Linear polysiloxane, usually poly(dimethylsiloxane), which is widely used as a non-resinifying oil and grease. Silicones with cross-linking properties are used as sealants, for example. Silicones have a very low surface tension (approx. 20 mN/m) and thus are very well capable of wetting most surfaces excellently while not being wetted themselves by most liquids. For this reason, also the smallest traces of silicones interfere with most coating processes. Cleaning silicone residues off surfaces is possible by means of special plasma processes.