密封材料一般应具有良好的物理和机械性能、回弹性高、压缩永久变形小、密封可靠、加工方便和使用寿命长。航空航天工业还要求密封材料能适应一些特殊的环境要求，如耐真空、耐辐射、无污染、无毒、耐高低温和耐航空燃料和火箭推进剂等介质的腐蚀。密封材料在使用时可以配制成液状或膏状，涂敷在两部件的接触面之间，在一定的条件下固化或呈不干性腻子起密封作用；也可以加工成各种形状的实心或空心圆环安装在两部件的接触面之间起密封作用。前者称密封材料只用于两部件接触面无相对运动的静密封部位；后者称密封件既可用于静密封部位，又可用于两部件的接触面有相对运动的动密封部位。
Generally, sealing materials shall have good physical and mechanical properties, high resilience, small compression permanent deformation, reliable sealing, convenient processing and long service life. The aerospace industry also requires that sealing materials can meet some special environmental requirements, such as vacuum resistance, radiation resistance, non pollution, non-toxic, high and low temperature resistance, and resistance to the corrosion of aviation fuel and rocket propellant and other media. The sealing material can be prepared into liquid or paste, applied between the contact surfaces of the two parts, solidified or in the form of non dry putty under certain conditions for sealing; it can also be processed into solid or hollow rings of various shapes to be installed between the contact surfaces of the two parts for sealing. The former says that the sealing material is only used for the static sealing parts where there is no relative movement on the contact surface of the two parts; the latter says that the sealing parts can be used for the static sealing parts and the dynamic sealing parts where the contact surface of the two parts has relative movement.