Accelerating the Era of "Desktop Industrialization": eSUN’s Flexible 3D Printing Materials and Their Applications

In recent years, flexible 3D printing materials have become increasingly important across industries such as manufacturing, healthcare, and consumer electronics due to their excellent elasticity, impact resistance, and wear durability. As the trend of "desktop industrialization" gains momentum, distributed manufacturing and personalized production are becoming more widespread, further driving the adoption of flexible 3D printing materials in both professional and everyday contexts.

eSUN’s Flexible Material Portfolio
eSUN has developed a comprehensive portfolio of flexible materials, including a wide range of TPU and TPE options:
TPU-95A, TPU-90A, TPU-87A, TPU-85A, TPE-83A, TPU-64D, TPU-HS (antibacterial), TPU-LW (lightweight), and TPU-Temp Color Change (temperature-sensitive).

Applications of Flexible 3D Printing Materials

1. Custom Prosthetics and Orthotics
The customizability of 3D printing makes it especially suited for medical and rehabilitative applications. TPU-printed prosthetic liners, insoles, and limb sockets conform well to body contours, offering both elasticity and comfort. Additionally, dynamic orthoses made with TPU can feature variable stiffness structures that intelligently adapt to mechanical demands during rehabilitation.

2. Industrial Use: Shock-Absorbing and Sealing Components
In industrial settings, flexible materials are used for shock pads, sealing rings, and protective covers. For example, in robotics, soft TPU-based biomimetic grippers can achieve a bending radius <2mm and a precise gripping force of 0.1–5N. Their surface microstructures provide anti-slip performance with a friction coefficient μ > 1.2. These materials are also ideal for producing flexible jigs and industrial seals in small batches.

3. Consumer Electronics: Impact-Resistant Cases and Flexible Parts
TPU’s flexibility and impact resistance make it ideal for customized protective cases and shock-absorbing parts. One of eSUN’s U.S. clients uses TPU to produce structural supports and guards for electric unicycles—delivering both rigidity and comfort. Additional components printed from TPU can be mounted on vehicle bumpers to provide cushioning during collisions and reduce damage or injury.

4. Fashion and Footwear: Customized Soles and Sportswear
3D printing is making strides in fashion and wearable tech. Flexible materials can be used to create sports shoes, slippers, backpacks, clothing, and watch straps. For footwear, 3D-printed midsoles with honeycomb structures enhance rebound while reducing overall weight.

New Flexible Material Launches from eSUN
eSUN is releasing three new flexible filaments: TPU-90A, TPU-85A, and TPU-64D. All three offer excellent durability and abrasion resistance, making them well-suited for shock-absorbing and soft-support components. They are also compatible with machines like the Bambu Lab H2D for dual-material printing.

1. TPU-90A
Combines a soft tactile feel with high hardness and durability. Ideal for footwear and tire-like functional components that require both flexibility and strength.

2. TPU-85A
Softer than TPU-95A and TPU-90A, it is ideal for shock-absorbing parts such as protective covers and cushioning elements.

△ Application Example: Tennis Racket Vibration Dampener

3. TPU-64D
Modified for lower processing temperatures and improved surface smoothness. It has high hardness and better printability under lower heat conditions.
In practice, TPU-64D can be used in footwear and protective applications. When used for sports shoe soles, it offers abrasion resistance 300% higher than traditional rubber and meets impact-resistance needs for high-stress conditions. With optimized structure design, it can also reduce weight by 30%.
For helmets, a 3D-printed honeycomb-truss hybrid layer using TPU-64D achieves energy absorption densities of 35kJ/m³—five times higher than conventional EPS—while enabling active ventilation channels for enhanced comfort and protection.

Printing Considerations for Flexible Materials

Equipment Tips

· Extruder: Use direct-drive (short-path) extruders. Materials with hardness above 85A require short heat breaks and strong gear grip.

· Nozzle: ≥0.4mm recommended.

· Build Plate: PEI or glass platforms are preferred. TPU adheres well, so high bed temperatures aren’t necessary.

Parameter Settings

· Temperature: 200–250°C. Harder materials like 64D and 95A typically perform well at ~220°C. Softer materials (90A, 85A) may require ~240°C for smooth extrusion.

· Flow Rate: 1.00–1.05 recommended. TPU tends to under-extrude, so increasing flow helps avoid layer separation.

· Retraction: Minimize or disable retraction to prevent filament deformation at the gear.

Other Tips

· Drying: TPU is highly hygroscopic. Always dry before printing.

· Spool Positioning: For softer grades (83A, 85A), ensure the spool is positioned close to the extruder to reduce tension and drag during feeding.

Multi-Material Printing Models: Hard and Soft in One

The advent of machines like Bambu Lab H2D has made it easier to print integrated models that combine flexible and rigid components.

Conclusion
Innovations in flexible 3D printing materials are transforming modern manufacturing, enabling more efficient, customized solutions across industries. As material technology continues to advance, its applications will expand—from intelligent manufacturing to healthcare and consumer electronics—unlocking new possibilities for the future.