Siraya Tech Flex TPU 64D Filament User Manual

1. Introduction

Flex TPU 64D is engineered for industrial-strength parts that require both structural stability and controlled flexibility, offering exceptional wear resistance and durability.

Key Features：

  • Shore Hardness 64D – Tough & Rigid
  • Excellent wear resistance
  • Structural stability, retaining controlled flexibility
  • Strong impact resistance
  • Balance of rigidity and flexibility
  • Anti-blocking formula brings better printing experience

  • ISO 10993 Tested, skin safety

2. Technical Specifications

Material  Thermoplastic Polyurethane (TPU)
Available Color Black
Shore Hardness 64D
Diameter 1.75mm ±0.05mm
Net Weight 1kg
Gross Weight 1.5kg (Including trays and other packaging)


3. Before Printing

(1) Drying

TPU is highly hygroscopic, meaning it readily absorbs moisture from the air. Wet filament leads to poor print quality (stringing, bubbling, weak parts, clogging). 

Drying Recommendation: Dry the filament thoroughly before every print, even if the spool is new.

Method: Use a dedicated filament dryer or convection oven at 50-60°C for at least 4-6 hours.

Note about drying:

  • Longer drying times may be needed if the filament has been exposed to humid air for extended periods.
  • Consider using a drying print box during long prints.

(2) Preparing for printing

Drying  At 50-60°C for at least 4-6 hours
Nozzle Size ≥ 0.4mm
Nozzle Material Standard brass or higher grade

AMS Compatibility
  • Compatible with Original Bambu Lab AMS.
  • Not compatible with AMS 2.
  • Not tested for AMS Lite yet.
Extruder Direct drive provides the best results
Bowden setups Compatible
Printer type Enclosure not required
Build Plate Surfaces
  • PEI (smooth or textured)
  • Glass with glue stick or Magigoo
  • Specialized flexible filament build surfaces
Build Plate Clean Isopropyl alcohol wipe
Storage When not in use, store the filament in a sealed, airtight bag or container with desiccant packs (like silica gel) to minimize moisture absorption.
Other Tips Use a brim or raft if printing parts with small contact areas or sharp corners.

 

4. Print Setting Recommendations

Flex TPU 64D is significantly more rigid than softer TPUs (like 95A, 85A), making it generally easier to print and less prone to kinking in the extruder. However, it still requires care typical for flexible filaments.

Nozzle Temperature  240-270°C Start in the middle (e.g., 255°C) and perform a temperature tower test for optimal layer adhesion and surface finish.
Bed Temperature 45°C A heated bed is recommended for first layer adhesion.
Print Speed 30-80mm/s

Start conservatively (e.g., 30-40mm/s) and increase speed gradually while monitoring print quality.

Reduce speed for complex geometries or fine details.
First Layer Start slower (e.g., 15-20mm/s) and slightly hotter (e.g., +5°C on nozzle) for best adhesion.  Ensure proper nozzle height (z-offset).
Retraction 1-2mm distance, 20-30mm/s speed for direct drive
  • TPU generally requires minimal retraction to prevent clogging and stringing.
  • Start with low values, potentially slightly more for Bowden but tune carefully.
  • Disable retraction during layer changes if stringing isn't an issue ("Wipe" settings can help).   
Cooling Fan Use moderate part cooling (e.g., 70-100%) Too much cooling can weaken layer adhesion; too little can worsen overhangs and stringing. Start low and increase if needed.   
Flow Rate (Extrusion Multiplier) TPU often requires a slightly lower flow rate (e.g., 93-96%) than rigid filaments. Calibrate for optimal results. Print a calibration cube or object to check dimensions and extrusion quality.

 

5. Post-Processing

(1) Part Removal

  • Allow the bed to cool completely before attempting removal.
  • Flexing the build plate (if applicable) usually helps release the print.
  • Use a scraper carefully if needed.

(2)Support Removal

Supports printed in TPU 64D can be challenging due to strong layer bonding. 

  • Optimize support settings in your slicer (e.g., increase Z distance, use support interface layers with a compatible material if doing multi-material printing, reduce support density).
  • Use needle-nose pliers and flush cutters for removal. The rigidity of 64D might make supports snap off more cleanly than softer TPUs in some cases.

(3) Finishing

  • TPU is difficult to sand effectively.
  • Use a sharp craft knife or deburring tool to carefully trim away strings, blobs, or support remnants.
  • Briefly applying heat (e.g., heat gun on low setting, very quick pass with a torch flame) can sometimes smooth surfaces or reduce fuzziness, but exercise extreme caution to avoid melting or burning the part.
  • Practice on test prints first.

6. Troubleshooting Common Issues

(1) Stringing/Oozing

  • Dry filament thoroughly.
  • Optimize retraction settings (distance, speed, Z-hop).
  • Adjust print temperature (lower might help, but don't compromise layer adhesion).
  • Increase travel speed.
  • Use wipe/coast settings if available.

(2) Clogging

  • Ensure filament is dry.
  • Check for heat creep (ensure hotend fan is working).
  • Increase nozzle temperature slightly within the recommended range.
  • Clean the nozzle.
  • Ensure extruder tension is appropriate (not too tight, not too loose).

(3) Poor Bed Adhesion

  • Clean build plate.
  • Adjust Z-offset (nozzle height).
  • Increase bed temperature (within range).
  • Use brim/raft.
  • Apply bed adhesive (glue stick, Magigoo).
  • Slow down first layer speed.

(4) Weak Layer Adhesion

  • Dry filament thoroughly.
  • Increase nozzle temperature.
  • Decrease cooling fan speed.
  • Ensure correct flow rate/extrusion multiplier.

(5) Extrusion Issues (Under/Over)

  • Calibrate E-steps and flow rate.
  • Check for partial clogs or restrictions in the filament path (including extruder gears and Bowden tube if applicable).
  • Ensure filament spool can rotate freely.

7. Safety Precautions

  • Print in a well-ventilated area to avoid inhaling fumes.
  • Be cautious around the hot nozzle and heated bed during operation.
  • Refer to the Safety Data Sheet (SDS) available on the Siraya Tech website for detailed safety information.
  • Regarding biocompatibility: While tested against ISO 10993 standards, this does not certify the material for medical implantation or prolonged direct skin contact. The end-user must perform their own testing and validation to ensure the final printed part is safe and suitable for its intended application

8. Contact & Support

For further assistance, questions, or feedback, please visit our website or contact our support team via support@siraya.tech.

You can also join our Facebook Filament group and post there for help. Replies to your posts will also help other users with similar problems.

Happy Printing!