Automotive sealing Development

For a long time , the vehicle must have a seal requires three functions : connecting , sealing and decorative. With the advancement of technology, the development of the automotive industry , especially in emerging new materials , environmental protection awareness of the car , comfort , safety, aesthetics have become increasingly demanding , the previous three functions for automotive sealing requirements are constantly introduce new and improved. To meet passenger vehicle performance and grades increasing needs, are from Applied Materials seals for passenger cars , product structure and production technology and other aspects of analysis, research trends strip door seal industry

Development of a passenger seal Review

Before the 1980s , because of the limitations of science and technology level , almost all automotive seals, mostly connected only considered to meet the performance and some sealing performance, with little regard for decorative, safety and comfort. Therefore , when the seal only consider using buses connect many aspects , such as the front and rear windscreens , side windows , door seal ; structure is very simple , mostly single types of plastic , one end connected to the body , one end connected to glass ; the material is natural rubber or styrene-butadiene rubber , plastics ( mainly modified PV C) based. Although such a seal to meet the connectivity and some sealing performance, but other properties such as elasticity , waterproof, noise canceling , isolation , dust , heat , weather , ozone resistance, anti-aging , etc. are poor, let alone the aesthetics and comfort . Due to the performance limitations of the material itself , the life of the car with the seal only 3 to 5 years, can not match the life of passenger cars ; color is also relatively simple ( almost entirely of black rubber ) , not to mention decorative and beautiful of it. Doors , body , luggage compartment seal are poor, large interior noise , dust, water is also very poor. The late 1980s, with the continuous improvement of passenger grade , with a seal on the passenger 's requirements have been increased .

Two seals currently used bus status

From the 1980s to the present , the automotive parts industry, the comprehensive performance requirements increasing, of course, the seal industry has great development.

( 1 ) before sealing the product mix has changed a lot . The original single types of plastic adhesive to now two types ( ie, dense or dense rubber and sponge rubber compound ) , three composite materials ( ie dense rubber, sponge rubber and steel or nylon composite skeleton ) , four composite materials ( i.e. dense rubber, sponge rubber or nylon and steel frame , four composite flocking material ) . Natural rubber ( or styrene ) and plastic , using a synthetic rubber EPDM (EPDM).

Application ( 2 ) the development of a new material . Abandoned strength , heat resistance, weather resistance, aging resistance are poor natural rubber ( SBR or ) and plastic , using a synthetic rubber EPDM (EPDM). E PDM has excellent heat resistance, weather resistance, ozone resistance , and its main physical properties are shown in Table 1. Due to the excellent characteristics E PDM , so the recent decades of sustained growth in sales volume .

( 3 ) Production farewell pure steam autoclave curing rubber extrusion original production process, using a more advanced multi- head extrusion microwave curing production process, as well as secondary processing injection molding process .

 Obviously, the primary seal is the most basic function is to seal needs water, every noise and dust . Indeed , the sealing effect can be further improved by improving the design . Now anti-friction material requirements are also increasing, so that the sealing performance can be maintained for longer , but also to reduce the damage during the original installation . The main role of the seal is to make the car as much as possible with the outside world, to maximize driver and passenger comfort . It should be said , and now the seal connecting , sealing , decorative, security, and so have a greater degree of improvement over the previous twenty- 1980s, but in the decorative, environmental aspects are still some gaps .

3 passenger trends sealing strip

The rapid development of the automotive industry , the performance of the car with a variety of seal put forward higher requirements. Development of new materials, new technology applications of science and technology for the development of the seal industry provides a space for development. Requirements for seals not only stay on the connection , sealing, decorative three functions, the car 's environmentally friendly, safe , comfortable and beautiful and so put forward new demands. This requires the selection of material from the sealing strip , structural improvements, the selection of the manufacturing process required to continue to improve .

( 1 ) From the choice of materials , not just stay on the E PDM applications. Molding process is relatively simple thermoplastic elastomers : T PV ( thermoplastic elastomer vaporization ), TPE ( thermoplastic elastomer ), T PO ( thermoplastic olefin ) ,high security seal etc. has been widely used in some areas. They have strong coloring , compound and recyclability good , but also to meet environmental requirements. Physical properties of thermoplastic elastomer in Table 1, the following advantages : excellent flex fatigue life ; temperature ; high impact strength ; density ; excellent chemical resistance and weathering resistance ; excellent electrical properties ; high high tear and abrasion resistance ; colorability ; renewable ; able to co-injection molding and extrusion pressure and total polyolefin ; low tensile and compression set .

( 2 ) structural improvements : The outer surface of the composite in harmony with the vehicle interior materials of different colors , such as color E PDM, colored thermoplastic elastomer ; using surface coating wear and lubrication materials instead of the original flocking material ; application various smooth surface coating , matte or four colored composite material .

( 3) Process Improvement : full speed with pre- shaped hot air vulcanization ordinary microwave hot air vulcanization process + + + , greatly improving the surface quality and production efficiency vulcanized sealing strips ; cancel the original molding process , replacing various secondary injection molding process , both to improve the efficiency and quality improvements ; online instead of the original hand- spraying spraying .

4 Conclusion

In short , with the continuous improvement of quality cars , buses seal performance requirements have been increased . Structure is reasonable, humane design , production process flow , automation, product safety , environmental protection metal security seals, recyclability , matching aesthetics, diversity is important to consider the performance of automotive sealing .