Computer-to-plate (CTP) is an imaging technology that helps transfer a digital image generated in a computer directly to a printing plate. Before CTP, the technology used was computer-to-film (CTF), in which the image output was passed to photographic film, which was then output to make the plate. This process is similar to darkroom photography, and CTP technology helps eliminate all darkroom processes, making it cost-effective. Compared to film-based printing, CTP is a faster process, so printing productivity is much higher.
Technology
The CTP method varies depending on the type of construction of the phototypesetter and the light source used to expose the surface of the printing plate. In terms of construction type, there are three different types: inner cylinder, outer cylinder and flatbed photocopiers. The two main light sources used to expose the plate are UV lamps and laser diodes. The wavelength and energy of the laser diode depend on the type of plate used. This technology is mainly used for newspaper and magazine printing. CTP machines adopt the most advanced and latest fiber laser to make plates, the imaging is accurate and fast. For plate making machines, our company has new and used machines. Thermal CTP machines and UV machines. Split machine and continuous machine.
Internal drum phototypesetter
In an internal drum image setter, the plate is placed in a cylinder and the imaging head moves along the axis of the cylinder to expose the plate. A rotating mirror at the end of the imaging head rotates around its axis to direct the laser to the desired portion of the fixed plate. This configuration makes it more difficult to use multiple lasers simultaneously, but using only one laser also has the advantage of uniform beam intensity over the entire plate imaging cycle.
External drum image setter
The plate is wrapped around a drum that can rotate around its axis, and the imaging head that projects the image onto the plate can be moved along that axis to focus the laser beam on the surface. A simple construction type allows multiple image heads to be arranged side by side and used simultaneously. This results in less imaging time required to expose the entire printing plate.
Flat Plate Image Setter
The image is reproduced line by line on a fixed flat printing plate by a laser beam that is deflected by a rotating multifaceted mirror and then copied onto the plate. Due to the setup, the laser beam becomes less accurate at the edge of the printing plate and is therefore mainly produced in smaller formats or with lower quality expectations.
Advantages of CTP
CTP has several advantages over traditional plate making. The biggest advantage is the removal of film-forming and chemically used layers. Thereby increasing clarity and detail. ctp avoids the potential loss of quality that can occur during film processing, including scratches and exposure variations in the film. The accuracy of phototypesetters is typically ±2%.
Plates are produced in less time, more consistently, and at lower cost. CTP can also improve alignment and image-to-edge repeatability compared to traditional methods.
In CTP, media is aligned (held in precise position) in the plate maker during the imaging process and is not dependent on individually aligned needle grids as is the case with film. Defects due to dust, scratches or other artifacts are minimized. Overall, however, CTP is favored for its faster process and cost effectiveness.
CTP systems can dramatically increase plate yield. Platesetters for newspaper production can output up to 300 12-inch (300 mm) plates per hour at 1,270 dpi (dots per inch), while for commercial applications, CTP systems can output 60 B1 plates at 2,400 dpi for higher screen counts. Overall, however, CTP is favored for its faster process and cost effectiveness.
Small portrait presses that typically create 1 or 2 color output can use anything from standard laser printers (for low quality/small batches) to high-end dedicated plate makers for higher quality and volume.
Main products: CTP plate making machine, PS plate, CTCP plate, double coating CTCP plate, thermal CTP plate, double coating thermal CTP plate, computer plate making machine. The production capacity of plate is as high as 40 million square meters, and 290 plate making machines are sold every year. The high quality printed board has been recognized by the global market, and the product quality is stable, which has passed the hg-t2694–95 standard.
