In today's rapid development of modern technology, with the printing process flexo printing technology is more mature and widely used in corrugated boxes, functional components of roller as flexo printing machine is the key, the manufacturing technology and manufacturing precision and variety also in the rapid development, in order to meet the needs of corrugated box flexo printing machine, flexo printing to wide high-speed, multi-color and high-grade color order. The characteristics of the metal roller with its low cost, short processing cycle, durable, good accuracy and selection of a wide range of anilox roll, as the largest family of family, widely used in high speed corrugating medium and high grade in the number of cartons flexo printing machine is the most common.
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One. The manufacturing technology of metal roller metal roller according to the different production methods, respectively, the metal roller manufacturing to photographic film print, corrosion crazing process, a copper in steel roller by computer control of the metal roller electronic engraving and checkered tool in steel roller surface directly to the metal roller mechanical extrusion production. Anilox roll production process because of its corrosion will make the roller surface texture seams, joints caused by ink uneven, also not easy corrosion production line number in the netted more than 100 lines per inch, therefore does not adapt to use in corrugated box printing process. Copper electric carving roller because of its texture is soft, not durable and not resistant to a water-based ink corrosion alkaline, carving depth and other shortcomings, limited its scope of application.
The universal application of corrugated box flexo printing machine, metal anilox roller, all manufacturing processes, extrusion, its accuracy is mainly determined by the manufacturing process of reticulate tool and roller and extrusion technology to ensure the. Now the domestic mechanical extrusion process level of manufacturing metal roller uneven, some good and some bad, the main difference is that the machining precision of the cutting tool precision and roller and anilox extrusion technology. A magnifying glass check inferior 25 times metal anilox roller, the roller network points of rough, not clear, shallow, network wall width, mesh line number is not accurate. Plus roller after manufacturing dimensions and tolerances of low accuracy, balance is not good, so the poor use effect.
Process technology is mature enough to ensure the roller surface length checker metal above 3000mm ink roller, the line number can be up to 300 lines per inch, cylindricity < 0.016mm, radial runout < 0.02mm, with 25 times the magnifying glass check, clear and smooth texture, network wall narrow, neat edge, therefore, excellent ink reservoir ink, ink performance. The metal roller must also withstand wear and good corrosion resistance, the use of today's international most advanced Heef-25 high efficient micro hard chromium plating process of crack, can make the roller surface hard chromium coating obtained than ordinary hard chromium plating coating was more hard, more smooth, more bright, more wear-resisting, the microhardness of the HV900 ~ 1050, micro crack layer number per square centimeter of up to more than 400, the use of the technology of metal anilox roller has excellent corrosion resistance and wear resistance. The metal roller the manufacturing process for the domestic and foreign various famous supporting the use of high speed corrugating medium and high grade in the carton flexo printing machine and manufacturers, obtained very good effect.
Two metal anilox roller function.
The surface of metal anilox roller is processed into a certain standard arrangement, shape, size and depth completely uniform network points, which play the following functions in operation work:
1 measuring storage ink. Metal anilox roller surface processing into the network points can accurately measure and store the ink. Specification (shape, size, depth) is not the same as the volume of the formation of the network points are also different. According to the different ink performance, printed material by ink performance and the printing content form (color, line thickness, area of flexo printing line) to ink performance, can choose the appropriate specifications of network points.
The 2 ink distribution function. Metal anilox roller surface is made of countless according to certain standard arrangement, shape, size and depth completely uniform network points, to transfer ink is distributed very evenly, the relative operating scraping rubber roll extrusion blow, the formation of a uniform layer of ink layer on the metal anilox roller surface.
3 transfer ink. The metal anilox roller, rubber roller, roller scraping plate composed of flexo printing machine inking printing system. Metal anilox roller rotates a circle, the full functionality of a measurement, ink, ink, the ink transfer process.
Three. Technical conditions of metal anilox roller.
The structure of 1 net (network points, network wall) netted by network points and net wall composition, network point is a squeezed carved into the same three-dimensional geometry (six cone, cone, four diamond cone and so on), the size of the pit. Between the pits and the pit wall called the network interface. In order to obtain sufficient storage feeding ink quantity, the more narrow the better network wall always asked to do, in order to secure volume as much as possible. Therefore, in order to ensure the precision of the machining tool, to achieve the best depth.
