News Details

In the automotive industry, rubber parts serve as key components that perform core functions such as sealing, shock absorption, and noise reduction. Its performance is directly related to the safety, comfort, and service life of the vehicle. As the core material of rubber products, mixed rubber can significantly improve the comprehensive performance of automotive rubber parts through scientific formulation and process optimization. This article will analyze how rubber compounds can provide safer and more comfortable solutions for the automotive industry from three aspects: material characteristics, process innovation, and application cases.

 

1、 Material characteristics: synergistic optimization of high temperature resistance, low volatility, and mechanical properties

1. Breakthrough in high temperature resistance performance

The engine compartment, exhaust system, and other parts of a car are exposed to high temperatures for a long time, and traditional rubber materials are prone to aging, deformation, and even failure. The introduction of silicone rubber compound provides a breakthrough solution to this problem. The Si-O bond energy in the molecular chain of silicone rubber is much higher than that of the C-C bond, allowing it to maintain stable physical properties above 250 ℃. For example, in the seals of automotive power steering pumps, components made of silicone rubber compound can withstand high temperatures of 175 ℃, extending their lifespan by more than 30% compared to traditional materials.

 

2. Low volatility and improved safety

Under high temperature conditions, traditional rubber may release volatile organic compounds (VOCs) or toxic gases, posing a threat to the health of occupants in vehicles. Silicone rubber compound achieves low volatility and low toxicity through molecular structure design. Experimental data shows that the content of harmful substances in the decomposition products of silicone rubber at 300 ℃ is less than 0.1%, far below the EU ROHS standard. This feature makes it widely used in automotive air conditioning pipelines, interior seals, and other scenarios, effectively reducing the risk of air pollution inside the car.

 

3. Precise control of mechanical properties

The mechanical properties of mixed rubber can be customized through formula design. For example, nitrile rubber (NBR) compound can balance oil resistance and cold resistance by adjusting the acrylonitrile content. In the automotive fuel system, the oil resistance of NBR rubber compound enables it to maintain sealing at an oil temperature of 150 ℃, while by adding white carbon black reinforcing agent, its tensile strength can be increased to over 20MPa, meeting the requirements of high-pressure fuel lines.

 

2、 Process Innovation: Optimization of the Entire Process from Formula Design to Mixing Technology

1. Formula design: synergistic effect of multiple components

The performance optimization of mixed rubber needs to start with formula design. Taking EPDM rubber as an example, when used in combination with recycled rubber, a segmented mixing process is required to ensure uniform dispersion of the recycled rubber. A certain automobile hose production enterprise adopts the process of "first stage mixing in the internal mixer+second stage mixing in the open mill", adding 40-50 parts of rubber oil and 100 parts of high wear-resistant carbon black to the formula, reducing the hardness of the hose to Shore A60 and increasing its wear resistance by 25%.

 

2. Mixing process: precise control of temperature and shear force

The mixing temperature and shear force directly affect the dispersibility of the rubber material. For example, during the mixing of butadiene rubber (BR), the temperature should be controlled below 140 ℃ to avoid chain breakage; And chloroprene rubber (CR) requires low-temperature slow mixing to prevent burning. A certain enterprise has reduced the temperature fluctuation range of the mixing machine to ± 2 ℃ by introducing an intelligent temperature control system, which has increased the Mooney viscosity stability of the rubber material by 40%.

 

3. Surface treatment: Improve the bonding strength between rubber parts and metals

Automotive rubber parts often need to be bonded to metal frames. By adding coupling agents (such as Si69) to the mixed rubber, the interfacial bonding strength between rubber and metal can be significantly improved. Experiments have shown that adding 3% Si69 EPDM rubber compound can achieve a peel strength of 15N/mm with galvanized steel plates, which is 60% higher than the sample without Si69 added.

 

3、 Application case: Comprehensive upgrade from seals to shock absorption systems

1. Sealing element: Long term sealing under high temperature and high pressure

Automotive oil seals, crankshaft oil seals, and other components need to withstand high temperature and high pressure oil impact. The oil seal made of FKM rubber compound is neutralized with calcium hydroxide (Ca (OH) ₂) to maintain its sealing performance even at an oil temperature of 200 ℃, extending its lifespan by 50% compared to traditional materials. After a certain engine manufacturer applied this material in the crankshaft oil seal, the oil leakage rate decreased from 0.3% to 0.05%.

 

2. Shock absorption system: significant improvement in NVH performance

Automobile shock absorbers need to balance elasticity and durability. By adding white carbon black and structural control agents to natural rubber (NR) compound, its dynamic fatigue life can be improved. After a suspension system supplier adopted this formula, the durability testing frequency of shock absorbers increased from 500000 to 800000 times, and the NVH (noise, vibration, and acoustic roughness) performance improved by 15%.

 

3. Pipeline system: dual guarantee of high temperature resistance and aging resistance

Car radiator hoses need to withstand high-temperature coolant and UV aging. The rubber compound is blended with silicone rubber and EPDM, and the vulcanization system is optimized to maintain flexibility at a high temperature of 175 ℃, while the ozone aging resistance time is extended to 2000 hours. After applying this material to a certain car model, the hose burst rate decreased from 0.5% to 0.1%.

 

4、 Future trend: integration of intelligence and sustainability

With the transformation of the automotive industry towards electrification and intelligence, rubber mixing technology is facing new challenges. For example, battery pack seals need to meet the requirements of electrolyte resistance, flame retardancy, and lightweight at the same time. The silicone rubber/ceramic fiber composite rubber compound developed by a certain enterprise has a density reduced to 1.2g/cm ³ and a flame retardant rating of UL94 V-0, providing a new solution for the safety of new energy vehicle batteries. In addition, the research and development of bio based rubber compounds is also accelerating. A laboratory has reduced the carbon footprint of rubber materials by 30% by combining natural rubber with bio based plasticizers.

 

conclusion

As the core material of automotive rubber parts, the performance optimization of mixed rubber directly promotes the technological progress of the automotive industry. From innovative materials with high temperature resistance and low volatility, to precisely controlled mixing processes, and to comprehensive upgrades in sealing, shock absorption, piping, and other systems, rubber mixing technology is providing cars with a safer and more comfortable driving experience. In the future, with the increasing demand for intelligence and sustainability, rubber mixing technology will continue to break through boundaries and inject new momentum into the high-quality development of the automotive industry.