What is CO2 cleaning (dry ice)?
It is a process in which solid carbon dioxide particles (dry ice) are thrown at high speed against a surface to clean it. The particles are accelerated with compressed air, usually in the order of 5.4 / 6.8 bar.
How does CO2 cleaning remove contaminants?
When a dry contaminant is removed, the process creates a compressive voltage wave between the coating and the substrate. This wave has enough energy to overcome the connection voltage by literally blasting the coating off the inside out. When removing a malleable or viscous coating such as oil, grease or wax, the cleaning action is a flow process similar to high pressure water.
What is dry ice made of?
It is made up of liquid CO2. Carbon dioxide (CO2) exists in a liquid state only at high pressure. Returning to the ambient pressure (the normal pressure that surrounds us), about half turns into gas and half into solid. The solid part, usually in the form of fluffy snow, is then compressed to form blocks of dry ice, pellets or nuggets.
How are dry ice pellets (granules) made?
Pressurized liquid carbon dioxide is brought to room temperature to produce snow. This snow is compressed and pushed through a mold to create the pellets.
Are there any dry ice pellets that are better than others?
Yes. Dry ice pellets vary in terms of uniformity of size and hardness. Uniformity ensures that performance is repeatable. The shape and density of the pellets directly affect the cleaning performance
How to store dry ice?
Since dry ice is at -78.5 ° C, putting it in the freezer won’t do any good. The best way to extend the shelf life is to store the ice in an insulated container. Depending on the quality of the container and how much ice you are storing, the sublimation loss will vary from 2 to 10% per day.
What are the best cleaning applications for carbon dioxide?
The range of cleaning applications for carbon dioxide is remarkable and can be easily demonstrated with just a few small examples: core boxes for ford, delicate electrical connections for Xerox, presses for the Chicago Tribune, mixing equipment for the Kraft, tire molds for Michelin. Carbon dioxide is exceptional in cleaning production line equipment as it eliminates the need for masking, cooling and disassembly. Users minimize downtime which maximizes production efficiency in cleaning manufacturing equipment for foundries, rubber or plastics molds, food manufacturers, printers and the semiconductor industry. Dry ice blasting is also widely used in the nuclear industry for decontamination. Whenever the volume of waste or health risks is involved, the feasibility of using carbon dioxide should be considered. Since carbon dioxide disappears on impact, it does not create additional waste. Competing processes such as shot blasting or solvents often present health problems.
How is carbon dioxide used in the printing industry?
The process is used to remove ink (both fresh and dry), dust, paper dust from continuous web and sheet fed presses.
How is carbon dioxide used in the semiconductor industry?
Semiconductor manufacturers use carbon removal to clean various types of processing equipment including: spreader trays, teos valves, gate valves and anodized screens.
How is carbon dioxide used in the food industry?
Carbon dioxide is very suitable for use in this type of industry given its food quality, to clean ovens, conveyor belts, molds, dry mixers, extruders, laminators and packaging and packaging equipment.
What is dry ice?
Dry ice is the solid form of carbon dioxide (CO2). Originally it was a brand name, now it has become the most common way of referring to carbon dioxide in its solid or frozen state. CO2 is a colorless, tasteless, odorless gas. which is found naturally in our atmosphere. It has a temperature of –78.5 ° C. At atmospheric pressure it evaporates into the air. It is called “dry ice” because it does not contain water. For cleaning purposes, dry ice is most commonly used in the form of 3mm diameter granules, called pellets.
How is dry ice produced?
