Ice blasting (also known as wet-ice blasting, frozen-ice blasting, or water-ice blasting) is a form of non-abrasive blasting where

frozen water Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opa ...

particles are combined with

compressed air Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, and o ...

and propelled towards a surface for cleaning purposes. Ice is one of several different medias commonly used for blast cleaning. Another common method of non-abrasive blasting is

dry ice blasting Dry-ice blasting is a form of carbon dioxide cleaning, where dry ice, the solid form of carbon dioxide, is accelerated in a pressurized air stream and directed at a surface in order to clean it. The method is similar to other forms of media bla ...

, which uses solid carbon dioxide as a blast media. Other forms of

abrasive blasting Sandblasting, sometimes known as abrasive blasting, is the operation of forcibly propelling a stream of abrasive material against a surface under high pressure to smooth a rough surface, roughen a smooth surface, shape a surface or remove su ...

use mediums such as

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

, plastic beads, and

baking soda Sodium bicarbonate (IUPAC name: sodium hydrogencarbonate), commonly known as baking soda or bicarbonate of soda, is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cation ( Na+) and a bicarbonate anion ( HCO3−) ...

History

The first ice blasting patent was filed in 1952, as a “means and methods for cleaning and polishing automobiles ” (US patent 2699403). In 1959, Unilever filed a patent for using ice blasting to remove meat from bone.

Method

Ice blasting is a method of industrial cleaning that uses a continuous supply of compressed air to accelerate suspended ice particles to high speeds. The ice particles are ejected from a nozzle toward the surface to be cleaned. The ice particles impact the

contaminant Contamination is the presence of a constituent, impurity, or some other undesirable element that spoils, corrupts, infects, makes unfit, or makes inferior a material, physical body, natural environment, workplace, etc. Types of contamination Wi ...

covering the surface, breaking it apart and knocking it off. Ice blasting uses significantly less water than pressure washing (around 10% of the water). As a result, one of its main advantages is easier containment compared to other industrial cleaning technologies. A wet spray forms around the surface during blasting, helping to capture airborne particulates and drag them downwards. Blasted off contaminants collect in a slushy pile beneath the blast zone. This means that, compared to other cleaning technologies, a more minimal containment setup can be used. In addition, much less waste is produced, since the minimal leftover slush melts and evaporates, leaving behind only the blasted off contaminant for disposal. Since ice blasting results in less airborne contaminants than other blasting media and requires simpler containment setups, it is often used for removing hazardous substances, such as

lead paint Lead paint or lead-based paint is paint containing lead. As pigment, lead(II) chromate (, "chrome yellow"), lead(II,IV) oxide, (, "red lead"), and lead(II) carbonate (, "white lead") are the most common forms.. Lead is added to paint to acceler ...

asbestos Asbestos () is a naturally occurring fibrous silicate mineral. There are six types, all of which are composed of long and thin fibrous crystals, each fibre being composed of many microscopic "fibrils" that can be released into the atmosphere b ...

, or for blasting in enclosed/indoor environments. It is also often used in areas where water is scarce since it requires much less water than pressure washing. Ice blasting cleans in three main stages: *Bulk Removal: The stage where major contamination is first removed. Speeding particles of ice impact the surface, breaking apart the layer of contaminant and knocking it off. Since ice is a solid, it can deliver a much higher impulse force on impact than liquid water. *Detail Cleaning: The stage where ice slides along the surfaces of the part. This provides a mechanical agitation that scrubs and polishes the surface, removing minute quantities of the remaining contamination from the surface. By definition, scrubbing means two solids moving relative to each other under applied pressure. Water as a blast-cleaning agent therefore cannot offer this property. *Final Rinse: The removed contamination is rinsed away. Some of the ice melts on impact to form water, which washes over the surface. Water is considered the universal solvent and so dissolves and washes away remaining contaminants. These cleaning mechanisms often leave metal surfaces much shinier than other cleaning methods.

Applications

Ice blasting can be used to clean many different surfaces and has applications across multiple industries. The minimal water usage and the absence of chemical ingredients provides a relatively eco-friendly cleaning solution. Also, ice blasting does not damage the surfaces being cleaned.

Lead paint/Asbestos Removal

In paint-stripping, ice blasting is used to overcome the cohesive bond of the coating. Depending on the paint or makeup of the bond, some coatings cannot be cleaned. Ice blasting is useful in removing lead paint, as it poses the least danger. Ice blasting has the lowest level of airborne contaminants for blasting technology in removing lead paint. Ice particles produce a blast mist, which helps to suppress dust or airborne particulates to minimize unintended dispersion. This characteristic of ice blast is of particular interest in terms of worker health and safety in the abatement process of asbestos and lead-based paint.

Molds

Ice blasting technology allows for thorough and efficient cleaning for molds in a wide range of industries, including

tire manufacturing Pneumatic tires are manufactured according to relatively standardized processes and machinery, in around 455 tire factories in the world. With over 1 billion tires manufactured worldwide annually, the tire industry is a major consumer of natura ...

, automotive production, and packaging plants. Since the method is non-abrasive, the cleanings will not damage molding surfaces. Ice blasting can be used on hot or cold molds, reducing the downtime in production facilities. Ice sublimates on impact, so entrapment of the blasting media is not a concern. Grit entrapment is the reason abrasive media such as sand cannot be used to clean online.

Deburring

In some applications, material removal is achieved without abrasion. This is particularly common in the removal of fine burrs arising from machined aluminum such as automatic transmission components, and small flashings from castings. In these situations, the metal is loosely attached to the parent metal and hence can be readily displaced by the momentum of the blasting agent. No abrasive erosion takes place as the remaining metal does not exhibit a smooth or rounded edge.

Oil/Grease

The scrubbing pressure of ice particles can be up to 300 bar. In many applications in oil and grease removal, ice blasting can produce essentially oil-free surfaces. In some metal finishing operations, ice blast has been shown to be superior to conventional acid pickling.

Rust

Ice blast is not abrasive. It does not remove strongly adherent tough coatings as abrasive media would. However, ice blast can remove coatings with weakened adhesion resulting from coating defects or corrosion. As an ice particle impacts on a coating, it causes a compressive stress on the coating and target system. On impact, the ice particle melts. The coating and target system under compressive stress will react in the opposite direction, producing a tensile stress. When the tensile stress exceeds the coating adhesion force, coating lifting takes place. The lifted coating is in the force of chips and is carried by the residual water.

Other Uses

Ice blasting has applications in many industries and is a solution for companies that value effective use of water, a low environmental impact, and low cost. The technology has been used for aerospace, chemical removal, nuclear decontamination, and municipal cleaning.

Safety

As with all blasting technology, proper eyewear and hearing protection is recommended. Blasting machines reach levels of 115 db. Depending on the contaminants being cleaned, the level of protection varies. However, ice blasting is the safest blasting technology because of the lack of air pollutants consistent with other blasting technology. Generally, light rain gear is sufficient protection. If ice blasting is used to clean hazardous materials, heavier protective clothing is recommended.

References

* Ing, Habil and Karpuschewski, Bernhard. "Cryogenic wet-ice blasting - process conditions and possibilities" Institute of Manufacturing Technology and Quality Management (IFQ), Otto-von-Guericke-University of Magdeburg, Germany. 2013. *"What is Ice Blasting?". Cryogenic Blasting - Precision Ice Blasting. 2009. * "Coulson Ice Blast- How It Works". Coulson Ice Blast. 2015.

Notes

{{Reflist Cleaning tools Cleaning methods