isogenix




What is Dry Ice Blasting?

Isogenix Dry Ice Blasting is a unique process that uses solid dry ice particles in high velocity airflow to remove contaminants from surfaces. This technique of deep aggressive cleaning utilizes the Carbon Dioxide (CO2) recycled from other industrial processes.

The Dry Ice Pellets are accelerated through high velocity nozzles to impinge upon the surface being cleaned. The thermal shock effect and kinetic energy of the dry ice pellets separate the residue from the surface without affecting the integrity thereof. The dry ice pellets vaporize on impact, leaving no other cleaning by-product and thus eliminating the added cost and inconvenience of secondary waste treatment and disposal.

Today the dry ice method of cleaning is quickly becoming favoured for environment as well as production reasons. Applications range from heavy slag removal to delicate semiconductor and circuit board cleaning. Just about anything that can be cleaned with normal grit-blasting, hydro-lazing, soap and water, or solvents and brushes, can be cleaned cleaner, faster, cheaper and safer with dry ice blasting.

 
 

The Process
As the pellets strike the surface, the thermal shock effect and kinetic energy separate the residue from the surface without affecting the integrity thereof.
The dry ice pellets vaporize on impact, creating a large volume of CO2 gas which rapidly expands and simply pops off the
coating/contaminant from the inside out. The process of Dry Ice blasting cleaning is three-fold:

First Step: Kinetic Energy (KE = 1/2mv2)

Energy associated with the mass density and impact velocity (supersonic) of the dry ice particles is transferred to the surface being cleaned and/or coating to be removed. This is the primary mode of cleaning, as is the case in traditional grit blasting applications.

Since CO2 particles have a relatively low hardness, the process relies on high particle velocities to achieve the required impact energy. The almost instantaneous phase change to a gas on impact, provides an almost non- existent coefficient of restitution in the impact equation. Even at high impact velocities and direct “head-on” impact angles, the kinetic effect of solid CO2 particles is minimal compared to traditional media. This unique characteristic contributes to the non-abrasive benefits of the dry ice blast process. Unlike traditional methods, the dry ice blast process doesn’t end here.

Second Step: Thermal Shock

The inherent low temperature of the CO2 particles (-79C) allows the dry ice blast process unique thermodynamically induced surface mechanisms. When the cold dry ice pellets impact with the surface, a small thermal differential is established between the surface coating/contaminant and the substrate. The micro-thermal shock promotes cracking and de-lamination of the contaminant, thus allowing pellets to penetrate and break up the surface layer.

 
 

Third Step: Reverse fracturing surface

As the dry ice impacts the surface it explodes into a harmless CO2 gas, which penetrates the cracks to get under the surface coating/contaminant. The gas rapidly expands about 800 times in volume and literally pushes the coating/contaminant from the surface. Since the dry ice evaporates into the air, only the contaminant is left for disposal.

Benefits

Dry Ice blasting offers significant advantages over other methods of cleaning.


Dry Ice Blast Cleaning Comparison Chart

 

Blasting Cleaning Technique

Waste for Disposal

Abrasive

Toxic
Electrically Conductive

Performance Comparison

Dry Ice

No

No

No

No

Excellent

Sand

Yes

Yes

No*

No

OK

Glass Beads

Yes

Yes

No*

No

OK

Walnut Shells

Yes

Yes

No*

No

Limited

Steam

No

No

No

Yes

Poor

Solvents

Yes

No

Yes

Yes

Limited


* Each of these blast cleaning materials becomes contaminated upon contact if used to clean hazardous objects. When that happens, these materials are then classified as toxic waste requiring safe disposal.

Frequently asked questions about Dry Ice, Dry Ice Production and Dry Ice Blasting.

If you cannot find the answer to your question on our website, please feel free to contact any of our offices for more information.

Q: What is dry ice?
A: Dry Ice is the solid form of Carbon Dioxide (CO2). CO2 is a colourless, tasteless, odourless gas found naturally in our atmosphere.

