Application of sleeve technology in flexographic printing
We are a big printing company in Shenzhen China . We offer all book publications, hardcover book printing, papercover book printing, hardcover notebook, sprial book printing, saddle stiching book printing, booklet printing,packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: info@joyful-printing.net
Advantages of sleeve technology
The sleeve technology has many advantages and can be summarized as follows.
1. The sleeve is light in weight, easy to load and unload, and the sleeve can be easily replaced by hand, which greatly reduces the labor intensity of the operator and can meet the needs of the printing manufacturer for fast, flexible and personalized production.
2. By using sleeves of different thicknesses, the required printing circumference can be changed, that is to say, only one type of outer diameter air-supporting roller can be used to meet the requirements of different printing circumferences in a wide range. The flexibility, such as sleeves with wall thicknesses of 10mm and 70mm, respectively, differs by a print circumference of nearly 400 mm.
3. The sleeve has a small footprint and is easy to store. It is manufactured using special processes and materials with high precision and long service life.
The rapid development of flexographic printing technology has led to the advancement of many new processes and new technologies. Sleeve technology is one of them. This technology has been favored by users since its birth, and its application has become more and more extensive. Judging from the situation, the sleeve technology will continue to maintain a good development trend. At home, the two companies Rotec and LASERLIFE may be familiar with each other. They are the world's leading manufacturers of flexographic printing sleeve products and are flexible around the world. The printing company provides a large number of high-quality sleeve products and perfect technical services, and has a high reputation in the industry. Why is the sleeve technology so popular? What is the charm of its space?
4. The use of a sleeve system reduces production and transportation costs at a low cost.
Because the sleeve technology has the outstanding advantages of the above aspects, it has been favored by the majority of flexographic printing plants since its launch, and has greatly promoted the rapid development of flexographic printing technology.
Classification and use of sleeves
Depending on the application of the sleeve, it can be divided into a patch sleeve, a jointless plate sleeve, a joint sleeve and an anilox sleeve.
1. Plate sleeve
The plate sleeve is specially designed for mounting photosensitive resin plates. This type of sleeve is easy to handle, easy to store and low in cost. Depending on the material of the surface layer, the plate sleeve can be further divided into a hard surface sleeve and a soft elastic surface sleeve.
(1) Hard surface sleeve
Hard surface sleeves, such as Rotec's Blue-Light sleeves, which are precision-machined hard polymers that are extremely hard, high hardness, impact and cut resistant, requiring foam The plated tape is attached to the sleeve. The hard surface sleeve is mainly used for printing on thick plates (1.7mm~7mm). The suitable substrate materials mainly include kraft paper, cardboard, paper bags and soft boxes. It is not suitable for high quality and fine product printing.
(2) soft elastic surface sleeve
The surface material of the soft elastic surface sleeve is elastic, compressible polyurethane foam, which has good compression performance and various hardnesses. It can be selected according to the type of the plate material and the specific conditions of the printing material. cylinder. The soft elastic surface sleeve is specially designed for CTP technology and high-quality thin flexo design. It requires a high-viscosity thin (0.1mm thick) adhesive tape to paste the plate. The soft elastic surface layer not only has good toughness, high processing precision, but also has high compressibility and can absorb vibration. Therefore, the combination of the soft elastic sleeve and the thin plate material can print fine high-gloss dots and dots. The increase rate is small, suitable for high-quality, fine product printing, such as barcodes, thin lines, mesh pattern, etc., and the printing quality and printing effect is very good.
The advantages of the soft elastic surface sleeve are mainly reflected in the following aspects.
1 Standardization of flexographic printing eliminates the need to apply a tape or pad combination to apply a plate to the headache.
2 can meet the requirements of both the screen adjustment and the solid printing, that is, the high-gloss small dots and the solid color blocks can be simultaneously printed on the same printing plate.
3 can effectively control the dot gain, so that the printing quality is significantly improved.
4 can reduce the wear on the printing plate and extend the life of the printing plate.
5 With high resilience and shock absorption performance, it can quickly restore the original shape and avoid vibration even during high-speed printing.
