The Ultimate Guide to Nylon Filaments in 3D Printing: Types, Properties, and Best Practices

Nylon is an exceptional material in the world of 3D printing, widely celebrated for its robust mechanical properties and versatile applications. Here at 3Dnatives, it holds a special place among our preferred filaments. Unlike more conventional materials such as PLA or ABS, nylon offers a unique combination of strength, flexibility, durability, and a remarkable ability to be dyed using common garment dyes. These specific attributes make it an engineering-grade material, ideal for producing functional parts that demand high performance and aesthetic customization. Understanding the different types of nylon and how to effectively utilize them can significantly elevate your 3D printing capabilities, allowing you to create parts that withstand considerable stress, wear, and environmental factors.

Exploring the Different Kinds of Nylon for 3D Printing

The market for nylon filament has expanded significantly, with numerous manufacturers offering various formulations. However, one of the most recognized and influential companies in this space is undoubtedly Taulman. Taulman has pioneered several popular nylon filaments, including the widely used 618 and 645 variants. In addition to these, newer formulations such as nylon 680 and the robust nylon 910 have also gained traction. Each type of nylon, often distinguished by a number (e.g., PA6, PA12), indicates specific polymer chains and, consequently, different mechanical and printing characteristics. This diversity allows users to select the optimal nylon for their specific project requirements, balancing properties like flexibility, strength, clarity, and ease of printing.

Nylon 618: The Flexible Workhorse

Nylon 618, often categorized as a variant of Nylon 6/66 (a co-polymer of Nylon 6 and Nylon 66), is a highly popular choice for FDM 3D printing due to its distinct properties. The first characteristic you’ll notice when handling nylon 618 is its remarkable flexibility. Compared to more rigid filaments like PLA, nylon 618 exhibits a certain pliability even before printing, giving the impression of an already “melted” or softened material. This inherent flexibility translates into printed parts that are tough, impact-resistant, and capable of bending without breaking, making it an excellent choice for functional prototypes, living hinges, or parts exposed to dynamic stresses. Visually, nylon 618 typically presents as a deep, opaque white, and achieving true transparency with this material is quite challenging due to its crystalline structure.

When it comes to printing, the recommended nozzle temperature for nylon 618 by manufacturers like Taulman typically falls between 235°C and 260°C (455°F and 500°F). However, just like with any 3D printing filament, these are starting points. We strongly advise conducting calibration tests with various temperature settings to pinpoint the optimal range for your specific printer and environment. For our setup, we’ve found that an ideal printing temperature often hovers between 242°C and 245°C (467.6°F and 473°F), adjusted slightly based on the ambient room temperature. This fine-tuning is crucial for achieving optimal layer adhesion, minimizing stringing, and ensuring a smooth, consistent extrusion.

One critical characteristic of nylon 618, and indeed most nylons, is its high hygroscopicity—its tendency to readily absorb moisture from the air. If nylon filament absorbs too much moisture, it can lead to several printing issues, including bubbling or sizzling sounds from the hotend, poor layer adhesion, increased stringing, and ultimately, significantly weaker and aesthetically compromised prints. While the water vapor produced during printing isn’t toxic, it’s a clear indicator of moisture contamination. To mitigate this, it is essential to store nylon filament in a dry, airtight environment, ideally with desiccant packs. For filament that has already absorbed moisture, a dedicated filament dryer or even a food dehydrator can be used to dry it thoroughly before printing, typically at temperatures around 60-80°C for several hours.

Nylon 645: Enhanced Strength and Clarity

Nylon 645 shares many similarities with its counterpart, nylon 618, often also being a Nylon 6/66 co-polymer variant. However, it distinguishes itself with a few key enhancements. Visually, nylon 645 tends to be more translucent than the opaque white 618, offering a slight improvement in clarity, although it still doesn’t achieve full transparency. More significantly, nylon 645 is formulated to be a little stronger and tougher than 618, providing increased durability and resistance to wear. This makes it suitable for applications where higher mechanical performance is required without sacrificing the inherent flexibility of nylon. The printing temperature for nylon 645 is generally the same as for 618, requiring similar hotend temperatures and careful moisture management. Like 618, it also readily accepts clothes dye, allowing for post-printing color customization, which is a major advantage for both functional and aesthetic projects.

The PETT Filament (T-Glase): A Clear Alternative

While often discussed alongside nylons due to its high-performance characteristics and application versatility, PETT (Polyethylene terephthalate glycol-modified) filament, widely known by the brand name T-Glase, is distinct from nylon. It is a polyester, a different class of polymer, but it shares nylon’s popularity as an advanced 3D printing material. T-Glase offers several compelling advantages, making it a favorite for specific applications. Foremost among these is its exceptional transparency, allowing for the creation of truly clear and glass-like parts. Unlike nylons, T-Glase prints at a significantly lower temperature, typically around 212°C (413.6°F), which makes it more accessible for a wider range of 3D printers and potentially reduces issues like warping that can be common with higher-temperature materials. Furthermore, T-Glase boasts excellent bed adhesion, often sticking reliably to various print surfaces without the need for extensive preparations. A significant benefit of T-Glase is its certification for use in food industries, making it suitable for printing food-safe containers, utensils, or other objects that come into contact with consumables, provided proper printing hygiene is maintained.

