Siraya Tech TPU Air User Manual

1. Introduction

Siraya Tech TPU Air isn't just another flexible filament; it's an active foaming TPU that puts you in control of the final weight and softness of your prints. Imagine creating parts up to 50% lighter than standard TPU, with a unique, soft, fabric-like texture straight off the print bed!

TPU Air unlocks exciting new possibilities for lightweight functional parts, custom padding, vibration dampeners, unique wearables, and so much more.

Key Features:

• Print Lighter, Print Softer: Harness the power of active foaming! Higher print temperatures create lighter, softer parts with that amazing textured finish.
• Dial-In Your Flexibility: Adjust print temperature to achieve hardness ranging from a firm ~85A down to a very flexible ~65A Shore.
• Surprisingly Easy to Print: Engineered for better pre-print stiffness, TPU Air is compatible with a wide range of FDM/FFF printers, including many Bowden setups.
• Unique Fabric-Like Finish: TPU Air prints boast a distinctive, appealing matte texture.
• Innovative Potential: Perfect for applications where weight reduction and tunable softness are key design elements.
  

2. Technical Specifications

Technology: Fused Filament Fabrication (FFF) / FDM

Material Type: Actively Foaming Thermoplastic Polyurethane (TPU)

Diameter: 1.75mm (+/- 0.03mm)

Filament Density (Unfoamed): ~1.15 g/cm³

Printed Part Density (Foamed): Variable, down to ~0.54 g/cm³ (at max foaming temp)

Printed Part Hardness: Variable, ~65A - 85A (Shore Hardness) depending on print temp/foaming

3. Before Printing

(1) Drying and Storage

TPU Air is hygroscopic (absorbs moisture), which severely impacts foaming and print quality, causing bubbles, stringing, and poor layer adhesion.

• Upon Opening: Immediately place the spool in a filament dryer or a sealed container with plenty of active desiccant (aim for <15% humidity). Print directly from the dry box if possible.
• Storage: Always store the spool back in the provided resealable bag with the desiccant pack, ensuring it's tightly sealed.
• Wet Filament? If you suspect moisture exposure, dry the filament thoroughly in a dedicated filament dryer or convection oven at 70°C - 80°C for 4-6 hours before printing.

(2) Preparing for printing

• Taming the Ooze (Retraction)

Active foaming materials naturally expand in the hotend, causing oozing during travel moves. Standard retraction settings are often ineffective.

Best Practice: Turn Retraction OFF in your slicer (set Retraction Distance and Speed to 0).

• Minimize Travel

Print one model at a time whenever possible. Avoid printing multiple separate objects simultaneously across the build plate.

Using your slicer's "sequential printing" feature (if available and suitable for the model) can also help.

Models designed with continuous extrusion paths (minimal jumping between features) will yield the cleanest results due to reduced oozing.

• Perfect Plate Adhesion

Too Sticky? If prints bond too strongly (especially on PEI), use a release agent like PVP glue stick, Magigoo, or even a light mist of Windex before printing. Let the bed cool completely before attempting removal.

Not Sticking? Ensure your bed is clean (wash with soap and water, then wipe with IPA) and perfectly leveled. A slightly slower, wider first layer (e.g., 20mm/s speed, 120% line width) can improve adhesion.

4. Print Setting Recommendations

TPU Air's magic lies in how it reacts to heat. Higher temperatures activate more foaming, resulting in lighter, softer prints. Use these settings as your launchpad and experiment to find the perfect results for your project!

Nozzle Temperature	230°C - 270°C	See the table below for how temperature affects hardness and density. Optimal Performance: We've found 260°C It's a great temperature to start your tuning. It offers a balance between lightweighting, softness, and print quality for many applications.
Nozzle Diameter	0.4mm - 0.8mm	Standard 0.4mm works great
Bed Temperature	30°C - 45°C	A little heat helps adhesion, but too much can make removal tricky.
Build Surface	Glass, PEI, BuildTak®, Wham Bam PEX, or similar	Recommendation: Start with PVP glue stick on glass or smooth steel for reliable adhesion and easier removal, especially as TPU can bond very strongly to surfaces like PEI.
Cooling Fan	100%	Helps set the foamed structure quickly as it prints
Print Speed	30 - 60 mm/s	Slower speeds often yield better results with flexible. Capable machines might handle up to 150 mm/s, but tune carefully.

 

Flow Rate / Extrusion Multiplier: Crucial! Because the filament expands as it heats, you must reduce your flow rate significantly, especially at higher temperatures. Over-extrusion will lead to poor results.

Calibration is essential: Print small test cubes (like a 20x20x10mm cube) at your target temperature, starting with the flow rates below and adjusting until you get clean surfaces without gaps or excessive bulging.

You can find validated print settings for some printers as a reference on the Siraya Tech Setting Profile Page.

Temperature vs. Hardness & Flow (Approximate Guide)

 

Note: Exact hardness and optimal flow rate depend on your specific printer, nozzle size, and other settings. Use this table as a starting point for calibration. It is important to dial in flow rate as it is related to the temperature and how much the tpu air expanded as well as the flow rate of the extruder.

5. Safety Precautions

• Always print in a well-ventilated area.
• Avoid touching the hot nozzle or heated bed during operation.
• Consult your 3D printer's safety manual.
  

6. Share Your Creations!

We're excited to see the innovative ways you use Siraya Tech TPU Air! Share your prints and tag us on social media! If you have questions or need support, reach out to us at support@siraya.tech or post on the Siraya Tech Filament FB Group.
Happy Printing!