The Interface-Contact Vacuum Sealing Processes

This is the authors' abstract. We don't add key points for this paper.

Recent advances in our understanding of the phenomena that determine the leak rate in demountable vacuum seals are presented. The description includes a survey of recent investigations of the vacuum sealing process and a comparison of the results obtained by various research groups. A systematic interpretation of the sealing mechanism is presented, in which the phases that may occur in the sealing process are summarized, and the characteristics of the tightening curve, releasing curve, accommodation, and normal sealing stages are established. The concept of sealing ability and tightening index are defined and used to explain the characteristic leak rate graphs. The influence of the size and profile of the surface roughness, waviness, local imperfection (scratches), seal width, and helium pressure are summarized or discussed. In conclusion, a system of concepts, graphs, and equations for expressing the operation of seals is presented and a way in which these should be used as a basis for classification and standardization of demountable vacuum seals is proposed.