Foam Blend with Phase Change Material for Shoe Shrinkage Control
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Solution Overview
Problem
The shoe manufacturing process faces challenges with dimensional stability of foamed shoe materials due to environmental temperature fluctuations, leading to increased energy consumption and inefficiency in the multi-stage temperature control of ovens.
Innovation Solution
A foam blend incorporating a phase change material with a transition temperature of 45°C-100°C is used, comprising a thermoplastic material, a blowing agent, a crosslinking agent, and a phase change material. This blend is used to create a foamed shoe body, where the phase change material stores and releases thermal energy to control shrinkage and reduce energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multi-stage temperature control of oven is used to control dimensional shrinkage, then dimensional stability is improved, but energy consumption increases and manufacturing efficiency decreases
Solution Approach 1:
The patent applies phase transition principle by incorporating phase change materials (such as paraffin, fatty acids, or their salts) into the foam blend. These materials undergo phase transitions at specific temperatures (45°C-100°C), absorbing or releasing latent heat to maintain stable temperature and control dimensional shrinkage of the foamed shoe body, thereby reducing reliance on energy-intensive multi-stage oven temperature control
Solution Approach 2:
The patent uses composite materials by combining phase change materials with thermoplastic materials (EVA, PU, POE, TPE, etc.) to create a foam blend. This composite formulation enables the material to possess both the functional properties of the base polymer and the thermal regulation properties of the phase change material, achieving dimensional stability through material design rather than process control
2Manufacturing precision
If multi-stage temperature control of oven is used to control dimensional shrinkage, then dimensional stability is improved, but manufacturing efficiency decreases due to extended cooling time
Solution Approach 1:
The phase change materials undergo phase transitions at predetermined temperatures during the cooling process, providing isothermal conditions that control shrinkage rate and final dimensions. This enables faster cooling cycles compared to conventional multi-stage temperature control, as the phase change materials actively regulate temperature rather than passively cooling
Solution Approach 2:
The phase change materials provide self-regulating thermal control within the foam blend, automatically absorbing or releasing heat as needed during temperature changes. This self-service mechanism eliminates the need for complex external temperature control systems and extended cooling times, thereby improving manufacturing efficiency
3Productivity
If phase change material is added to foam blend, then cooling and shrinkage time is shortened and energy consumption is reduced, but material composition complexity increases
Solution Approach 1:
The patent formulates composite foam blends by integrating phase change materials with common thermoplastic polymers used in shoe manufacturing (EVA, PU, POE, TPE). This approach incorporates the functional benefits of phase change materials into existing material systems without requiring entirely new material platforms, thereby limiting composition complexity to practical levels
Solution Approach 2:
The patent optimizes parameters such as phase change material content (5-20 parts by weight per 100 parts rubber), transition temperature (45°C-100°C), and processing conditions to achieve the desired balance between cooling efficiency and material complexity. By controlling these parameters within specific ranges, the patent manages material complexity while maximizing productivity benefits
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 use of the foam blend with a phase change material shortens the cooling and shrinkage time of the foamed shoe body, saves energy, and stabilizes the setting shrinkage of the finished product, improving the overall efficiency and quality of the shoe manufacturing process.
Implementation Method 1
a phase change material is added in an amount of no more than 15 phr based on the total content of the thermoplastic material to mix with the thermoplastic material, wherein the transition temperature of the phase change material is 45°C-100°C
Implementation Method 2
the phase change material stores thermal energy during the foaming process... the phase change material releases the stored thermal energy in the aging environment
Data Source
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AI summary
Provided is a foam blend incorporating a phase change material for foaming and making a foamed shoe body, comprising a thermoplastic material, a blowing agent, a crosslinking agent and a phase change material; the phase change material is added in an amount based on the total content of the thermoplastic material, and is mixed with the thermoplastic material in an amount of no more than 15 phr, wherein the transition temperature of the phase change material is 45°C-100°C. Another embodiment provides a method for making a foamed shoe body from a foam blend, comprising the steps of filling the foam blend into a mold for heating and foaming to form a semi-finished product of the foamed shoe body, and placing the semi-finished product of the foamed shoe body in an aging environment for shrinking and molding into a finished product of the foamed shoe body. The method thus can shorten the time of cooling and shrinkage of the foamed shoe body and save energy consumption in the manufacturing process.