Cryogenic blasting, also referred to as dry ice cleaning, is an advanced surface cleaning and preparation technique that employs solid CO2 in the form of pellets or micro-particles. These are accelerated at high velocity by a compressed air stream.

Upon impact, the dry ice undergoes instantaneous sublimation, transitioning directly from solid to gas. This rapid phase change generates a micro- explosive effect that dislodges contaminants without without damaging the treated surface.

With its extremely low temperature of -78.5°C, dry ice blasting is particularly effective at removing coatings, oils, greases, inks, adhesives, and other surface residues. As the solid CO2 sublimates, it turns directly into gas and disperses harmlessly into the atmosphere, leaving no secondary waste behind. Unlike traditional blasting methods, there’s no media to clean up afterward; the only material left is the dislodged contaminant, which can be easily collected by vacuuming or brushing.

Applications

One of the key strengths of dry ice cleaning is its adaptability. The process can be finely adjusted to suit a wide range of applications, from delicate cleaning tasks to demanding industrial jobs.

By controlling air pressure, ice particle size, and feed rate, operators can safely treat sensitive components like soft
metal alloys, electrical wiring, and sensors. When configured for higher intensity, the same system can remove tough contaminants such as asphalt, corrosion, and welding slag with ease.

Surface preparation

Dry ice cleaning offers a reliable way to remove a wide range of surface contaminants, like oil, dust, release agents, and fingerprints, without altering or degrading the substrate. Because the process is completely dry, there’s no need for rinsing or chemical pre-treatment, making it ideal for surface preparation. Once cleaned, the part is immediately ready for painting or coating, with no drying time required.

Finishing of components

Dry ice cleaning is a safe and efficient solution for removing residues and flash from a wide range of materials, including PEEK, PBT, Acetal, Nylon, LCP, ABS, UHMWPE, Nitinol, and more. As a non-abrasive method, it preserves surface integrity and leaves no residue behind. Compared to manual techniques, dry ice cleaning delivers faster, more consistent results, ensuring improved quality and repeatability in the removal of imperfections.

How it works

Kinetic energy

The cryogenic blasting process uses the high-speed impact of dry ice pellets, which are propelled to supersonic speeds by compressed air through specially designed nozzles.

The kinetic energy from the combination of mass and velocity is transferred directly to the surface, effectively removing contaminants. This impact-driven cleaning method is similar to traditional techniques like
sandblasting or water blasting.

Thermal differential

The extremely low temperature of dry ice pellets (-78.5°C) generates a thermal effect that further enhances the cleaning efficiency.

When the pellets come into contact with the surface, the rapid temperature change creates a thermal shock, causing
contaminants to become brittle and rigid. This makes it easier for the contaminants to break off and separate from the surface, accelerating and improving the overall cleaning process.

Micro-explosions

When the dry ice pellets make contact, they sublimate, transitioning directly from solid to gas, which causes a rapid expansion that assists in removing contaminants.

The expanding CO2 gas infiltrates the microfractures and pores of the residue, generating micro-explosions that help dislodge and separate the contaminants from the surface. This effect simplifies and accelerates the cleaning process.

Supercritical CO2

Under certain temperature and pressure conditions, CO2 reaches its “critical point”, where it exhibits partially liquid properties.

In this state, with its strong solvent action, CO2 enhances cleaning efficiency, allowing for a more thorough removal of
contaminants. Moreover, due to the sublimation process, dry ice ensures that the surface is left pristine, without any damage.