Dry ice blasting is an innovative, environmentally-friendly cleaning technology that uses solid particles of carbon dioxide (CO2), commonly known as dry ice, as a cleaning agent. These particles are propelled at high speed onto the surfaces to be cleaned by a pneumatic blasting system. On impact, the dry ice undergoes instantaneous sublimation, passing directly from a solid to a gaseous state, without passing through a liquid state. This creates a thermal shock to the contaminated surface, loosening particles or layers of dirt without damaging the substrate.
This process is extremely effective in removing various types of contaminants, such as greases, oils, waxes, production residues and even certain coatings, without the need for chemical solvents, water or abrasive methods. It is therefore particularly suitable for cleaning sensitive parts or in environments where the use of water is prohibited or undesirable.
The speed at which dry ice particles are propelled depends largely on the system used, as well as a number of adjustable parameters, such as pressure, air volume and nozzle type.

In addition to its advantages in terms of efficiency and environmental friendliness, dry ice blasting is also appreciated for its ability to considerably reduce the time required for cleaning.

Ce processus est extrêmement efficace pour enlever divers types de contaminants, tels que les graisses, les huiles, les cires, les résidus de production, et même certains revêtements sans nécessiter l’utilisation de solvants chimiques, d’eau ou de méthodes abrasives. Il est donc particulièrement adapté pour le nettoyage de pièces sensibles ou dans des environnements où l’utilisation d’eau est prohibée ou non souhaitable.
La vitesse à laquelle les particules de glace carbonique sont propulsées dépend largement du système utilisé, ainsi que de plusieurs paramètres ajustables, tels que la pression, le volume d’air et le type de buse.

En plus de ses avantages en termes d’efficacité et de respect de l’environnement, le nettoyage cryogénique est également apprécié pour sa capacité à réduire considérablement le temps d’arrêt des équipements industriels, puisqu’il peut souvent être réalisé sans démonter les machines ou les équipements. Cette méthode contribue également à la prolongation de la durée de vie des actifs en évitant l’usure prématurée liée à des méthodes de nettoyage plus abrasives.

Dry ice blasting dates back to the 1950s. However, it was not developed and marketed as an industrial cleaning technique until the 1980s. The method was invented and explored as an alternative to traditional cleaning techniques, which used chemical solvents, pressurized water or abrasive methods that could damage surfaces or be harmful to the environment.
The fundamental discovery behind dry ice blasting is the ability of dry ice to sublimate – i.e. to go directly from a solid to a gaseous state without passing through a liquid state – on contact with the surfaces to be cleaned. This unique property enables contaminants to be effectively removed without leaving residues, unlike traditional cleaning methods which can leave secondary waste or require additional cleaning.

The introduction of this technique has revolutionized many industries by offering a non-abrasive, water-free and environmentally friendly cleaning solution. Dry ice blasting has proved particularly useful in sectors such as aerospace, automotive, food and beverage, plastics, foundry and electronics, where the cleanliness of equipment and components is crucial, and where the use of water or solvents can pose safety, quality or environmental problems.
Since its introduction, dry ice blasting technology and equipment have evolved considerably, offering greater efficiency, improved operator ergonomics and greater adaptability to a wide range of industrial cleaning applications.

Cryogenic Cleaning: Process and Comparison with Sandblasting

Cryogenic cleaning operates in three main stages, utilizing dry ice in the form of pellets or particles:

1. Projection: The dry ice particles are placed inside a cryogenic cleaning machine, then accelerated at high speed using a jet of compressed air through a specially designed projection nozzle. This acceleration allows the particles to strike the surface to be cleaned with high kinetic energy (Ec = 1/2 mV²).

2. Thermal Shock: The impact of dry ice particles on the surface creates a thermal shock that weakens the bond between the dirt and the surface. The temperature difference between the dry ice (approximately -78.5°C) and the surface causes rapid thermal contraction of the dirt layer, making it easier to remove.

3. Sublimation: Upon impact, the dry ice transitions directly from a solid to a gas (sublimation), expanding significantly by a ratio of 1 to 400 or 1 to 700 (depending on ambient temperature). This rapid expansion helps “blow” the dirt off the surface without abrasion or damage, leaving it clean and dry, without water or solvent residues.

This process allows for effective cleaning without using chemicals, without generating secondary waste, and without damaging surfaces, making it an environmentally friendly and safe method for many industrial applications.

Comparison Between Cryogenic Cleaning and Sandblasting

Cryogenic cleaning and sandblasting are two industrial cleaning methods, but they differ in principles, cleaning media, and impact on treated surfaces:

Cleaning Media:

• Cryogenic cleaning: Uses solid dry ice particles that sublimate upon contact with surfaces.
• Sandblasting: Uses solid abrasive particles such as corundum, glass, or grit.

Mechanism of Action:

• Sandblasting: Works through mechanical abrasion, where solid particles strike the surface and physically erode or remove dirt, paint, rust, etc.
• Cryogenic cleaning: Works through thermal shock and sublimation, where the cold contact of dry ice particles with the surface creates a thermal shock that weakens contaminants before sublimation expels them from the surface.

