Cigarette Packaging Design causes and solutions of printing duplexes

Cigarette Packaging Design causes and solutions of printing duplexes

Printing double image is one of the common printing faults. Although the side image cannot be directly observed by vision, it increases the dot area and deteriorates the acute Angle of the edge, affects the order and color restoration of the image, reduces the image clarity and seriously affects the printing quality. There are many specific reasons for the double shadow, including printing machinery, printing technology and paper. The general types of double shadow are divided into three categories, namely, transverse double, longitudinal double and irregular double. I will briefly introduce the causes and solutions of these three types of printing duplexes.

Horizontal duplexing of printing duplexing

Horizontal double shadow refers to the shallow shadow appears in the axis of the dot or line left and right, its position is relatively fixed, double shadow has light and heavy. I think horizontal gaping is generally caused by the following three reasons:

The double shadow caused by axial displacement occurs during the operation of the two rollers

Offset press roller thrust bearing is to prevent the drum axial moving parts, if thrust bearing wear or loose, there are gaps, the helical gear under the action of axial thrust, if there is any string of drum and transverse ghosting, multi-color machine with axial fine-tuning organization is loose, bearing wear, can make the printing press under normal working state plate cylinder and rubber roller axial relative displacement, This causes horizontal double shadow. Solution: We should pay attention to the maintenance of the printing press at ordinary times, and replace the bearings with serious wear in time to avoid it.

Double shadow caused by axial paper transfer error

This kind of fault is generally due to the paper tooth axis axial channeling caused by the paper is not accurate, and produce double. Solution: adjust the gap between two tight rings and the end face of the roller paper tooth shaft.

Double shadow caused by flounces of paper

Falbala paper paper margin due to the longer, the first color printing pressure to drag the tip edge extrusion and gradually move into, the after the first color embossed into the second color, originally is the first color extrusion folded paper and released, this kind of fold and release a quantity to contain randomness, lead to a residual before the next unit rubber cloth of imprinting and the current mark can't overlap, This causes double shadow. Most of this kind of double shadow occurs in the two corners of the first color trailing edge, there is no middle, the solution: paper drying paper processing, so that the paper becomes relatively flat and then printing.

Cigarette Packaging Design Cigarette packaging design of vertical duplexes

Longitudinal double shadow refers to the light shadow appears in the dot or line axis forward, its position is fixed, double shadow has light and heavy, branch department and the whole layout of two kinds. It is believed that longitudinal double shadow is generally caused by the following three reasons:

Blanket can not be completely reset after each transfer, resulting in double

The pressure between the drum is too large or the drum radius is not properly configured, the rubber blanket is under the action of the friction force on the embossing surface, the displacement is large, and the transfer cannot be completely reset, resulting in double image. Solution: reasonable adjustment of printing plate drum and rubber drum lining data, so that they meet the requirements of synchronous rolling; Under the premise of ensuring ink transfer, reduce printing pressure.

A double image caused by a loose blanket

The rubber blanket is not tight, the displacement is large in the rolling process, and the rubber blanket is not tight, there are two situations: first, the overall tension is not tight, causing a large area of double; Second, the rubber cloth cutting skew or iron splint fashion is not good, resulting in local tension is not tight and local double. This kind of double production in the trailing part, the general double production only in the beginning of a few dozen. Solution: if the blanket is not tight, re-tighten it; If the local tension is not tight, check whether the rubber blanket cut skew or loaded badly, find out the reason and correct.

A double image caused by the dislocation of the printing plate during operation when the plate is not taut or the plate is cracked

Solution: tighten printing plate; If the plate has cracked, you need to change the plate.

Cigarette Packaging Design describes the irregular duplexes of printing

Irregular gaffing refers to the double diameter drum offset press in the continuous operation of the printed gaffing (neither transverse gaffing, nor longitudinal gaffing). Irregular duplexes are caused by the printing machine itself, as well as by the operation of the printing process. The main reason for the machine is the double diameter roller two sets of teeth installation accuracy is not enough. Printing process operation problems, mainly long-term use of dental pad is worn, precision decline. Usually pay more attention to the maintenance of the machine, so that the machine is in good running condition, the situation of the double shadow will be controlled, the quality of printing will be improved.

Printing double image is often the devil that printing masters will not go away, but as long as we learn more printing technology and constantly summarize experience, we will stay away from the devil and restore the true image!