Application of the hottest sleeve technology in fl

The application of sleeve technology in flexographic printing (II)

processing accuracy of sleeve

in the process of sleeve processing, the most important and critical link should be accurate post-processing to ensure that all indicators are controlled within the specified error range. In particular, if the corrugated roller sleeve wants to constantly contact the doctor blade, it must ensure the coaxial operation. For the corrugated roller, even if it is slightly uneven or concave, it will have a negative impact on the service life of the doctor blade and sleeve. Generally speaking, the higher the number of lines added to the wrinkle roll, the thinner its wall, the more sensitive it is to the force of the mechanism, and the more obvious the impact on accuracy. In addition, the cylindricity, concentricity and perimeter errors are also very important to the sleeve. Therefore, it is necessary to process the sleeve as accurately as possible

it is worth noting that there may be some deformation of the sleeve after it is removed. Therefore, when measuring the error of the sleeve, the sleeve should be installed on the air support roll. It is best to stand for 5 minutes first to ensure that all compressed air is discharged. After the sleeve gradually adapts to the air support roll and reaches stability, the measurement can be carried out, so as to obtain truly accurate sleeve error measurement data

1. diameter size and error

the sleeve must have an accurate diameter size, which is the most basic requirement. Generally speaking, the diameter tolerance of the sleeve is ± 0.001 inch. In addition, in order to hold the sleeve tightly with the air support roll of the printing machine during expansion and contraction, the inner diameter of the sleeve must be slightly smaller than the outer diameter of the air support roll of the printing machine, and the error between them is generally controlled within 0.0015 inch, that is, the inner diameter of the sleeve is 0.0015 inch smaller than the outer diameter of the air support roll of the printing machine, In this way, the sleeve can be firmly and tightly sleeved on the air support roller of the printing machine

2. Concentricity

concentricity is a very important spatial tolerance index for all corrugated rollers. It indicates the deviation between the sleeve and the absolute central axis when it rotates if it can open up a market that is relatively unnoticed by other peers. This is the dynamic balance index of one side of the sleeve. If the runout error cannot be eliminated, the sleeve will be inconsistent in the circumferential direction. Once it exceeds the allowable tolerance range, it is likely to produce streaks or ink bars on the printed matter during the printing process. The concentricity error of the sleeve is generally controlled within 0.001 inch

3. cylindricity

cylindricity is also very important for sleeves. The cylindricity tolerance of corrugated roller sleeves is generally controlled within 0.0005 inch

it must be pointed out that the above data should be measured at both ends and the middle of the sleeve

installation and unloading of sleeve

sleeve is generally installed on the gas support roller neopentyl 2 alcohol, which is mainly used to produce plasticizers for polyester resin, unsaturated polyester resin, oil-free alkyd resin, polyurethane foam and elastomer, polyester powder coating, insulating materials, non printing ink, synthetic plasticizer, etc. the gas support roller is a supporting device for sleeve application, and its appearance is similar to that of the printing plate roller. There is an air inlet at one end of the air support roll, from which compressed air can be filled into the air cavity of the air support roll. In addition, some small exhaust holes are distributed on the surface of the air support roll, which are connected with the air inlet, and the compressed air filled through the air inlet can be evenly released from these small exhaust holes. In other words, when compressed air is filled into the air inlet hole of the air support roll, the compressed air will be evenly discharged from the exhaust hole of the air support roll, forming an air cushion layer on the surface of the air support roll, so that the inner diameter of the sleeve is related to its own characteristics and environment, expands and floats on the air cushion layer, so that the sleeve can slide back and forth on the air support roll at will, so that the sleeve can be installed, unloaded or replaced, The sleeve can be easily replaced even on a wide flexographic press

after installing the sleeve, turn off the air pump or cut off the compressed air, the air between the air support roll and the sleeve will be released, and the sleeve will shrink and wrap on the surface of the air support roll, and finally be closely and seamlessly integrated with the air support roll

precautions for use

1. Be sure to keep the surface of the sleeve clean and free from dust, solvents or dry ink blocks. These impurities may gradually penetrate into the interior of the sleeve, corrode or damage the compressible layer in the middle, cause the decline of its resilience and compressibility, and ultimately have a negative impact on the quality of printed matter

2. proper methods must be selected to clean the sleeve to avoid damage to the sleeve material. For example, the corrugated roller sleeve cannot be cleaned by ultrasonic or chemical cleaning methods, nor by sodium hydroxide solution, otherwise the elastic compressible material of the sleeve will be deformed, and its original shape cannot be restored and maintained. In addition, because the surface of the corrugated roller sleeve uses metal aluminum as the coating, some cleaning fluids may damage the aluminum. Therefore, these problems must be considered when selecting cleaning methods and cleaning solvents

3. the compression layer material of the sleeve must be protected from contacting or sticking with organic solvents, cutting fluid, grinding fluid and polishing fluid, so as to prevent its deformation and ensure that the state of the sleeve remains unchanged

4. When installing the sleeve or removing the sleeve from the air support roll, sometimes the operator may twist or rotate the sleeve slightly. Be careful not to move too much, otherwise the sleeve will deflect and even damage the sleeve

5. In order to prevent the sleeve from deformation or damage, it is best to store the sleeve on a special support. Do not put the sleeve aside casually! In particular, the corrugated roller sleeve should pay more attention to this point, otherwise it is easy to cause the breakage of ceramics at both ends, and a small piece will form a small crack. When the sleeve is installed on the bearing of the printing machine, the small crack will become larger and larger, and eventually the sleeve will be scrapped in terms of performance and price

conclusion

in a word, the emergence and development of sleeve technology has provided great advantages and convenience to the majority of flexographic printers, adapting to and promoting the development of modern flexographic printing technology. At present, many flexographic printing enterprises have adopted sleeve technology. It can be said that the application of sleeve technology has become the development trend of flexographic printing. We believe that sleeve technology will achieve greater development in the near future. Let's wait and see

source: Xinhua Printing