Working with engineering materials for 3D printing often requires more effort than additive manufacturing from the most popular filaments such as ABS or PLA. In case of materials based on polyamides (most often PA6 or PA12), as important as the parameters of the 3D printing process is the preparation of the material before its start. Often, it is the proper storage of the filament that determines the success of the 3D printing process.
Materials based on polyamides are distinguished by strong hygroscopicity, which means that they easily bind water coming from the air. During 3D printing, as a result of increasing the temperature, the water contained in the material reacts with the polymer material and a hydrolysis reaction takes place. In practice, this means that these materials are more difficult in the 3D printing process, because the absorbed water can cause problems related to the quality of the 3D print (breaks in the layers of filaments or losses are created). Moistened material can be recognized already at the stage of 3D printing of the first layers – then you can hear the characteristic shooting of the material in the head, which is caused by water particles in the filament.
We have written about drying methods in the 3D Printing Center. Let us remind you – when it comes to drying, we can approach the problem in two ways, i.e. home or professional. The home method involves drying using an oven. Filaments should stay in the oven 1-4 hours, but the longer they dry, the better.
On the other hand, when it comes to professional applications, manufacturers of 3D printing accessories come out against them. One of the solutions available on the market is a filament dryer of the Chinese manufacturer Wanhao – Box 2.
Wanhao Box 2 – unboxing
We bought a filament dryer with a view to improve the quality of 3D prints made of nylon-based materials. The choice went on Wanhao Box 2.
What do we get when ordering Wanhao Box 2? In the box, in addition to a solid device made of black sheet metal, you will find a power cable, a plastic tube that leads the material to the 3D printer and a short instruction manual (also available in electronic version). I will reveal, however, that the operation of the dryer is very simple and does not require technical knowledge – but basic knowledge about the temperature ranges for individual types of materials is necessary.
Dryer – inside and out
Below is a download from the manufacturer:
Temperature range for selected types of filaments, recommended by the manufacturer:
In the device, the heat source is a PCB on the bottom of the device. The dryer has been enriched with a sealing layer from the inside, which prevents heat loss. There is also a strip of plastic around the door to ensure a constant temperature and low humidity environment. The device is equipped with a temperature and humidity sensor – information about these parameters is displayed on a touch screen.
Communication with the device takes place via the above-mentioned display. After startup, four pieces of information are available on the screen:
- Humidity- thanks to the sensor, the device informs us about the humidity inside the chamber. The desired level is less than 15%,
- Balance, used by the device to estimate the length of the material remaining on the spool,
- Time, remaining until the end of the drying cycle of the material.
Most of the above-mentioned parameters can be changed using the options contained in the “Settings” tab (the gear icon in the top right). The following options are available in the menu:
- Temperature – after clicking, the user sets the temperature for drying the material. The maximum temperature that can be reached is 110 ° C, but the manufacturer does not recommend exceeding 80 ° C,
- Time – before starting, the material drying time is set via the touch screen
- Balance calibration inside the device,
- Material profile settings, where you can set the filament diameter and estimated density (optional).
When the parameters are set, go back to the main screen by pressing the “Back” button in the upper left corner, then press the “Start” button. Lighting inside the device is provided by LEDs. The chamber lights up green during rest, and red during operation.
Which filaments can be dried? The spools can weigh up to three kilograms – the device is adapted to all standard filament diameters (from 1.75 to 3 mm). The dimensions of the device chamber are 39.5 x 27 x 42 cm, the maximum dimensions of the spool are 23 cm in diameter and 13 cm in width.
What does working with the device look like? Installing the filament is very easy. Place the material inside the device and eject the end of the material through one of the ports on the front or back of the device. The device is equipped with a tube that leads the material to the extruder of the 3D printer in a closed system, preventing the material from re-moistening.
At 3D Printing Center, we use Zortrax Inventure 3D printers, which, due to the insulated, heated working chamber, allow for 3D printing from high-temperature materials of high quality. The investment in a filament dryer allowed us to achieve better quality 3D prints from hygroscopic materials, such as nylon-based filaments. The device is noiseless, and thanks to its solid insulation, its external walls do not heat up, which makes it completely safe to use.
Below are photos of exemplary 3D printed nylon prints of the quality that were achieved thanks to the material dryer. Most of the prints we make are the intellectual property of our clients, so we cannot use their photos in publications on the 3D Printing Center. Below, 3D prints made of PA6 material, 3D printed on a Zortrax Iventure 3D printer.