Knitted Shoe Upper with Polyurethane Injection Arch
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Solution Overview
Problem
Current shoes with knitted uppers face issues such as limited elasticity and breathability due to thermosetting yarns, poor protection in impact zones, and stiffness from the sole, leading to discomfort and reduced wearability.
Innovation Solution
A structure and procedure for making a shoe with a knitted upper that integrates a sole made by direct injection of polyurethane, using an arch structure with slots to control polyurethane injection and create joint points between the upper and sole, resulting in a single, homogeneous body with improved flexibility and lightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thermosetting yarns are used in the knitted upper to provide structure and stability, then the upper gains strength and shape retention, but elasticity and breathability are reduced
Solution Approach 1:
The patent applies local quality by using thermosetting yarns only in specific strategic locations within the knitted upper (such as the heel counter, toe cap, and arch support areas) rather than throughout the entire upper. This allows the upper to maintain strength and shape retention in areas requiring structural support while preserving elasticity and breathability in areas that need to conform to the foot's natural movements.
2Strength
If the sole is made with greater thickness to provide protection and durability, then strength and protection are improved, but flexibility and weight are reduced
Solution Approach 1:
The sole is constructed with variable thickness, featuring greater thickness in areas requiring enhanced protection such as the heel and toe regions, while maintaining reduced thickness in areas where flexibility is prioritized such as the midfoot and forefoot. This localized thickness variation allows the sole to provide maximum protection where needed while preserving the shoe's overall flexibility and reducing unnecessary weight.
3Strength
If stitching or gluing methods are used to join the upper and sole, then structural integrity is achieved, but stiffness and discomfort are introduced
Solution Approach 1:
The patent merges the upper and sole into a unified, seamless construction by integrating the sole directly into the knitted upper structure. This integration eliminates the need for separate stitching or gluing operations, thereby maintaining structural integrity while avoiding the stiffness and discomfort associated with traditional joining methods. The continuous knitted structure allows for natural flexibility and movement across the entire shoe.
4Object-affected harmful factors
If a thin layer of leather is added to protect the knitted upper, then protection against blows is improved, but weight and stiffness increase
Solution Approach 1:
The patent employs composite materials by integrating thermosetting yarns within the knitted upper structure to create a protective framework that replaces the need for additional leather layers. These composite yarns provide impact resistance and structural reinforcement while maintaining the lightweight and flexible characteristics of the knitted material, thereby achieving protection without the weight and stiffness penalties of traditional leather overlays.
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 method achieves a shoe with enhanced flexibility, lightness, and breathability, providing optimal foot grip, protection, and comfort while reducing weight and production costs, and eliminating stitching-related issues.
Implementation Method 1
in which the upper on the shoe-tree is subjected to a steam jet that dampens and softens a thermosetting polymer yarn present in the weave
Implementation Method 2
followed by a drying step in which the upper passes through a high-temperature kiln to remove the residual humidity of the preceding step and make the upper return to the desired dimensions by taking the thermosetting polymeric yarn to the melting temperature
Implementation Method 3
followed by a parking step in which the upper on the shoe-tree yields heat to the environment to lower the temperature of the upper
Implementation Method 4
which is followed by a stabilization step in which the upper on the shoe-tree transits through a very low-temperature refrigerator that stabilizes the thermosetting polymer yarn to fix the upper dimensionally
Data Source
AI summary
A procedure for making a shoe including steps of weaving/construction of an upper, forming the upper in which two previously constructed stockings are a tube that is closed on one side while the other end of the tube remains open, subjecting the upper to a steam jet that dampens and softens a thermosetting polymer yarn, and passing the upper through a high-temperature kiln. Construction of the sole entails inserting the upper into a shoe-tree of a mould, positioning the shoe-tree with the upper and closure between two rings of the mould for polyurethane injection. Because of the presence of the arch structure a barrier that limits the passage thereof to the inner part of the upper, with filling of the mould, passage of predetermined quantities of polyurethane only through the slots of the arch structure permitting joint points to be created between the sole and upper and with the inner.