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Vol. 7
September Issue
Year 2006
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in Vol. 7 - September Issue - Year 2006
A Cool Way to Increase Productivity and Quality



Author: Marco Pellegrino


Online-cleaning of a hot ingot mould


Gentle cleaning of a core box

 In the Spotlight

Benefits of an in-house dry ice production

Having an in-house dry ice production will make you profit from many advantages:

Better and faster cleaning results: The fresher the dry ice, the more effective the cleaning as dry ice stored for several days deteriorates meaning cleaning time can take twice as long or longer than cleaning with freshly made dry ice.

Less dry ice used: As the cleaning results are much better and quicker with fresh dry ice than with dry ice stored for several days, dry ice usage is significantly reduced. Making your own dry ice when you want it avoids lengthy storage which minimises dry ice sublimation losses. In-house dry ice production thus reduces dry ice use by 30-50%.

More flexibility: Making your own dry ice means you can clean whenever you want and you do not have to wait for dry ice delivery. This allows dry ice cleaning to be easily integrated into the daily working process and be planned as fixed cycle times.

Shorter production downtime: As freshly made dry ice ensures faster cleaning results, production stoppages are kept to a minimum.

Improved Logistics: With in-house dry ice production you do not have to worry about where and when to buy your dry ice, what time it will be delivered and how long you have to store it. You can produce it on demand and just in time.

All these benefits lead to more flexibility and quality in the daily working process, reduce costs and increase productivity.

Many companies already know the advantages of cleaning with dry ice and successfully use this non-abrasive cleaning method in a wide range of applications such as the gentle but powerful cleaning of moulds. ASCO CARBON DIOXIDE’s ASCOJET division specializes in developing this proven technology to meet individual client needs with the aim of increasing work productivity, quality and flexibility.

ASCOJET dry ice blasting means moulds and machines do not have to be disassembled thus saving enormous time in comparison with traditional sand or glass bead blasting. Even hot moulds (e.g. ingot moulds) can be cleaned on-line. ASCOJET dry ice blasting has a minimal effect on mould temperature allowing virtually continuous production.

ASCOJET dry ice blasting is non-abrasive so surfaces are not damaged or altered in any way. This technology is therefore highly recommended for gentle and effective cleaning of surfaces of any type or material and in a wide range of industries. A good example being in foundries for the gentle cleaning of ingot moulds, core boxes and high pressure die casting moulds.

Because dry ice blasting is a dry cleaning method, delicate parts like switch boards and other electrical components can be cleaned safely. As the dry ice pellets sublimate immediately after impact on the surface, there is no residual blasting media left behind after cleaning. Therefore the time and costs associated with the disposal of blasting media are eliminated. For this reason and because no solvents or chemicals are needed, ASCOJET Dry Ice Blasting is an ecologically friendly cleaning technology.

The Process

Dry ice is 100% solid CO2. Inside a pelletizer liquid CO2 is converted into dry ice snow by controlled expansion. This dry ice snow (ca. -79°C) is pressed through an extruder plate to make small pellets. These pellets are fed into the ASCOJET Dry Ice Blasting Unit and conveyed to the blasting gun, from where they are shot at a speed of up to 300m/s onto the contaminated surface. Due to the sudden thermo shock generated on the surface to be cleaned, the coating or dirt contracts, becomes brittle and cracks. This cracking of the surface allows the pellets to reach in under the dirt and remove it.
The additional kinetic energy removes the coating/dirt from the surface. Immediately after impact, the pellet sublimates and goes back to atmosphere as a pure CO2 gas without leaving any moisture behind. The only thing left is the coating or dirt removed from the surface; no blasting media has to be disposed of. As dry ice cleaning is virtually non-abrasive, the surface quality is maintained.

ASCOJET: More than just a Cleaning Method

In the field of this technology ASCO has specialized in offering individual and complete solutions for the specific needs of customers. These individual solutions can start with a single dry ice blasting machine and grow to include in-house dry ice production linked to timed CO2 delivery and can include special projects like noise control booths or specially developed blasting guns. The full ASCOJET solution increases productivity and cleaning quality and flexibility.




Author: Marco Pellegrino, Manager Dry Ice Blasting
For Information:
ASCO CARBON DIOXIDE LTD, Industriestrasse 2
8590 Romanshorn, Switzerland
Tel: +41.71.466 80 80
E-mail: pellegrino@ascoco2.com
www.ascojet.com