TPU Flexible Filament: Perfect for Gaskets, Grips, and More

Sometimes rigid plastic just won't cut it. When you need a part that bends, stretches, absorbs shock, or creates a seal—that's when TPU earns its place in your project.

TPU (Thermoplastic Polyurethane) is the go-to material for printing flexible parts. It's rubber-like but printable, durable but forgiving, and it fills a gap that PLA and PETG simply can't touch. Here's everything you need to know about this versatile material.

What Makes TPU Different

Unlike rigid filaments that hold their shape or shatter under stress, TPU flexes and returns to its original form. Think of it as the middle ground between hard plastic and rubber—it has the printability of a thermoplastic with the functional properties of an elastomer.

On a molecular level, TPU consists of alternating hard and soft segments. The ratio between them determines how flexible the final material is. Manufacturers measure this flexibility using the Shore hardness scale—lower numbers mean softer, more flexible material.

Most 3D printing TPU falls in the 85A to 95A range:

• 85A TPU — Very soft and flexible, similar to a rubber band. Great for grips and padding but challenging to print.
• 95A TPU — The sweet spot for most applications. Flexible enough to bend and compress, rigid enough to print reliably.
• 98A+ TPU — Stiffer, approaching semi-rigid territory. Easier to print but less rubber-like in feel.

For most projects, 95A TPU delivers the best balance of flexibility and printability. It's what we typically recommend and use at Mandarin3D.

TPU's Superpowers

TPU brings capabilities that no rigid filament can match:

Flexibility without fatigue. TPU can stretch up to 500% and bend repeatedly without cracking or losing its shape. Living hinges, flexing joints, and parts that need to deform all work beautifully in TPU.

Impact absorption. Drop a PLA print and it might crack. Drop a TPU print and it bounces. This shock-absorbing quality makes TPU ideal for protective cases, bumpers, and padding.

Abrasion resistance. TPU wears like leather—it's tough against friction and rubbing. Wheels, belt guides, and anything that contacts moving parts benefits from this durability.

Chemical resistance. Oils, greases, and many solvents don't faze TPU. Industrial applications often use TPU specifically because it handles exposure to harsh substances.

Grip and friction. TPU's naturally tacky surface grabs onto things. Handles, grips, and feet printed in TPU stay put where rigid plastics would slip.

Real Applications for TPU

Here's where TPU actually makes sense—projects where flexibility is a feature, not a limitation:

Gaskets and Seals

Custom gaskets are one of TPU's killer applications. Need to seal an odd-shaped enclosure? Replace a worn seal on vintage equipment? Create a watertight closure for an electronics project?

TPU can be printed to exact specifications, creating seals that conform to irregular surfaces. For best results, print gaskets at 100% infill with layer heights of 0.2mm or less—smoother surfaces seal better. The flexibility allows the gasket to compress and form a tight seal while the material's durability means it won't tear during installation.

Protective Cases

Phone cases are the classic example, but TPU works for protecting anything. Camera equipment, tools, electronics—TPU cases flex on impact rather than transferring shock to what's inside. The material won't crack if dropped and provides grip that keeps devices from sliding off surfaces.

Tool Grips and Handles

Ever used a tool that left blisters or slipped at the wrong moment? TPU grips solve both problems. The material conforms to hand shapes, provides cushioning during extended use, and its natural tackiness improves control.

Custom grips for screwdrivers, bike handles, game controllers, kitchen utensils—anywhere you interface with an object repeatedly, TPU can make it more comfortable and secure.

Vibration Dampeners and Bumpers

Machinery vibrates. Sometimes that's fine; sometimes it loosens fasteners, generates noise, or damages components. TPU dampeners absorb vibration energy, protecting both equipment and operators.

At Heineken's bottling plant in Seville, TPU bumpers guide glass bottles through high-speed production lines, preventing breakage that would otherwise be inevitable with rigid guides.

Wheels and Rollers

TPU wheels grip surfaces, absorb bumps, and resist wear. RC cars, robots, material handling equipment—any application where a wheel contacts a surface benefits from TPU's combination of grip and durability. Unlike rubber, TPU won't degrade from UV exposure or dry out over time.

