Among the current combinations of safety shoe sole materials, double-layer soles have become the most convenient and best solution. The wear-resistant and non-slip properties of the outsole can protect the sole of the foot and the light and soft characteristics of the midsole. Comfort when walking.

From this point of view, the current best combination method is RU/PU, using rubber (RU) to make the outsole, polyurethane (PU) as the midsole, and then through the adhesive or chemical bonding function and PU itself The adhesive function bonds the outsole and midsole together. Of course, the outsole of the shoe can also be polished, polished, and carved.
There is also a combination of sole materials, PU/TPU (polyurethane/thermoplastic polyurethane). The outsole made of thermoplastic polyurethane is extremely tough and wear-resistant. The midsole is made of polyurethane, which is comfortable and convenient to wear. The outsole made of thermoplastic polyurethane meets the needs of contemporary designers. This is because the sole made of TPU can produce colors. Bright soles, and the carving craftsmanship on the soles can also be varied.

The other is a double-layer sole made of PU/PU (polyurethane/polyurethane) material combination. Both the outsole and the midsole are made of polyurethane. For the outsole, a particularly dense polyurethane material must be used to maintain the wear resistance and method characteristics of the outsole; for the midsole, foamed polyurethane must be used for comfort considerations. For example, MKsafety® Co., Ltd. uses the double-layered sole of safety shoes (work shoes) produced by Bayer’s secondary foaming process, which is light and comfortable to wear, wear-resistant and non-slip.