FAQ

Generally speaking, dry ice blasting is a combination of 3 effects:
Kinetic effect:
When dry ice particles hit a surface at the speed of sound, the contaminant cracks.
Thermal effect:
The low temperature of dry ice (-78.5 ° C) makes the contaminant fragile, it peels off: the bond between the coating and the underlying surface is reduced.
Explosive effect or sublimation:
Dry ice is projected using compressed air and dry ice blasting machines.
Dry ice penetrates into the cracked and peeled contaminant, and immediately sublimes (change from solid to gaseous state in a ratio of 1 to 400): an “explosive effect” occurs and blows the contaminant off the surface.
By blasting dry ice particles onto hard contaminants such as paint, varnish… the process produces a compression wave between the coating (contaminant) and the substrate (surface). This wave has sufficient power to break the cohesion and detach the contaminant, which by gravity ends up on the ground.
For malleable or viscous contaminants like oil, grease or wax, the cleaning action is a process comparable to high-pressure cleaning. As the particles hit the surface, they are compressed and flattened, producing a high-speed 360 ° spray that cleans surfaces.

Sandblasting works like a chisel, but dry ice blasting works like a spatula. The sand cuts or chisels the contaminant, while the dry ice lifts it after loosening it.
In addition, sandblasting generates a lot of dust, and it is generally not possible to clean in place.

Dry ice sublimates on impact (changing from a solid to a gaseous state or sublimation) and returns to the atmosphere as carbon dioxide (CO₂).
CO₂ is a naturally occurring element that makes up less than 0.04% of our atmosphere.

It is transferred from an unwanted place to a place where it can be more easily “taken care of”.
The dry contaminants fall on the ground (or on a plastic sheet): one can then use a broom, a vacuum cleaner or place everything in a container for reprocessing.
For viscous contaminants such as grease, it is necessary to act methodologically, such as high-pressure cleaning. Cryogenic firing is carried out from point A to point B, while guiding the contaminant towards the pickup point (B).

The decohesion or detachment of the contaminant takes place at a certain energy threshold. When the decohesion threshold is lower than the damage threshold, you can clean without danger. When it is higher, you might damage the surface.
The hardness of dry ice is comparable to that of chalk.
Since the majority of parts cleaned with CO₂ are production equipment (cast iron, steel, stainless steel, aluminium) there is no damage. You can also clean more fragile substrates (surfaces) such as plastics, electronic boards, monuments, copper, fabrics, etc.
A preliminary test will make it possible to define the feasibility of the dry ice cleaning project.

Example of application not recommended:
Stripping a marine-grade varnish on soft wood (pine, fir): the pressure necessary to loosen the varnish from the wood.

You can clean up to three or five times faster when the equipment is hot. Adherence to the majority of contaminants is lower at higher temperatures. The dry ice sublimes at the time of impact, unlike the sandblasting that leaves the abrasive media trapped.
Abrasive cleaning methods are generally banned on-site in the industries.

This is unlikely, but it depends on the mass of the target object.
Heavy moulds, for example, will not be damaged at all because the temperature drop is insignificant compared to the mass of the mould.
With thin, critical tolerance substrates, you may need to do some testing to determine if the drop in temperature will affect the structure of the surface.

The level of surface cooling depends on three primary factors:
a) the mass of the target surface
b) the duration of application
c) dry ice consumption per hour

A tire mould would typically drop 175 to 162 ° C during the application of dry ice blasting.
With a very thin mould, the temperature drop may be greater.
The cooling of the tool is in the great majority of cases minimal.