I faced the bonding problem in my shoe factory, my sole is EVA with TPR and upper is PU synthetic leather. The bonding problem happened the EVA with TPR and they are easy open, could somebody teach me how to solve it?
2020/02/26
According to Nanpao’s experience, please find the following suggestions.
（1）Hand made shoes factory usually use grafted adhesive (No.793) to laminate outsole and upper.
（2）Production line shoes factory need primers(EVA：1019K、TPR：1015FS、PU leather：111M) & PU glue (NP-71) to laminate outsole and upper.
How to solve your problem：
（1）To check both side EVA and TPR if still glue on it or the glue only one side left.
（2）Both side left glue 🡪 It means the issue should be your pressing machine or your workers not probably use the glue.
（3）One side left glue 🡪 It means you are not using correctly primer on it.