The process of ensuring the printing quality of milk packaging film

In order to ensure the printing quality of milk packaging film, it is also necessary to pay attention to the control of printing tension, printing pressure, printing speed and drying temperature during the printing process, formulate stable and reliable process standards, standardize the process flow, and ensure the smooth production of scale. get on.

1. Printing tension should not be too high. In the printing process of polyethylene film, the control of printing tension is the key. Because the stretch rate of the polyethylene film is relatively large, it is prone to tensile deformation under the action of the traction force of the printing machine. If the tension value is too large, the polyethylene film will have a large tensile deformation, and the overprinting failure will occur, affecting the printed matter. Quality and precision, so the printing tension should be set smaller.

2. Grasp the pressure of printing. According to the printing method, printing ink and substrate materials, etc., the printing pressure is controlled within an appropriate range. If the printing pressure is too large or too small, the print quality may be adversely affected. Printing pressure is too high, the ink is easy to spread, the graphic is easy to get thicker and wider, and even the stencil, the bar code cannot be read; if the printing pressure is too low, the amount of ink is insufficient, and the graphic is easy to become thin, narrow, and even incomplete .

3. The speed of printing should be appropriate. Fast printing can increase production efficiency and output, but printing speed is not as fast as possible. The size of the printing speed should be matched with the drying speed of the ink, the viscosity, the temperature of the drying oven, and the temperature and humidity of the workshop.

4. Set the drying temperature properly. The temperature setting of the drying oven of the printing press is generally around 40°C. Otherwise, the shrinkage and deformation of the polyethylene film may easily occur, thus affecting the overlay accuracy. Therefore, when setting the temperature of the drying oven, it is necessary to comprehensively consider factors such as the characteristics of the substrate materials, printing speed, printing tension and printing patterns to ensure that the ink solvent is fully evaporated and dried to ensure the fastness of the ink.