Expandable Thermoplastic Polyurethane Beads for Low-Temperature Foam Processing
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Solution Overview
Problem
Moldable thermoplastic polyurethane foams require high energy consumption during production and have challenges with storage and transport due to high bulk density, especially when produced as beads.
Innovation Solution
Developing expandable thermoplastic polyurethane beads with a Shore hardness of A 44 to A 84, using lower hardness and lower melting point TPU with better flowability, allowing for production and processing at lower temperatures, and incorporating a blowing agent to reduce energy requirements and improve adhesive bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If TPU foams are produced using conventional methods with high steam pressure (4.5-7 bar) and temperature (145-165°C), then the foam structure is stable, but energy consumption is high
Solution Approach 1:
The patent changes the key parameter of Shore hardness from conventional high values (>80 A) to lower values (44-84 A, preferably 62-80 A). This parameter change enables the TPU to be processed at lower temperatures and pressures, directly reducing energy consumption while maintaining stable foam structure. The lower hardness TPU has better flowability and requires less thermal energy for processing.
2Stability of the object's composition
If TPU beads are produced with high bulk density, then structural stability is maintained, but storage and transport space efficiency deteriorates
Solution Approach 1:
Instead of producing fully dense TPU beads and then attempting to reduce density, the patent inverts the approach by incorporating a blowing agent during the bead production process itself. This creates expandable beads with lower bulk density from the start, improving storage and transport efficiency while maintaining structural stability through the blowing agent framework.
3Strength
If TPU with higher hardness is used, then mechanical strength is improved, but flowability and adhesive bonding capability deteriorate
Solution Approach 1:
The patent changes the Shore hardness parameter to an optimized range (44-84 A, preferably 62-80 A) that balances mechanical strength with flowability and adhesive bonding capability. This parameter optimization allows the lower hardness TPU to maintain sufficient mechanical strength while exhibiting improved flow characteristics and adhesive bonding performance during processing.
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 enables the production of thermoplastic polyurethane foams at lower temperatures and pressures, reducing energy consumption and improving handling and storage, while maintaining elasticity and performance across temperature variations.
Implementation Method 1
expandable thermoplastic polyurethane, preferably in bead form, comprising blowing agent
Implementation Method 2
The Shore hardness of the thermoplastic polyurethane is from A 44 to A 84, preferably from A 62 to A 82, particularly preferably from A 62 to A 80... the melting point... starts below 130° C., more preferably below 120° C.
Data Source
AI summary
Expandable thermoplastic polyurethane comprising blowing agent, wherein the Shore hardness of the thermoplastic polyurethane is from A 44 to A 84.