In the flexographic printing, the cells of the anilox roller are inevitably blocked by the ink skin, the paper coating or the paper hair or other dirt, and the quality of the printing and the normal use of the anilox roller must be promptly cleaned. There are seven methods, but the points that should be noted are the same, that is, both the heavy cleaning effect and the damage to the anilox roller must be avoided.
First, the chemical cleaning method
The caustic soaked in the anilox roller net, etc. was dissolved with a caustic soda solution and then rinsed with a high-pressure water jet. When cleaning, the anilox roll is placed in a closed tank, while rotating, while showering with hot alkali, then high-pressure water jet cleaning, and finally blow dry with compressed air. During this period, the lye and fresh water were separately recovered and filtered. The advantage of this method is that the damage to the anilox roller is small, and the cleaning effect is good, especially for the fine network of more than 1,000 lines per inch.
Second, spray "sand" method
The compressed air is used to spray the "sand" particles to the anilox roller to expel ink and other dirt from the cells. "Sand" is not really grit, but instead of fine particulate matter that has a lower hardness than the surface of the anilox roll, it is forced by compressed air from the lance into the rotating anilox roll. The following points should be mastered in the operation: the spray gun should be kept at a certain distance from the anilox roller, and it should be vertical (not deflectable, otherwise it could easily damage the wall of the cell). The speed of the spray gun and the rotation speed of the anilox roller should be properly controlled and kept stable. . The pressure of the spray “sand†should also be controlled properly and constant, while lighter, the cleaning effect is poor, and it is easy to damage the anilox roller. Therefore, this method is not suitable for daily use and is only suitable for compartmental use.
Third, drying baking soda method
Similar to the second method, but the use of specially prepared dried baking soda powder as a spray "sand", non-toxic and soft, not easy to damage the anilox roller, decontamination effect is good. Do not exceed 40 psi air pressure during spraying. This method can be provided not only by dedicated service stations, but also in-house, especially on large flexographic printing presses.
Fourth, the low temperature method
Dry ice particles made of liquid carbon dioxide are used as a spray and sprayed with an air gun at an air pressure of 80 to 100 psi to the anilox roll. The advantage of this method is that it is beneficial to environmental protection. The disadvantage is that the dry ice particles are usually larger than 0.04 inches, and it is not easy for the net holes below 200 lines to be injected.
Fifth, spray plastic particle method
This method is often advertised as a method of no wear on the ceramic anilox roll. Similar to other spray methods, a closed groove puts the anilox roll into rotation while the spray gun moves at a certain distance, angle and speed. With polyethylene particles, the injection pressure is approximately 60 psi. The plastic particles are soft, but the edges are sharp. When they are sprayed onto the surface of the cell, they will pop out. The dirt in the cells will be brought out. Then the plastic particles will be separated from the dirt by an air washing room. Plastic particles can be recycled again. The latest development of this method has been applied to the cleaning of YAG laser-engraved anilox rolls of 1000 to 1500 lines per inch.
Sixth, ultrasonic cleaning
Suitable for high-precision laser-engraved ceramic anilox roller cleaning, the existing dedicated service station, but also by the printing plant itself. However, the operation of this method should be based on the size of the anilox roller, the characteristics of the texture, and the design characteristics of the cleaning equipment. For example, the finer the reticulation, the thinner the wall of the cell wall, and the time for ultrasonic treatment cannot be too long.
Due to the characteristics of water-based inks, many ultrasonic cleaners adopt a pre-soaking method to soften the ink residue in the dryness of the cells, and then perform ultrasonic treatment. The pre-soaking time often accounts for 80-90% of the entire cleaning time. The pre-soaking solution is specially formulated, and the PH is high, which contributes to the softening of the ink residue. The sonic level during the ultrasonic treatment can be reduced and the cleaning effect can be achieved without damaging the cells.
It is important to carefully balance the following factors in ultrasonic cleaning:
The force of ultrasound directly affects the strength of the cavitation. The recommendation regarding the level of the cavitation has varied greatly from the past to the present, because in the past most narrow anilox rolls only had to be partially immersed, but now there are wide anilox rolls, ultrasonic cleaning. It needs to be completely submerged with a large groove, so the strength of the ultrasonic wave also makes a big change.
The frequency of ultrasonic waves is inversely related to the strength of the cavitation. As the frequency increases, the bubbles shrink in size and their intensity decreases. In general, 40 kHz (40,000 cycles per second) is used as the minimum level, making the bubble size suitable for decontamination into the cell, but it is not absolute, depending on the specific circumstances of the device.
The temperature of the cleaning solution has a great influence on the strength of the cavitation. The high temperature reduces the viscosity of the cleaning liquid and increases the strength, which is advantageous for the cleaning effect. The general temperature should be between 120 and 140 degrees Fahrenheit. Use specific cleaning fluids for specific equipment. (such as laser engraved ceramic anilox roller), the temperature when cleaning should also be mastered according to the cleaning equipment manufacturer's recommendation.
The cleaning time is also critical. Too long time can damage the surface coating or the mesh of the anilox roller. It is better not to exceed 5 minutes for ultrasonic cleaning with pre-soaking method, but it is not absolute.
Seven, laser cleaning
The most recent method uses a special lens laser to shoot an anilox roller, which can vaporize residues such as inks, adhesives, waxes, and silicones without damaging the anilox roll.
