TITLE: INVESTIGATING OF PLASTIC INJECTING MOLDING PROCESS OPTIMIZATION IN COMPLEX SHAPE PRODUCT PRESENTED BY: MR. AHMAD AIZUDDIN ABD AZIZ PhD STUDENT.

Transcription

1 TITLE: INVESTIGATING OF PLASTIC INJECTING MOLDING PROCESS OPTIMIZATION IN COMPLEX SHAPE PRODUCT PRESENTED BY: MR. AHMAD AIZUDDIN ABD AZIZ PhD STUDENT.

2 Overview Introduction Methodologies Result and discussions Conclusion

3 INTRODUCTION INJECTION MOLDING Manufacturing process for making complex shapes from polymeric materials. The process involves heating up the polymer, injecting the molten polymer into a mold, cooling the polymer in the mold, and ejecting the part. Injection molding is a complex technology with possible production problems. They can be caused either by defects in the molds or more often by part processing which is molding.

4 CONT The common defect are: Warping Short shot Sink marks Flash Weld lines

5 Product Phone Cover model

6 Nowadays, in mobile phone manufacturing or industries are made a lot of accessories as a protector from damage or made a very nice appearance. The phone cover also one of the accessories is made to protector the mobile phone from damage. The whole part for phone cover (upper and bottom casing, transference keypad and screen) is not injected in the same mold simultaneously, they are come batch by batch instead of their type, which means, for example, the upper and bottom casing come from one mold and the other pieces also comes from one mold.

7 cont

8 cont The main problem is to inject the whole of part for phone cover (upper and bottom casing, transference keypad and screen) which come in diversity of shape, size, and volume in one mold need the most optimize injection parameter setting because if one piece is rejected, the set is not completed, in order to replace the rejected piece, it needs another injection which will lead to more cost and higher inventory.

9 OBJECTIVES The main objectives of the project are: To simulate the product using CAD software. To find the optimum moulding parameter of plastic injection moulding process. To analyses the material flows of two and threeplate molds in injection molding process.

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11 Prepare CAD Saved in x_t file type for MPI simulation

12 Meshing A continuous surface or volume is broken into many connected but discrete elements, forming a mesh. The time required to mesh the part will depend on the size and complexity of the part.

13 Runner layouts H-type (branched) Radial-star

14 Type of Gate Chosen AC Technology, C-MOLD Design Guide. New York, USA.

15 Type of Gate Chosen AC Technology, C-MOLD Design Guide. New York, USA.

16 RESULT AND DISCUSSION

17 In order to find the most optimize layout arrangement of phone cover mold, the result from 2 layouts should be compared. The selected results of each layout that will cover are: 1. Fill time 2. Average velocity 3. Clamp force 4. Pressure 5. Time to reach ejection temperature (Cooling time) 6. Volumetric shrinkage.

18 1. Fill time Standard H-Types Radial-Star 3.148s 3.176s The Fill time result shows the position of the flow front at regular intervals as the cavity fills. At the start of injection, the result is dark blue, and the last places to fill are red. The shortest time is H-type layout with 3.148s but two part in H-type layout will get flashing defect. Even fill time in radialstar layout takes 3.176s, this layout is the most balanced with all the part filled almost uniformly.

19 2. Average velocity Standard H-Types Radial-Star 953.4cm/s 754.3cm/s The Average velocity, part show the result of the velocity profile across the part thickness, calculated at the end of cooling time. From the result, can see that the H-type layout reach over cm/s rather than over 754.3cm/s in radial-star layout

20 3. Clamp force Standard H-Types Radial-Star 38 tonne 28 tonne Clamp force is the force required to hold the mold closed while an opposing pressure is exerted by the plastic injected into the cavity. Clearly can see that radial star layout just need 28 tonneclamp force, while the stabdardh-type just need 38 tonneclamp force. This means the parts of radial star layout should be no defect of flashing.

21 4. Pressure Standard H-Types Radial-Star < MPa < MPa The Pressure result is generated from a Fill analysis, and shows the pressure distribution through the flow path inside the mold at the time the result was written. The radial star layout got the lowest pressure which is MPa compared to h-type layout which over MPa. This is because radial star layout have bigger runner size and volume.

22 5. Time to reach ejection temperature (Cooling Time) Standard H-Types Radial-Star 50.05s 30.19s

23 6. Volumetric shrinkage Standard H-Types Radial-Star The Volumetric shrinkage result shows the volumetric shrinkage for each area as a percent of the original volume.

24 Comparison Criteria H-type Radial-star Fill time Average velocity Clamp force Pressure Time to reach ejection temperature Volumetric shrinkage X X X X X X Radial-star was chosen as the most optimize runner layout

25 Advantages & Disadvantages Two & Three Plate Molds

26 Conclusion Results show that three plate moulding satisfy both process quality and the product quality characteristics in this injection moulding process. The radial star layout was the better layout for parts injection molding process. Although this optimization study only emphasis in the runner layout and product configuration in the mold, the proposed approach is feasible and effective to assist the today manufacturing industry needed for complex shape.

27 REFERENCES [1] Stanek, M., Manas, D., Manas, M., Javorik, J. Simulation of injection molding process by cad mould rubber. Int. J. Math. Comput. Simul., 5.5, (2011). [2]Chen,W.C.,&Lin,S.B,Int.J.App.Phys.Math.,Vol.3,No.6, (2013). [3] Dang, X.P. Simulation Modelling Practice and Theory 41, (2014). [4] P.K. Bharti et al. Int. J. Eng. Sci. Tech., Vol. 2(9), (2010). [5]Shen,C.,Wang,L.,&Li,Q.J.Mater.Proc.Tech.,183.2, (2007). [6]Tang,S.H.,etal.J. Mater.Proc.Tech.,171.2, (2006).

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