
Sterilising
In biology and medicine, a differentiation is made between disinfection and sterilisation. unterschieden. Disinfection is understood to mean the reduction of disease-causing germs by several orders of magnitude, so that the risk of infection can be largely excluded. Sterilisation is intended to completely kill and remove all biological germs, bacteria, viruses and bioactive molecules on the treated surface. Conventional sterilisation uses heat in superheated steam or hot air. There is a lot of experience with these time-proved procedures. Much research has been done to determine at which temperature over which period of time which type of germs can be completely killed. Annealing at 500 °C definitely kills all germs. However, many substrates are sufficiently temperature-resistant to be completely sterilized by thermal processes, especially textiles and many plastics. This is why radiation sterilisation with high-energy radiation is often used. But complete sterilisation can also be achieved by plasma sterilisation without any temperature increases which are critical for substrates used in practical applications. Plasma cleaning processes which remove organic contaminations without any residues are also suitable for sterilising instruments and materials used in medicine and laboratory. High-energy UV radiation splits organic molecules; by reaction with the radicals of the process gas, ineffective molecules are generated, and germs are mechanically destroyed by ion bombardment. By means of sufficiently intensive treatment, the residues of biological substances can be removed completely. Plasma sterilisation is of advantage particularly when the surface of components is to be modified by plasma cleaning, plasma activation and plasma etching. Sterilisation is the equivalent of antiseptic cleaning.