What are the factors that affect the compression permanent deformation of PET Velcro Braided Sleeve?

The quality of Cable Sleeve products is mainly derived from the compression permanent deformation of the Pet Velcro Braided Sleeve, which is one of the important performance indicators of Cable Sleeve products. The size of the compression permanent deformation of the PET Velcro Braided Sleeve is related to the elasticity and recovery of the PET Velcro Braided Sleeve. The magnitude of the permanent deformation is mainly governed by the change in the recovery ability of the cable bushing. Factors affecting the recovery ability include the force (viscosity) between molecules, the change or destruction of the network structure, and the displacement between molecules. When the deformation of the Cable Sleeve is caused by the stretching of the molecular chain, its recovery (or the size of the permanent deformation) is mainly determined by the elasticity of the Cable Sleeve: if the deformation of the Cable Sleeve is accompanied by the destruction of the network and the molecular chain The relative flow of this part can be said to be irrecoverable, and it has nothing to do with elasticity. Therefore, all factors that affect the elasticity and recovery of the Cable Sleeve are factors that affect the compression permanent deformation of the PET Velcro Braided Sleeve. These factors include elasticity, impact elasticity (resilience), elasticity and modulus, compression set, tear set, etc.

1. Elasticity - the elasticity of the Cable Sleeve should be a theoretical concept, which indicates the difficulty of the internal rotation of the molecular chain segment and the side group of the Cable Sleeve, or the flexibility of the molecular chain of the Cable Sleeve and the force between the molecules. size. For PET Velcro Braided Sleeve, its elasticity is also related to the density and regularity of the cross-linked network.
2. Elasticity and tearing permanent deformation - it is often said that the natural Cable Sleeve has good elasticity, but its tearing permanent deformation is often very large, which is mainly due to the large elongation of the natural Cable Sleeve, and the elongation process The destruction of the network and the displacement of the molecular chain are very large, the recovery process after the break is long and the unrecoverable part increases. If compared with the permanent deformation of a fixed length, the permanent deformation of the natural Cable Sleeve is not necessarily very large.
3. The impact elasticity or resilience is measured under the condition of constant load (or constant energy), and its elasticity is directly related to the crosslinking degree or modulus of the vulcanized rubber. It expresses the elasticity and viscosity of the Cable Sleeve ( or absorption).
4. The compression set is measured under constant deformation conditions, and its value is related to the elasticity and recovery ability of the Cable Sleeve.
In the range of higher strain rates, the dynamic stress-strain relationship of PET Velcro Braided Sleeve is related to the strain rate, and the elastic modulus, yield stress and flow stress all increase with the increase of the strain rate, so in the dynamic experiment The material exhibits a pronounced strain rate effect. While under low strain rate loading, the PET Velcro Braided Sleeve is not sensitive to strain rate.