Instructions for Use IFU for ultrasonic cleaning of 3D resin prints

1. Introduction

Ultrasonic cleaning is an effective method for removing uncured resin from 3D printed parts, especially those with intricate details or internal cavities. By utilizing high-frequency sound waves, ultrasonic cleaners can clean parts more thoroughly and efficiently than manual methods.

2. Equipment and Materials

  • Ultrasonic Cleaner: Select a unit with a capacity suitable for your largest prints. For small to medium-sized prints, a 2–6 liter cleaner is adequate; larger prints may require a 10–30 liter unit.

  • Cleaning Solution: Use water for effective resin removal. Alternatively, specialized resin cleaning fluids can be used. Avoid the use of isopropanol IPA since it poses safety and performance concerns.

  • Containers: If using cleaning fluids, place the resin print in a container filled with the chosen cleaning fluid, and then submerge this in the ultrasonic cleaner filled with water. This method minimizes the risk of contaminating prints.

3. Cleaning Procedure

  1. Preparation:

    • Remove the print from the build plate and eliminate any support structures.

    • Perform a preliminary rinse with the chosen cleaning fluid to remove excess resin.

    • Relatively high polarity non flammable cleaning fluids, such as Cleaning Fluid Bio, are recommended for ultrasonic cleaning of durable prints. Water can be used with water washable prints.
    • If using IPA, despite it is not recommended to eliminate the risk of fire and explosions and the decrease of mechanical strength of prints, place the resin print in a sealed bag or container filled with IPA, and then submerge this in the ultrasonic cleaner filled with water. This method minimizes the risk of fire associated with using flammable solvents directly in the cleaner. 

  2. Ultrasonic Cleaning:

    • Place the print in a container with your chosen cleaning fluid: Cleaning Fluid Bio is recommended.

    • Submerge the container in the ultrasonic cleaner filled with water.

    • Set the cleaner to operate at room temperature (20–22°C) to prevent warping.

    • Run the cleaner for 4 minutes. For prints with complex geometries, an additional 2-minute cycle may be necessary. Longer times are required with biocompatible prints to eliminate leachables and extractables.

  3. Post-Cleaning:

    • Remove the print from the container and allow it to dry completely.

    • Inspect the print for any residual resin; repeat the cleaning process if necessary.

4. Special Considerations

  • Hollow Prints: Ensure that hollow prints have adequate drainage holes to allow cleaning solution to reach internal surfaces. Orient the print to facilitate air escape and solution ingress.

  • Delicate Features: For prints with fine details, use the gentle mode on the ultrasonic cleaner to prevent damage.

  • Solution Maintenance: Monitor the clarity of the chosen cleaning fluid; replace it when it becomes cloudy or after cleaning approximately 20–30 prints to maintain cleaning effectiveness.

  • Biocompatible prints: Biocompatible prints require maximum elimination of leachables and extractables with water and specific cleaning fluids. For more info read: Instructions for Use IFU for biocompatible resins

5. Safety Precautions

  • Avoid placing flammable solvents like IPA directly into the ultrasonic cleaner's tank. Always use the container-in-water method to mitigate fire risks. 

  • Operate the ultrasonic cleaner in a well-ventilated area away from heat sources and open flames (if IPA is used despite its use is not recommended) 

  • Regularly inspect and maintain the ultrasonic cleaner to ensure safe operation.