An impression cylinder, in printing, is a cylinder that comes into contact with the substrate during the printing process. The substrate is usually paper but can also be other materials, such as plastic or metal. The main purpose of the impression cylinder is to transfer the image from the printing plate to the substrate.
The first step in the printing process is to create the image on a printing plate. The printing plate is usually made of metal, and the image is created by either etching the image onto the plate or by using a photochemical process. Once the image is created on the plate, it is then transferred to the impression cylinder.
The impression cylinder is made of a hard, smooth material, such as steel. It is covered with a layer of rubber that has been vulcanized. The vulcanization process gives the rubber a hard, smooth surface that is resistant to wear. The rubber is also slightly porous, which helps to grip the paper and hold it in place during the printing process.
The printing process begins when the substrate is fed into the printing press. The substrate is fed into the press between the printing plate and the impression cylinder. The plate and cylinder are inked, and the inked image is transferred to the substrate.
The purpose of the impression cylinder is to apply pressure to the back side of the printing plate, which is in contact with the paper. This pressure causes the ink on the front of the printing plate to be transferred to the paper.
The amount of pressure applied by the impression cylinder can be adjusted to control the amount of ink that is transferred to the paper. This, in turn, affects the density of the printed image.
To achieve the highest quality print, the impression cylinder must be made of a material that is hard and smooth. Common materials used for impression cylinders include steel, chrome, and ceramic.