CTP application experience (1)

1. How to ensure the smooth implementation of the CTP system

The CTP plate-making machine, which is similar to the structure of the image-setter, is not an obstacle to the development of the CTP. One of the reasons why it cannot develop rapidly earlier is that the corresponding process cannot meet the needs in the past period of time. Digital proofing and automatic imposition are the only way for the application of CTP systems. If these technologies are not really solved, the CTP system will not develop. In other words, the CTP system depends not on the CTP platesetter itself but on the process. A complete graphic arts digital process from typesetting to output control is the basis of the CTP system. The key to successfully implementing a CTP system is:

1). Having more than two years of experience in using Postscript's electronic prepress system, this experience ensures that prepress technicians are familiar with basic file processing and troubleshooting, and can quickly identify and solve font problems, missing images, and poorly constructed documents. .

2). More than half of the jobs are Postscript or files compatible with the Postscript format.

3). Adequate print consumption: A certain amount of money is required to implement a CTP system. A printing plant must consume a certain number of plates to get a corresponding return on investment.

4). High-quality printing plate operations: The printing plant must guarantee the quality of the printing plate.

5). The main work does not exceed 4 colors, and the printed cable is lower than 175 lpi.

6). Has 6-12 months of digital proofing experience: Digital proofing is one of the most controversial technologies in the CTP workflow because it has an impact on both the customer and the press shop. Customers and print operators need to be trained in various digital proofing techniques. In addition, the success of printing is also related to the company's technical staff, their technical level and learning ability directly affect the speed of the introduction of CTP, the company needs to carry out the necessary training for such technical personnel. When the tasks handled by the server are very heavy, it is very important to increase the system administrator to ensure that the server and the network can operate normally. Since the CTP system affects the entire printing company, all departments involved need to carry out a series of adjustments and training.

Platemaker:

From the perspective of plate-making equipment, after several years of development, manufacturers have introduced a variety of direct plate-making systems with mature technologies that can automatically be printed, can deal with different sizes and different types of plates, and greatly increase platemaking speed. Such as the prestigious Triumph 3244 series, there have been thousands of Quansheng series of computer direct machine in the successful operation of the country. Its new 20-watt thermal laser head, unique SQUARESPOT square photosensitive imaging technology. He won the GATF Technology Award from the American Printing Technology Foundation five times and enjoyed a reputation in the field of computer-to-platemaking and quickly expanded into the field of digital offset printing. Built-in laser cooling system and debris collection unit (for ablation type rinse-free plates, with a proven external drum design, the drum rotates at a constant speed during exposure, ensuring consistent imaging. For accurate registration, use A unique temperature compensation system, which can adjust and compensate for thermal expansion and contraction of the printing plate caused by changes in the ambient temperature during the imaging process, ensuring the same machine at different times and even different printing plates Can accurately register, the exposure is consistent and repeatable.

CTP plate:

The key to computer-to-platemaking technology is the matching of plates and imaging systems. Silver salt plate material: high sensitivity, high resolution, high printing rate, must be operated under a safe lamp, and the silver salt removal process must be properly handled. Photosensitive resin plates: Similar to ordinary plates, they must be treated in water-based chemicals. However, compared with the silver salt version, the sensitivity, resolution, and durability of the photosensitive resin plate appear to be very low. With new high-sensitivity resin emulsions, product consistency and graphic robustness can be ensured – this is also the most important consideration when selecting media. Hybrid Plates: Adding a low-sensitivity silver halide mask layer during exposure to conventional emulsions provides the advantage of a compromise between the two materials. However, this mixture requires a long platemaking line and two waste removal channels, as well as more complex manufacturing processes. Thermal plate: can be operated under sunlight, high resolution copying, accurate imaging, and the potential for simplified process, plate, film, proofing can be imaged on the same device. However, the thermal technology is not as mature as the visible laser system. Therefore, the heat-sensitive selection is very limited, and the thermal technology still has the potential to be tapped.

2. Common problems and solutions when using CTP
The maturity and development of CTP technology brings different production benefits to the manufacturers who use it. In the face of new technologies and new processes, due to the operator's experience or pre-production documents and other reasons, there are often problems that require our attention in practical work.

1). Size issues

(1) The size of the created document does not match the actual required size.
(2) The required amount of bleeding was not taken into account when making the document.
(3) The text or image is too close to the finished cutting line.

Solution:

(1) Define "Document Settings"/"Page Size" as the finished product size.
(2) The amount of bleeding on the page should be taken into consideration when making the document, which is generally 3mm.
(3) The distance from the text or image to the finished cutting line is at least 5mm, preferably more than 8mm.