TPU Filament Guide - Flexible Print Settings

What is TPU?

TPU is a flexible thermoplastic elastomer that combines the properties of rubber and plastic. It offers excellent elasticity, abrasion resistance, and impact absorption. TPU maintains its flexibility across a wide temperature range and is ideal for applications requiring bend, stretch, or compression.

Common applications include phone cases, watch bands, gaskets, seals, protective bumpers, shoe insoles, and drone parts. TPU is available in various shore hardness ratings, with 95A being the most common for 3D printing.

Typical Print Settings

Setting	Recommended Range	Standard Value
Nozzle Temperature	210-230°C	220°C
Bed Temperature	40-60°C	50°C
Print Speed	15-30 mm/s	20 mm/s
Cooling	50-100%	75%
Retraction Distance	0-1 mm (direct drive) Limited on bowden	0.5 mm / avoid bowden
Layer Height	0.12-0.28 mm	0.20 mm

Important: TPU prints best on direct drive extruders. Bowden systems can work but require very slow speeds and minimal retraction to prevent filament buckling in the tube.

Strengths

Excellent flexibility - Bends and stretches without breaking
High abrasion resistance - Withstands wear and friction
Impact absorption - Perfect for protective applications
Chemical resistant - Resists oils, greases, and many solvents
Wide temperature range - Maintains flexibility from -40°C to 80°C
Good layer adhesion - Layers bond well for durable prints
UV resistant - Better than PLA or PETG for outdoor use

Weaknesses

Very slow printing - Requires slow speeds to prevent issues
Difficult on bowden systems - Flexible filament can buckle in long tubes
Stringing issues - Challenging to eliminate stringing completely
Highly hygroscopic - Absorbs moisture rapidly, must be dried
Poor bridging - Flexibility makes overhangs and bridges difficult
Expensive - Costs more than standard filaments
Post-processing challenges - Difficult to sand or smooth

Drying Guidance

TPU is extremely hygroscopic and must be dried before printing. Wet TPU produces extensive stringing, bubbling, and weak layers.

Method	Temperature	Duration
Filament Dryer	55-60°C	4-6 hours
Food Dehydrator	55°C	4-6 hours
Oven (not recommended)	55°C	4-6 hours

Critical: TPU absorbs moisture very quickly. Store in a dry box and consider printing directly from a heated dry box to maintain optimal quality.

Storage Guidance

TPU requires aggressive moisture protection. It absorbs water faster than most filaments and degrades quickly when exposed to humidity.

Store in airtight containers with fresh desiccant immediately after use
Use dry boxes with active drying for best results
Consider printing directly from a heated dry box
Vacuum-seal for long-term storage
Re-dry before each print session if stored in open air

Common Problems

Filament Buckling in Bowden Tube

Flexible filament compresses instead of being pushed through. Use direct drive extruder or print extremely slowly (10-15 mm/s) with minimal retraction.

Excessive Stringing

TPU strings significantly. Dry thoroughly, use minimal retraction (0.5-1mm on direct drive), reduce temperature, and slow down travel moves.

Stringing troubleshooting

Under-Extrusion

Printing too fast or extruder tension too tight. Slow down print speed and adjust extruder tension to grip without deforming the filament.

Under-extrusion solutions

Poor Layer Adhesion

Usually caused by wet filament or insufficient temperature. Dry the filament and ensure proper nozzle temperature.

Related Tools

Spool Weight Calculator - Calculate remaining filament
Print Cost Calculator - Estimate print costs

Frequently Asked Questions

It's possible but challenging. Bowden systems work better with harder TPU (95A-98A shore hardness). Use very slow speeds (10-15 mm/s), minimize or disable retraction, and ensure the bowden tube has no gaps. Direct drive extruders are strongly recommended for TPU.

95A is the most common and easiest to print. Softer TPU (85A-90A) offers more flexibility but is harder to print. Harder TPU (98A) is easier to print but less flexible. Choose based on your application: 85A for maximum flexibility, 95A for balanced properties, 98A for easier printing.

Most commonly caused by wet filament. TPU absorbs moisture very quickly and must be dried before use. Also reduce nozzle temperature by 5-10°C, use minimal retraction, and slow down travel speed. Some stringing is normal with TPU.

Direct drive: 20-30 mm/s is typical. Bowden: 10-15 mm/s or slower. First layer should be especially slow (10-15 mm/s) for good adhesion. TPU requires patience; rushing leads to failed prints.

Some TPU formulations are food-safe, but 3D printed TPU objects have the same concerns as other filaments: bacteria can harbor in layer lines, and brass nozzles may contaminate the material. Check the manufacturer's specifications and consider food-safe coatings for food contact applications.

TPU Filament - Complete Guide