at reduced scale. The component was analysed and simulated by using Plastic Advisor 6.0 software By comparing the results at different injection pressures and melt temperatures, the optimum injection pressure and melt temperature were found at 300 Mpa and 210 C for the given component without mold defects and the same was considered to the prototype component at reduced scale. This analysis provided sufficient information results such as fill time, Confidence fill, Pressure drop, and Quality prediction without mold defects like weld lines, air traps etc. Finally, the component was approved by the customer. KEYWORDS: ABS, Polypropylene, Plastic Flow Analysis, Injection Moulding and Milling Machines PROBLEM STATEMENT A product designer from any industry, designs the product, be it a single component or an assembly of components, based on two main factors, viz., functionality &aesthetics. The application, functional and aesthetic failure of previous part. A leakage from rollers cavity, lack of firm grip between tank to main body, heavy in size & weight and cost of part is high.the plastic industries having high intension to remodel of cooler tank which is the one of main assembly part of domestic air cooler, studied for inducing the required changes from previous design which was made up of ABS material, then developed a new design, improving manufacturability, comfort ability and final usage. OBJECTIVES OF PROJECT Modelling of the air cooler tank part and Mold Tool assembly parts by using Pro/Engineer. Wild fire 2.0. Mold flow analysis by using Plastic Adviser 6.0. Study of the behaviour of Polypropylene as an injection material. Focus on different issues like Weld lines, Air traps, pressure drops, temperature conditions, injection pressure, fill time, plastic flow and including input and output parameters. Calculation for number of part to be produced in a shift with the help of plastic analysis. Cost Analysis. The four stiffeners are provided to give solid strength to the rollers.

2 110 Viswa Mohan Pedagopu INTRODUCTION Injection moulding is a process that forms the plastic into a desired shape by melting the plastic material and forcing the plastic material under pressure into the mould cavity. Injection moulding is a cyclic process. Material is fed into a heated barrel, mixed, and forced into a mold cavity where it cools and hardens to the configuration of the mold cavity. The process cycle for injection moulding is very short, typically between 2 seconds and 2 minutes, and consists of the following four stages Clamping, Injection, Cooling and Ejection some disadvantages of this process are expensive equipment investment, running costs may be high, and parts must be designed with moulding consideration Process Parameters Figure 1 Material-(Polypropylene) Injection Pressure (Mpa) Melt Temperature ( C) Mold Temperature ( C) Mold Cooling Rate (Sec) Performance Characteristics Fill Time Confidence Fill Injection Pressure Pressure Drop Flow Front Temperature Weld lines, Air traps and sink marks MODELLING Modeling of Component Modeling of Mold base tools

3 Modelling, Manufacturing of Mold Tool and Plastic Flow Analysis of an Air Cooler Tank 111 1: Core 2: Cavity 3: Ejector Pin 4: Sprue Bush 5: Locating Ring 6: Riser 7: Ejector Plate 8: Core Back Plate 9: Cavity Back Plate Figure 2 Figure 3: Dimensional View of the Part

4 112 Viswa Mohan Pedagopu Figure 4 Figure 5 Figure 6 Figure 7 PLASTIC FLOW ANALYSIS 3D solids-based plastics flow simulation that allows plastics part designers to determine the manufacturability of their parts during the preliminary design stages and avoid potential downstream problems, which can lead to delays and cost overruns. Animates plastic injection fill process and automatically creates web reports within pro/engineer browser. Access library of common plastic materials and automatically select from typical injection-molding machine parameters. Identify optimal injection locations to reduce cycle time and improve product appearance. Identify potential mold-filling problems such as short shots, air traps, and weld lines. Improve design quality and reduces manufacturing cycle times and rework of moulds.

