What is the prime/deprime procedure?

For the Ultimaker S5 Pro Bundle, extra procedures have been implemented to ensure consistent and reliable filament handling. At the start and end of each print job, some material is purged through the nozzle. The prime/deprime procedure adds time to the total print job duration, but it ensures reliable loading and unloading as this fixed routine yields a reproducible filament tip shape, which is crucial for passing through the Material Station and Ultimaker S5.

This article explains exactly what happens during these procedures, and why this is necessary.

Loading material

With the Material Station, the filament is loaded into the Ultimaker S5 without interaction of the user. Often, print jobs are started remotely via Ultimaker Digital Factory and there is no operator near the Ultimaker S5 Pro Bundle. Whilst traveling through the Pro Bundle, the filament tip needs to be able to smoothly travel through the various components of the extrusion train. Therefore, it is important to ensure that the materials are loaded correctly and that the material extrudes well from the nozzle.

Prime procedure

If the previous print was made with materials that have very different properties than the materials required for the next print, such as higher or lower printing temperatures, or contrasting colors, this may cause print quality issues. To prevent these issues, the Ultimaker S5 Pro Bundle initiates the prime procedure.

The prime procedure ensures that:

  • The previous material is purged from the print core
  • The new filament is properly primed and ready for extrusion on the first layer


During the prime procedure, the print head will move to the side of the printer, and material is purged through the nozzle. Extrusion is done in several sequences. In between, the print head moves to a different location; this ensures that the extruded material falls down and does not remain stuck to the nozzle. Doing one single long purge would be faster, but the resulting very long string can get caught around the Z spindle or end up on the print bed.

Note: It is recommended to regularly remove these strands from the inside of the printer.

Once this procedure is finished, the Ultimaker S5 Pro Bundle will continue with the next step of print preparation: active leveling. Thanks to the prime procedure, the tip of the nozzle will be clean. Therefore, no residual material on the nozzle can interrupt the leveling process or disturb the readings.

Deprime procedure

At the end of a print, or when an end of filament has been detected, the Ultimaker S5 Pro Bundle will initiate the deprime procedure. The goal of this process is to ensure that the material will unload back into the Material Station with a clean tip and no strings.

When a print is finished, the print head will again move to the side of the printer and purge some material. This purge is to eliminate print job-specific influences, such as retractions, flowrates, or (user-set) temperatures. After this purge, which stabilizes the process, the deprime starts with a material-specific retract, followed by a cooldown period.

The first step, in which the filament is pulled back a short distance at a high temperature, creates a thin strand of material inside the hot-end. The print core will then cool down to the break temperature. The break temperature is a material-specific property. Upon reaching this temperature the filament is retracted further, breaking off the solid filament from inside the print core. The material will now (since firmware 5.8.0) wait in this parked position above the print head for two hours (most materials, but 60 hours for PVA), or until the next print job is started. When the timer runs out, or if the next print job requires different materials, the filament will be fully unloaded back to the Material Station.

Note: The parameters for the prime and deprime procedure are material specific. Ultimaker has tested and optimized these parameters for all Ultimaker materials. For third-party materials, we rely on our Material Alliance partners to correctly update their material profiles in the Marketplace. When a material is optimized for the Material Station, the compatibility is shown in the Marketplace. Not selecting the correct material type on the Ultimaker S5 Pro Bundle may cause issues with the prime and/or deprime procedures, such as failing to unload the material.

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