What are the reasons for the loss of sealing performance of the Automotive Wiring Harness Protection Sleeve?

The synthetic Cable Sleeve used in the Automotive Wiring Harness Protection Sleeve is a viscoelastic material. Therefore, after a long period of use, the compression amount and rebound blocking ability will be deformed and gradually lose elasticity, and eventually leak and lose sealing performance.

1. The pressure of the working medium
The working pressure of modern hydraulic equipment is increasing day by day. Long-term high-pressure action will cause the Automotive Wiring Harness Protection Sleeve to deform and lose its sealing performance. Therefore, appropriate pressure-resistant Cable Sleeve should be selected according to the working pressure during design. The higher the working pressure, the higher the hardness and high pressure resistance of the material used should be. Generally, to improve the pressure resistance of the Automotive Wiring Harness Protection Sleeve and increase the elasticity of the material, it is necessary to improve the material formula and add plasticizers. However, if the automotive wire harness protective cover with plasticizer is soaked in the working medium for a long time, the plasticizer will be gradually absorbed by the working medium, causing the volume of the Automotive Wiring Harness Protection Sleeve to shrink, and may also cause negative compression of the Automotive Wiring Harness Protection Sleeve. Therefore, these shrinkages should be fully taken into account when calculating the compression of the Automotive Wiring Harness Protection Sleeve and designing the mold. So that the pressed automotive wire harness protective cover can still maintain the necessary size after soaking in the working medium for 5-10 days.
2. Temperature
High temperatures will accelerate the aging of Cable Sleeve. The higher the operating temperature, the greater the compression set of the automotive wiring harness cover. When the permanent deformation is greater than 40%, the Cable Sleeve loses its sealing performance and leaks. The initial stress value formed by the compression deformation of the Cable Sleeve will gradually decrease and disappear with the relaxation process and temperature drop. The initial compression of the O-shaped automotive wiring harness protective sleeve that works at sub-zero temperatures may be reduced or completely disappeared due to a sharp drop in temperature. In the case of -50~-60°C, the Cable Sleeve that is not resistant to low temperature will completely lose its initial stress. Because the initial compression of the car wire harness protective sleeve depends on the coefficient of linear expansion.
3. Compression and stretch
The various rubber formulations used in the production of Automotive Wiring Harness Protection Sleeve will produce compression stress relaxation in the compressed state, and the compression stress will decrease with time. The longer the use time, the greater the compression rate and stretching, the greater the stress drop caused by the relaxation of rubber stress, so that the O-shaped Automotive Wiring Harness Protection Sleeve is insufficient in elasticity and loses its sealing ability.