Why does filament need drying?

Plastic absorbs moisture due to its porous nature, allowing water molecules to penetrate its structure over time. Humid filament can cause a myriad of printing issues, including decreased adhesion between layers, printing artifacts such as filament swelling, stringing and bubbling, extrusion inconsistencies, and even filament degradation within the printer's hotend.

Image 1: 3D printing with humid filament. Source: Drywise.

When filament storing methods are not sufficiently good or the filament in question is an advanced and very hygroscopic material (such as PA, PVA, BVOH or TPU), filament drying solutions must be employed prior to printing to ensure optimal print quality. For polymers that demonstrate a high tendency to absorb moisture from the surrounding air, the manufacturer usually lists filament pre-drying as a requisite.

Consequences of using humid filament

Using dry filament is essential for several reasons. Firstly, from a practical standpoint, it helps prevent extrusion problems such as clogging, and in consequence the premature degradation of the printer's extrusion system, ensuring its longevity and optimal performance.

Video 1: Close look at dry vs. humid filament. Source: Recreus.

Secondly, dry filament is crucial for maintaining aesthetic integrity, particularly in prototyping and design projects where precise detailing and surface finish are paramount. Lastly, for engineering applications requiring functional parts to meet specific criteria such as dimensional stability and accuracy.

Image 2: How different levels of humidity affect the strength of parts 3D printed with PA. Source: BCN3D.

Using dry filament is imperative to ensure the components fulfill their intended functions effectively. Technical parts 3D printed with humid filament may be more prone to breakage, lose special properties, or not fit into bigger assemblies due to changes dimensions caused by surface imperfections. 

When home drying methods fail

While there are several methods available for drying filaments at home, including using low-temperature ovens, food dehydrators, or DIY filament dry boxes with desiccants, these approaches may not always yield accurate or advantageous results. Achieving optimal filament drying, particularly with hygroscopic or advanced filaments, necessitates meticulous management of temperature and humidity levels to prevent overheating or filament damage.

Image 3: Drying filaments in a home oven may destroy the spool. Source: Magigoo.

Furthermore, household ovens and dehydrators may lack uniform heat distribution, leading to inconsistent drying outcomes. In contrast, professional-grade filament dryers provide superior control and ideal conditions for effectively drying filaments, thereby enhancing print quality and minimizing the risk of printing defects.

Professional filament dryers

When choosing a professional filament dryer, it's essential to consider several key factors. Firstly, the material needs must be assessed (standard or advanced filaments) to ensure that the dryer is compatible with the required drying parameters and that it offers the right spool capacity. Secondly, it must be decided whether a universal filament dryer is the right choice or a brand- or printer-specific dryer would be a more beneficial option. Thirdly, the user must consider if offline drying is adequate or inline drying capabilities are required for direct feeding and simultaneous printing.

Image 4: Various types of filament dryers. Source: F2P.

Another factor to consider is the drying method employed, since desiccant-based dryers (passive drying via aborption) may be more affordable but dryers that use hot air circulation as the drying method (active drying) tend to deliver better results faster. Lastly, many professional filament dryers come with additional features like sensor, automated controls, alarms or add-ons to enhance efficiency and elevate the user experience in professional environments. Taking all the above factors into consideration when choosing the filament dryer ensures selecting a dryer that meets the demands of professional 3D printing setups and offers the adequate performance to match the most often used 3D printing materials and workflow characteristics.

Top 5 filament dryers

In this rundown we will discuss in detail the features of top 5 professional filament drying solutions to help you choose the right filament dryer for your workflow.

Sunlu filament dryers

The FilaDryer S2 by Sunlu stands as an exceptional solution for drying a diverse array of materials, ranging from PLA, ABS, and PETG to highly moisture-absorbent options like BVOH and PA. Its accommodating design supports 1 spool (Ø210 x 85 mm) and filament diameters of 1.75 mm, 2.85 mm, and 3.00 mm. With pre-configured parameters for common materials and the flexibility to customize settings, users can effortlessly optimize their drying process.

Video 2: The FilaDryer S2 filament dryer by Sunlu. Source: Sunlu.

Direct feeding capability streamlines the workflow, allowing dried filament to seamlessly transition into 3D printing projects. The circular hot air drying mechanism, controlled via an intuitive 4.6-inch LCD touchscreen, ensures even heat distribution, maximizing thermal efficiency while maintaining a maximum drying temperature of 70 °C. Sunlu's commitment to innovation, recognized with a silver award at the 2022 Muse Design Awards, is evidenced by the FilaDryer S2's sleek design with anti-slip feet that also prevent heat accumulation.

Video 3: The FilaDryer S4 filament dryer by Sunlu. Source: Sunlu.

The FilaDryer S4 is a cutting-edge filament dryer designed for a wide range of materials, including PLA (also wood/marble/silk), ASA, ABS, PA, PC, PETG, HIPS and TPU. Its smart design maximizes space, accommodating up to 4 spools efficiently. With a powerful PTC heating element and triple-fan setup, it's approximately seven times more potent than its predecessor, the FilaDryer S2, boasting a heating power of 330 W. This ensures rapid heat-up, drying, and substantial energy savings. Additionally, it features heat-resistant PTFE tubing and an automatic humidity control system, making it perfect for daily printing with multiple materials or 3D printers.

R3D filament dryer

The D1 filament dryer by R3D is a compact, efficient, and silent device engineered to deliver 360º omnidirectional heating up to 70 °C. Its standout feature is its wall-mountable design, which minimizes filament path curvature, thereby reducing the risk of filament breakage.  

