NBR (nitrile butadiene rubber), with its excellent oil and heat resistance, has been widely used in the field of seals. However, its relative lack of wear resistance limits its potential application in high-wear environments. In order to improve the wear resistance of NBR seals, it is necessary to start from many aspects such as formula optimization, processing process improvement and adjustment of the use environment. The following is a detailed discussion of these aspects, supplemented by specific data to enhance the clarity of the description.

1、analysis of the basic characteristics and wear resistance of NBR materials

NBR seals are widely used in automobile, construction machinery and hydraulic equipment because of their excellent oil resistance and heat resistance. However, under high friction or high load conditions, the relatively low hardness and elastic modulus of NBR result in insufficient wear resistance. The wear of NBR rubber is mainly reflected in volume reduction and surface loss, which is affected by many factors such as hardness, elasticity, heat resistance and type of filler. Therefore, enhancing the wear resistance of NBR seals should be considered from multiple perspectives such as molecular structure, filler ratio, plasticizer selection and processing technology.

2、formula optimization strategy - strengthen the wear resistance of NBR seals

Increase the proportion of wear-resistant filler

Carbon black: As a key filler to enhance the wear resistance of rubber, carbon black with fine particle size and high structure can effectively improve the hardness and wear resistance of rubber. The results show that when the amount of N330 carbon black is 30 parts, the wear resistance of NBR is significantly improved, and the wear amount is reduced by about 15%.

Silica: not only can enhance the tensile strength of rubber, but also improve the wear resistance. The experimental data show that the wear resistance of NBR is increased by about 12% by adding 15 parts of silica.

Introduction of nanomaterials

Nano-alumina: Appropriate addition (such as 3 parts) can greatly improve the wear resistance (about 25%) and tensile strength of NBR, but too much addition will reduce the flexibility of the seal.

Nano-calcium carbonate: Adding 5 parts of nano-calcium carbonate can reduce the rubber wear by about 10%, and the effect is significant in practical applications.

Optimized vulcanization system

The combination of sulfur vulcanization and peroxide vulcanization system can improve heat resistance while ensuring wear resistance. The experiment shows that when 2.5 parts sulfur and 0.8 parts peroxide are vulcanized, the wear resistance of NBR seals is increased by about 18% and the high temperature stability is enhanced.

Use a crosslinker

Cross-linking agents such as bisphenol A can increase the molecular cross-linking density of rubber and improve the wear resistance. The experimental results showed that the wear resistance of NBR increased by about 20% after adding 2 parts of bisphenol A.

3、process optimization measures - improve the wear resistance of NBR seals

Enhance mixing uniformity

Increasing the mixing temperature and extending the mixing time can make the filler distribution more uniform, enhance the strength of the rubber structure, and thus improve the wear resistance. The experimental data show that when the mixing temperature is increased to 145℃ and the mixing time is extended to 15 minutes, the wear resistance is increased by about 10%.

Precise control of vulcanization conditions

Vulcanization temperature and time are very important to the physical properties of rubber. Although high temperature rapid vulcanization can improve efficiency, it may lead to the formation of internal bubbles. Experiments show that when the vulcanization temperature is controlled at 150℃ for 12 minutes, the wear resistance is improved by about 15%, and the sealing performance is not affected.

Surface treatment technology

For example, plasma surface treatment, laser engraving and sandblasting can form a protective layer on the NBR surface to enhance wear resistance. The results show that after plasma surface treatment, the wear resistance of NBR seals is increased by about 20%, and the surface hardness and scratch resistance are significantly improved.

4、optimize the use of the environment - extend the life of NBR seals

Reduce friction

Reducing friction by optimizing seal design and using lubricating oil can effectively reduce wear.

Control working environment

The high temperature and high humidity environment will accelerate the aging of NBR and reduce the wear resistance. It is recommended that the operating temperature should not exceed 100 ° C and the humidity should be kept below 50%.

Scheduled maintenance

Check the wear of seals regularly and maintain or replace them to ensure the stable operation of the equipment. Studies have shown that semi-annual inspection can significantly extend service life.

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