The low-end polyester CTP plate used in small offset printing is an offset printing plate made by a laser printer that prints images on a special polyester material. This kind of low-end polyester printing has stable performance, simple plate making process, and low price. It is particularly suitable for use on small format monochrome offset presses with 8 open sides.
This kind of polyester plate needs to pay attention to the following problems in practical application.
(1) Before printing on the machine, it is better to reinforce the printing plates and graphics by means of a forging machine so that the toner can be cured while the adhesion between the toner and the printing plate is increased. The product lines printed in this way are clear, crisp, and strong in three-dimensional. Under the appropriate pressure of the machine, the printing plate can bear 20,000 impressions of printing force, otherwise printing less than 5,000 copies will result in plate-off phenomenon, and the lines have obvious burrs. It is necessary to control the balance between the solid-state temperature and the solid-state time in the operation of the fixed-plate machine so that the printing plate is not deformed and the toner is sufficiently cured.
(2) In order to prevent dirt, the printing plate must be fully moistened before it is placed on the machine.
(3) There are two types of polyester plates on the market today: one is a water-based plate, and the other is a wetting plate. The water-based version can be made with ordinary tap water as a fountain solution without adding any substances; the dampening solution used in the wetting plate is the same as the ordinary PS plate.
(4) Polyester plates on the market produce corrosive gases when imaged with a laser printer, which damages the components of the printer.