Improved measurement and
modelling of the fluidity of compression Moulding
compounds
Ernst Schmachtenberg, Klaus Skrodolies
Pontstraße 49, 52062
Abstract
In the development of fibre-reinforced plastics (FRP), the
consistent computer-assisted simulation of all the processes involved in the
design, production and application of these parts (Computer Aided Engineering,
CAE) is an extremely valuable tool. For a number of years, the IKV has been
consistently developing the EXPRESS simulation program for the compression
moulding of long fibre-reinforced moulding compounds. A further step in the
development of the program involves the ability to also take elongational effects and wall slippage into account in the
simulation. The influence of these effects on the moulding pressure profile is
first described in an analytical model. With this model, it is possible to
analytically calculate the moulding pressure profile during the compression
moulding of simple disc geometries with isothermal flow. Comparison with the
measured moulding pressure curve from isothermal models shows a considerable
improvement in the calculation with the new model, and hence this will also be
implemented in EXPRESS. Because of the pronounced relationship between the wall
slippage factors and the temperature and shear rate, the calculation of the
moulding pressure profile for non-isothermal models is still being researched
at IKV.