Essential Materials and Printer Upgrades for Nylon Printing

Printing with nylon, particularly the higher-temperature variants like nylon 618 and 645, demands more than just a roll of filament; it requires specific considerations for your 3D printer setup. The most crucial component is often the print surface. As explained in our previous articles, we highly recommend using a Garolite G11 (or G10/FR4) printing tray. This material offers exceptional adhesion for nylon, significantly minimizing common problems like warping and part detachment during printing, which are notorious challenges with nylon due to its tendency to shrink as it cools. The robust nature of Garolite also makes it durable and resistant to the higher temperatures nylon printing often necessitates.

Beyond the print bed, if you intend to print frequently with nylon or produce large nylon parts, adapting your printer’s hardware is highly advisable. The elevated print temperatures for most nylons (well above 240°C) necessitate an all-metal hotend. Standard hotends with PTFE liners can degrade and release toxic fumes at these temperatures, leading to nozzle clogs and potential health hazards. An all-metal hotend ensures reliable and safe extrusion at the required temperatures. Furthermore, upgrading to an aluminum extruder (or a geared, all-metal extruder) can provide more consistent filament feeding, which is vital for materials like nylon that can be slippery and require precise control. Similarly, a print trolley made of aluminum offers increased stability and rigidity, especially beneficial for larger prints or machines operating at higher speeds.

While many online resources advocate for the use of a heated bed for T-Glase and other PETG-like filaments, our experience has shown that it’s not always strictly necessary for T-Glase, especially when paired with a Garolite G11 plate. We have successfully printed numerous objects with T-Glase on our non-heated Garolite G11 plate, achieving excellent adhesion and flawless results without any warping or detachment issues. However, for most nylon types (like 618 or 645), a heated bed is often crucial for preventing warping by keeping the lower layers warm and reducing thermal stress. An enclosed print chamber is also highly recommended for nylon to maintain a stable, warm ambient temperature, which further minimizes warping and improves print quality.

The Versatile Dyeing Process for Nylon Prints

One of the most appealing and unique advantages of nylon filament, particularly types like 618 and 645, is its remarkable receptiveness to coloring with standard clothing dyes. This feature opens up a world of customization possibilities, allowing users to achieve vibrant, lasting colors on their 3D printed parts. The dyeing process is relatively straightforward and can be easily performed at home with minimal equipment. For those who may have missed our previous guides, here is a detailed recipe to achieve beautifully colored nylon prints:

1. Prepare the Dye Bath: Begin by bringing approximately ½ to 1 liter of tap water to a rolling boil in a pot. The amount of water may vary depending on the size of your printed object, ensuring it can be fully submerged.
2. Pre-Heat the Object: Carefully plunge your printed nylon object into the boiling water for about 5 minutes. This crucial step raises the object’s temperature, preparing its polymer structure to absorb the dye more effectively and evenly.
3. Mix the Dye: While the object is pre-heating, dilute your powdered clothing dye in a separate small amount of boiling water according to the dye manufacturer’s instructions to create a concentrated solution. Once dissolved, add this concentrate to your main pot of boiling water, stirring thoroughly to ensure an even distribution of color.
4. Dyeing Immersion: Gently place your pre-heated 3D printed object into the dye mixture. Allow the object to remain immersed for approximately 30 minutes. For deeper or more intense colors, you may extend the immersion time, checking periodically until the desired hue is achieved.
5. Rinse and Dry: After dyeing, carefully remove the object from the pot and rinse it thoroughly under warm running water. This step helps to wash away any excess dye from the surface, preventing color bleed. Once rinsed, allow your newly colored item to air dry completely.

• It is important to remember that this dyeing technique works perfectly with nylons 618 and 645 due to their specific chemical compositions. However, T-Glase (PETT) is not suitable for this type of dye. Fortunately, T-Glase is typically available in a variety of pre-colored options, allowing you to choose your desired color directly from the filament spool.

Where to Purchase Quality Nylon Filament for 3D Printing

Acquiring high-quality nylon filament is the first step towards successful nylon 3D printing. You have several options for purchasing your filament coils, whether directly from a company’s website or through a local reseller. Buying directly from reputable manufacturers like Taulman ensures you receive authentic products and often provides access to detailed technical specifications and support. However, local resellers can offer a significant advantage by saving you shipping time and costs, and sometimes even providing personalized advice. For our part, we frequently source our filament from trusted suppliers such as “imprimante 3D France” because they stock a wide variety of nylon types and are incredibly knowledgeable, offering invaluable guidance on material selection and printing parameters. When choosing a supplier, always look for companies with a strong reputation for quality filament and excellent customer service. Consider exploring different brands beyond Taulman as well, such as Polymaker’s CoPA (Copolymer of Nylon) or MatterHackers’ NylonX (carbon fiber infused nylon), to discover materials best suited for your specific projects. Reading reviews and engaging with the 3D printing community can also provide excellent insights into reliable sources.

Nylon’s exceptional combination of strength, flexibility, chemical resistance, and dyeability makes it an indispensable filament for advanced 3D printing applications. By understanding the different types available, preparing your printer appropriately, and mastering printing techniques, you can unlock a vast potential for creating durable, functional, and aesthetically pleasing parts. Embrace the learning curve, experiment with settings, and enjoy the robust results that nylon offers. Happy printing!