Effects on the Surface:

• Cryogenic cleaning: Non-abrasive, does not damage the treated surface, and leaves no secondary residue, as the sublimated dry ice disperses into the atmosphere.
• Sandblasting: Potentially abrasive, can alter the texture of the surface or cause damage if improperly applied. Generates secondary waste (used abrasive particles and removed materials) that must be collected and disposed of.

Applications:

• Cryogenic cleaning: Ideal for precision cleaning, sensitive equipment, and environments where water or residues are problematic.
• Sandblasting: More suitable for removing thick coatings, rust, or preparing surfaces before painting or coating, where abrasion is necessary.

Environmental and Safety Considerations:

• Cryogenic cleaning: More environmentally friendly, reduces the risk of chemical contamination, and minimizes operators’ exposure to hazardous chemicals.
• Sandblasting: Can generate harmful dust and waste, requiring strict control measures for operator safety and environmental protection.

Conclusion

The choice between cryogenic cleaning and sandblasting depends on the type of contamination to be removed, the surface material, environmental considerations, and specific cleaning objectives. Additionally, sandblasting produces a significant amount of dust, making on-site cleaning generally impractical.

On impact with a surface, dry ice undergoes sublimation, changing from a solid to a gaseous state without becoming a liquid. This process releases carbon dioxide (CO₂), a natural component of air, which participates in essential ecological cycles such as photosynthesis. Although CO₂ is a greenhouse gas, its release in this context does not introduce chemical pollutants into the environment, integrating into natural cycles without contributing directly to global warming.

During dry ice blasting, contaminants are removed from the surface in an efficient and controlled manner. Here’s a precise and concise explanation of what happens to contaminants:
-Dry contaminants: After being loosened from the surface by the action of dry ice blasting, these particles fall by gravity. They can be collected on a specially prepared surface, such as plastic sheeting, for easy removal. Disposal is then simple, using an industrial vacuum cleaner, or by direct collection for reprocessing or appropriate disposal.
-Viscous contaminants: For more adherent substances, such as grease or oils, the cryogenic method also loosens them, but their collection requires specific planning. The process is carried out by guiding these contaminants from their initial location (point A) to a predefined collection point (point B), where they can then be further processed or cleaned, for example, using high-pressure cleaning or other appropriate methods to ensure complete removal.
This strategic approach to contaminant collection ensures that dry ice blasting does not simply move dirt from one point to another, but contributes to efficient and environmentally-friendly waste management.

Contaminant decohesion or detachment occurs at a certain energy threshold. When the decohesion threshold is below the damage threshold, it’s safe to clean. When it’s higher, you could 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, aluminum) 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 determine the feasibility of the cryogenic cleaning project.

Example of a non-recommended application:
Removal of marine-grade varnish from soft wood (pine, fir): the pressure required to remove the varnish defibers the wood.

You can clean up to three or five times faster when the equipment is hot.
The adhesion of most contaminants is weaker at higher temperatures.
Dry ice sublimates on impact, unlike sandblasting, which leaves abrasive media trapped in the interstices.
Abrasive cleaning methods are generally banned in-situ in industry.

The level of surface cooling depends on three primary factors:

a) the mass of the target surface
b) the duration of application
c) the dry ice consumption per hour

A tire mold might typically drop from 175 to 162°C during dry ice blasting.
With a very thin mold, the temperature drop may be even greater.

In the vast majority of cases, tool cooling is minimal.

Will the process create condensation?
Condensation can only occur if you cool the substrate (surface) below the dew point, which varies according to the local climate.
If you’re cleaning a hot mold, it’s unlikely that you’ll cool the mold below the dew point. Condensation is therefore rare.

The adhesion of most contaminants is weaker at higher temperatures.
Dry ice sublimates on impact, unlike sandblasting, which leaves abrasive media trapped in the interstices.
Abrasive cleaning methods are generally banned in-situ in industry.

From liquid CO₂ under high pressure. When the pressure of liquid CO₂ drops to atmospheric pressure, 50% turns into gas and 50% into dry ice.

The dry ice is then compressed into 3 mm blocks, sticks or pellets. The ice is then placed in a suitable container. Click on the following link to find out how to store solid CO2.

How are dry ice pellets made?
Pressurized liquid CO₂ is brought down to atmospheric pressure: the result is dry ice.
This snow is compressed and pushed through a die or matrix to form pellets.

The machine capable of performing this task is a pelletizer. There are 2 versions:
– hydraulic version,
– mechanical version

The first version (hydraulic) offers higher ice density, and therefore greater stripping power.
However, it is possible to work with mechanical ice without any problem.

The range of dry ice blasting applications is incredible.
A small sample of our clientele easily illustrates this: Révillon (chocolate factory), ITW (electronic boards), virbac (medical), 3s Developpement (car preparation workshop)…

Dry ice blasting is excellent for cleaning production tools in line, because masking, caulking, cooling and disassembly are not necessary. We’ve achieved outstanding results cleaning production equipment in foundries, plastics processing, the food industry, printing…
Dry ice blasting is also widely used in the nuclear industry for decontamination.