What Are Purge Materials?
Purge materials are materials that are specially formulated to clean the internal geometry of extruders and/or aid in the transition between two print materials. Purge materials can be useful to purge filament hot ends, but they are especially useful with Gigabot X's pellet extruder due to the large amount (~20g) of plastic contained in the pellet extruder.
Applications of Purge Materials
Purge materials are useful for the following:
- Cleaning contaminants from the extruder
- Unclogging nozzles
- Transitioning between materials with drastically different printing temperatures (>30C)
- Transitioning between materials with drastically different viscosities at the purging temperatures
- Cleaning previously extruded material from the extruder
- Cleaning previously extruded colorants from the extruder to aid in color transitions
When switching an extruder from one material to another, the new material can be used to push out the previously used material for both filament and pellet extruders. However, for the Gigabot X pellet extruder, a purge material can be used as an intermediary between the two materials to aid in the material transition, as well as address some of the scenarios listed above. Instructions for this process can be found in the Loading and Changing Gigabot X Materials article.
Recommended Purge Materials
At re:3D, we use:
- Dyna-Purge F2 Pellets: This material maintains a good viscosity over a range of temperatures, allowing transitions between drastically different materials.
- Dyna-Purge F2 Purge Sticks: Dyna-purge produces purge sticks for use with filament extruders.
- ASA Clean’s purge material with glass fiber: This material gently scrubs the internal geometries of the Gigabot X pellet extruder to remove carbonized buildup.
Purge materials are typically formulated for specific applications, print temperatures, and materials, and we recommend exploring purge materials specific for your 3D printing application.