TPU
A flexible, abrasion-resistant thermoplastic elastomer
Typical values for the temper in the title
TPU is a thermoplastic elastomer: flexible and elastic like rubber, but melted and molded like plastic, and recyclable. It comes in a wide hardness range (database: Shore A75 to D75), with very high abrasion and tear resistance, and good resistance to oils and fuels.
It is used for wheels and rollers, belts and dynamic seals, cable jackets and flexible tubing, soles and protective covers, and flexible FDM printing.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 25-55 MPa | |
| Elongation A | 300-600% | |
| Modulus of elasticity E | 0.01-0.5 GPa | |
| Density ρ | 1.20 g/cm³ | |
| Shore hardness | A75-D75 | |
| Machinability | not applicable | relative rating in the site database |
Structure and family
| Feature | Value | Meaning |
|---|---|---|
| Type | thermoplastic elastomer (polyurethane) | flexibility and abrasion resistance |
| Hardness | Shore A75 to D75 (database value) | by grade |
| Families | polyester / polyether |
Typical values per producer data sheets.
Grades and versions
In TPU, hardness (Shore) is chosen first, then the type: polyester or polyether.
| Version | Properties | When to choose it |
|---|---|---|
| Polyester-based TPU | more abrasion and oil resistant | wheels, belts |
| Polyether-based TPU | more resistant to hydrolysis and microbes | use in water and humidity |
| Printing grades | flexibility by Shore | flexible printed parts |
Applications
- Wheels and rollers
- Belts and dynamic seals
- Cable jackets and flexible tubing
- Soles and protective covers
- Flexible FDM printing
Fabrication
Processing
Usually molded or extruded. Machining a soft material is difficult, so it is not common (database: not applicable).
Joining
Ultrasonic and hot-gas welding, and bonding.
Hydrolysis
Polyester-based TPU is sensitive to hot water long term. For water, choose polyether.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| PA12 (Nylon 12) | 50 MPa | Laser/Ultrasonic | PA12: stiffer, absorbs little water · material page |
| PVC | 40-60 MPa | Hot Gas / Spin | flexible PVC: cheap, less abrasion resistant · material page |
| HDPE / LDPE | 20–30 MPa | Hot Gas / Butt Fusion | LDPE: flexible, weak · material page |
Common mistakes
Using polyester TPU in a warm humid environment
Hydrolysis degrades it. Polyether is more suitable.
Ordering without specifying hardness
The range is very wide.
Assuming it is ordinary rubber
It melts when hot and is not suited to high temperatures like some rubbers.
Equivalents, standards and supply
| ISO | ISO 16750 |
|---|---|
| Standards | Producer specification |
| Forms | pellets · profile · strip · overmold |
| Producers | Covestro Desmopan · BASF Elastollan · Lubrizol Estane |
Learn more
Values are typical for an unfilled grade (unless stated otherwise) and for comparison only. In polymers, properties depend on grade, filler, temperature, moisture and load duration. For design, rely on the producer data sheet for the specific grade. Sources: ASTM classification standards (D8033, D5205, D5204, D6394, D4067 and others), producer data sheets, and the METAL HUB materials database.
Updated: October 31, 2026