Dry Ice Blast Cleaning
Dry ice blast cleaning is similar to conventional media blasting except that the abrasive media is replaced by pellets of dry ice which literally disappear as soon as the cleaning cycle is complete.
Dry ice is the solid form of carbon dioxide (CO2) which has the unusual property of subliming, or changing directly from a solid to a gas without an intermediate liquid phase, leaving no solid residue. At atmospheric pressure it sublimes at minus 78.7°C providing a cooling effect of 628 kJ/kg.
Clean Surface blasters accelerate dry ice pellets to high speed using compressed air available from standard industrial compressors. They offer one of the most advanced and environmentally friendly methods of surface cleaning or decontamination.
The dry ice, although hard in appearance, does not rely on its abrasive properties for effective cleaning. This minimises the risk of damage to the substrate, or the areas adjacent to the workpiece, making Clean Surface blasters ideal for cleaning delicate substrates such as printed circuit boards or highly polished moulds. In the latter case, the blasting can often take place with the mould still hot and in-situ.
By adjusting the simple pneumatic controls on a Clean Surface blaster, cleaning conditions can be altered to ensure removal of only the contaminants from surface coated components, allowing the bond between substrate and coating to remain intact. Alternatively, the cleaning parameters can be set to the optimum level and both contaminant and coating can be removed in one operation.
When the pellets impact on a substrate with a tightly bonded layer of surface contamination, or unwanted coating, small solid dry ice particles enter the pores of the contaminant and any thermal cracks created within it by the cold dry ice.
As soon as the dry ice particles impact and penetrate the surface contaminant, energy is released causing the particles sublime into a much larger volume of CO2 gas. The gas then rapidly expands and simply blasts the contaminant away from the substrate into the airstream.
Because the dry ice sublimes during the cleaning process, there are no problems associated with disposal of the blasting medium and no debris to clear away other than the material removed, which is usually found as a fine dust. Compared to solvent cleaning, there are no toxic fumes, no hazardous liquid wastes to dispose of and, as CO2 is inert, no chemical reactions take place.
To find out more about dry ice cleaning, please read on, call +44 116 224 0072 or e-mail firstname.lastname@example.org