One of the most important areas of use of dry ice is surface blasting. During cryogenic cleaning, the dirt is blasted without causing any damage to the surface where ordinary cleaning products are helpless.
Dry ice blasting is non-toxic, because no hazardous chemical substances are used. When using this technology, the surfaces are cleaned very gently, therefore, by using suitable pressure, it is possible to clean even the microchips or other sensitive surfaces.
Dry ice blasting includes 3 stages:
- Kinetic. In compressed air flow, dry ice pellets contact with the cleaned surface in a speed of sound;
- Thermal. Sudden reduction of the temperature of the upper layer (temperature of dry ice pellets – -79oC) causes a “thermal shock” and increases the fragility of the coat;
- Sublomation. Having penetrated through the coat of pollutants down to the cleaned surface, dry ice pellets encounter warmer temperature and immediately sublime (change the solid state into vapour). CO2 particles increase up to 700 times immediately, the process analogous to explosion occurs and the coat of pollutants is removed from the surface.
Advantages of dry ice blasting
- No additional cleaning waste remains;
- No damage caused to cleaned surfaces and mechanical constructions;
- It is easy to clean hardly accessible areas without dismantling constructions or equipment;
- No moisture remains, therefore, the electric and electronic equipment can be cleaned.
Dry ice is used to clean the following pollutants:
- Dirt, oil, fatty accumulations, petrol, resin, tar;
- Toxic waste, soot, slag;
- Glue, impregnation mixtures, powder;
- Heavy metals;
- Welding slag;
- Oil of cast moulds;
- Varnish, paint;
- Algae, mucous, molluscs.