China's demand for special rubber products is growing, and a large number of special rubber products are still heavily dependent on imports. For the automotive industry, there is still a big gap between China's rubber and plastic seals industry and foreign advanced level in terms of design and production technology and production equipment of high-speed rotating oil seals; in terms of testing technology, the testing and Simulation of various important parameters of oil seals are basically blank. In recent years, due to factors such as system adjustment and reform, the research on product reliability and life span has basically stopped in enterprises. Enterprises and scientific research institutes focus on large-scale production and Research on new product structure, as well as the digestion, absorption and localization of imported technology, which has significantly increased the development of new products.

1. Representative New Products

Octagonal Seals: An Octagonal Seal was developed by Freudenberg. It is specially designed for the sealing system of a new type of octagonal piston with an inner diameter of 8-25mm micro-cylinder.

With reliability, it can play a permanent sealing role on the piston rod.

Piston rod seal with optimized sealing function: Baose Xiaban developed piston rod seal with optimized sealing function, which is suitable for hydraulic system of forklift, agricultural machinery, engineering machinery, locomotive and injection moulding machine. It has the advantages of fast installation, no damage to the seal and long service life.

Large multi-limb seals: multi-limb seals developed by the Seal Research Institute of Guangzhou Academy of Mechanical Sciences are key components of oil film bearings, which have double sealing functions:

The five "lips" of multi-limb seals play the roles of sealing water, oil and dust.

YG2000 composite O-ring: developed by Shanghai Yigang Hardware Sealing Material Co., Ltd. is a transparent fluoroplastic-coated fluororubber O-ring, which can withstand all media except elemental fluorine and molten metal sodium.

In recent years, some new products have emerged in defense research.

2. Process equipment and testing technology

Seals production equipment and testing technology are developing towards automation, low cost and high reliability.

Molding technology: The rubber injection moulding technology with high efficiency, advanced and high quality is widely used abroad. The screw reciprocating injection machine for small products and the screw plunger injection machine for large-sized products can effectively improve the appearance quality and performance of sealing parts and save raw materials. Parker produces O-rings with injection machines, which are used to make products with very small flying edges, combined with liquid nitrogen refrigeration trimming, plastic grain trimming and water-stone washing. The appearance quality of the products has reached a fairly high level.

In terms of vulcanization process equipment, many domestic sealing parts manufacturers have equipped vacuum flat plate and injection machine, and the ordinary flat plate vulcanizer has also been reformed by circulating oil heating to ensure the process stability.

Austria's Aconomos Company has made great breakthroughs in the traditional manufacturing of sealing rings. The company's machined equipment for seals can be machined to produce seals. It is suitable for the production of seals of various materials. Its market share is expanding year by year.

In detection technology:

The latest development is the use of optical systems. For example, Freudenberg and other companies have adopted the third generation of new optical system developed by KMK Company, which completely replaces manual inspection. The quality inspection of seals has been successfully integrated into the production process. This image processing system achieves extremely high detection speed and accuracy, and can detect the smallest defects on the surface of seals. Such as cracks, slip lines, pores, bubbles and impurities, the operation is simple and convenient, and can effectively ensure the consistency and reliability of the results. There are two kinds of linear detection system and rotary detection system in this system: linear detection system is recorded by 16 cameras according to the geometrical shape and surface state of O-rings and other products, and analyzed by intelligent software. Through automatic separation or reversal of parts, the optimal detection of surface, hole, slip line and abnormal factors can be achieved. Seals with burrs on the flying edge can also be picked out separately for repairing. Waste and defective products can also be packed into different containers according to different standards, which can detect 30,000 O-rings per hour. Rotary detection system can test the abnormality of sealing surface as small as (+0.02 mm) by additional deformation. It can analyze 1800 ~ 3600 parts per hour and determine whether the spring is assembled in place. Both systems can be fully automated. At present, they are mainly used to detect seals with high quality requirements.

The visualization technology of oil seal studied by NOK Company in Japan is the first successful visualization of oil film flow state in oil seal and rotary shaft in the world, which improves the accuracy of theoretical and practical coincidence verification. Molecular dynamics simulation technology is used to analyze and simulate intermolecular activities to predict the poles of gas and oil for rubber and plastics. The influence of limiting state was analyzed to analyze the effect of oil additives on rubber and plastics.

Domestic seals enterprises have also introduced oil seal detection devices based on measuring lip tension of oil seals; gas-sensitive detector (Italy), which measures lip sealing performance of oil seals by detecting pressure changes, has a high detection rate and can detect 1200-1800 oil seals per hour.

3. Development of Die Design and Processing Technology

In the design and processing of rubber and plastic seals mould, advanced countries have all adopted CAD/CAE/CAM technology. The manufacturer attaches great importance to the secondary development of the design software, and has good processing fluidity analysis ability of materials in the die cavity. Processing and manufacturing have become common