With the rapid advancement of automotive technology, rubber products and materials in the automotive industry are undergoing a revolutionary transformation. In the past, automotive rubber products primarily focused on basic wear resistance and sealing performance. However, in today’s evolving driving demands and the increasing importance of sustainability, the demand for high-performance rubber products and advanced materials has become more pronounced. This article delves into this transformation, analyzing the fresh face of the new generation of automotive rubber products and materials.
1. Car tires
In order to save energy, rubber materials should have low rolling resistance, that is, high rebound. However, the high-speed stability of tires requires materials with high wear resistance and creep, that is, low rebound. As tire usage conditions improve, winter anti-skid tires, ultra-low rolling resistance tires, safety tires, dual-tread pattern tires, etc. will be further promoted and applied and will evolve towards energy saving, high speed, stability, lightweight, and durability.
The recently developed terminally modified S-SBR materials can meet the above conflicting performance requirements. The tire tread can use E-SBR, S-SBR, NR, IR, and other rubbers, and the carcass can use NR, BR, IR, and other rubbers. In addition, tire materials that are more energy-saving and safer, such as silicone rubber and S-SBR, will also be used.
2. Automobile door and window rubber seals
Sealing products account for 25%-28% of the weight of automotive rubber parts (excluding tires). Recently, EPDM rubber with ozone resistance and weather aging resistance has been widely used in automobile door and window seals, and gradually replaced traditional NR and CR rubber. Each vehicle can use various sealing strips 10-15 meters long. In order to further reduce costs and improve appearance, foreign manufacturers have used TPE materials to manufacture automotive door and window seals.
3. Oil seal
Oil seal materials are mostly oil-resistant materials such as nitrile, hydrogenated nitrile, and acrylic rubber. Due to the improvement of heat resistance, the demand for the dosage and variety of special rubber (such as fluorine rubber) is increasing.
4. Car air hose
There are different requirements according to the location where it is assembled and used, such as oil resistance, bending resistance, shock absorption performance heat resistance, etc. Therefore, there are many types of materials, such as CR, NBR/PVC, EPDM, ECO, CSM, ACM, and other rubber. Recently, in order to reduce costs and be lightweight, TPO and TPEE have begun to be used, and the shock-absorbing properties of their products are fully considered in the shape design.
5. Hoses for water systems
Including radiator hoses, heater hoses, etc., most of them use SBR and EPDM rubber. As the ambient temperature of the engine room increases, peroxide vulcanized EPDM rubber begins to be used.
6. Brake rubber hose
is generally used. Recently, in order to meet the requirements of heat resistance and aging resistance, the use of EPDM or EPDM/IIR rubber has begun to be promoted.
7. Hoses for lubrication systems
When lubricating oil is used, as the ambient temperature becomes higher and higher, the amount of various additives such as antioxidants also increases. Although NBR rubber has excellent oil resistance, it hardens when antioxidants are added. Therefore, ACM rubber, which has good resistance to various additives, and FKM rubber, which has heat resistance and oil resistance, are now used.
8. Power steering hose
Under normal circumstances, the inner skin of the power steering tube is made of NBR, and the outer skin is made of CR. However, with changes in temperature and additives, HNBR/CSM materials have begun to be used to make hoses.
9. Fuel pipe
NBR rubber is generally used. With the application of electronic injection devices and the increase in oxygen-containing element fuels, FKM, HNBR, CSM, and other rubbers have begun to be used. The inner and outer skins can also be made of different materials, and the outer skin can be made of EPDM, TPO, and other materials.
10. Hoses for air conditioners
As the air conditioning medium is converted from CFC-12 to HFC-134a, the compressor lubricating oil is also converted from mineral oil to PAG lubricating oil, and the air conditioning hose is also converted from NBR rubber to PA/EPDM blend-modified material. In order to withstand PAG lubricating oil, the hose is made into a 4-layer composite pipe, which is PA/IIR/polyester/EPDM from the inside to the outside. The IIR material has good water penetration resistance.
11. Shock-absorbing products
Shock-absorbing products such as buffer blocks, rubber pads, and rubber sheets are generally made of NR and SBR materials. With the improvement of heat resistance requirements, some products use EPDM, but the dynamic characteristics and durability of EPDM are not as good as NR, so NR is still the main product.
As a more ideal buffer block material has not yet been found, shock-absorbing blocks sealed with silicone oil are currently being used, which can basically meet the shock absorption requirements of modern automobiles.
12. Rubber dust cover
The most important thing is that the material is required to have good weather resistance (how long the material can be used in the natural environment is collectively referred to as weather resistance), and it must have bending resistance, oil resistance, wear resistance, and other properties according to the different parts used. Constant velocity universal joints are generally made of weather-resistant CR materials, but with the improvement of heat resistance requirements, some European, American, and Japanese vehicles have begun to use TPEE.
TPEE materials can meet the requirements of weather resistance, oil resistance, and heat resistance while achieving the purpose of being lightweight.
13. Rubber belt
V-shaped transmission belts and toothed belt materials require high strength, large modulus, and good thermal stability. The traditional material is CR rubber, but because its heat resistance limit is 110°C, heat-resistant and durable HNBR rubber has recently been used instead.
HNBR’s heat resistance is 40°C higher than CR, and its lifespan is 2 times longer than CR rubber.
In the ascent of high-performance automotive rubber products and materials, we witness a significant leap in the automotive industry. These innovations not only enhance the performance and safety of vehicles but also lay the foundation for environmentally friendly and sustainable transportation. Looking ahead, with the continuous development of technology, we have reason to anticipate more innovations and breakthroughs that will bring further exciting changes to the field of automotive rubber products and materials. May this transformation not only drive the automotive industry forward but also usher in a future of safer, more efficient, and enjoyable travel experiences.
