Shoe Midsole Shaft Mold Through-Hole Formation
Solution Overview
Problem
The existing injection foam molding method for midsoles struggles to form through-holes in the lateral direction, leading to manufacturing difficulties, quality issues, and increased costs due to the need for post-processing to remove gaps and burrs, which affects the buffering performance and weight reduction of the midsole.
Innovation Solution
A midsole forming device with a shaft mold extending beyond the mold boundaries and press grooves on the molds to prevent parting lines and burrs, allowing for the integration of through-holes without post-processing, enabling lightweight, high-quality midsoles with improved impact absorption and design flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a shaft mold is installed inside the mold to form through-holes in the lateral direction, then the buffering function is improved, but gaps are generated between the mold and shaft mold causing molding defects
Solution Approach 1:
A shaft extension portion is introduced as an intermediary element that fills the gap space between the shaft mold and mold wall. This extension portion prevents molding material from entering the gap, thereby eliminating parting lines and burrs on the through-hole inner surface while maintaining the buffering function of the through-holes
2Manufacturing precision
If post-processing is performed to remove gaps and burrs, then the through-hole quality is improved, but manufacturing time and cost are increased
Solution Approach 1:
The shaft extension portion is designed to prevent gap formation and material intrusion during the molding process itself, eliminating the need for subsequent post-processing operations. This preliminary preventive action achieves high-quality through-holes while maintaining production efficiency
3Manufacturing precision
If the shaft mold is tightly closed to the inner wall of the mold, then gap formation is reduced, but manufacturing complexity increases
Solution Approach 1:
The shaft mold is segmented into a main shaft portion and an extension portion. The extension portion specifically addresses the gap issue by filling the space between the shaft and mold wall, while the main shaft maintains its molding function. This segmentation solves the precision problem without requiring complete redesign of the entire mold system
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution allows for the production of lightweight, high-quality midsoles with excellent impact absorption and restoring force, reduced manufacturing time, and cost-effectiveness by eliminating the need for post-processing and ensuring precise through-hole formation without defects, thereby enhancing durability and consumer satisfaction.
Implementation Method 1
after a liquid raw material containing a foaming material is injected into a mold having a size slightly smaller than that of the midsole to be manufactured, heat and pressure are applied to the mold, such that chemical reaction is made inside the mold, thereby performing molding in a shape of a midsole
Implementation Method 2
heat and pressure are applied to the mold, such that chemical reaction is made inside the mold, thereby performing molding
Data Source
AI summary
A midsole molding apparatus which enables production of a high-quality midsole is provided. The apparatus includes a through hole, which passes laterally through a midsole used for a shoe, to be integrally formed, preventing traces of forming the through hole from being left in the through hole and on the periphery of the through hole and a shaft mold crossing the inner space of upper and lower molds, forming extending portions such that the ends of the shaft mold extend beyond the boundary of the inner space, and seating the extending portions in press recesses of the upper and lower molds to seal the insides of the molds so as to prevent raw material from leaking from inside the molds when foaming and forming a midsole, to prevent parting lines and burrs from forming on the inner surface of the through hole passing laterally through the midsole.