Cleaning of 3D prints

3D printed resins are often cleaned with isopropanol (IPA) or ethanol. For many photopolymer materials, alcohol-based cleaning can significantly reduce mechanical performance, weakening parts and increasing fragility. For safer post-processing routes, discover our processing auxiliaries and cleaning products, designed to increase safety and biocompatibility without chemically attacking 3D prints.

For most applications, correct use of these post-processing auxiliaries is often sufficient for cleaning our biocompatible resins used in many dental and biomedical workflows.

Sterilization methods

The most commonly used sterilization methods for medical devices include:

• Steam autoclaving
  Steam autoclaving is fast and cost-effective, and is widely used in dental and biomedical applications. Typical cycles operate between 120°C and 135°C for up to 30 minutes. Printed parts with Tg and HDT below ~120°C may deform. Steam exposure can also increase moisture uptake; dehydrating sterilized parts in an oven is recommended to remove trapped humidity. Residual uncured species and reaction byproducts may leach out during sterilization and can affect biocompatibility.
• Low-temperature hydrogen peroxide gas plasma
  Hydrogen peroxide gas plasma sterilization is suitable for resins with relatively low Tg and HDT, as the process typically runs at 37–44°C for approximately 75 minutes. It uses concentrated hydrogen peroxide and electromagnetic fields to form a gas plasma, generating reactive species and UV energy to inactivate microorganisms.
• Ethylene oxide (EO)
  Ethylene oxide sterilization at room temperature is commonly used for low Tg/HDT materials to avoid deformation by heat and steam. EO is effective against microorganisms, but it may react with the surface of printed parts (alkylation) and can leave residues that may impact mechanical performance and biocompatibility if not properly managed.
• Irradiation
  Electron-beam and gamma irradiation can sterilize 3D printed parts, but may induce color and mechanical property changes, such as:
  • Color shift from clear to greenish or pink
  • Color shift from white to brownish
  • Embrittlement and rigidity increase (Young’s modulus), or softening with increased elongation

  For more information, see: Polymer Materials Selection for Radiation-Sterilized Products .

Conclusions

• The device manufacturer is responsible for sterilization, for certification of biocompatibility, and for the final mechanical performance of the selected cleaning and sterilization workflow for the intended device and use conditions.
• Aesthetics, mechanical performance, and biocompatibility depend on the post-processing and sterilization processes applied.
  
• Learn more about biocompatibility of our 3D resins and about certification of biomedical devices and food and pharma packaging.
• Reference on performance and testing context: performance properties of our 3D resins.