2 net shape metal anilox roller different reticulate shape decides the different volume and storing and feeding amount of ink, reticulate shape mostly tetragonal prismoid shaped, hexagonal, and Pyramid, six angle shaped, diamond and so on. The same line number, net shape, volume is different. In the same line number, select the appropriate anilox shape, can achieve better printing effect.
3 roller line number we can put the net as by a convex line intersected, and each inch (25.4 mm) in length and convex line number is netted lines, also is the net specifications. Line number more, more net points per unit area, ink layer transfer more uniform. But at the same time, network point also is small, the volume is relatively small, ink layer is thinner, a corresponding reduction in the amount of ink.
Metal anilox roller wire selection mainly depends on the actual inking printing products, generally in the 165 ~ 300 line / inch. Field printing large area can choose line 165 lines per inch, and gradation of color flexographic printing 55 ~ 85 lines can choose 180 ~ 300 line / inch. At the same time, the number of roller and flexo printing line number has an important relationship, the number of roller must be flexo printing line number 3.5 ~ 4 times, so as to ensure that the resulting ink point minimum dot not high light flexo version in roller network points, influence printing quality the amount of.
Cable arrangement angle metal anilox roller 4 reticulate arrangement angle refers to the angle between the axes and the roller. The general case, tetragonal prismoid, Pyramid is 45 degrees, and the hexagonal, six angle connected shaped, diamond is 60 °, there are 30 °. Industry colleagues all know, if the roller and flexo printing screen angle of coincidence or the number of roller and flexo printing line number disproportionate, printing will crack. So the flexo printing cable arrangement angle must avoid anilox roller wire arrangement angle.
To adjust the amount of ink, in addition to select the appropriate anilox line and network points outside of the shape, the rubber scraper roller and metal anilox roller contact pressure micro adjustment can also make corresponding adjustment of the amount of ink, ink amount of metal anilox roller is also affected by other factors: such as the viscosity of the ink, network points of congestion, wire wear, rationality and the roll wear surface hardness of scraping rubber rollers and change of physical and chemical properties, high curve shape, the center distance between the two roller pressure caused by insufficient limit line, flexo printing, printing material physical properties etc..
Four. The metal anilox roller use conditions
The 1 metal anilox roller precision
(a) the size precision roller: outside diameter size must be minimum range greater than the ink roller and rubber scraping the center distance between the length, size must be larger than the printer name format is more than 50 mm, the shaft gear and bearing size meet the design requirements, the wire number and arrangement and reticulate shape selection.
(two) the roller shape and position accuracy: roller surface cylindricity is less than 0.016mm, the radial bearing for reference, the roll surface and the shaft gear runout is less than 0.02mm.
(three) the roller roller balance: balance must be static balance, the unbalance control in the smallest range. High speed roll must also make dynamic balance check.
(four) roller surface roughness: the surface of roller working surface roughness of 0.8 μ M
2 related parts of the precision
(a) rubber scraper roller:
The quality of nitrile rubber material, shore hardness 65 ~ 75 degrees, the roller surface of drum high volume and high curve shape must correspond with the working tension. The roller surface roundness is less than 0.016mm, the radial bearing for reference, the roll surface and the shaft gear runout is less than 0.02mm, the surface of the work surface roughness must be less than 0.8 μ m, balance requirements
(two) a printing plate roller, flexo printing, embossing roller, bearing, gear and other precision meets the relevant requirements.
Properties, viscosity, filtration conditions 3 ink, printing materials by performance meets the requirements of printing with ink.
4 printing pressure corrugated box flexo printing belongs to light pressure, so the contact pressure between the rolls must be in strict accordance with the requirements of debugging, to ensure uniform pressure line. If the pressure is too large, non normal wear and tear, mechanical fatigue, cause deformation of rollers, even the shaft neck fracture. At the same time also damaged plate, affect the quality of printing products.
