One example of the lack of circumferential overprint by blankets

In the four-color offset printing press for many years, there are often problems with overprinting of the printing products. The crosshairs are very accurate, and the size of the crosshairs at the tip is different. Under normal circumstances, it is generally believed that the stripping tension after the imprinting of the paper through the four color groups is large and the blanket is not the same. During an inspection of the machine, an audible noise was heard from the second color group. According to experience, it was judged that the sound was made when the blanket was not tight. Therefore, the machine stopped immediately, stretched the blanket, and reprinted. Imprinting is more accurate than the original.

According to the characteristics of the air-cushion blanket, the blanket can always be deformed during the printing process. When the blanket is printed under slack, it will make the print on the paper more prolonged than the actual one. Conversely, if it is shorter, changing the tightness of the blanket can change the circumference of the print, so that the overlay can be accurately printed. purpose. This method is easy to operate, and can receive satisfactory results, but it needs special emphasis, this can only be fine-tuned in the case of unable to solve the pull plate method, especially when relaxing the blanket should pay attention to safety and to prevent Ghosting and other failures must not be abused.

(Yangzhou Xinhua Printing Co., Ltd. Mo Guoxin)

Reprinted from: Printing Technology