Flexible parts in TPU.

Thermoplastic polyurethane is the elastomer of FDM printing: rubber-like, stretchy, abrasion-resistant and tough. It exists in a print shop for the parts a rigid polymer cannot do — anything that must flex, stretch, grip, seal or absorb a shock.

Its most valuable use, though, is a timing one. Rubber components are normally moulded, which means committing to a tool before anyone has held the part. TPU lets you print the gasket, fit it, discover it is 2 mm too narrow and the profile is wrong, and print it again on Thursday — all before the tooling conversation happens.

• Gaskets and seals — dust sealing, enclosure lids, panel joints.
• Bumpers, feet and pads — impact absorption and anti-slip.
• Grommets and strain reliefs — protecting cable at a panel entry.
• Bellows and flexible joints — covering travel on a moving assembly.
• Protective sleeves and grips — over handles, tooling and instruments.
• Living hinges and flexures — where a printed rigid hinge would snap.

TPU is not one material. It comes in a range of shore hardnesses that behave very differently in the hand — a soft grade that squashes under thumb pressure and a firm one that holds its shape and only yields under real load are both TPU, and swapping one for the other will make a part fail at its job.

The most reliable way to specify it is not a number: send the rubber part you are replacing, or describe what the part has to do — squash, spring back, grip, hold a shape while sealing. We will match it as closely as the available grades allow and tell you if what you want sits between two of them.

That last row is worth reading twice. A flat gasket is frequently a die-cutting job rather than a printing one, and we would rather cut it than print it if that is the right answer.

TPU is harder to print than rigid filament and it is honest to say so, because it shows up in the price. A flexible filament wants to buckle rather than feed, so it needs slower speeds, carefully tuned retraction and a well-constrained filament path. Print times are longer than an equivalent PETG part, sometimes considerably.

That is our problem rather than yours, but it is why TPU parts are quoted at a higher rate per hour of machine time — and why very large flexible parts are sometimes better split into sections. Send the geometry and we will tell you whether it prints sensibly as one piece.