Published on Sat Jul 15 2023 23:14:15 GMT+0000 (Coordinated Universal Time) by Alex

eSun TPU 95A: A Deep Dive into Flexible 3D Printing

eSun’s TPU 95A filament has become a popular choice for makers looking to add flexibility and durability to their 3D printed parts. This article provides a comprehensive overview of this filament, including its specifications, best practices for printing, and a detailed assessment of its key characteristics.

What is TPU 95A?

TPU stands for Thermoplastic Polyurethane. The “95A” refers to its Shore hardness, a measure of material hardness. 95A indicates a relatively soft, flexible material. This makes it suitable for printing parts that need to bend, flex, or absorb impact. Think phone cases, gaskets, RC tires, or custom wearables.

Specifications

• Material: Thermoplastic Polyurethane (TPU)
• Shore Hardness: 95A
• Diameter: Typically 1.75mm (check your spool!)
• Tolerance: +/- 0.05mm (manufacturer claims, mileage may vary)
• Print Temperature: 210-230°C (This is a starting point; more on this later)
• Bed Temperature: 30-60°C (Optional, but often recommended)
• Printing Speed: 20-40 mm/s (Slower is often better)
• Density: 1.20 g/cm³
• Tensile Strength: 35 MPa (Along printing direction)
• Elongation at Break: 450% (Along printing direction)
• Spool Size: 1kg

Printing Tips for eSun TPU 95A

TPU can be a bit finicky compared to filaments like PLA or PETG. However, with the right settings and some patience, you can achieve excellent results. Here are some crucial tips:

• Slow Down: This is the golden rule. TPU, especially softer variants like 95A, struggles with high speeds. Start around 20 mm/s and gradually increase if your printer can handle it.
• Direct Drive Extruder is Ideal: While bowden extruders can work, direct drive systems minimize the distance the filament travels, reducing opportunities for it to buckle or bind.
• Retraction: Use minimal or no retraction. Retraction can cause the flexible filament to compress and clog the nozzle. If you must retract, keep the distance very short (0.5-1mm) and the speed slow.
• Extrusion Multiplier: Slightly increase your extrusion multiplier. Due to its flexibility, TPU can sometimes underextrude. A slight bump of 5-10% can help.
• Disable Part Cooling Fan (or Use Very Low Fan Speed): Excessive cooling can lead to poor layer adhesion with TPU. Try printing with the fan completely off, or set it to a very low speed (20-30%).
• Bed Adhesion: A heated bed is recommended (30-60°C). Blue painter’s tape, PEI sheets, or BuildTak surfaces provide good adhesion. A thin layer of glue stick can also help.
• Nozzle Temperature: Experiment within the recommended range of 210-230°C. Start lower and increase if you see layer adhesion issues.
• Dry Your Filament: TPU is hygroscopic, meaning it absorbs moisture from the air. This can lead to stringing, bubbling, and poor print quality. Dry the filament before printing, especially if it’s been sitting out for a while. Filament dryers are ideal, but an oven at a low temperature (40-50°C) for a few hours can also work. Always research the proper drying temperature and time for your specific TPU variant before putting it in an oven.
• Use a Constrained Filament Path: On some printers, you can create a constrained filament path between the spool and the extruder to help prevent kinking or tangling.

Key Considerations

• Stringing: TPU is prone to stringing. Proper temperature, retraction, and cooling adjustments are key to minimizing this.
• Clogging: Incorrect settings (especially retraction) can easily cause clogs with TPU.
• Support Material: Removing support material from TPU prints can be challenging. Design parts to minimize the need for supports, or consider using dissolvable support material (e.g., PVA).
• Storage: Store TPU in an airtight container with desiccant packets to prevent moisture absorption.

eSun TPU 95A Assessment (Out of 10)

Here’s an assessment of eSun TPU 95A based on key performance indicators, rated on a scale of 1 to 10 (1 being the worst, 10 being the best):

• Print Quality: 7/10 (Good detail, but can require fine-tuning for optimal results)
• Toughness: 8/10 (Excellent impact resistance and durability)
• Flexibility: 9/10 (Very flexible; ideal for parts requiring bending or compression)
• Warping: 9/10 (Minimal warping, especially with a heated bed)
• Adhesion: 7/10 (Good adhesion with proper bed surface and temperature)
• Moisture Sensitivity: 4/10 (High moisture sensitivity; requires drying)
• Color Range: 7/10 (Decent range of colors available)
• Temperature Range: 8/10 (Offers a good range of operational temperatures)
• Odor & Fumes: 8/10 (Generally low odor and minimal fumes)
• Spool Winding Quality: 8/10 (Typically well-wound, reducing the risk of tangles)

Average Score: 7.5/10

Conclusion

eSun TPU 95A is a solid choice for 3D printing projects requiring flexibility, durability, and impact resistance. While it can be a bit more challenging to print than rigid filaments like PLA, the results are well worth the effort. By following the tips outlined in this guide, you can unlock the potential of eSun TPU 95A and create functional, resilient parts for a wide range of applications. Remember to experiment with your printer settings to find the sweet spot for your specific setup and always keep your filament dry!

Written by Alex