Technical Paper: PIM International, Vol.1 No. 2 June 2007, pages 54-56, 1269 words

Authors: C. Hinse [1], R. Zauner [2], R. Nagel [2], P. Davies [3] and M. Kearns [3]

[1] SimpaTec GmbH, Schloss-Rahe-Str. 15, D-52072 Aachen, Germany
[2] Austrian Research Centers GmbH, A-2444 Seibersdorf, Austria
[3] Sandvik Osprey Ltd., Red Jacket Works, Milland Road, Neath SA11 1NJ, United Kingdom

Abstract

The injection moulding process as part of a PIM manufacturing process can be divided into several stages including filling, packing and cooling. Each of these stages can affect the dimensional precision and the performance of the moulded part after ejection and also have an effect on the debinding and sintering process.

Computer Aided Engineering has been widely adopted and proved to be an important tool for part and mould designers. Design and process variables of design can be evaluated with simulation before the mould is actually constructed. In this manner, potential defects are identified and eliminated in the design phase of part and mould. In addition to this, design can be refined and even be optimised according to the simulation, to improve the engineering in the technical way and also to be more cost efficient. [1-3].

Status quo

Computer simulations have become an important tool for engineering polymer processing operations. They supersede the traditional “trial and error” methods that are no longer are adequate to compete in today’s competitive environment.

The basic principles governing the processing of thermoplastic materials were established in the early 1950’s. The root of modern computer simulation in injection moulding can be traced back to early work of Wang and Hieber at Corness University. However, in the past the complexity and sophistication of polymer processing engineering have restricted its in-depth application to only the most critical problems.

Modern computer simulation offers the means to apply the full capabilities of plastic engineering routinely and economically, to optimise polymer processes such as injection moulding. Demands for the substantially higher levels of quality and productivity in plastics processing can be met only through computer modelling of the relevant operations. So the benefits of using simulation software starts with the development of new parts until the serial production of parts. All in all, simulations can help the engineer in the way of:

• Part design
• Gate design
• Setting of process parameters
• Changing and optimisation of process parameters
• Mould design
• Choosing of injection moulding machine
• Reduction of material consumption

Simulation has a big potential in reducing costs and development and manufacturing time. Today, simulations are still mostly used for troubleshooting and not during development of new parts.

Further sections of this article include:

- Governing equation
- Case study
- Results
- Component fabrication
- Conclusion
- References

Figures and Tables:

Fig. 1 LED heat sink

Fig. 2 Comparison of 3D-simulation and real part at filling degree of 10%

Fig. 3 Comparison of 3D-simulation and real part at filling degree of 60%

Fig. 4 Full 3D Model of the part within the mould

Fig. 5 Injection moulded LED heat sinks

Fig. 6 Sintered component