Function analysis of automatic fault detection sys

Function analysis of automatic fault detection system for flexographic printing

in the process of flexographic printing, there are often spots, stripes, ghosting, inaccurate overprint, inconsistent ink color and other problems, all of which are very detrimental to production. Therefore, in the process of high-speed printing, whether the printing registration system works stably and how the printing quality is, these are the situations that the operator must know clearly at any time, and must actively take measures to control it, so as to ensure the smooth progress of production and the improvement of product quality. Automatic fault detection system is such a new type of auxiliary equipment. It can reduce the scrap rate and downtime, so as to save production costs, improve production efficiency and profit margin. It can be said that it is the eye of the operator to observe the operation of the machine

with the development of economy and the improvement of living standards, people have higher and higher requirements for product quality, and printing materials are increasingly high-grade. In order to gain a foothold in the increasingly fierce market competition, printing enterprises must improve the quality of printed matter and shorten the production cycle as much as possible. under these circumstances. Automatic fault detection system gives full play to its own advantages and functions, and is favored by people. It has become an important part of flexographic printing machine. The core purpose of automatic fault detection system is "prevention and prevention", and the goal is no waste products. In order to achieve the desired satisfactory effect, the automatic fault detection system can appear and point out the possible problems before obvious and perceptible faults are formed on the printed matter. In this way, the waste of materials can be greatly reduced, especially for the printing of soft films that are expensive and have poor printability, such as printing on substrates such as plastics, transparent films and metal foils. Therefore, automatic fault detection system can help printers improve production efficiency, reduce waste of raw materials, reduce production costs and obtain satisfactory products

I. detection process of automatic fault detection system

a CCD camera is installed behind the last color deck of the printing machine. Through certain methods, the printing image captured by the lens is stored in the memory of the computer. The operator can clearly see the color and overprint details of the printing effect on the screen. The refresh frequency, magnification, vertical and horizontal automatic scanning of the image are automatically controlled by the computer. Generally speaking, the order of fault detection is from left to ancient. The operator only needs to input the circumference of the embossing cylinder and select the appropriate magnification, then the image can be clearly observed, and 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 automatically compare a series of images printed later with the main image as the benchmark. If the deviation is relatively large, it may cause faults, waste products and defective products, and the automatic fault detection system will give a warning. The monitors of some fault detection systems also have a multi window ("picture in picture") function. The advantage of "picture in picture" is that the operator can compare the currently printed image with the main image or the image printed a few days ago. The effect is more obvious and the work is more convenient

some fault detection systems also use two monitors, one for "fault analysis" and the other as a "real-time image monitor". The two monitors work in series one after another to track the occurrence of any suspicious events, such as the lines of the doctor blade, color deviation or tiny dust particles, which may lead to printing failures and waste products. Usually, these defects cannot be observed by human eyes until a large number of printed materials are printed and waste products appear obviously, which is bound to cause huge waste

there are also some more advanced and advanced devices, which have the function of warning prompt and can send a warning to the operator in time. This system can analyze and classify the data. When there are changes in the downtime, damaged parts and fracture conditions recorded on the printer, the system will notify the printer operator of the possible problems and clearly display the corresponding fault phenomenon on the monitor. If you want to observe more clearly and closely, the operator can also zoom in on the corresponding parts, or call up the main image for comparison

II. Auxiliary function

printing is an important link in the replication process. In order to improve the overall management level of printed matter detection and printing process, many automatic fault detection systems are equipped with auxiliary function modules or other tools to improve production efficiency. One of the applications of these auxiliary tools is cold seal detection and glazing detection. In flexographic printing, the application of cold seal liquid adhesive and glazing oil is becoming more and more common, and the quality requirements of printing materials are becoming higher and higher

in the process of cold seal fault detection, there are mainly two problems: 10. Turn on or turn down the iris aperture on the condenser under the stage. First, adhesive is a transparent material, which is difficult to see with the naked eye, especially when it is used on white opaque film materials. Second, when this adhesive is applied to the back of the drum substrate material, the automatic fault detection system will not work. There is no doubt that if the overprint inaccuracy can not be detected in the printing process, it will affect the quality of the final product and cause customers to reject the product

in terms of fault detection, if a quality data collection and reporting tool is adopted, it can bring great convenience to process control. A typical report will show the printing speed, the specific location of the fault on the drum and the type of fault on the screen. According to these information prompts, the printer operator can easily track and observe when the fault occurred, where the fault occurred, and the extent of the fault of the printed matter. Some software also provides a "Drum Recording" function, which allows the printer operator to take the imprint drum to the rewinding position and cut it off from the point of failure. With this tool, the flexible packaging printer can estimate the scrap rate of the printed piece and make necessary adjustments to reduce the scrap rate and improve the profit margin in the future printing process. This tool also helps to implement the quality assurance system

III. barcode detection

many of the live parts rejected or returned by customers are caused by unqualified barcode printing. The control of bar code has become a major problem in quality control. In fact, it is impossible for us to require the printing operator to test each bar code printed one by one to verify whether it can be recognized or read. Therefore, printers need an auxiliary tool to detect bar codes to automatically identify and locate bar code signals. The bar code detection system can check the size, quality, contrast and "decoding performance" of the bar code, so as to improve the overall quality level of the printed matter

the automatic fault detection system has greatly improved flexographic printing, made the printing quality reach a higher level, and entered the market that has been occupied by gravure printing. The combined automatic fault detection system has made considerable achievements in flexographic printing and gravure printing. Since this technology is suitable for any other phenomenon that the size or shape of the object changes relatively due to external force, other printing methods will recognize this and learn from it