Siraya Tech Flex TPU Air TDS

Download TDS in PDF version

1. Product Introduction

Flex TPU Air Filament Key Features

  • Tunable Results: Controlled foaming via nozzle temperature.
  • Half the Weight: Up to 50% lighter than standard TPUs.
  • Tunable Hardness: Print between 63A and 78A Shore hardness.
  • Matte Finish: Unique, fabric-like texture.
  • Easier Printing: Stiffer pre-extrusion filament improves compatibility.
  • Strong Bonds: Excellent layer adhesion for durable ＆ flexible parts.

⚙ Application

Siraya Tech TPU Air is a unique foaming flexible material ideal for:

  • Lightweighting: Significantly reducing weight for drone parts, robotics, and more.
  • Shock Absorption & Cushioning: Creating insoles, seals, and various dampening components.
  • Customization: Printing unique matte-textured wearables and accessories.
  • Functional Prototyping: Rapidly validating prototypes requiring variable flexibility.

2. Property Data

Specifications

Data

Name

Flex TPU Air

Color

Black, White

SKU

ST3020, ST3021

Net weight (KG)

1

Gross weight (KG)

1.5

Package Dimensions

21*21*7.5 cm

Diameter (mm)

1.75±0.03

Material Type

Actively Foaming Thermoplastic Polyurethane (TPU)

 

Material Properties

Measure

Method

Filament Density (g/cm3)

1.15

ISO 1183

Melt Index (MFI)

8g/10min

190°C, 2.16kg

 

Mechanical Properties

Print @ 240C

Print @ 250C

Method

Printed Part Density (g/cm³)

0.88

0.7

ISO 845

Vicat Softening Temp (°C)

83

74

ISO 306

Hardness (Shore A)

78

71

ISO 7619

Tensile Yield Strength (MPa)

6.3

4.4

X-Y, ISO 527

Tensile Breaking Strength (MPa)

10.3

7.2

X-Y, ISO 527

Elongation at Break (%)

629

605

X-Y, ISO 527

 

Mechanical Properties

Print @ 260C

Print @ 270C

Method

Printed Part Density (g/cm³)

0.59

0.51

ISO 845

Vicat Softening Temp (°C)

65

53

ISO 306

Hardness (Shore A)

68

63

ISO 7619

Tensile Yield Strength (MPa)

3.4

2.8

X-Y, ISO 527

Tensile Breaking Strength (MPa)

5.0

3.8

X-Y, ISO 527

Elongation at Break (%)

547

475

X-Y, ISO 527

 

3. Workflow

Drying and Storage

Note: 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.

Dry Steps
  • Put the filament in a dedicated dryer or convection oven.
  • Dry 4-6 hours at 70°C - 80°C before printing.

 

  • Printing Profile

Printer

Download Link

BambuLab

Creality

Qidi

Flashforge

 

  • Recommended Printing Conditions

Parameter

Recommendation

Notes

Nozzle Temperature

230−270°C

Higher temps = more foaming (lighter/softer). 260°C recommended starting point.

Recommended Nozzle Diameter

0.4mm−0.8mm

0.4mm standard nozzle works well.

Build Plate Temperature

30−45°C

Avoid excessive heat to prevent over-adhesion.

Recommended Build Surface
  • Glass (w/ PVP glue)
  • PEI (w/ release agent)
  • Steel Plate (w/ PVP glue)
  • PC Film

Use release agent (PVP glue, Magigoo) on PEI or highly adhesive surfaces.

Cooling Fan Speed

100

Helps solidify the foamed structure quickly.

Print Speed

30−60mm/s

Slower speeds generally improve quality. Up to 150 mm/s possible with careful tuning.

Retraction

Off Recommended

Set Distance & Speed to 0. Material expansion causes oozing; retraction is generally ineffective.

Flow Rate / Extrusion Mult.

See Below

MUST be reduced significantly at higher temps (e.g., ~55-60% @ 260°C). Calibration required.

 

  • Temperature vs. Hardness & Flow (Approximate Guide)

Print Temp (°C)

Approx.

Shore Hardness

Resulting Properties

Starting Flow Rate (%)

230°C - 240°C

~85A

Denser, Stiffer, Less Foaming, Less Texture

~85% - 90%

250°C

~75A

Balanced Foaming, Noticeably Lighter/Softer

~65% - 70%

260°C

~70A

Optimal Balance, Good Foaming & Softness

~55% - 60%

270°C

~65A

Max Foaming, Lightest, Softest, Max Texture

~50% - 55%

 

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.

  • Tips

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