Image 5: The D1 filament dryer by R3D. Source: F2P.

Ideal for a variety of filaments, including PLA, ABS, PETG, PA, TPU, and ASA, the D1 offers automatic settings for many materials. It conveniently accommodates one 1 kg spool of filament with diameters ranging from 1.75 mm to 3.00 mm. Equipped with an LCD screen and backlight, the D1 ensures user-friendly operation and monitoring of drying parameters.

PrintDry filament dryer

The PrintDry Pro3 filament dryer offers optimal drying solutions for a variety of materials, including PLA, ABS, PETG, PA, PVA, TPU, ASA, and PP. With a drying temperature capacity of up to 85 °C and six preset options, users can easily tailor the drying process to their specific filament requirements. Its digital timer with auto shut-off functionality ensures convenient and precise control over drying times. The dryer accommodates two spools, with the option to expand storage capacity through separately available extensions for 2 small spools or 1 large spool.

Image 6: The PrintDry Pro3 filament dryer. Source: MatterHackers.

Featuring a double-wall structure for enhanced insulation and a spool adapter included, the PrintDry Pro3 is designed to maintain consistent temperatures using a closed-loop system. This intelligent design ensures efficient heating control, with the heating unit automatically turning on or off based on preset temperature thresholds, resulting in optimal filament drying performance.

Drywise filament dryer

The Drywise filament dryer, from the creators of the renowned Magigoo adhesive, Thought3D, offers active, desiccant-based inline drying for industrial desktop 3D printer users, especially those working with engineering filaments like PA, ABS, TPU, and PET. The list of specific compatible materials is updated regularly and available on the manufacturer's website. Available for either 1.75 mm or 2.85 mm filaments, Drywise is compatible with any spool size and format since the spool is not present in the machine for drying. With a quick pretreatment time of just 50 minutes before printing begins, Drywise optimizes the printing process by drying only the section of filament being used at any given time.

Video 4: The Drywise filament dryer by Thought3D. Source: Drywise.

Pre-calibrated settings tailored to specific materials further streamline operation. Its inline functionality eliminates the need for extensive pre-printing drying, reducing moisture re-absorption risks. A guided input and output port ensure seamless filament feeding. Additionally, an optional filament preheater add-on aids in pre-drying highly hygroscopic materials. Equipped with smart sensors to prevent overheating and overdrying, a user-friendly interface, comprising a 4.3" touch panel, LED lights, and auditory signals, the Drywise filament dryer is a great example of safety, efficiency and usability.

Mass Portal filament dryers

The FD1 filament dryer by Mass Portal offers comprehensive filament management, featuring drying, conditioning, and feeding capabilities for 1.75 mm, 2.85 mm, and 3.00 mm filaments. Utilizing a rotating desiccant disc, a unique solution from Mass Portal, it efficiently dries a wide array of materials, including ABS, Nylon, PC, PET(g), PMMA, TPU, and PA CF. Equipped with inbuilt overcurrent and overheating protection, an open/close door sensor, and a fully insulated metal chassis, it ensures safety during operation.

Video 5: The FD1 filament dryer by Mass Portal. Source: Mass Portal.

The FD1's features include a glass front door, illuminated chamber, touchscreen interface, carrying handle, and replaceable HEPA and active carbon filters. It integrates seamlessly with the advanced FabCloud software, enabling remote monitoring and custom profile creation. With USB, Ethernet, and WiFi connectivity, the FD1 offers versatility and convenience for filament management in 3D printing applications.

Image 7: The industrial FD5 filament dryer by Mass Portal. Source: Mass Portal.

The FD5 filament dryer by Mass Portal shares the innovative rotary desiccant renewal and direct feeding features of the FD1, along with the pre-configured settings, USB, Ethernet, and WiFi connectivity, and access to the advanced FabCloud software. With an extended drying temperature capability of up to 150 °C ideal for high-performance polymers such as PEEK or PEI, the FD5 filament dryer is perfect for demanding applications.

Image 8: The chamber of the FD5 filament dryer. Source: Mass Portal.

With a larger capacity suitable for one 5 kg spool or two 3 kg spools, the FD5 facilitates large-format or batch 3D printing sessions with materials ranging from PLA, ABS, Nylon, PC, PET(g), PMMA, TPU or PA CF to advanced options like PEI and PEEK. Inspired by industrial injection molding technology, the FD5 employs a fascinating 9-step drying process: ambient air is filtered and pre-dehumidified as it enters the chamber, heated, and circulated to absorb moisture from the filament, then evacuated and used to partially regenerate the desiccant before exiting through filters. This sophisticated process ensures precise moisture control independent of the surrounding environment, optimizing filament quality for superior printing results.

Choosing the perfect dryer

This table serves as a comprehensive summary of all the essential parameters pertinent to filament dryers, streamlining the process of selecting the most suitable option. It encompasses crucial factors such as capacity, compatible diameters, and materials, alongside detailing the drying method employed, the range of temperatures utilized, and the corresponding drying times. Furthermore, it highlights any extra features that may distinguish one dryer from another, providing users with a clear and concise overview to facilitate informed decision-making in choosing the optimal filament dryer for their needs.

Table 1: An overview of filament dryers. Source: F2P.

Whether you engage in hobbyist printing with standard polymers or pursue advanced applications with engineering materials and superpolymers, and irrespective of the brand of filament or 3D printer utilized, as well as the nuances of workspace setup and workflow, this table offers an invaluable overview of the filament dryers available on the market.