Processed TPE|TPR products, open to the air for a period of time (generally 1 ~ 3 months), the surface of the product cracks or cracks.

　　Cracking causes:

　　General causes: The products with cracking are mostly TPE|TPR products containing SBS base material. The reason for cracking is that the SBS TPE component contains unsaturated double bonds, which are easily oxidized by oxygen and ozone in the air when stored for a long time, resulting in degradation of the material due to aging.

　　Special reasons: the product processing process to do adhesive spraying process, solvent and TPR products contact for too long, and because of the processing process products may be stressed, easy to intensify the products cracking. Such as toys and shoe soles processing, this type of situation may occur.

　　TPE|TPR materials and products with low hardness (15~45A) containing SBS base material are prone to cracking. The thinner the thickness of the product, the more obvious the cracking.

　　TPE|TPR products cracking improvement measures

　　For TPE|TPR products already made, if cracking occurs, it is impossible to make up for it. If you want to improve it, you can only start from the initial material. Depending on the specific situation, the following three improvement measures can be used:

　　SEBS does not contain unsaturated double bonds and has good anti-aging and anti-cracking properties.

　　2. If SBS must be used (based on the wear-resistant requirements and the convenience of gluing and spraying), the addition of anti-oxidation and anti-UV agents in the blending system should be considered.

　　3. If it is necessary to use in the long-term sun, rain or light environment, it is recommended to use PP + EPDM system of thermoplastic elastomer.