5 speed running speed and the amount of ink to a certain extent, is running slow. A large quantity of ink, ink transfer a small amount of running speed. The stable operation speed, can obtain the amount of ink is stable. Because the ink viscosity is proportional to the amount of ink, and therefore, a large area printing can adopt a slightly slower speed and the viscosity of the slightly higher ink and low lines of anilox. And the color tone printing with fast speed and low concentration of ink and high net line number.
Five. Maintenance metal anilox roller.
Metal anilox roller is an important part of high precision, great value. The anilox roller, rubber roller and a printing plate roller scraping the flexo printing machine inking system for flexible contact, wash synchronous transfer, it is different with the scraper system, wear is extremely small roll. In fact, the vast majority of anilox roller damage is caused by accidental and man-made factors and improper maintenance reasons, only a few belong to normal wear and tear. Therefore, metal anilox roller maintenance is very important and very necessary.
1 to actively prevent and eliminate accidents and man-made damage factors of metal anilox roller surface is coated with wear-resistant hard chromium, but its hardness is HB180 ~ 240, can not withstand the impact of hard objects and planning mill. Therefore, in the process of installation, debugging, use and cleaning, must be circumspect, hanging light with care, prevent collision scratch the surface. To prevent the ink is not filtered out of hard particles and agglomeration in between the two rollers, rubber roller roller surface worn out groove.
2 strictly to do the cleaning and cleaning metal anilox roller after work and a long time shutdown, must conduct a thorough cleaning of the ink transfer system, and use clean cloth to wipe clean. Because water-based ink in the residual liquid in the bottom points dried difficult to dissolve Yu Xinmo, unless dissolved very long time. "Once blocked, will affect the amount of ink. Have found that roller jam should be removed, to protect the roller surface outside part, and then soaked in alcohol, ester, mixed solution of water and ammonia is placed inside a few days, can also be liquid handling dissolved alkaline detergents or strong detergents with warm water, or solvent oil ink resin dissolve (most water-based ink from acrylic acid or maleic, generally using aromatic or ketone solvents). In the cleaning machine should pay attention to protect the rubber roller and a flexible version, do not use the rubber swelling solvent (such as xylene, ester, ketone solvents). The new roller must take the surface protective grease clean before use, if free fatty acid is mixed with the ink, easy to stick and mesh plug. Cleaning appliances can only use wire brush or brush, prohibited the use of steel wire brush to clean, so easy to scratch the roller surface reticulate.
The 3 temporary shutdown metal anilox roller to separate from and a printing plate roller, but the anilox roller and rubber scraper roller rotate to contact, to prevent the ink dry deposition in the back of the net.
4 prohibited metal anilox roller and rubber roller without scraping ink state contact rotation, because of dry friction causes the rubber roller heating damage, rubber particles falling block mesh.
Six. Repairing the metal anilox roller and re manufacture
Damaged metal anilox roller can be sent to the professional roller manufacturing company to repair or re making of Surveying and mapping. Such as shaft gear wear can be sprayed steel, welding or hard chrome plating, increase the processing and re grinding to size requirements. At the same time, also can be the head of the restructuring, head to repair the broken.
Remediation of metal anilox roller and re system must pay attention to the following questions:
Repair of 1 metal anilox roller must put the whole roll surface grinding, and then re making reticulate, and hard chromium plating. Roller diameter after repair will be reduced, care must be taken to limit diameter after repair. Because of too small diameter than with rubber scraper roller center distance adjusting range and can not be used. If the eccentric enlarged eccentricity adjusting gear distance can enlarge the regulation range, but it is too reduced outer diameter will cause the roll line speed inconsistent tendency to expand, accelerate wear flexo printing edition, influence printing quality.
The 2 surveying and mapping to produce metal anilox roller, must check the original design size, mesh line number can be re selection.
The 3 metal anilox roller repair and reproduction at the same time, deal with the rubber scraper roller carefully check. Damaged roller often caused serious damage, scraping roller rubber so, must at the same time to repair damaged rubber scraper roller.
Metal anilox roller because of its excellent performance and economic performance, with the rapid development of flexo printing technology today, there is still a position can not be ignored. In the use of metal anilox roller, correct knowledge and understanding of its characteristics, grasp its use and maintenance methods, it can make the metal anilox play a greater role and economic benefits in ink roller flexo printing corrugated box in the middle.
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