5 Modelling, Manufacturing of Mold Tool and Plastic Flow Analysis of an Air Cooler Tank 113 Table 1 Figure 8 Figure 9 Figure 10 Figure 11

6 114 Viswa Mohan Pedagopu MANUFACTURING OF CORE AND CAVITY Figure 12: Vertical Milling Machine Figure 13: Aluminium for Core & Cacity{Raw Material} Figure 14: Manufacturing of Core Part Figure 15: Manufacturing of Cavity Part Figure 16: Core & Cavity Table 2 Table 3

7 Modelling, Manufacturing of Mold Tool and Plastic Flow Analysis of an Air Cooler Tank 115 Figure 17: Maximum Injected Figure 18: Intake Injection Figure 19: Intake Injection Pressure Vs. Intake Pressure Pressure Vs. Fill Time Pressure Vs. Cycle Time Figure 20: Production of Cooler Tank RESULTS AND DISCUSSIONS The result of this Dissertation has been fulfilled the intention to find out the optimum values for the selected material, machine, process and process parameters. The defects were predicted at different values [IP at 100MPa, 200MPa and Temp. at 200ºC - 210ºC - 220ºC,] analysed and found the injection pressure 300MPa, temp.210ºc were optimum. Stiffeners have been added to the four corners of the bottom of the cooler tank by giving taper shaped impression and prevent warpage of the components has been identified after injection mold.by Plastic adviser, it was known that the increased temperature affecting the injection pressure, fill time, cycle time. But the maximum allowable melt temperature depends on the polymer being used for the component. In order to prove the above said statement the part was produced at the reduced pressure approximately 40MPa and constant temperature 210ºC in the hydraulic injection moulding machine and found there was no the weld,weld lines, air traps, sink marks. Hence, with this project it was proved that the plastic flow analysis was economical, product cost reduction and easy process. CONCLUSIONS Mould flow analysis for cooler tank using polypropylene material at different temperature and pressure conditions analysed and found the optimum parameters injection pressure at 300Mpa and melt temperature at 210ºC. At the optimum parameters, the plastic adviser predicts that the component will be free from weld lines, air traps, sink marks. Finally a good quality component can be expected with less cycle time.

8 116 Viswa Mohan Pedagopu By considering the above plastic adviser reports, it can be concluded that the part produced has excellent quality before going to the injection moulding. The cost of the component is reduced approximately to 50% by replacing material. The number of component produce per shift has been predicted. Mold tools core and cavity of the component are manufactured and the product was also manufactured. The Component air cooler tank has been modified and approved after the following changes: Material replaced from ABS to Poly propylene. Providing four stiffeners at the bottom of the tank. Thickness of the tank is reduced from 3mm to 2.5. Sweep is provided at the periphery of the component. REFERENCES 1. Mr.Jianxin Jiao and Siew Ling Teo, DESIGN of an Unplasticized Polyvinyl Chloride (UPVC) Pipe Fitting Injection Mould School of Mechanical and Production Engineering Nayang Technological University, Singapore. 2. Mr. D.Cheshire The Spectrum of Plastic Materials Brydson, J, Plastics Materials, Butterworth s 9th Ed (1999). 3. Mr. McAllister, William D, Materials Science and Engineering: An Introduction, and John Wiley and Sons. 4. Mr. Mohammad. Illustration and application of design of experimental (DOE). University of Technology Malaysia 5. Mr. Oswald, Tim A; Lih-Sheng Turng, Paul J.Gramamn. Injection Molding Handbook Oswald, Tim A. International Plastics Handbook. Hanser Verlag Mr. Clive Maier, Teresa Calafut Polypropylene: The definitive user's guide data book Reviews William Andrew, Technology & Engineering & Handbook of polypropylene and polypropylene composites 7. Mr. Clive Maier, Mr. T. Calafut Plastic injection molding process and parameters 8. Mr. Huntsman 2005/1st edition Manual of Processing Parameters of Injection Molding Modeling of Polymer Processing, 9. Mr. Iwan Halim Sahputra Comparison of Two Flow Analysis Software for Injection Moulding Tool Design Department of Industrial Engineering, Petra Christian University, Surabaya, Indonesia. 10. Mr. Lei Xie Æ Gerhard Ziegmann Microsyst Technol (2009) 15: Springer link Influence of processing parameters on micro injection molded weld line mechanical properties of polypropylene (PP)