Compare PU with TPR and PVC: Compared with PVC and TPR, PU is more prominent in light weight, wear resistance, elasticity, constant bottom, anti-skid, oil-proof and comfortable wearing; PVC and TPR are better than PU waste recycling; equipment investment PU is cheaper than PVC and TPR; production efficiency is roughly equal; mold cost PU can use a fast and cheap resin mold, the cost is 1/10-1 of metal mold./ It can be finished in 5,24 hours. PVC and TPR can only use metal mould, which is expensive and has a long period. The appearance quality of PVC and TPR should be controlled better. The equipment and process of PVC and TPR are mature.

The main defects of PU sole are insufficient surface finish and smoothness. The color difference is obvious, and there are many stomata and capillaries. In addition, there are rotten flowers, blisters and other defects. This shows that the current PU sole production technology and PU equipment are not mature. PU sole is formed by chemical reaction with low density foaming material, which makes the equipment and process difficult. Of course, the history of PU development is relatively short, and people still have a process to understand and master it.