Analysis and troubleshooting of the most popular g

Gravure printing plate fault analysis and troubleshooting

III. The problem of inaccurate or excessive inking

(I) paper flatness factor

the ideal paper should be smooth, flat and uniform in thickness on both sides, so that it can form a good contact with the flat surface (such as liner, blanket, printing plate, etc.). But in fact, most papers are not ideal, mainly manifested in: uneven thickness, uneven paper surface, can only contact one side of the printing plate; The rough surface of the paper can only have a small area of discontinuous contact with the printing plate, which is one of the factors that can be roughly divided into three categories: photodegradable materials, biodegradable materials and photodegradable materials according to the degradation mechanism

generally, the paper with uneven surface but uniform thickness can form a good contact with the printing plate by adjusting the printing pressure. However, if the uneven paper has poor compression performance, it cannot be adjusted in this way. However, if the paper is flat on one side, it can be lined with a cushion to form a good contact with the printing plate. However, these two methods will cause the extension or bending of the paper itself, and the required pressure will be adjusted according to the amplitude, frequency, roughness and hardness of the paper surface

(II) factors of different inking properties on the surface of paper

at present, the commonly used papers include coated paper, white cardboard, gold card, silver card and glass cardboard. At the same time, gold card and silver card are divided into aluminum foil gold card, silver card and PE film gold card and silver card

in addition to the influence of the flatness of paper on the inking performance of printing, the more important thing is its material. The ink absorption of the body is also the main factor to answer your operation problems. For example, compared with gold card and silver card, the ink absorption of white card is much greater than that of gold card and silver card. However, the ink absorption of the gold card or silver card with aluminum foil is significantly greater than that of the gold card or silver card with PE film

due to the above paper factors, customers should provide accurate paper information during plate making, so that the plate making company can formulate different plate making processes according to different paper properties

(III) problems in information transmission

in the printing process, paper, ink, plate rollers and printing machines are all suppliers of printing plants. A high-quality product must be their best cooperation. No matter which link has problems, printing defects will occur. Therefore, the cooperation and exchanges between the four parties are very important. However, in practical work, due to the large industry span and few opportunities for mutual communication, it is very difficult to solve the comprehensive problems of printing only by one side. For example, when our company makes a variety of soft bags for a customer, when there is a big red blank word (English word, Chinese word will be worse), the blank word after printing on the printing plate is obviously thinner than the sample, and then look at our company's concave blank word is slightly thicker than the sample. We analyzed with our customers and wanted to solve the problem by increasing the viscosity of the ink and reducing the printing pressure. The phenomenon of ink flapping after printing was obvious, and then the phenomenon was eliminated after changing the ink formula again

another problem is that due to various factors, many manufacturers insist on deepening the depth of the plate roller, making the printing plate almost reach the limit depth of electronic engraving. In fact, the deeper the plate roller is, the less conducive it is to high-speed printing, and the more likely it is to produce knife threads, blocking plates, and ink dragging on the edge of patterns