When a part needs to bend, the first thought is often “make it softer”. With TPU, this is only the beginning. Flexibility comes from both the material and the shape: a thick, solid part can remain quite rigid, while a thin lattice made from the same filament can be compressed easily.
Therefore, TPU is not chosen just by feel. It should be clear how the part will be pressed, how often it will bend, and whether the purpose is sealing, traction, protection or just a nice touch.
Where TPU is of real use
Typical jobs are plugs, soft feet, guards, flexible covers, and parts that need to take a light shock. TPU is also useful when a hard edge would scratch the surface or when the workpiece must be inserted and removed by bending.
In sealing, however, the word "flexible" is not enough. Pressure, contact surface and direction of deformation are important. The printed part has layers and should not automatically be assumed to be equivalent to a factory rubber seal. If leakage, pressure or safety depends on it, a test must be made in the actual conditions.
TPU is not an automatic spring replacement. It can spring back after bending, but the behaviour depends on the specific model, material, thickness and number of cycles. For a mechanism with repetitive loading, it is wise to print a test part first.
Flexibility is designed in
With hard plastics, a small change in wall thickness is often felt mainly as a change in strength. With the TPU, the same change can visibly change the squeeze feel as well. Thicker walls, dense ribs and a compact shape make the part more difficult to bend. Thinner sections and hollow structures make it more flexible.
There is no universal wall thickness or infill. A reasonable choice is an approximate range that depends on the model, material and direction of loading. If you just send us a file with no explanation, we see the geometry, but not how you want the finished part to feel. Add a note: should it flex with fingers, stand steady under weight, or just not scratch.
Holes and channels also need attention. The flexible wall may shift during assembly, so fit is not judged by the nominal size in the model alone. For an important assembly, a trial part usually costs less than a batch that turns out to be too tight.
What to expect from the surface
TPU is printed from filament, layer by layer. Layer lines remain visible, and very fine edges do not look moulded. For a soft part, this rarely affects function, but it matters for a cover, handle or visible guard.
Removing supports from a flexible material may leave a rougher area. Orientation is therefore particularly important: the visible or contact side should not rest on supports when the geometry allows. The decision depends on the model and the material, because sometimes fewer supports mean a less suitable direction of the layers.
When to choose rigid material
If the part needs to hold an accurate angle, guide a shaft, or maintain a dimension under constant pressure, PETG, ABS, or another hard material may be more reasonable. TPU is strong where deformation is desired. When deformation is a problem, flexibility becomes a disadvantage.
There are also mixed tasks: a hard body with a soft pad for example. Such models require manual review and compatibility depends on the specific materials and geometry. Not every combination connects reliably just because it can be put into one machine.
How much does TPU printing cost?
The regular TPU is 0.06 €/g and the very soft TPU 85A — 0.08 €/g; machine time is €1.70/hour. The minimum order is €6 including VAT. The final price is not just the weight multiplied by the price per gram: walls, infill, supports, part height and print time all factor in. The exact amount is visible after uploading the file.
The most useful preparation on your part is a brief description of the function. Tell us how the part should be bent, which surface is important and what it will be assembled with. Thus, the choice does not remain "soft or hard", but is linked to the real task.
See available materials, read how the price is formed or upload a model for a quote.