(Video Web Inspection) In the flexographic printing process, spots, streaks, ghosts, misprints, inconsistent ink colors, and other problems often occur, all of which are detrimental to production. Therefore, when the high-speed printing press process, whether the printing registering system works stably and how the printing quality is, these are the circumstances that the operator must clearly understand at any time, and must take active measures to control it, ensure the smooth progress of the production and improve the product. the quality of. The automatic fault detection system is such a new kind of auxiliary equipment, which can reduce the reject rate and reduce the downtime, thereby saving the production cost, increasing the production efficiency and the profit rate. It can be said that it is the operator's eyes to observe the operation of the machine. With the development of economy and improvement of living standards, people's requirements for product quality are getting higher and higher, and printed materials are becoming increasingly affluent. In order to gain a firm foothold in the increasingly fierce market competition, we must improve print quality. At the same time as possible to shorten the production cycle. In this case, the automatic fault detection system has fully exerted its own advantages and functions, and has been greatly favored by people. It has become an important part of the flexographic printing press. The core purpose of an automatic fault detection system is "prevention and prevention," and the goal is no waste. In order to achieve the expected satisfactory results, an automatic fault detection system can appear and point out possible problems before an apparent and perceptible fault is formed on the printed matter. In this way, material waste can be greatly reduced, especially for the printing of flexible films that are expensive and poor in printability, such as plastics, transparent films, and metal foils. Printing, and the quality of prints is quite high, can be called "first-rate". Therefore, the automatic fault detection system can help printers to increase production efficiency, reduce waste of raw materials, reduce production costs and obtain satisfactory products. First, the detection process of the automatic fault detection system A CCD camera is installed behind the last color group of the printing machine, and the detection function can be realized. Through a certain algorithm, the lens stores the captured snapshot of the printed image in the computer's memory. The operator can clearly see the color of the printing effect and overprint details on the screen, and the refresh rate, magnification, and aspect of the image. Automatic scanning and so on can be completed by computer automatic control. In general, the fault detection sequence is from left to right. The operator only needs to enter the circumference of the impression cylinder and select the appropriate magnification to be able to clearly observe the image. Then the system can automatically store the image in the computer memory as the main image. Once the main image is stored, the system will compare a series of images printed after some time with the main image as a reference. If the deviation is relatively large, it may cause malfunction, waste and defective products, and the automatic fault detection system will warning. Some fault detection system monitors also have a multi-window (picture-in-picture) function. The advantage of “picture-in-picture†is that the operator can discharge the current printed image together with the main image or the image printed several days ago. For comparison, the effect is more obvious and it is more convenient to work. Another failure detection system uses two monitors, one for "failure analysis" and the other as a "real-time image monitor." In this case, the two monitors work in tandem and track any suspicious events, such as squeegee blade lines, color deviations, or tiny dust particles. These are possible. It can cause printing failures and the occurrence of defective products. Usually, people who do not observe these problems in the naked eye can not be observed by the naked eye until a large number of prints have been printed and apparently appear scrapped. This will inevitably cause huge waste. There are also more advanced and more advanced devices that have warning warnings to warn operators. This kind of system can analyze and classify the data. When there is a change in the situation on the printing press, the system will notify the press operator of the problems that may occur, and clearly display the corresponding fault phenomena on the monitor. If you want to see more clearly and more closely, the operator can also zoom in or out on the corresponding part, or call up the main image for comparison. Second, the auxiliary function printing is an important part of the replication process, in order to improve the overall level of management of print inspection and printing process, many automatic fault detection systems are equipped with auxiliary function modules or other tools to improve production efficiency. One of the application areas of these auxiliary tools is cold-sealing inspection and gloss inspection. In flexo printing, the application of cold-sealing liquid adhesives and coating oils is becoming more and more common, and the quality requirements for prints are also increasing. . There are two main problems in the cold seal fault detection process. The first problem is that the adhesive is a transparent material that is difficult to see with the naked eye, especially when it is used on white opaque film materials. The second problem is that when the adhesive is applied to the back of the roll substrate material, the automatic fault detection system does not work, and there is no doubt that if overprinting cannot be detected during the printing process, Problems will affect the quality of the final product, and customers are likely to refuse to accept the product. In terms of fault detection, if a quality data collection and reporting tool is used, process control can be greatly facilitated. A typical report will show on the screen the printing speed, the specific location of the fault on the drum, and the type of the fault. Based on this information, the press operator can easily follow and observe when the fault has occurred. , where the fault occurred, and the degree of failure of the printed matter. Some software packages also provide a "drum record" function that allows the press operator to take the impression cylinder to the rewind position and cut it off from the point of failure. With this tool, flexible packaging printers can estimate the reject rate of the prints and make necessary adjustments to reduce scrap rates and improve profitability in the future printing process. This tool also contributes to the implementation of a quality assurance system that closely links printers and customers. Third, the bar code detection In addition, there is a very important task: to ensure that the bar code is accurate and reliable. For printers, many of the jobs rejected or returned by customers are caused by the failure of bar code printing. Therefore, the control of bar codes has become a major issue in quality control. In fact, we cannot ask the printing operator to test every bar code printed one by one to check whether it can be identified or read. Therefore, the printer may need an auxiliary tool for detecting the barcode to automatically identify and locate the barcode signal. The bar code detection system can check the size, quality, contrast, and “decoding performance†of the bar code, and in some cases, can improve the overall quality level of the printed matter. The automatic fault detection system can greatly improve the flexographic printing, ensuring that it reaches a higher level and enters the market that has been occupied by gravure printing. The combined automatic fault detection system has achieved considerable success in flexographic and gravure printing. Moreover, since this technology is suitable for any web material printing process, in the future, other printing methods will also realize this and draw lessons from it: lower scrap rate, guarantee high quality and high accuracy of prints, which is the basic requirement to improve profitability , And automatic fault detection system can help you achieve this desire.