Fine gravure printing is three parts by printing, seven parts by plate making!


Published on:

2017-04-21

It is often said that "seven points by the plate, three points by the printing", no doubt that the quality of the printing plate is critical for gravure printing. Among them, the plate cylinder processing accuracy on the impact of overprinting is particularly important.

Fine gravure printing is three parts by printing, seven parts by plate making!

It is often said that "seven points by the plate, three points by the printing", no doubt that the quality of the printing plate is critical for gravure printing. Among them, the plate cylinder processing accuracy on the impact of overprinting is particularly important.

The main indexes of printing plate cylinder mechanical processing accuracy precision

Circular runout of the printing plate cylinder, coaxiality, roundness, taper of the cone hole, etc.. Among them, the printing plate cylinder processing accuracy on the impact of overprinting is the most direct and critical, other factors can be expressed in varying degrees for the running of the printing plate cylinder circular runout.

A, round runout

Impact one: the error will change the length of the printing path

Plate cylinder circular runout error is large, will lead to irregular changes in film tension, and varying degrees of change in the length of the entire printing path.

Impact two: large deviation of the cone hole will affect the printing register

In addition, the plate cylinder is through its two ends (with key slot) of the tapered hole to position and transfer torque, and the tapered hole at both ends of the plate cylinder have respectively with the frame of the two fixed plate (with key) cone head closely with the two fixed plate cone head and its key on the plate cylinder played the role of axial positioning and radial positioning, and by the cone hole to drive the movement of the plate cylinder.

If the plate cylinder ends of the cone hole deviation is large, it will make the fixed plate cone head and cone hole can not achieve close cooperation, printing will affect the running accuracy of the printing plate cylinder, thus affecting the printing register.

Impact three: the concentricity of the cone hole and the cylinder affects the smoothness of the cylinder

In addition, the concentricity of the cone hole and the cylinder at both ends of the printing plate cylinder also directly affects the smooth operation of the printing plate cylinder. If the plate cylinder in the installation (welding) cone hole can not reach a good concentricity, will certainly bring adverse effects on the printing register.

Second, the plate cylinder diameter deviation will cause register deviation

Generally used for OPP film, PET film printing, the plate cylinder diameter difference of 0.03mm, and for PE film printing, it is 0.05mm. If the plate cylinder diameter deviation exceeds the difference, it will bring great difficulties to the printing. Therefore, when processing gravure plate cylinder, the diameter error of the plate cylinder must be strictly controlled within the allowable size deviation, while the plate should be installed in strict accordance with the design plate sequence, otherwise it will not cause unnecessary register deviation.

Third, the register mark error will affect the system tracking register

The register mark is the information source of the register system, which records the relevant data information of the register (including horizontal register and vertical register). During the printing process, the register information is adjusted to the register of the print based on the amount of change in mark displacement. Therefore, the plate cylinder must ensure that the location of the registration mark is accurate, if it is beyond the adjustable error range, it will affect the system's tracking registration, and will not achieve the purpose of accurate registration.

Fourth, the cleanliness of the plate cylinder will affect the installation progress

When installing the plate, you must ensure that the cone hole at both ends of the plate cylinder and the solid plate head clean, not sticky ink or other impurities, otherwise it will affect the installation progress. After the plate is installed, the application of hand test rotation, check whether the plate cylinder is flexible, whether there is loose phenomenon. Before printing, you can also use the indexing table or radial runout meter to detect the existence of circular runout plate cylinder, in order to timely adjustment, to ensure the quality of printing.