It is produced by liquid CO2: carbon dioxide is “frozen” by compressing carbon gas at a high pressure. When released, in the form of liquid carbon dioxide, it expands rapidly and evaporates, cooling to the freezing point (-109.3 degrees Fahrenheit or –78.5 degrees Celsius) to become solid “snow”. This snow is compressed and extruded through a die which gives the final dimensions of the pellets (or granules, depending on the die used). The equipment that produces the pellets is called a pelletizer. This “snow” also forms in the nozzle of a fire extinguisher carbon dioxide when used. Liquid CO2 is taken from a pressurized reservoir by dropping it to ambient pressure to produce snow. The snow is then pushed through a nut to produce the pellets. This system is a mechanical and circular process during which the pellet extrudes very slowly before making contact with a pin which cuts it to a uniform length. Another type of system uses a hydraulic ram to form “noodles” which break to varying lengths as they pass through the nut.
Is dry ice a food product?
Yes, it is composed solely of carbon dioxide which is also used to make bubbles in soft drinks or mineral water. But be careful not to swallow it in its solid form, it is burning.
How can dry ice be stored?
Since dry ice has a temperature of –78.5 ° C, putting it in the freezer will not help. Dry ice should be stored and transported in well insulated containers. Good quality containers will limit the evaporation of the pellets to a low daily percentage. Depending on the climate and the thickness of your container, the typical sublimation of dry ice is approximately 2 to 10% per day.
What is dry ice blasting?
Dry ice blasting is a process similar to sandblasting, cleaning with abrasives where dry ice is accelerated in a stream of pressurized air (or other inert gas) in order to impact and clean a surface. Particles are accelerated by compressed air, usually in the 5-7 bar range. The advantage of using solid CO2 or dry ice pellets as blasting material is twofold. First of all, the very low temperature of the dry ice pellets causes thermal shock due to freezing and the resulting contraction facilitates the detachment of the contaminant from the base material. Secondly, the dry ice pellets vaporize into carbon gas, which means that only the original contaminant remains to be disposed of. This natural evaporation of dry ice pellets is the major advantage of the dry ice cleaning method. Today, most applications are able to use standard industrial air. There are also dry ice cleaning equipment that allows you to work at very high pressures.
Does dry ice block have any advantages over pellets?
Yup. Perhaps the most important benefit of dry ice block is consumption. The block has many other important advantages over pellets. It is easier to transport because the pellets tend to become compact during transport turning into a block. The block is easier to buy and has a lower cost than pellets. The dry ice block also has a longer shelf life. Pellets have a higher surface – mass rate which makes them more hygroscopic, i.e. they attract water. During storage, the pellets become blocks making them unusable. Furthermore, the high surface – mass rate causes the pellets to sublimate faster than the block.
Where did the technology originate from?
It was invented at Lockheed in the 1970s when a paint engineer, Calvin Fong, was attempting different methods of removing paint from aircraft. The technology was not commercially available until Alpheus bought the license and patent from Lockheed and introduced it to the market in 1987. There have been many technological advances in this field since then.
Where can I find dry ice pellets, chunks and / or blocks?
We are also dry ice producers. Contact us freely to get quotes and to request any kind of information on the matter.
What are the best cleaning applications for CO2?
The range of CO2 cleaning applications is impressive and is easily demonstrated in a sample of our applications. CO2 stands out in the cleaning of in-line production equipment because it eliminates the need for masking, cooling and disassembly. Users minimize downtime, which maximizes production efficiency. We have achieved extraordinary results in the cleaning of production equipment for foundries (cleaning of rubber and plastic molds, injection molds, extrusion, casting and core boxes) in food inductors, publishing and in the semiconductor industry. Dry ice blasting is also widely used in the nuclear industry for decontamination and asbestos removal. You can also remove graffiti, restore facades of historic buildings by removing soot and remove carbon deposits after fires. Furthermore, the advantages of on-site cleaning and the evaporation of the blasting medium make cleaning with dry ice very effective also in the automotive and aerospace industries: * removal of welding residues from robots; * cleaning of pneumatic molds; * reconditioning of engine blocks; * cleaning engine parts. At any time the volume of waste or health risks are an issue, the viability of CO2 should be examined. Since CO2 disappears on impact, it creates no additional waste. Competing designs such as granular blasting or solvents often present disposal problems or health risks.