2. Seamless plate sleeve
A seamless plate sleeve, also known as a sleeve plate, is a seamless plate that is directly engraved on the sleeve, which is somewhat similar to a gravure cylinder. With the development of computer direct plate making technology and laser engraving technology, the application of seamless plate sleeves has become more and more popular. At present, many flexographic printing manufacturers in China have used seamless plate sleeves.
The seamless plate sleeve can complete the continuous pattern or the printing of the same background product, such as wrapping paper, cigarette filter tipping paper, wallpaper and so on. In addition, if such seamless plate sleeves are not imaged, they can be used for coating, full glazing, and printing in solid areas.
The seamless plate sleeve is mainly composed of an inner layer, an intermediate layer and a surface layer. The inner layer material of the sleeve is mainly made of special multi-layer glass fiber (GFK), which has the advantages of light weight, low rotational inertia and high bending strength, and can ensure stable rotation even in the case of high-speed printing. The middle layer of the sleeve is made of special urethane rubber, which has high elasticity and compressibility. The compressibility of the middle layer has a great influence on the construction and performance of the sleeve. It can not only increase the wall thickness of the sleeve. It is also capable of absorbing the tensile deformation produced by the sleeve. In the printing process, it is because of the compressibility of the intermediate layer that the smooth running of the sleeve is ensured, and good printing quality is obtained. The surface layer of the sleeve is mainly composed of a hard polymer coated with rubber or a synthetic material.
3. Adaptor sleeve
As an intermediate between the gas struts and the plate sleeve, the main function of the joint sleeve is to increase the diameter of the drum or gas struts. The joint sleeve also has a compressible layer, which has an inflation hole like a gas strutting roller. The printing machine is connected to two air pumps, one of which inflates the gas urging roller, and the other air pump inflates the joint sleeve. It is not necessary to remove the sleeve from the gas struts when replacing the sleeve.
4. Anilox sleeve
The anilox sleeve was produced about seven or eight years ago, a little later than the plate sleeve, and was widely known in the past two years. It is precisely because of the light, fast and many other advantages of the plate sleeve that the original intention and purpose, the anilox roller manufacturers have begun to try to develop the anilox roller sleeve.
Most of the inner layer of the anilox sleeve is made of a compressible material. The compressibility of the inner layer can be used to mount and fix the winder sleeve on the bearing of the printing press. The compressible inner layer is air. To control. The intermediate layer of the anilox sleeve is made of a composite material such as fiberglass or carbon fiber. The surface of the anilox sleeve is covered with a sheath of metal aluminum or nickel metal for the purpose of absorbing centrifugal force and protecting the ceramic layer from cracks.
Sleeve machining accuracy
In the processing of the sleeve, the most important and critical part should be accurate post-processing to ensure that the indicators are controlled within the specified tolerances. In particular, the anilox roller sleeve must continuously contact the squeegee blade, and the coaxial operation must be ensured. For the anilox roller, even if it is only slightly uneven or pitted, the service life of the squeegee and the sleeve will be generated. Bad effects. In general, the higher the number of screen lines of the anilox roll, the thinner the wall is, the more sensitive the force to the mechanism is, and the more obvious the impact is. In addition, the cylindricity, concentricity, and perimeter error are equally important to the sleeve, so it is necessary to make the sleeve as precise as possible.
It is worth noting that since the sleeve may be deformed after being removed, the sleeve should be mounted on the gas-supporting roller when measuring the error of the sleeve. It is best to let it stand for 5 minutes to ensure all the The compressed air is discharged, and the measurement is performed after the sleeve and the gas-supporting roller are gradually adapted and stabilized, so that a truly accurate sleeve error measurement data can be obtained.
1. Diameter size and error
The sleeve must have a precise diameter size, which is the most basic requirement. In general, the sleeve has a diameter tolerance of ± 0.001 inches. In addition, in order to allow the sleeve to be tightly held together with the air-holding roller of the printing press when expanding and contracting, the inner diameter of the sleeve must be slightly smaller than the outer diameter of the printing machine's gas-supporting roller. The error is generally controlled within 0.0015 inches, that is, the inner diameter of the sleeve is 0.0015 inches smaller than the outer diameter of the gas-feeding roller of the printing press, so as to ensure that the sleeve is firmly and tightly placed on the air-supporting roller of the printing press. .
