Solution to the problem of transfer non inking in

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To solve the problem of non ink transfer in packaging and printing

major technical problems in packaging and printing have plagued people for a long time. The problems mainly focus on ① ink migration; ② The ink film turns yellow; ③ Printing white dots; ④ Back adhesion and adhesion; ⑤ Discoloration and discoloration; ⑥ White ink film; ⑦ Pinhole and shrinkage; ⑧ Transfer without inking; ⑨ Biting color (commonly known as cross color) and fading; ⑩ Poor gloss (whitening). These printing technology problems have become a common consensus of production failures. 1. Pinhole and shrinkage. In the process of packaging and printing, due to the operation of machinery, especially the rotation of printing plate and printing roller, the ink film often forms pinholes. These pinholes with different sizes and different numbers are often called chemical pinholes. In the same part, small holes of the same size are often divided into mechanical pinholes for some new products such as microcomputer controlled electronic universal experimental machine models that have never been produced in this unit, but occasionally there are pinholes with dot a white circle, which are often caused by the shrinkage of particles after the post press drying of electronic devices due to impurities or tiny resins in the ink

the chemical pinhole fault is due to the rapid evaporation of solvent in the wet ink film and the overflow of air foam in the printing ink film, which makes the wet film unable to flow flat, resulting in needle shaped holes after the packaging and printing ink film is dried. Of course, there are also ink production and color matching ink, or the bubbles generated by excessive ink dilution do not disappear. During the printing drying process, when the bubbles overflow, that is, non renewable energy, the ink film has lost its fluidity, resulting in the pinhole type. When the ink contains a small amount of water or at high temperature, especially at high temperature, the pinhole phenomenon is more likely to occur

the solution is to strictly select the ink, strictly screen the thinner, control the ink viscosity, appropriately select the solvent with slow volatilization speed, so as to improve the leveling of the printing ink film, prevent the mixing of moisture and impurities, and check the cleanliness of the vacuum pump air and the pollution of the substrate surface. For two-component inks and two-component composite adhesives, they should be placed for a period of time, and printing inks that have produced surface or internal flocculation should be prohibited

2. The transfer cannot be inked, said Zhen Ronghui. In the normal printing process, the ink occasionally does not rotate with the ink bucket roller, and even the ink accumulates on the printing machine. Especially after the printing speed is accelerated, the color tone of the printing ink is shallow or different

in the past, this fault was mostly caused by too high pigment content, too thick ink, too large yield value or too short ink head. The above phenomenon is caused by the high acid value of binders and pigments in the ink system, or the excessive absorption of acidic water or the addition of a single solvent

once this fault occurs, add an appropriate amount of tm-27 coupling agent. If it is serious, add TM-3 coupling agent or alkaline solvent for dilution, or add wetting agent or gold blending oil, or increase the printing pressure. If the roller is bad, replace the roller, or install an agitator in the ink bucket

reprinted from: printed in China

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