It is one of the means by which the printing company dreams to implement automatic quality monitoring of prints in the printing process. Especially in the modern high-speed roller printing, if it is not discovered and eliminated in time, it means that a large number of defective goods are lost. Therefore, it is necessary to use quality automatic monitoring technology for drum printing presses. Monitoring method.
Pumping style monitoring
Basically similar to roll paper online observation system, but added some computer hardware and software. Generally, a camera is installed on a cross bar to move around mechanically and a set of strobe light device is added. During printing, the camera moves along with the strobe light while scanning the image. The captured image information can be viewed on the computer screen by the operator and automatically compared with the standard sample information stored in the computer. If there is a difference, a warning signal is issued on the display to remind the operator to correct or eliminate it in time. However, in this mode, the image signal captured by the camera can only be local and intermittent. Only after the camera has been walked horizontally, can it complete the scan of the full-width signal (not on the same printed surface) of a print, and then start the second scan, which means that not all of the prints are missing. When scanned, all such monitoring can only be considered as pumping style monitoring.
Continuous monitoring
Continuous monitoring, as the name implies, is to continuously monitor, so it is also called 100% comprehensive monitoring. It completely compensates for the lack of pumping style monitoring and the methods and methods used are completely different. It eliminates the cross-bar that drives the camera's movement and at the same time has multiple cameras fixedly mounted across the entire printing web. The strobe light is also replaced by continuous lighting. In addition, the camera used was changed to a line scan type, which means that these cameras are no longer taking "rectangular snapshots". Instead, the scanned images are continuously scanned line by line, and the standard sample information stored in the computer is also used. By contrast, any defects or quality problems cannot be missed.
Pixels and resolution of line cameras used in automatic monitoring systems
The camera has a series of pixel levels, such as 512, 1024, 2048, or 4096, and the roll resolution of the automatic monitoring system is calculated based on the roll width ÷ (number of heads scanned x number of pixels per head). For example, 1200mm roll width, installation of six 1024-pixel scanning head, the lateral resolution of the roll is 0.2mm, which is sufficient to meet the general requirements for defect monitoring, requires higher, often using a monitoring system with a resolution of 0.1mm You can.
The Function and Benefit of Continuous Quality Automatic Monitoring Technology
Continuous quality automatic monitoring system has three usages:
1. As an early warning device, for some tiny tricks that can be accepted by the client, it only sends an amber light signal and shows the flaw on the display screen. However, no marks are made on the actual printed matter. Or to be removed, only to remind the operator should be taken care of or whether to take any relevant measures.
2. Marking and even rejecting defective scraps Continuous quality automatic monitoring systems can be connected to marking devices such as inkjets or labellers, so that it can not only monitor defects but also occur Marks are printed on the prints, or a label is attached to the edge of the printed product at the winder and the finished product inspector is removed. Under normal circumstances, the automatic monitoring system used for the elimination of defective scraps is more controlled than the aforementioned warning system. In many cases, both warnings and rejections must be combined. Therefore, four calculation programs can be used. Two of them are coarser and are used to reject scraps, while the other two are adjusted more precisely. As an early warning. This can be easily adjusted by the operator on the console.
3. Quality data collection and summary report In addition to the above two functions, the continuous quality automatic monitoring system can also provide all the information for quality statistics and analysis, deposit it into the database, and connect it with the computer of the quality inspection department or other management departments for inspection. .
Suitable for flexo printing
The automatic quality monitoring system for print products has been used for a long time in roller type gravure printing machines and cylinder type offset printing machines. In recent years, due to the development of flexographic printing, many people are interested in asking whether the automatic quality monitoring system for printing products is also applicable to flexographic printing presses. Of course, this answer is affirmative.
However, there are some special cases of flexographic printing that should be noted, including:
1. The format of the flexographic print has changed greatly. In terms of width, the change from the narrowest centimeter to more than two meters wide is very large. However, this can only be solved by adding more cameras in the continuous monitoring system. However, if the longitudinal length is longer, omissions may also increase in the pumping style monitoring. In continuous monitoring, there is no problem at all, just enter a print length data in the computer. Therefore, in general, in a flexographic printing press, an automatic quality monitoring system is adopted, and continuous type is suitable. The following is also the same.