Q: What is Isogenix Dry Ice Blast Cleaning?

A: Dry ice blasting is similar to other forms of shot blasting such as sand blasting, bead blasting, or soda blasting. In dry ice blast cleaning the media(dry ice pellets) are accelerated by compressed air to impact on the contaminated surface and clean.

Q: Why would I use Isogenix dry ice instead of other blasting methods?

A: Isogenix Dry Ice Blast Cleaning leaves no additional waste stream behind as traditional methods often do. When the dry ice impacts on the substrate it sublimates(vaporizes).The Isogenix system delivers a far superior clean that reaches into small cavities that other media would not reach.

Q: How does the Isogenix system work?
A:
Dry Ice blast cleaning functions at -80 Degrees Celsius when it comes in contact with the contaminated area. The temperature difference between the dry ice and the substrate causes a thermal shock reaction. This causes the contaminant to instantly freeze and loosen form the substrate through the process of reverse fracturing..

Q: Where does the contaminant go when blasted?

A: There are various contaminants depending on the application. Dry contaminants will break into small pieces or a powder that can simply be swept up. Larger contaminates do not become airborne and can be collected after cleaning. Wet contaminant such as grease or oil can be ‘herded’ into specific areas and easily removed. The area that is left behind is clean and dry and the operator will clean methodically from top to bottom thus preventing the re-positioning of the oils and grease

Q: Do the dry ice pellets or contaminant ricochet?

A: When the dry ice pellets are blasted at supersonic speeds created by the compressed air stream they will vaporize and return into a gas once again. The contaminant will be moved away by the air stream and the Isogenix operator is well trained to ensure his safety and those around him/her.

Q: Will dry ice blasting damage the substrate?

A: The Isogenix dry ice blasting process will not damage the substrate. The operator has been extensively trained to ensure that the correct pressure is applied to ensure the safe removal of contaminants without any damage to the substrate. Isogenix has specialised equipment for all possible applications and we clean extremely sensitive equipment with great effect.

Q: Can Isogenix Dry Ice Blast Cleaning be used to clean tools while they are hot and still online?

A: Absolutely. The Isogenix system works better when used on hot substrates as the thermal shock effect causes the contaminates to loosen faster..

Q: Does dry ice blasting cool the substrate?

A: Yes, but not dramatically. The amount of cooling depends on the substrate material, the dwell time of the dry ice blast stream, and the dry ice usage. For example, a 76cm by 76 cm rubber mould may have an initial temperature of; 162.8°C. After the tool has been blasted clean (approximately 12 minutes), the temperature of the mould is about 148.9°C.

Q: Will Isogenix dry ice blasting cool the substrate?

A: There is a initial cooling on the blasted area but no a dramatic difference in temperature of the substrate. It does depend on the composition of the substrate but your Isogenix operator would not concentrate on one area for very long as the cleaning does work extremely fast.

Q: Would the use of the Isogenix system and the drop in temperature damage the hot mould?

A: Through experience, we have found that the surface area being cleaned is too small to register and the comparable tensile stress is far below the point of what most moulds will encounter during normal heat treatment.

Q: Can Isogenix Dry Ice Blast Cleaning cause condensation?
A: As condensation occurs when the substrate temperature falls below the dew point, it really depends on the climate that the blasting is completed in. When cleaning hot surfaces there is rarely condensation as the temperature does not fall below the dew point. There are however methods that we use should condensation occur such as the use of heaters or heat lamps.

Q: Can the Isogenix system be used in an enclosed area?

A: Absolutely. Most of our cleaning is completed while the equipment is still online and in the plant. It is important to ensure that there is proper ventilation as CO2 is 40 % heavier than air and we recommend that all vents are placed at ground level

The Isogenix representative will be able to assess your needs and recommend the proper system configuration to ensure your productivity is maximized. Our operators are extensively trained and all safety precautions will be in place to insure the safe cleaning of our equipment without harming the environment.

 
 
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