least one processing aid chosen from molecules and combinations of molecules capable of interacting with the particulate filler particularly with silicon if a siliceous filler is used to the detriment of the hydrogen bonds that this particulate filler establishes especially between its own atoms and or with those of the silicone oil and capable of being removed from the preparation mixture by devolatilization and in that actions are taken to ensure that this processing aid is in the presence of water in the preparation mixture in accordance with this third method of implementation it is preferable for the processing aid to be readily removable from the preparation mixture for this purpose it is beneficial for it to be easily removed by devolatilization for example by heating in a vacuum or in a gas stream under these conditions it is clear that as processing aid molecules of low molecular weight will be preferred silazanes hmdz being preferred difunctional or preferably monofunctional hydroxylated siloxanes amines preferably ammonia and or alkylamines diethylamine being particularly preferred organic acids formic and or acetic acids being preferred and mixtures thereof as indicated above the products more particularly selected as processing aids are those having a low molecular weight this proves to be the case especially for the amines and the organic acids mentioned above with regard to the products employed in the process according to the.