What Is a Dry Ice Cleaning Machine?
A dry ice cleaning machine is a device that blows dry ice onto the surface of the object to be cleaned.
The dry ice is crushed into a powder form and compressed air is used to blow it onto metal surfaces and other adhering surfaces. The sudden drop in surface temperature causes thermal contraction, which weakens the adhesive strength of the adherend, and the evaporation of the dry ice causes the volume between the surface and the adherend to expand 750 times, enabling the adherend to be peeled off.
A compressor is connected to the cleaning machine via a hose, and powdered dry ice is sprayed from a special air hose. At this time, safety protective equipment such as safety glasses, earplugs, leather gloves, and long-sleeved shirts are worn, and work is performed with adequate ventilation to prevent oxygen deficiency and carbon dioxide poisoning.
Uses of Dry Ice Cleaning Machines
Dry ice cleaning machines are used for mold cleaning, surface preparation, part finishing, and adhesive removal (to weaken the bond of painted surfaces).
In the automotive industry, for example, they can be used to clean molds, deburr parts, and remove adhesives. In the food industry, it is used to clean production lines and remove adhesives. In the aviation industry, it is used for safety control inspections and surface preparation prior to painting. In the tire and rubber industry, it can be used to remove material stuck to molds, and in the textile industry, it can be used to remove fibers from machinery.
It is the powder that is applied by the cleaner, which prevents scratching and makes it possible to clean hard-to-reach areas. The size and amount of particles and compressed air pressure can be adjusted to suit a wide range of fields and user preferences.
Principle of Dry Ice Cleaning Machines
The surface treatment with dry ice cleaning machines does not rely on solvents to remove contaminants. It is possible to clean without cooling or decomposition processes on the production line, which significantly reduces time and improves productivity.
Because it is a clean cleaning method that eliminates worker hazards from solvents and decomposition as much as possible and leaves no troublesome wastewater treatment or residue on the production line, it is used in a wide range of fields, notably in the food industry.
Types of Dry Ice Cleaning Machines
Dry ice cleaning machines are available in a variety of cleaning methods. In the dry ice pellet cleaning method, air is mixed with dry ice pellets of 3 mm in diameter and sprayed. In the dry ice powder cleaning method, dry ice pellets are crushed to the appropriate size inside the washer or nozzle and mixed with air and sprayed.
The dry ice powder cleaning method may also use liquefied CO2 or block dry ice. Powdered dry ice extracted from liquefied CO2 is mixed with air and sprayed, so it can be cleaned anytime a liquefied CO2 tank is available. However, it is less powerful than pellets or pellet grinding type. Another method is to shave block dry ice to produce dry ice powder, which is mixed with air and sprayed.
How to Choose a Dry Ice Cleaning Machine
The use of solvents in factory cleaning raises issues of worker health management and environmental pollution. On the other hand, dry ice is non-toxic and its raw materials are made from by-products such as petroleum refining, making it an increasingly important technology in terms of environmental measures.
Points to note are as follows.
- Not suitable for polishing.
- Not suitable for cleaning soft materials such as pure aluminum, paper, and wood.
- Ventilation is required.
- Not suitable for locations where there is a risk of explosion of gas, vapor, dust, etc., due to static electricity generation.
- It is not good at cleaning epoxy resin-based paints, adhesives, and black rust.
Structure of Dry Ice Cleaning Machines
Dry ice cleaning machines are available in two-hose and one-hose types, each with a different structure.
1. 2-Hose Type
The two-hose type has two hoses connecting the main body of the cleaner to the gun and has a simple structure. However, the hoses are difficult to handle, and it is difficult to control the amount of dry ice consumed.
2. 1-Hose Type
In contrast, the one-hose type has only one hose connecting the main body of the cleaner to the gun. The structure is more complicated, but it is more powerful because the amount of dry ice consumed can be controlled and the nozzle can be designed freely. There are several nozzle outlet shapes, diameters, and bends to choose from, depending on the area to be cleaned.