Starting from the application of commercial CTP, printing enterprises will directly lead to the process integration of pre-press, printing and post-press processing, that is, on the basis of realizing PS and PDF files directly into printing plates, the automatic transmission of internal data realizes process management, Online proofing and PPF/JDF (CIP3/CIP4) file generation can even allow customers to order paper and ink, track the production status of printed parts, etc. through the Internet. Therefore, new approaches to optimize commercial CTP applications can be summarized as follows.
1. Establish CTP plate quality control method
At present, the possession of commercial CTP in my country has entered a stage of rapid growth, but the overall level is far behind developed countries. The reason for this backwardness is that domestic printing companies have insufficient understanding of the digitalization of the printing production process triggered by CTP, which leads to data distortion in the data transmission process and excessive fluctuations in printing plate quality, and lack of overall understanding of the CTP printing plate production process. Control methods and strategies. Insufficient quality stability of the printing plate is caused, and there is also the problem of excessively high error rate of the printing plate due to the outdated quality control means of CTP and its printing plate production data. Therefore, the focus of establishing a new method for optimizing commercial CTP applications should focus on establishing a benchmark for design work. There are 3 aspects to set the conditions for developing the plate and to detect the output quality of the printing plate.
(1) Establish equipment work benchmarks
First of all, the printing plate and its matching flushing solution must be selected according to the actual printing conditions and product quality requirements;
The second is to correctly set the exposure parameters of commercial CTP equipment according to the printing plate and processing conditions, control the exposure fluctuation range, establish a solution to compensate for underexposure or overexposure caused by laser fading and environmental changes, and set various screen modes. Exposure parameters.
(2) Set the printing conditions
First of all, under the correct exposure conditions or within the allowable exposure fluctuation range, the processing conditions under stable printing plate quality should be obtained. Including developing temperature, developing concentration, developing time, brush speed, washing state, drying temperature, etc.;
The second is to establish and ensure the control mechanism and management method of flushing condition consistency in the flushing cycle.
(3) Detect the output quality of the printing plate
First of all, based on the established commercial CTP equipment working benchmark and plate processing conditions, establish a method to judge whether the equipment working benchmark drifts;
The second is to judge whether the imaging quality of the printing plate meets the printing requirements according to the graphic composition of the printing plate, whether the washing conditions of the printing plate match the exposure, and whether the state of the liquid medicine meets the washing requirements for stable printing plate quality, etc.
Therefore, the realization of commercial CTP printing plate quality control needs to establish a test standard plate according to the product characteristics of the printing enterprise, and optimize and determine the control parameters of each link in turn according to the changes in various elements in the standard plate, and integrate them to meet the requirements of commercial printing. The advanced control mode and management mechanism realize digital control, procedural management and simplified evaluation to ensure the stability and consistency in the dynamic production process of printing plates.
2. Optimize the control parameters and form a model operation control
Determine test parameters and metrics
The test parameters and indicators in this paper are selected according to the actual application requirements of commercial CTP, including the determination of the best exposure parameters of commercial CTP, the optimization of printing plate flushing control parameters, the dynamic test of the printing plate state and the actual printing test.
In terms of determining the best exposure parameters of commercial CTP, it is mainly to test the control parameters of the commercial CTP optical system such as focus ability, laser energy and drum rotation speed. These parameters are completed by means of segmented exposure combination, and the data such as dots, density and micro-line resolution status of each strip are measured by instrument testing.
In terms of the combined test of the main benchmark parameters of commercial CTP equipment, a comparative experiment of light energy and rotation speed on the dot area and density of the printing plate was carried out with 2400dpi output. It can be seen that the quality of the printing plate is the best when the dot area and density are both the minimum. .
(3) According to the product structure, establish a model operation control
In view of the current situation that printing enterprises have entered the era of meager profits, the application of commercial CTP by printing enterprises is to bring quality improvement, time shortening and benefit improvement to enterprises. Maintain technological continuity and innovation, and maximize the technological differences with similar enterprises. Therefore, commercial CTP must form a modeled job control according to the product structure.
After evaluating commercial CTP in recent years, the comprehensive conclusion obtained is: for non-quality commercial printed matter, under the condition of 20 FM screen or 175-200 dpi output screen, use the same paper, ink and printing equipment. The printing quality is basically the same Or the visual effect is basically the same. The same operation control mode can be used. In terms of plate processing conditions, the thermal CTP plate is more tolerant than the photosensitive CTP plate. As long as the plate is processed according to the control method obtained by the above method, the repeatability of the plate can be guaranteed. Higher than 99.9%; In terms of printing resistance, the printing resistance of the purple laser CTP plate is better than that of the thermal CTP plate, and it is more suitable for the printing of long-run jobs, and the purple laser CTP has better adaptability to the printing plate, while Thermal CTP is more limited.
The purpose of printing enterprises to introduce commercial CTP is to use advanced CTP technology to obtain quality, time and efficiency. Through the optimization of commercial CTP application methods, this paper establishes a set of scientific, objective and systematic CTP equipment and printing plate control methods, which provides a practical and effective means for optimizing the application of commercial CTP, which can help Printing enterprises can break through many bottlenecks of CTP application in the most reasonable way, which has a good guiding role and application value for accelerating the improvement of commercial CTP work efficiency and simplifying control links.