First, the chemical cleaning method
The caustic soaked in the anilox roller net, etc. was dissolved with a caustic soda solution and then rinsed with a high-pressure water jet. When cleaning, the anilox roll is placed in a closed tank, while rotating, while showering with hot alkali, then high-pressure water jet cleaning, and finally blow dry with compressed air. During this period, the lye and fresh water were separately recovered and filtered. The advantage of this method is that the damage to the anilox roller is small, and the cleaning effect is good, especially for the fine network of more than 1,000 lines per inch.
Second, spray "sand" method
The compressed air is used to spray the "sand" particles to the anilox roller to expel ink and other dirt from the cells. "Sand" is not really grit, but instead of fine particulate matter that has a lower hardness than the surface of the anilox roll, it is forced by compressed air from the lance into the rotating anilox roll. The following points should be mastered in the operation: the spray gun should be kept at a certain distance from the anilox roller, and it should be vertical (not deflectable, otherwise it could easily damage the wall of the cell). The speed of the spray gun and the rotation speed of the anilox roller should be properly controlled and kept stable. . The pressure of the spray “sand†should also be controlled properly and constant, while lighter, the cleaning effect is poor, and it is easy to damage the anilox roller. Therefore, this method is not suitable for daily use and is only suitable for compartmental use.
Third, drying baking soda method
Similar to the second method, but the use of specially prepared dried baking soda powder as a spray "sand", non-toxic and soft, not easy to damage the anilox roller, decontamination effect is good. Do not exceed 40 psi air pressure during spraying. This method can be provided not only by dedicated service stations, but also in-house, especially on large flexographic printing presses.
Fourth, the low temperature method
Dry ice particles made of liquid carbon dioxide are used as a spray and sprayed with an air gun at an air pressure of 80 to 100 psi to the anilox roll. The advantage of this method is that it is beneficial to environmental protection. The disadvantage is that the dry ice particles are usually larger than 0.04 inches, and it is not easy for the net holes below 200 lines to be injected.
Fifth, spray plastic particle method
This method is often advertised as a method of no wear on the ceramic anilox roll. Similar to other spray methods, a closed groove puts the anilox roll into rotation while the spray gun moves at a certain distance, angle and speed. With polyethylene particles, the injection pressure is approximately 60 psi. The plastic particles are soft, but the edges are sharp. When they are sprayed onto the surface of the cell, they will pop out. The dirt in the cells will be brought out. Then the plastic particles will be separated from the dirt by an air washing room. Plastic particles can be recycled again. The latest development of this method has been applied to the cleaning of YAG laser-engraved anilox rolls of 1000 to 1500 lines per inch.
Sixth, ultrasonic cleaning
Suitable for high-precision laser-engraved ceramic anilox roller cleaning, the existing dedicated service station, but also by the printing plant itself. However, the operation of this method should be based on the size of the anilox roller, the characteristics of the texture, and the design characteristics of the cleaning equipment. For example, the finer the reticulation, the thinner the wall of the cell wall, and the time for ultrasonic treatment cannot be too long.
Due to the characteristics of water-based inks, many ultrasonic cleaners adopt a pre-soaking method to soften the ink residue in the dryness of the cells, and then perform ultrasonic treatment. The pre-soaking time often accounts for 80-90% of the entire cleaning time. The pre-soaking solution is specially formulated, and the PH is high, which contributes to the softening of the ink residue. The sonic level during the ultrasonic treatment can be reduced and the cleaning effect can be achieved without damaging the cells.
It is important to carefully balance the following factors in ultrasonic cleaning:
The force of ultrasound directly affects the strength of the cavitation. The recommendation regarding the level of the cavitation has varied greatly from the past to the present, because in the past most narrow anilox rolls only had to be partially immersed, but now there are wide anilox rolls, ultrasonic cleaning. It needs to be completely submerged with a large groove, so the strength of the ultrasonic wave also makes a big change.
The frequency of ultrasonic waves is inversely related to the strength of the cavitation. As the frequency increases, the bubbles shrink in size and their intensity decreases. In general, 40 kHz (40,000 cycles per second) is used as the minimum level, making the bubble size suitable for decontamination into the cell, but it is not absolute, depending on the specific circumstances of the device.
The temperature of the cleaning solution has a great influence on the strength of the cavitation. The high temperature reduces the viscosity of the cleaning liquid and increases the strength, which is advantageous for the cleaning effect. The general temperature should be between 120 and 140 degrees Fahrenheit. Use specific cleaning fluids for specific equipment. (such as laser engraved ceramic anilox roller), the temperature when cleaning should also be mastered according to the cleaning equipment manufacturer's recommendation.
The cleaning time is also critical. Too long time can damage the surface coating or the mesh of the anilox roller. It is better not to exceed 5 minutes for ultrasonic cleaning with pre-soaking method, but it is not absolute.
Seven, laser cleaning
The most recent method uses a special lens laser to shoot an anilox roller, which can vaporize residues such as inks, adhesives, waxes, and silicones without damaging the anilox roll.
Tablet Cases,Pu Laptop Bag,Tablet Leather Case,Protective Laptop Bag
Guangzhou Ysure Electronic Technology Co., Ltd. , http://www.ysurecase.com