TPE and TPR material performance differences
Both TPE and TPR belong to SBC styrene thermoplastic elastomer polymer blend modified alloy elastomer material.
The TPE is based on SEBS and the TPR is based on SBS. The difference in TPE and TPR performance is mainly due to the different molecular structures of the substrate SEBS and SBS. The SBS molecular structure contains unsaturated carbon-carbon double bonds (as shown in Figure 1, SEBS is a saturated carbon-carbon single bond).
The unsaturated carbon-carbon double bond in SBS is an unstable chemical structure that is attacked by a medium having high electronegativity and is easily destroyed.
TPR is based on SBS substrates and is susceptible to aging or cracking when exposed to solvents such as ozone, light, and ultraviolet light. The lower the hardness of the TPR (hardness is less than 40 A), the worse the strength, the more likely the crack will occur. In actual situations, there are many cracks in toy products produced by soft TPR.
In contrast, SEBS has relatively stable chemistry due to its saturated carbon-carbon single bond. SEBS modified TPE has better high temperature resistance (TPE can withstand high temperatures of 80 to 90 degrees, while TPR can only withstand temperatures of 60 to 70 degrees), aging resistance and UV resistance and crack resistance.
During the transportation of goods, the temperature inside the container usually reaches 60 to 70 degrees due to the accumulation of heat. If TPR materials are used, such high temperatures may cause the product to soften and deform, and at higher temperatures, the TPR materials are relative. In the case of TPE, it is easier to surface tack. Many users use soft TPR as a toy, and all users have exported to foreign users. The products stick together and cannot be separated.
Summary: TPR materials with low hardness (less than 40A) have poor high temperature resistance, and are prone to stickiness when exposed to high temperature surfaces, and the possibility of aging cracking is high. Therefore, for toys with lower hardness, we generally recommend using better TPE materials. The cost is relatively high, but the quality is guaranteed.