A press mechanism refers to the mechanical components and systems within a printing press that enable the printing process. It encompasses a variety of elements that work together to transfer ink from the printing plate to the substrate, apply pressure, and ensure consistent and accurate reproduction of the image.
The press mechanism includes the following key components:
- Plate Cylinder: The plate cylinder holds the printing plate, which carries the image to be printed. It rotates during the printing process, transferring the inked image onto the substrate.
- Blanket Cylinder: The blanket cylinder is responsible for transferring the inked image from the plate cylinder to the substrate. It is covered with a rubber blanket that conforms to the substrate’s surface, ensuring proper ink transfer and even pressure distribution.
- Impression Cylinder: The impression cylinder is located opposite the blanket cylinder and applies pressure to the substrate. It presses the substrate against the blanket cylinder, allowing for the transfer of ink from the blanket to the substrate. The pressure exerted by the impression cylinder must be carefully controlled to achieve consistent print quality across the entire print run.
- Grippers: Grippers are mechanical devices that hold and transport the substrate as it passes through the press. They grip the leading edge of the substrate and move it from one printing station to the next, ensuring precise registration and alignment.
- Ink Train: The ink train consists of various components, such as ink rollers, ink fountains, and ink ducts. It delivers ink from the ink fountain to the ink rollers, which distribute and transfer the ink onto the printing plate.
- Feeder System: The feeder system is responsible for feeding the substrate into the press. It typically consists of feed boards, feed rollers, and guides that position the substrate accurately before it enters the printing unit.
- Delivery System: The delivery system receives the printed substrate from the press and transports it for further processing or finishing. It may include delivery tables, conveyors, or stackers to collect and organize the printed materials.
- Control Systems: Press mechanisms also involve control systems, such as motors, sensors, and actuators, which ensure precise and synchronized operation of the press components. These systems regulate speed, tension, pressure, and other variables to achieve consistent and reliable performance.
The press mechanism is a complex arrangement of mechanical, electrical, and pneumatic systems working in harmony to achieve accurate and efficient printing. Proper maintenance and adjustment of the press mechanism are essential to ensure optimal print quality, registration, and overall press performance.
It’s worth noting that the specific components and configurations of the press mechanism may vary depending on the type and model of the printing press, as well as the printing process being employed, such as offset lithography, flexography, or gravure.