Modified Thermoplastic Polyurethane — or MTPU — is a next-generation midsole material that combines the resilience of TPU with a softer, more cushioned ride. Developed through advanced physical foaming processes, MTPU offers a compelling blend of energy return, softness, and long-term durability, making it an emerging material in both athletic and safety footwear categories.
While it shares structural DNA with traditional TPU, MTPU takes things a step further by tuning performance through material modification and microcellular engineering.
What Makes MTPU Different?
Unlike traditional TPU, which can sometimes feel firm underfoot, MTPU is processed using supercritical gas foaming, resulting in a lighter, more elastic structure. This makes it softer on impact while maintaining rebound and shape stability.
The result is a midsole foam that delivers:
- Responsive cushioning without excessive softness
- Reliable rebound across temperature ranges
- Improved compression recovery after repeated impacts
- A stable ride with less weight and more comfort
This balance is especially valuable in footwear designed for long hours on foot — from workers and hikers to everyday wearers seeking performance without compromise.
Key Material Properties of MTPU
MTPU typically performs within the following range:
- Energy Return: 65–75%
- Density: 0.20–0.28 g/cm³
- Compression Set: <10% after 24 hours at 50% strain
- Tensile Strength: ~10–13 MPa
- Elongation at Break: 300–450%
- Temperature Range: Performs between −20 °C to +40 °C
- Shore A Hardness: 45–60 depending on compound blend
These values make MTPU an ideal candidate when you need a midsole that offers lasting comfort, performance consistency, and resistance to fatigue over time.
MTPU vs EVA and TPU
When compared to traditional midsole foams, MTPU sits comfortably between EVA and standard TPU in terms of softness, responsiveness, and durability.
- EVA: Lightweight and soft, but compresses over time and lacks energy return
- TPU: Extremely durable and responsive, but can be too firm and heavy
- MTPU: Softer than TPU, more resilient than EVA — making it ideal for hybrid applications
This makes MTPU an appealing choice in applications where all-day comfort and long-term performance are required but without the bulk of heavier foams.
Design Advantages
For footwear designers and developers, MTPU opens the door to new combinations of performance and expression. It molds easily into multi-density midsoles, can be used with TPU shanks and heel cages, and works well in color-blocked zones. This makes it both a functional and aesthetic asset in modern sole tooling.
Final Thoughts
While still emerging compared to long-established materials like EVA and ETPU, MTPU represents a thoughtful evolution — refining what’s possible in terms of softness, strength, and comfort. Its growing popularity in high-performance footwear categories signals its value to brands looking for fresh solutions grounded in material science.
If you're developing footwear that demands lasting comfort, resilient rebound, and modern technical performance, MTPU is a material worth exploring.
