Dry-ice blasting is a particle spray procedure which uses CO2 granulate as a spray agent. Unlike most other blasting media, which keep their solid state during the entire work process, the frozen CO2 sublimates instantly to CO2 gas when it impinges on the surface. This means that no spray agent residues are left behind, offering a wide range of applications for this technology.
Production of dry ice pellets
The dry ice pellets used must be fresh, otherwise there will be a lower cleaning performance and the pellets will sublimate to gas. Even when kept in appropriate cool boxes, these dry ice pellets can only be stored for a few days.
To date, dry ice pellets have been produced in large hydraulic presses called pelletisers and delivered on request. This usually takes a lot of effort and is expensive, particularly for small quantities. This is why dry-ice blasting is often not used as a cleaning method, even though it enables very efficient work. However, there is already a machine on the market which produces dry ice for workshop applications – and only during cleaning and precisely in the required quantity. In terms of logistics, only two things are required: Liquid CO2 as a raw material, which can be stored in bottles without any losses, and a compressed air supply or compact compressor.
Procedure and effect of dry-ice blasting
The dry ice pellets – solid CO2 at a temperature of -79 °C – impinge on the surface at a high speed of 150 m/s. Like all other spray processes, the accelerated particles lose their kinetic energy when they impinge on the surface. Their Mohs hardness is approximately the same as that of gypsum.
When the micro-fine ice pellets at a temperature of -79 °C impinge on the dirt or layer to be removed, the temperature differential/abrupt cooling and kinetic energy cause the dirt to become fragile and brittle and break up. This makes it easier to remove the dirt at a later stage.
Subsequent particles penetrate into the cracks in encrusted dirt and applied paint and sublimate there from a solid state to a gaseous state. This involves a 400-fold increase in volume and the dirt is blasted off on a microscopic scale.
Advantages of dry ice blasting
Since dry ice blasters work without chemicals, there is no need to dispose of waste water; there is also no spray agent residue left behind. It is possible to clean particularly delicate surfaces with minimal effort.
No residue: There is no need to dispose of waste water, chemicals or spray agent residue after dry ice blasters have been used. Only the sprayed substances are left behind. Depending on the amount and composition, these substances are either blown off using the compressed air present or sucked up using vacuum cleaners.
Cleaning without preparatory work: Vehicle parts do not have to be laboriously disassembled before cleaning. The pellets easily reach into the smallest nooks.
Time can be saved thanks to quick and effective cleaning with dry ice.
Environmentally friendly cleaning without additional chemicals or spray agents.
Surfaces are not damaged.