Dry ice blasting is a non-abrasive process that uses compressed air to shoot dry ice pellets at a surface. Unlike abrasive blasting, it does not leave blasting residues behind. Instead, the dry ice turns into gas and goes into the venting system. With this method, there is no need to clean up secondary waste from abrasive materials.
It is used in various industries, including the automotive, aerospace, power, pharmaceutical, electrical, electronical and food industries.
While the method is praised for its advantages, it also comes with several disadvantages. In this article, we’ll go over the different aspects of dry ice blasting to better understand when it’s worth it, and which alternatives to consider.
Dry Ice Blasting Applications
Dry ice blasting is ideal to clean production line equipment or sensitive components. For example, it is used to clean painting equipment, electronic components, dies, and molds. At high velocity, the blasting media can remove contaminants like grease, surface rust, and paint from all types of substrates, whether they are made of plastic, rubber, or metal.
Dry ice blast cleaning can also prepare surfaces for painting and coating. But since it is non-abrasive, it does not generate a texture that improves adhesion, making it less efficient than other cleaning methods like sandblasting, chemical cleaning, and laser cleaning.
What is Dry Ice?
Dry ice is the solid form of carbon dioxide (CO2). It is obtained by bringing carbon dioxide at -109.3°F (-78.5°C), which is the temperature at which it freezes and turns into solid.
Disadvantages of Dry Ice Blasting
1. High Consumable Costs
Dry ice blasting comes with high consumable and operating costs, including recuring costs for dry ice pellets and compressed air. It is also an energy-hungry technology, so it is very expensive in terms of energy consumption (air compressors are among the highest recurring expenses in factories).
2. Dry Ice Shortages
Dry ice, like all consumables, needs to be stored in sufficient quantities to keep the production line running. This puts manufacturers at risk if there is a shortage or a supply line disruption, which is increasingly likely with the current global situation. In Europe, the rising cost of natural gas in 2022 has caused dry ice shortages. A similar problem happened in the US in 2022 due to a shortage of CO2.
At normal atmospheric pressure, dry ice pellets go from solid to gas when they unfreeze, producing carbon dioxide gas. This reaction is called sublimation, and it happens when pellets hit the surface during the blasting process. Dry ice can also naturally sublime in your storage units or during transport.
If carbon dioxide is allowed to build up, workers can lose consciousness or even die from asphyxia. This is particularly dangerous in small rooms. Explosions can also occur in closed containers due to pressure buildups.
Making sure you have a good ventilation system in relevant areas is essential to safety.
4. Personal Protective Equipment (PPE)
The blasting process generates intense noise levels, sometimes reaching 115 dB during cleaning. Hearing protection is highly recommended to prevent permanent damage to hearing.
Workers handling dry ice also need to wear insulated gloves, as dry ice pellets can burn the skin (frostbites). Additional PPE like safety glasses and face shields may be needed, depending on how dry ice is handled.
5. Not as Environmentally Friendly as Claimed
Dry ice blasting is often advertised as environmentally friendly. The argument is that dry ice blasting is made from reclaimed CO2 and that the cleaning process does not add CO2 to the atmosphere.
In truth, dry ice is made from the CO2 harvested when refining ammonia, ethanol, petroleum, or other chemicals—processes that are far from good for the environment.
The cleanliness of the process also depends on how dry ice users manage the CO2 gas generated during blasting. If the gas is vented into the atmosphere, then the process is not clean. If the gas is captured, frozen, and turned into new dry ice pellets to be used again, then the process is greener.
This can be done by adding a recovery unit and a pelletizer to your manufacturing process. But this equipment is expensive, and the conversion rate from liquid CO2 to dry ice is ∼40%, which means that ∼60% is released into the atmosphere. The high energy consumption of air compressors and storage tanks also adds to the ecological footprint, especially if the energy doesn’t come from a renewable source. Finally, dry ice pellet delivery trucks add an additional layer of pollution.
Dry ice blasting is certainly cleaner than alternatives like chemical cleaning, but it’s wrong to call it ecofriendly. It adds CO2 to the atmosphere and could be replaced by cleaner technologies like laser cleaning.
Laser Cleaning: An Alternative to Dry Ice Blasting
Laser cleaning can be used to remove contaminants from surfaces with the sheer power of light, but it is limited to metal surfaces. The process can remove all types of contaminants, including oil, dust, corrosion, oxides, electrolytes, and coatings.
Compared to dry ice blasters, laser cleaners are faster, more precise, less noisy, easier to integrate, cleaner for the environment, and have lower operating & maintenance costs.
Unlike dry ice cleaning, laser cleaning can generate a texture that improves adhesion. Lasers are used to prepare or clean surfaces for applications like:
- Coating and painting
- Thermal spray coating
Laser cleaning solutions include automated and manually operated machines. If you want to learn more, contact our laser experts today.