Experience on consumables and environmental select

Experience of consumables and environmental selection for label printing

1 The label pattern of paper

is mainly on the spot, which puts forward requirements for the smoothness, whiteness and gloss of the paper. If you want to obtain a satisfactory label field printing effect, the smoothness of the paper should be high by using special data processing software, so as to ensure that the printed matter has a uniform density value, so that the surface of the printed matter will not be scratched. Because the paper with high gloss and whiteness can enhance the contrast between ink and paper, make the picture and text clearer, and make the flexographic ink show a bright effect with stronger initial clamping force, gloss and whiteness are particularly important when choosing flexographic label paper. The whiteness and gloss of the paper should be selected under the condition that the opacity of the paper is consistent. The whiteness should be higher than 85% and the gloss should be higher than 55%. The tensile strength of paper is another important selection index. Only if the tensile strength is good, can the paper be stable in the whole printing process, and the label maintain good overprint accuracy. The surface strength of the paper is also an important indicator. Only if the paper has good surface strength can the field printing be full, and there will be no printing surface blooming and uneven color

2. The oil energy consumption is reduced by 40000 tons of standard coal ink every year. As an example of upgrading and improving the product of the vertical experimental machine, the ratio of pigment is too high (higher than 35%), which will increase the viscosity of the ink and thixotropy, affecting the transmission of the ink. At this time, it is necessary to stir the ink and store the ink at a suitable temperature (20 ℃). When choosing the ink, we should also consider the particle size of the ink and the drying performance of the ink. In particular, when there are not only large-area color blocks, but also words, lines or eye-catching images on the label, we should consider that different patterns have different requirements for the drying speed of the ink. Too thick pigments will cause certain wear on the wrinkle roller, and we should also pay attention to the selection of ink

3. Printing environment

when printing labels with flexo, environmental factors are very important. The drying speed of printing ink in the printing text, lines and other parts will be accelerated due to the volatilization of ammonia and amine substances, so it is necessary to improve the micro environment of printing ink, and add a humidifying device at the ink tank to inhibit the volatilization of such substances and control the drying speed. In addition to controlling the micro ring, the control of the overall environment in the printing process is also very important. When printing labels with different types of paper and patterns (mainly on the ground or lines), the choice of humidity is different. Generally, the humidity of waterproof paper printing needs to be higher, and the humidity of large-area field needs to be lower. Too high ambient temperature will affect the drying effect of inks (water-based inks, solvent based inks) and cause printing products to appear paste and other phenomena; Too low temperature will cause the viscosity of the ink to increase, so it is necessary to stabilize the temperature and humidity of the printing environment within a certain range. In China, the four seasons in northern China change obviously, and the temperature and humidity vary greatly. It is best to close the printing environment and install humidifiers, air conditioners and other equipment to create an environment suitable for flexo printing; Due to the rainy weather in the south, the dehumidification of the workshop should be a key point to create a flexo printing environment. The ambient temperature and humidity suitable for flexo printing are generally: the temperature is about 25 ℃ and the humidity is 50% - 60%

4. Operators

in label flexo printing, human factors are also key. Operators should mainly have the following qualities: high heart; Have a certain understanding of mechanical principle and electrical knowledge; Have a certain chemical knowledge base; Master various printing processes; Good at summarizing. Only by summarizing and refining the problems in printing in time can we continuously improve our ability