Automatic Quality Inspection and Analysis of Tobacco Packaging (Part 2)

To solve the problem of process control, the key is to be aware of the problem in time before the human eye can identify it. From a technical point of view, this goal can be achieved. To be able to find the subtle, gradual changes in the printing process, the accuracy and sensitivity of a CCD device that records these changes is high. The AVT system is implemented using three arrays of YOCCDs. It scans the entire print width step by step through the rapid movement of the camera. Through the previous analysis of the printing problems, those process problems will not automatically disappear once they appear. Even if they are scanned step by step, they will never miss the accumulated process problems. However, for the randomly occurring problems, the visible range of array CCDs is currently limited, and it is not possible to monitor 100% of the entire printing width. In order to ensure that 100% of the print defects are detected, one must use a linear CCD camera. The accuracy and sensitivity of the line I~CCD cannot reach the high level of the array CCDN, but it scans the entire printing width in real time through a linear scanning method and will never miss any waste generated.

The comparison of process control and quality assurance is shown in Table 1.

This high-quality printing of cigarette packs, combined with printing process control and quality assurance systems, is an optimal solution. Process Control and Quality Assurance Integration Solution AVT specifically develops Printvision Argus, a product that combines process control and quality assurance for the specific needs of the cigarette package printing industry. After applying Argus, printing waste can be significantly reduced, waste products can be avoided, and customer satisfaction can be improved. At the same time, due to better monitoring methods, the startup speed of the printing press can also be significantly improved, and the efficiency of the use of the equipment is greatly improved.

Argus uses two cameras, an array CCD and a linear CCD, respectively. Array CCD cameras can detect all kinds of progressive printing process problems such as color difference, registration, and cutting lines at the first time. When a defect is detected, the system automatically triggers the alarm system. At the same time, the discovered defects are framed on the screen with different colored boxes and can be easily compared with the standard images stored during system setup. Each color represents a different type of defect. In this way, even if the operator is at a far distance, it is easy to identify the type of defect and take timely measures. Front OCCD cameras are very sensitive to changes in contrast, requiring the energy of the lighting source to be very high. This feature makes it possible for the array CCD to resolve very subtle image changes. At the same time, the front OCCD camera is also equipped with a very high-precision optical lens and an excellent zoom system that can locally enlarge the image and make judgments easily, so it is the best technology for process control. Another group of cameras using a linear CCD keeps track of all the defects that have occurred in real time. Whether they are cumulative process problems or randomly generated problems, once the system detects defects, the system flags these defects for later processing. Be removed to ensure that defective products do not flow into the hands of customers. Argus also stores all detected defects in the system's built-in SQL database, and can generate quality reports for each job and each roll, facilitating internal quality management and communication with customers. While not changing the hardware configuration, it is also possible to focus on specific applications by selecting different software modules. Barcode confirmation - identify barcodes on the machine and classify barcode quality according to international standards.

Precise color control makes precise 所L ab control of a pair of color changes during printing. Reflective module a pair of high reflective material support.

The selection of these special modules expands the system's application area and application scope. At present, domestic cigarette pack printing plants pay more and more attention to automatic quality inspection, and companies considering the introduction of automatic monitoring systems are also increasing. This will greatly help the stability and improvement of printing quality. When the customers purchase these systems, they must choose their own quality testing program according to their own equipment conditions and process flow, and take the right medicine.

(Author/Bai Weimin Ai Weite Co., Ltd. Shanghai Representative Office)

Source of information: <printing magazine>. 2005 (6)