Dry ice blast cleaning, also known as cold spray, uses compressed air as the power and carrier, and dry ice particles as accelerated particles, which are sprayed onto the surface of the object to be cleaned through a special jet cleaning machine, using high-speed moving solid dry ice Energy conversion such as momentum change (Δmv), sublimation, and melting of particles quickly freezes dirt, oil, residual impurities, etc. on the surface of the object to be cleaned, thereby condensing, brittle, and peeling off, and is simultaneously removed with the airflow. It will not cause any damage to the surface of the object to be cleaned, especially the metal surface, nor will it affect the finish of the metal surface.
The specific cleaning process includes: low-temperature freezing peeling, purging peeling, and impact peeling.
cryogenic peeling
When dry ice particles at -78.5°C act on the surface of an object to be cleaned, they first freeze and embrittle the dirt. The dirt ruptures on the surface to be cleaned and changes from a viscoelastic state to a solid state. The brittleness increases and the viscosity decreases, making the adsorption force on the surface decrease sharply, while the surface area increases, and some dirt can be automatically peeled off.
purge stripping
In an environment where compressed air is used as power, it produces shearing force on the embrittled dirt, causing mechanical fracture. Due to the large difference in low-temperature shrinkage ratio between the dirt and the surface of the object to be cleaned, stress concentration occurs at the contact surface. Dirt is peeled off under the action of shear force.
Impact peeling
When the high-speed dry ice particles collide with the increased dirt surface, the above-mentioned kinetic energy is transferred to the dirt, overcoming the reduced adhesion force, and the resulting shear force causes the dirt to be swept away with the airflow, achieving The purpose of removing dirt.