2. Concentricity
Concentricity is a very important spatial tolerance indicator for all anilox rolls. It indicates the amount of deviation of the sleeve from the absolute center axis when it is rotated. This is an indicator of the dynamic balance of one side of the sleeve. If the runout error cannot be eliminated, there is an inconsistency in the circumferential direction of the sleeve. Once the allowable tolerance is exceeded, it is likely that a streak, that is, a ink stick, will be produced on the printed product during printing on the upper machine. The concentricity error of the sleeve is generally controlled within 0.001 inches.
3. Cylindricity
Cylindricity is also important for sleeves, and the cylindricity tolerance of anilox roll sleeves is typically controlled to within 0.0005 inches.
It must be pointed out that the above data should be measured at both ends and in the middle of the sleeve.
Sleeve installation and unloading
The sleeve is generally mounted on the gas strutting roller, which is a matching device for the sleeve application, and its appearance is similar to that of the plate roller. There is an air inlet hole at one end of the gas supporting roller, from which the air chamber of the gas supporting roller can be filled with compressed air, and in addition, some small vent holes are distributed on the surface of the gas supporting roller. The vent hole and the air inlet hole are continuous, and compressed air filled through the air inlet hole can be uniformly released from the small vent hole. That is to say, when the compressed air is filled from the air inlet of the gas strutting roller, the compressed air is uniformly discharged from the vent hole of the gas strutting roller, and an air cushion layer is formed on the surface of the gas urging roller to make the sleeve The inner diameter expands and expands on the air cushion so that the sleeve can be arbitrarily slid back and forth over the gas struts, so that the sleeve can be installed, unloaded or replaced, even on wide-format flexographic presses. The sleeve can be replaced very conveniently.
After the sleeve is installed, the air pump is turned off or the compressed air is cut off, the air between the gas struts and the sleeve is released, and the sleeve is shrunk and coated on the surface of the gas strutting roller, and finally with the gas strutting roller. Tightly and seamlessly integrated into one.
Precautions for use
1. Be sure to keep the surface of the sleeve clean and free of dust, solvents or dry ink. These impurities may gradually penetrate into the inside of the sleeve, causing corrosion or damage to the compressible layer in the middle, resulting in its resilience and Decreased compressibility and ultimately adversely affects print quality.
2. Always use the appropriate method to clean the sleeve to avoid damage to the sleeve material. For example, the anilox sleeve cannot be cleaned by ultrasonic or chemical cleaning, nor can it be cleaned with sodium hydroxide solution, otherwise the elastic compressible material of the sleeve will be deformed and the original shape cannot be restored and maintained. . In addition, since the surface layer of the anilox roll sleeve is made of metal aluminum as a coating layer, some cleaning liquids may cause damage to aluminum, and therefore, these problems must be considered when selecting a cleaning method and a cleaning solvent.
3. The compression layer material of the sleeve must be protected from contact or adhesion to organic solvents, cutting fluids, grinding fluids and polishing fluids to prevent deformation and to ensure that the state of the sleeve remains constant.
4. When installing the sleeve or removing the sleeve from the gas-supporting roller, sometimes the operator may twist or rotate the sleeve slightly. It should be noted that the action should not be too large or too strong, otherwise the sleeve will be deflected or even Damage the sleeve.
5. In order to prevent the sleeve from being deformed or damaged, it is best to store the sleeve on a special bracket. Do not leave the sleeve on hold! In particular, the anilox roller sleeve should pay more attention to this point, otherwise it will easily cause the chipping of the ceramic at both ends. A small piece will form a small crack. When the sleeve is mounted on the bearing of the printing machine, a small crack It will become bigger and bigger, and eventually the net sleeve will be scrapped.
Conclusion
All in all, the generation and development of the sleeve technology has provided great advantages and conveniences for the majority of flexographic printers, adapting and promoting the development of modern flexographic printing technology. At present, many flexographic printing companies have adopted sleeve technology. It can be said that the application of sleeve technology has become a trend in the development of flexographic printing. I believe that in the near future, the sleeve technology will achieve greater development. Let us Wait and see.