Sealing is the key basic technique to ensure the safe, reliable, and long-life operation of mechanical equipment. The sealing industry is not large, but as the core parts of machinery, pumps, pipes, and valves, it almost covers the industrial fields such as automobile, aerospace, navigation, petroleum, chemical industry, energy, and metallurgy, and plays an important role in the whole process of industrial development. Among them, rubber plastic seal is the general name of rubber plastic seals. Because of its simple structure, compact size, resilience, self-lubricating, chemical corrosion resistance, and other advantages, it is the most used sealing element in mechanical equipment.
In recent years, rubber and plastic seals have made breakthroughs in theoretical mechanism research, material preparation technology, forward design technology, and product production technology. China’s rubber and plastic seal industry has also made great progress. Among them, the rubber and plastic sealing Market of medium and low speed and medium and low pressure have been relatively mature, which can meet the domestic demand; The situation that the key seals of high-end equipment such as aviation, aerospace, and marine heavy industry are heavily dependent on imports has also been improved. In general, the technical level of the domestic rubber and plastic sealing industry has reached a new level. However, with the development of new industrial technology, mechanical equipment is becoming more and more high-quality and high-performance and the working conditions of rubber and plastic seals are becoming more and more demanding. In addition, the global awareness of environmental prote ction is improving; The rubber and plastic sealing technology is also facing many new challenges due to the increasing emission standards of gas and liquid at the sealing parts and other factors.
New challenges give birth to new demands. The silicone rubber sealing industry is accelerating innovation and reform. More and more enterprises have joined the ranks of adjusting the industrial structure and increased investment in R & D, production, and testing of the experimental equipment . Breakthroughs and progress have been made in relevant sealing materials and structures. It can be expected that with the acceleration of the innovation and reform of rubber and plastic sealing technology, the personnel quality, technical equipment, raw and auxiliary materials, processing technology, production environment, and management level of the whole industry will be further improved, the relevant standard system will be improved day by day, and there will be more and more original technologies. The overall scale of the original industry in the domestic rubber and plastic sealing industry is small, there are few varieties and product lines, the quality is unstable, and the standard le vel is low A series of problems such as weak technical force will be gradually improved and solved. In short, the industrial structure of rubber and plastic sealing is changing, and the industrial pattern is accelerating, which needs to be paid great attention to by domestic rubber and plastic sealing practitioners.
Rubber plastic seal seems simple, but it is still a systematic project. Good seal design covers material development, structural design, manufacturing process, and inspection. The sealing performance is determined by the whole system composed of these four parts. Any problem in any link will lead to sealing failure. Therefore, the current situation and trend of the four aspects will be summarized in detail.
Due to the small scale and weak technical strength of the domestic rubber and plastic sealing industry as a whole, most sealing manufacturers adopt reverse design means, focusing on measuring, imitating, and manufacturing foreign mature sealing products to meet the needs of customers. In recent years, with the implementation of an industrial strong foundation engineering policy and the increasing demand for high-end equipment for domestic seals, China’s sealing industry has developed rapidly. Reverse design can no longer meet the requirements of the development of high-performance and high- quality seals. The forward design has gradually become the main design means to meet the needs of the host equipment.With the development of new technology, the industrial field has gradually begun to introduce the method of intelligent design: using a computer to simulate the designer’s thinking activities and simulate or reproduce the designer’s creative design process on the computer. For the sealing industry, intelligent design is the result of the further development of the forward design.
The sealing mechanism is the basis of explaining how to prevent leakage and failure analysis and is the basis of theoretical and numerical simulation research. Macroscopically speaking, sealing can be realized when the contact stress of the rubber plastic sealing interface is greater than the medium pressure, and the greater the contact stress, the better the sealing effect. However, on the one hand, due to the influence of surface roughness, there will be microleakage channels between the interfaces, and there will still be running, emitting, dripping, and leakage ; On the other hand, the larger contact stress will lead to the deterioration of the friction and wear performance of the dynamic seal interface and accelerate the seal failure. Therefore, good sealing needs to solve the contradiction between preventing leakage and reducing friction. Taking the oil seal as an example, it has been proved that there is a lubricating oil film between the contact interfaces in the process of use, which greatly reduces the friction, and the oil seal can achieve zero leakage.
