Integrally Formed Waterproof Shoe Upper via Vacuum Shaping
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Solution Overview
Problem
Conventional shoe manufacturing is labor-intensive and costly due to the need to sew together upper and midsole components of different materials, and the resulting shoes do not provide a snug fit as they retain the volume of the last inserted during production, leading to discomfort.
Innovation Solution
A method involving a moisture-permeable and waterproof shoe with an integrally formed upper, where a shoe-shaped inner sleeve unit and upper unit are assembled with a last, heated, and then vacuum-sealed to shrink, forming a three-dimensional structure that fits comfortably around the foot without the need for extensive sewing or multiple components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the upper and midsole cardboard are sewn together to form a 3D upper structure, then the structural integrity is improved, but the manufacturing complexity and labor intensity increase
Solution Approach 1:
The patent merges the upper and midsole cardboard into a single integrally formed 3D upper structure by injecting molding material into a mold cavity that forms both components simultaneously. This eliminates the need for separate sewing operations and reduces manufacturing complexity while maintaining structural integrity.
Solution Approach 2:
The patent replaces the mechanical sewing process with an injection molding process. The molding material is injected under pressure to form the 3D upper structure, substituting the mechanical needle-and-thread system with a thermal and pressure-based forming system that achieves both upper and midsole formation in one operation.
2Ease of manufacture
If the last is inserted into the 3D upper structure to form the shoe, then the shaping process is simplified, but the manufacturing cost increases due to multiple components
Solution Approach 1:
The patent combines multiple components (upper and midsole cardboard) into a single integrally formed 3D upper structure through injection molding. This reduces the number of components from two separate pieces to one unified structure, simplifying the overall manufacturing process while maintaining ease of shaping using the last.
3Ease of manufacture
If the last volume exactly corresponds to the interior space volume, then the molding process is simplified, but the shoe fit becomes poor and uncomfortable
Solution Approach 1:
The patent modifies the volume parameter of the mold cavity to be slightly smaller than the last volume (creating an interference fit). This parameter change allows the molded upper structure to shrink and conform tightly to the last shape, improving fit accuracy while maintaining manufacturing simplicity through the injection molding process.
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
This method reduces manufacturing costs, minimizes labor, and ensures a snug, comfortable fit by allowing the shoe upper to shrink back to its original volume after the last is removed, providing good coverage and elasticity.
Implementation Method 1
placing an assembly of the upper unit, the shoe-shaped inner sleeve unit and the last in a heating device to heat the assembly of the upper unit, the shoe-shaped inner sleeve unit and the last to a predetermined heating temperature and a predetermined heating time
Implementation Method 2
placing the assembly of the upper unit, the shoe-shaped inner sleeve unit and the last in a vacuum bag, after which air is evacuated from the vacuum bag for a predetermined vacuum time
Implementation Method 3
placing the vacuum bag, which contains the assembly of the upper unit, the shoe-shaped inner sleeve unit and the last, in a freezing device to freeze the vacuum bag to a predetermined freezing temperature and a predetermined freezing time
Data Source
AI summary
A method for making a moisture-permeable waterproof shoe includes: (A) sleeving an inner sleeve unit on a last; (B) coating a bonding agent on an inner surface of an upper unit; (C) sleeving the upper unit on an assembly of the inner sleeve unit and the last; (D) placing an assembly of the upper unit, the inner sleeve unit and the last in a heating device; (E) placing the assembly in a vacuum bag; (F) placing the vacuum bag in a freezing device; (G) removing the assembly from the vacuum bag; (H) pulling out the last from the inner sleeve unit; and (I) fixing a sole to a bottom portion of a three-dimensional upper structure.