Strain Reliefs and Cable Management

The flexible portion where a charging cable meets the connector? That's the job TPU was made for. Custom strain reliefs prevent cable damage at bend points, extending the life of expensive cables and providing a clean, professional look.

TPU vs. Other Flexible Filaments

You'll sometimes see TPE (Thermoplastic Elastomer) mentioned alongside TPU. Here's the relationship: TPU is a type of TPE. TPE is the broader category—like "vehicle" to TPU's "car."

Other TPE variants exist (TPA, TPC), but TPU dominates 3D printing because it offers the best balance:

• Easier to print than softer TPE variants
• More durable under repeated stress and wear
• Better chemical resistance for industrial applications
• More consistent results across different printers

If someone says they're printing "flexible filament," they almost certainly mean TPU.

Printing TPU: What to Expect

TPU isn't as forgiving as PLA, but it's not as difficult as its reputation suggests. The key is understanding what makes it different.

Why TPU Is Trickier

The same flexibility that makes TPU useful also makes it challenging. In a Bowden tube system (where the filament travels through a tube to the print head), flexible filament can buckle, bunch up, or compress instead of feeding smoothly.

This is why direct drive extruders—where the motor sits right above the nozzle—work much better with TPU. The short, constrained path prevents the filament from misbehaving. Our BambuLab P1S printers handle TPU well, though print speeds need to stay moderate.

Print Settings That Work

Temperature: 220-240°C nozzle temperature. Start around 230°C and adjust from there. TPU is less sensitive to temperature variation than you might expect.

Bed temperature: 40-60°C. Some TPU prints fine on a cold bed, but light heating improves adhesion.

Speed: This is the big one. TPU needs to print slowly—typically 20-50mm/s, sometimes slower for softer variants. Pushing speed causes jams, under-extrusion, and failed prints.

Retraction: Keep it minimal. TPU stretches, so aggressive retraction just pulls the filament like taffy without actually retracting it. This causes stringing, but stringing is easier to deal with post-print than the jams aggressive retraction causes.

Cooling: Moderate. TPU doesn't need blast cooling like PLA, but some airflow helps with overhangs and fine details.

Stringing Is Normal

TPU strings. Accept this going in. The material's stretchy nature means thin threads form when the nozzle travels between areas. Post-processing with a heat gun (briefly) or simply pulling off strings by hand handles most of it.

Minimize stringing by printing one object at a time rather than multiple objects with lots of travel moves between them.

When to Choose TPU (And When Not To)

Use TPU when:

• The part needs to flex, bend, or compress
• Impact resistance matters
• You need grip or friction
• Sealing against liquid or air is required
• Vibration damping would help
• The part contacts moving surfaces that would wear rigid materials

Skip TPU when:

• The part needs dimensional precision (TPU's flexibility makes tight tolerances harder)
• High temperatures are involved (TPU handles up to about 80°C)
• The part needs to be food-safe (TPU is non-toxic but not rated for food contact)
• Rigidity is actually what you need
• You're on a tight timeline (TPU prints slower)

Cost and Availability

TPU typically costs 1.5-2x what PLA costs. For specialty variants (carbon-filled TPU, specific Shore hardnesses), expect to pay more. The material is widely available from major filament manufacturers.

For most applications, standard 95A TPU in basic colors does the job. Save the exotic variants for projects that specifically need their properties.

Getting Your TPU Project Made

If you've got a project that needs flexibility—custom gaskets, protective cases, grips, bumpers, or any of the applications we've discussed—TPU might be exactly what you need.

At Mandarin3D, we print TPU regularly on our BambuLab P1S printers. The direct drive extruders handle the material reliably, and we've dialed in settings that produce consistent results.

Ready to see what TPU can do for your project? Upload your model and select TPU as your material. If you're not sure whether TPU is the right choice for your application, reach out—we're happy to discuss your project and recommend the best material for the job.

Flexibility might just be the feature your design has been missing.