The main components of flexographic printing machines
The flexographic printing machine mainly consists of four components, namely the unwinding and feeding component, the printing component, the drying component, and the rewinding and receiving component. In modern flexographic printing machines, there are generally measurement and control devices such as tension control, edge control, registration control, and print observation, as well as mechanical status monitoring and fault diagnosis systems. In addition, in order to expand the scope of application, some flexographic printing machines are also equipped with devices such as glazing, laminating, hot stamping, slitting, die-cutting, punching, screen printing, and gravure printing units, becoming a flexographic printing joint production line.
Unwinding and feeding components
The printing speed of flexographic printing machines generally reaches 150m/min (or even higher). In normal operation, in order to reduce the number of shutdowns and waste of roll materials, a unwinding and feeding device must be installed. The function of unwinding and feeding is to unfold the printed material in rolls, continuously and stably feed the printed material into the printing component, and control its speed, tension, and lateral position before the printed material reaches the first printing component. The unwinding feeding component consists of a coil holder and a set of guide rollers, which are arranged in a straight line with the printing component. The material roll rack is controlled by electric or hydraulic components for lifting, and is generally locked by pneumatic components to the axis of the roll paper. The end of the roll paper is equipped with a detector.
Tension control system
The unwinding feeding component is also equipped with a digital controlled electromagnetic braking tension system. He can achieve optimal tension control for different substrates and is not affected by dust and dirt. The tension compensation control adopts a loop type self detection system, which can continuously maintain the tension stability of the paper (or film) as the diameter of the roll paper decreases.
Drive roller
The unwinding feeding component is also equipped with a driving roller machine. The drive roller is an easily adjustable and variable speed feed roller that controls the speed at which the web paper smoothly enters the printing unit and, together with the roll brake device, generates unwinding tension on the strip to adapt to the production of different substrates (such as cardboard, thin paper, plastic film, etc.), while ensuring that the web paper maintains the correct longitudinal position.
Floating roller
The floating roller machine for unwinding feeding components can reduce the fluctuation of unwinding tension and shorten the downtime when replacing the material roll, in order to improve the efficiency of flexographic printing machines. Most flexographic printing machines are equipped with continuous roll changing devices, which are particularly important for connecting the material roll without stopping the machine.
Edge control system
The unwinding and feeding device of the high-end flexographic printing machine is also equipped with an edge control system. One edge control system is installed in front of the printing unit, and the other edge control system is installed in front of the die-cutting table. This design keeps the material roll in the correct position throughout the entire production process.
Printing components
The printing components are the core of flexographic printing machines, using a short ink path ink conveying system. There are two ink rollers, or even one ink roller with an ink scraper, which can achieve uniform and quantitative transfer of ink from all ink to the surface of the printing plate.
