The Printout Controller converts the input data into so-called A frame, which is a contrasting, separated set of data about the printed image. On this basis, the machine modulates a laser beam that illuminates an electrostatically charged, curving cylinder (photoreceptor), covered with a suitable photo-sensitive material, creating an electrostatic latent image.
Methods of digital printing in offset printing house
A colouring powder (toner) mixed with a powdered ferromagnetite (usually iron) called a carrier (developer) is close to the surface of the cylinder and glued to it in areas exposed to the laser. The colouring powder is then transferred to the printed substrate (usually paper, but also transparent or coloured film, self-adhesive paper or paper to transfer the print to other items), and is thermally bonded to it. The electrophotographic method originates from the photocopying technique and was developed in 1938. Chceck, how we use offset and digital printing methods – visit our webpage www.printpackpoland.com.
This method began to be implemented in digital printing at the end of the 1980s. One manufacturer developed a specific combination of the electrophotographic method and the traditional offset technique: instead of the powder dye, a liquid ink is used, which is transferred from the photoconductor to the offset rubber and transferred from it to the offset rubber. The use of offset rubber allows printing on various substrates, even those that are not possible to be printed by machines operating in electrophotographic printing technology (e. g. metallised films or self-copy prints that are not resistant to high temperature).
Characteristisc of digital printing – point of viev of offset printing house
The features of digital printing are as below:
- digital computer recording allows direct or indirect printing,
- if there is an intermediate medium, the image on that medium is deleted and saved again after each printing cycle,
- you can change any graphic or text elements for each subsequent printout (personalisation),
- the device usually lacks a printed form (not applicable to risography).
A specific form of printing is digital recording itself, the print image is created in a digital printing machine and directly at the starting point of the print.