Dynamic waterproof and breathable shoe sole, shoe, and method for manufacturing the same

A method for manufacturing a dynamic waterproof and breathable shoe sole, comprising the following steps:

• Step S1:
• preparing an elastic midsole layer using a supercritical fluid foaming process:
• placing thermoplastic polyurethane elastomer particles into a foaming mold;
• after sealing the mold, injecting supercritical carbon dioxide as a physical foaming agent, wherein a saturation temperature is 160-185° C., a saturation pressure is 12-25 MPa, and a saturation time is 20-40 minutes;
• subsequently rapidly releasing pressure to atmospheric pressure at a depressurization rate of 8-15 MPa/s to obtain a foamed sheet having a microcellular closed-cell structure;
• placing the foamed sheet into a cutting mold and cutting the sheet to form the elastic midsole layer provided with the recessed groove structures and the water-guiding and air-permeable grooves;
• Step S2:
• preparing the wear-resistant outsole layer and sealing assembly using a two-shot injection molding process:
• setting a temperature of a first injection unit to 210-230° C., and injecting a wear-resistant thermoplastic material into an outsole mold to simultaneously form the flow-guiding channels (1), the sealing valve seats, and the funnel structures;
• after the mold is opened, inserting a prefabricated annular sealing member into the sealing valve seat by a robotic manipulator;
• subsequently closing the mold, setting a temperature of a second injection unit to 190-210° C., and injecting a thermoplastic elastomer material to form an integrally bonded structure with the annular sealing member at the sealing valve seat;
• Step S3:
• preparing a pre-assembled component of the dynamic sealing column and the end cap structure:
• performing a secondary injection molding process, including first injection-molding a main body of the dynamic sealing column using rigid TPU or nylon as a material, with an injection temperature of 220-240° C.;
• then placing the molded dynamic sealing column body into an end-cap mold, overmolding a thermoplastic elastomer layer on a surface of the sealing head, while integrally forming the end cap structure at a top of the dynamic sealing column, wherein the end cap structure is made of supercritical-foaming-grade TPU and an injection temperature is 190-210° C., thereby forming the pre-assembled component;
• Step S4:
• assembly:
• installing the pre-assembled component obtained in Step S3 into the recessed groove structure of the elastic midsole layer, applying a waterproof adhesive along an edge of the end cap structure to seal and fix the end cap structure to an inner wall of the recessed groove structure, and inserting the dynamic sealing column into the flow-guiding channel;
• Step S5:
• lamination:
• bonding the assembled elastic midsole layer obtained in Step S4 with the wear-resistant outsole layer prepared in Step S2 using a hot-press lamination process, wherein a hot-press temperature is 80-100° C., a pressure is 0.3-0.6 MPa, and a pressure-holding time is 30-60 seconds, thereby completing preparation of the shoe sole.