Muhammad Sheharyar Muhammad Khizar Shafique Muhammad Umer Farooq

Injection Molding Simulation Analysis of a Computer Exhaust Fan Using SolidWorks Plastics

A model of computer exhaust fan was created and studied in this paper using Solidworks Plastics. In this way, several construction factors of the object under consideration could be studied e.g. melt temperature, injection temperature, gate selection and mesh sizes. All the main aspects of polymer simulation were studied using photographs and tables. Thus defects could be detected easily and by selecting optimum parameters for the product, these defects could be removed before the practical application of the product.

Computer fan, as the name signifies, is a type of fan used in computers for cooling and exhaust purposes. It removes the hot air thus keeping the computer cool. Better fans are needed for complex computers. Moreover, these fans are used in other appliances too for the same purpose, heat exhaustion. The simulation of a polymeric part in SolidWorks -includes various steps. A mesh of the designed part has to be created. Smaller mesh size increases accuracy of simulation, which can be very effective in concluding the results, but this also increases simulation time (depending on processing power of the system). On the other hand, larger mesh size can be used which, although, creates a decrease in accuracy but increases the simulation time of the designed part.

S. No.

Property Value

1. Max. Melt Temp. 320C

2. Glass Transition Temp. 147C

3. Specific Heat Constant 1700 J/(kg.K)

4. Thermal Conductivity 0.173 W/(m.K)

5. Elastic Modulus 2400 MPa

6. Poissons Ratio 0.38

7. Thermal Expansion

Coefficient

7 x10-5 C-1

If incorrectly placed, the gate location can have adverse effects on the designed part. It could be responsible for weak weld lines, gas trapping and jetting which resulted in poor appearance, less mechanical properties and irregular color of product.

Introduction Material Selection

Simulation Results

Conclusions

Designing

The material should have following properties: Should bear external stresses due to strong

rotation of the fan Should bear hot currents when ventilating the

heat from CPU Should be fully insulated to avoid any electrical

discharges Should be light weight so as to require lesser

energy to rotate around its axis

Keeping in view all these constraints, Polycarbonate made by Bayer MAKROLON coded 2605 is chosen to make computer fan. It has the following properties, Melt & mold temperature are one of the most

important parameter in the simulation of a polymeric part. They had many prominent effects on the molded part. Thus they were varied to study their effects. Both have almost same effects. Both of them effect volumetric shrinkage, shear stresses, air traps, weld lines and pressures at end of fill.

SolidWorks Plastics is very helpful in analysis of injection molding simulation process. The analysis shows that the number of gates, melt temperature, mold temperature and packing pressure holding time are important in injection molding process because these parameters has greater effect on weld lines, volumetric shrinkage, frozen layer and sink marks that are the main defects in the part quality. From the analysis simulation, SolidWorks Plastics provides the sufficient information about the processing parameters to avoid the defects in actual injection molding process.

The author would like to grab this opportunity to thank Dr. Shafiq Irfan, without whose guidance and continued support, this paper would have been far from possible. Moreover. The author is grateful for the resources the department has provided for making this project a success

References

Department of Polymer and Process Engineering

University of Engineering and Technology Lahore, Pakistan.

Gate Location

Melt and Mold Temperature

1. M.R. KAMAL, A.I. ISAYEV, AND S.J. LIU, 2009, Injection Molding: Technology and Fundamentals Michigan: Hanser Publications. 2. JAY SHOEMAKER, 2006. Moldflow Design Guide, USA: Hanser Publications. 3. DAVID WATSON, 2008. CAD Tutor, ed. by Matt Bill, USA: John Wiley and Sons Publications. 4. FISCHER, J. 2013. Handbook of Molded Part, Warpage and Shrinkage, UK Intermediate Technology Publication. 5. SHEN, J. 2010. Design and Molding Simulation of the Plastic Part, USA: John Wiley and Sons Publications.

Acknowledgement

If incorrectly placed, the gate location can have adverse effects on the designed part. It could be responsible for weak weld lines, gas trapping and jetting which resulted in poor appearance, less mechanical properties and irregular color of product.

Figure 2: Pressure at End of Fill for 1 and 2 gates respectively

11.5 1212.5 13

13.514

14.515

15.5

260

270

280

290

300

% Volume Shrinkage

Mel

t Te

mp

erat

ure

Melt Temperature Effect

12.612.7

12.812.9

1313.1

13.2

80

90

100

110

120

% Volume Shrinnkage

Mo

ld T

emp

erat

ure

Mold Temperature Effect

Figure 1: General 3D Design of front and back side of Computer Fan