A Comprehensive Guide to Flexible Filament (for Beginners)

In this guide, we will discuss the pros and cons of using flexible filament, the hardware requirements for printing with it, and the best practices to overcome the challenges associated with this material.

We will also provide pro tips to optimize your printing experience and explore common applications and popular brands of flexible filament.

What is Flexible Filament?

Flexible filament, also known as TPE or TPU, is a unique type of thermoplastic elastomer that combines the properties of hard plastic and rubber. Its elasticity allows the material to stretch and bend, making it ideal for a wide range of applications in industries such as footwear, aerospace, automotive, and more.

Some people will use it to create vibration-dampening components, grip sleeves, or phone cases.

Pros and Cons of Flexible Filament

Flexible filament offers a range of benefits and challenges Let’s explore the pros and cons of using flexible filament in your projects.

Pros:

Flexibility and Softness: Flexible filaments are known for their elasticity, allowing them to stretch and bend easily. This makes them ideal for creating functional prototypes, custom tools, and end-use parts with elastic properties.

Excellent Vibration Dampening: The rubber-like properties of flexible filaments make them great for applications requiring vibration dampening. This is particularly useful in mechanical or industrial parts where reducing vibrations is crucial.

Long Shelf Life: Flexible filaments have a long shelf life compared to other materials. This means you can store them for extended periods without worrying about degradation or loss of elasticity.

Good Impact Resistance: Products printed with flexible filaments can withstand significant impacts without deforming. This makes them suitable for parts that require durability and resistance to damage.

Cons:

Difficult to Print: Printing with flexible filaments can be challenging, especially if you are used to working with more rigid materials like PLA. They require specific settings and techniques to avoid issues such as clogging, kinking, and stringing.

Poor Bridging Characteristics: Flexible filaments have poor bridging characteristics, making it difficult to create overhangs or bridges in your prints. This limitation may restrict the complexity of designs you can achieve.

Possibility of Blobs and Stringing: Due to the elasticity of flexible filaments, they are prone to blobs and stringing during printing. This can affect the overall aesthetic quality of your prints and require additional post-processing.

May Not Work Well on Bowden Extruders: While some partially flexible filaments can work with Bowden extruders, most fully flexible filaments require a Direct Drive extruder for optimal results. The shorter distance between the drive gear and the melt zone is essential to prevent kinking or coiling of the filament.

Understanding the pros and cons of flexible filament will help you make informed decisions and overcome the challenges associated with printing this material. With the right hardware and best practices, you can harness the unique properties of flexible filaments for your 3D printing projects.

Hardware Requirements for Printing with Flexible Filament

To ensure the best print quality when working with flexible filament, it is important to check if your 3D printer meets the necessary hardware requirements. Here are some key factors to consider:

Direct Drive Extruders: While some partially flexible filaments can work with Bowden extruders, most fully flexible filaments require a Direct Drive extruder for optimal results. The shorter distance between the drive gear and the hot-end’s melt zone allows for efficient filament feeding. Additionally, the filament pathway should have tight tolerances to prevent kinking or coiling.

Slow and Consistent Feed Rates: Flexible filaments generally print best at slow and consistent feed rates. Sudden changes in print speed can cause the filament to compress and potentially result in a jam. It is recommended to start with a slower speed, such as 1200 mm/min (20 mm/s), and adjust based on trial and error for optimal results.

Reducing Resistance from the Filament Spool: Flexible materials can stretch when pulled into the nozzle, leading to under-extrusion. To mitigate this, consider mounting the filament spool above the printer so that it unwinds in a downward direction, reducing resistance. Using a bearing on the spool’s hub can also help it spin more freely.

Tuning Retraction Settings: The elastic nature of flexible filament makes it sensitive to quick movements like retractions. It is advisable to disable retraction when starting with flexible materials. Once you are confident with the print settings, you can add a small amount of retraction at a slower speed to address any potential oozing.

Optimizing Travel Movements: Minimizing the number of retractions is essential when printing with flexible filaments. Utilize features like Simplify3D’s “Avoid crossing outline for travel movement” to choose new paths between points, reducing the need for retractions and improving print quality.

By ensuring your 3D printer meets these hardware requirements, you can overcome some of the challenges associated with printing flexible filaments and achieve successful results.

Common Applications of Flexible Filament

Flexible filament, with its unique elastic properties, has a wide range of applications across various industries. Its flexibility and durability make it an ideal choice for many different products. Here are some common applications where flexible filament is commonly used:

Vibration Dampening: Flexible filament is excellent for reducing vibrations in mechanical and electronic devices. It can absorb shocks and vibrations, providing stability and preventing damage to sensitive components.

Grip Sleeves: Flexible filament is often used to create comfortable and ergonomic grip sleeves for tools, handles, and sports equipment. Its soft and flexible nature provides a secure and comfortable grip, enhancing user experience and reducing fatigue.

Phone Cases: Flexible filament is a popular choice for phone cases due to its ability to absorb impact and protect the device from accidental drops and bumps. It provides a cushioning effect, preventing damage to the phone’s delicate components.

Footwear: The footwear industry extensively uses flexible filament for insoles, shoe soles, and other components. Its elasticity and durability make it ideal for providing comfort, shock absorption, and flexibility in footwear.

Medical Devices: Flexible filament is widely used in the medical field for creating prosthetics, orthotics, and other wearable medical devices. Its flexibility allows for a snug and comfortable fit, while its durability ensures long-lasting performance.

These are just a few examples of the many applications of flexible filament. Its versatility and unique properties make it a valuable material in various industries. Whether it’s for reducing vibrations, enhancing grip, protecting devices, or creating comfortable and functional products, flexible filament offers endless possibilities.

Popular Brands of Flexible Filament

When it comes to flexible filament, there are several popular brands that have gained recognition for their high-quality products. Here are some of the top brands to consider when choosing flexible filament for your printing projects:

NinjaTek Ninjaflex, Armadillo, Cheetah: NinjaTek is a well-known brand in the 3D printing community, offering a range of flexible filaments with different levels of hardness. Ninjaflex, Armadillo, and Cheetah are their popular product lines, known for their excellent elasticity and durability.

Polymaker PolyFlex: Polymaker is another reputable brand that offers high-quality flexible filament. Their PolyFlex line is known for its ease of printing and outstanding performance, making it a popular choice among 3D printing enthusiasts.

eSun TPE: eSun is a trusted brand that offers a wide range of 3D printing filaments, including flexible TPE filaments. Their TPE filament is known for its flexibility and softness, making it suitable for various applications.

Sainsmart Flexible TPU: Sainsmart is a brand that has gained popularity for its affordable yet reliable 3D printing filaments. Their Flexible TPU filament offers good flexibility and impact resistance, making it a great choice for projects that require durability.

OVERTURE TPU Filament:

GIANTARM TPU Filament

DURAMIC 3D TPU Filament

These brands have established themselves as leaders in the flexible filament market, providing users with high-quality materials that deliver excellent results. Whether you are a beginner or an experienced 3D printing enthusiast, choosing a filament from one of these trusted brands will ensure a smooth printing experience and reliable, flexible prints.