Thermoformable Polyamide Ionomer Shoe Stiffener
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Solution Overview
Problem
Existing shoe stiffeners, such as heel counters and toe puffs, require materials that are both thermoformable at temperatures below 100°C and offer high mechanical properties like rigidity and resilience, as current materials like Surlyn may not be rigid enough and require higher temperatures for thermoformability.
Innovation Solution
A thermoformable polymer composition comprising a blend of polyamide resin and ionomer resin, with specific weight percentages and neutralization of methacrylic acid with metal ions, is used to create a shoe stiffener that is thermoformable at temperatures below 100°C, impregnated into a fibrous material like non-woven fabric, allowing for increased stiffness and reduced thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If Surlyn® ionomer resin is used as shoe stiffener, then thermoformability is improved, but rigidity is insufficient
Solution Approach 1:
The patent applies composite materials by combining polyamide resin (providing rigidity) and ionomer resin (providing thermoformability) in a blended composition. This composite approach allows the shoe stiffener to simultaneously achieve both rigidity and thermoformability that neither material could provide alone.
Solution Approach 2:
The patent changes the thermal parameters of the ionomer resin by blending it with polyamide resin, which modifies the melting and thermoforming temperature range. The composite composition enables thermoforming at temperatures below 100°C while maintaining structural rigidity, representing a parameter change in the thermal behavior of the material.
2Object-affected harmful factors
If temperature for thermoformability is reduced below 100°C, then protection of heat-sensitive footwear components is improved, but material rigidity may be compromised
Solution Approach 1:
The blended composition of polyamide and ionomer resins creates a composite material that maintains rigidity even at lower thermoforming temperatures. The polyamide component provides structural strength while the ionomer component enables low-temperature thermoforming, thus protecting heat-sensitive components without sacrificing rigidity.
Solution Approach 2:
The patent changes the thermal processing parameters by formulating a resin blend that achieves adequate rigidity at temperatures below 100°C. This parameter change in processing temperature protects heat-sensitive footwear components while the composite composition ensures sufficient rigidity is maintained.
3Weight of moving object
If thickness of shoe stiffener is reduced, then weight of footwear is decreased, but mechanical strength may be compromised
Solution Approach 1:
The composite resin blend provides enhanced mechanical properties per unit thickness, allowing the shoe stiffener to be made thinner without compromising strength. The synergistic combination of polyamide and ionomer resins creates a material with superior strength-to-thickness ratio, enabling weight reduction while maintaining mechanical integrity.
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 provides shoe stiffeners with enhanced rigidity and resilience, enabling reduced thickness and weight while maintaining shape retention, suitable for use as heel counters or toe puffs in footwear.
Implementation Method 1
the polymeric material should be thermoformable... at a temperature around 70-80°C... the temperature at which the polymeric material should be thermoformable should not be higher than 100°C
Implementation Method 2
Surlyn® is a resilient material, and this property allows the shoe to recover its shape even after having being deformed
Data Source
AI summary
The present invention relates to the field of shoe stiffener for footwear and in particular to shoe stiffener such as heel counter and toe puff. The shoe stiffener of the present invention comprises a thermoformable polymer composition and a fibrous material.