Dry ice is now affordable
July 1st 2007

Dry ice has long offered a method of cleaning components, and now new technology is available to make the process more feasible both technically and economically.

Icevent Technology has introduced Triventek's patented Pelletiser PE80 and Recovery Unit RE80 equipment which can reduce the cost of dry ice by half, and also is suitable for automated applications since now the user can make his own dry ice when and where he wants it.

Dry ice is solid carbon dioxide at -78.5°C whose unique property is that at atmospheric pressure it changes directly from solid to gas phase without going through a liquid phase.

This is exploited by blasting pellets much like an abrasive blaster with the critical differences that the cleaning medium disappears harmlessly as gas, leaving no residue, and without damage to the component.

Components ranging from turbine blades to mobile phone fascia lenses are successfully cleaned with no damage, mess or costly waste disposal. The aggression of blasting can be tuned so that a wide variety of contaminants from welding slag to solder flux can be cleaned off substrates ranging from speciality steels through to microelectronics.

'Flash' and vent tails are quickly and safely removed from plastic parts.

In the past the relatively high cost of dry ice has been a disincentive to wider takeup, but that has changed with this new technology designed to be operated close to the point-of-use, i.e.

on site production.

The efficient recovery of waste 'revert' gas means that the cost of dry ice can be halved. Table 1 illustrates increasing affordability Making dry ice cheaply on site also overcomes the logistical problem of arranging for delivery of dry ice from centralised dry ice factories. The distribution of dry ice is particularly 'tight' because of the perishability of dry ice whereby it can disappear at the rate of 5- 15% per day, even in an insulated container.

The production of dry ice can therefore be fully integrated into an automated component cleaning operation, with supply direct to the blasting apparatus.

This means that many projects which previously foundered on concerns over dry ice supply are being revived to take profit from this new technology.