In album printing, there are many unpredictable printing problems, some human factors, some machine failures, some weather reasons, and the causes of substrate. Let's see the specific impact of album printing overprint.
In overprinting, some plates belong to metal materials. When they are installed on the cylinder of the printing machine, the pressure of the plates will slightly deform, especially in terms of length and width, which will have a little impact on the overprinted plates, not the cause of overprinting.
The change of plate thickness and plate surface size is also the cause of overprinter album printing error. When the plate is installed on the cylinder, it must be bent manually. When a metal object is bent, a neutral layer is formed, the interior of the surface is compressed, and the exterior is stretched. This will make the front and back of the plate have different radii, and the surface tension is large, resulting in "collapse" phenomenon, leading to the elongation of the size surface of the plate.
Through the above reasons we have no way to solve, then in order to ensure the position is accurate, use the minimum tension value, reduce the number of plate pulling, and use the plate with the same thickness. In printing, it is necessary to reduce the number of adjustment plates. If it is necessary to adjust, it is also necessary to follow a clear direction, rather less than more, the position must be accurate, and do not use force, otherwise the plates will be easily deformed.
The dimensions and specifications of the unprinted semi-finished products shall be consistent with the plates. In order to ensure the accuracy of overprinting, the paper folding machine staff should carry out sampling test before paper folding to see whether they meet the specifications and plate sizes. Especially in the case of seasonal changes, room temperature and humidity instability, it should be paid full attention to. If the paper size is found to exceed the allowable tolerance range, it should not be printed. The humidity needs to be readjusted to avoid overprinter and paper problems.
The plates used by each printer should be checked carefully before installation. All plates shall be of the same size and, where possible, of the same thickness.
Album overprinting is also wrong because of the substrate, paper also accounts for a large part of the reason, especially in the seasonal temperature and humidity is not the same environment easily lead to overprinting errors. Paper is a thin layer of material interwoven with natural plant fiber, which has strong hydrophilicity. Moreover, the paper made of fiber interweaved has numerous pores of different thicknesses, which have capillary adsorption on water. Therefore, paper is a material with strong water absorption.
The inaccuracy of the graphic printing records sometimes results in that the cutting knife is not sharp, and the image album and knife have some influence. Therefore, this area can be avoided as long as the inspection does not covet the cutting of the disposable cutting tool. In many cases, it can be avoided as long as the small details above, the printing machine and processing of the inaccurate overprint of the album are carefully done to avoid these situations It happened.