2. Flexographic printing materials change. Different papers, cardboards, foils, plastic films and composite materials, for example, have different transparency or light reflectance in terms of paper and film, and must be adjusted accordingly in the monitoring system. For example, the illumination system must have reflected light and transmitted light. In the diffuse lighting, two fluorescent lamps are installed on the two sides of the camera. The camera receives the light reflected indirectly by the paper roll, and the directly diffused light does not enter the camera, so that the printed information on the roll is line by line. Sweep into the computer and compare it with the standard sample information. If the printed transparent or semi-transparent material is encountered, the third fluorescent lamp installed under the scroll must be activated, just facing the position of the scan line of the camera, allowing the camera to scan line by line.
3. Changes in press speeds The speed of modern presses is extremely common and commonplace in any type of printing process, as is flexographic printing. From high speed to high speeds of 365 meters per minute or more, the higher the speed, the more important the automatic monitoring system is, and the more significant it is. And it turns out that because of the use of an automatic monitoring system, operators can confidently increase the speed of the vehicle, and can do other things during the high-speed operation of the machine, as long as the indicator light on the console turns from green to red. Go back to the console to handle it.
If you want to ask whether the use of automatic monitoring system speed limit? In fact, the speed of the vehicle should be limited only if the scanning signal of the ingestion is difficult to identify the defect.
4. Pattern changes in printing There are many variations in the pattern of flexographic prints, and the differences are quite large. Such as decorative paper, artificial fiberboard wood grain, etc., was the problem of automatic monitoring systems for many years. However, in recent years, the technical level of the automatic monitoring system has been able to cope with any fine and complex patterns.
5. What are the flaws or defects that can be detected?
The continuous automatic monitoring system can detect various flaws or defects. In flexographic printing, such as: paper, knife marks, dust embedded stripes, bubbles, trachoma, misprints, stains, and stripes.
For more demanding prints, such as securities or medical prints, cameras with higher resolution can also be installed so that finer stripes or smaller paper can be inspected. When purchasing an automatic monitoring system, the person wishing to purchase can also provide proofs for defects or defects that can be checked out for testing. Think to meet the requirements and purchase again...
Obviously, the continuous quality automatic monitoring system can make the quality of printed products stable, the rate of defective rejects decrease, and the loss reduced. At the same time, it also improves the level of production management and quality management supervision, improves the image and credit of printing companies, and improves competition. Force to expand business sources. Its role and benefits are many and huge. The same applies to flexographic printing, in which a large variety of factors such as the printing format and the material variety change. (China Packaging News)
Pumping style monitoring
Basically similar to roll paper online observation system, but added some computer hardware and software. Generally, a camera is installed on a cross bar to move around mechanically and a set of strobe light device is added. During printing, the camera moves along with the strobe light while scanning the image. The captured image information can be viewed on the computer screen by the operator and automatically compared with the standard sample information stored in the computer. If there is a difference, a warning signal is issued on the display to remind the operator to correct or eliminate it in time. However, in this mode, the image signal captured by the camera can only be local and intermittent. Only after the camera has been walked horizontally, can it complete the scan of the full-width signal (not on the same printed surface) of a print, and then start the second scan, which means that not all of the prints are missing. When scanned, all such monitoring can only be considered as pumping style monitoring.
Continuous monitoring
Continuous monitoring, as the name implies, is to continuously monitor, so it is also called 100% comprehensive monitoring. It completely compensates for the lack of pumping style monitoring and the methods and methods used are completely different. It eliminates the cross-bar that drives the camera's movement and at the same time has multiple cameras fixedly mounted across the entire printing web. The strobe light is also replaced by continuous lighting. In addition, the camera used was changed to a line scan type, which means that these cameras are no longer taking "rectangular snapshots". Instead, the scanned images are continuously scanned line by line, and the standard sample information stored in the computer is also used. By contrast, any defects or quality problems cannot be missed.
Pixels and resolution of line cameras used in automatic monitoring systems
The camera has a series of pixel levels, such as 512, 1024, 2048, or 4096, and the roll resolution of the automatic monitoring system is calculated based on the roll width ÷ (number of heads scanned x number of pixels per head). For example, 1200mm roll width, installation of six 1024-pixel scanning head, the lateral resolution of the roll is 0.2mm, which is sufficient to meet the general requirements for defect monitoring, requires higher, often using a monitoring system with a resolution of 0.1mm You can.
The Function and Benefit of Continuous Quality Automatic Monitoring Technology
Continuous quality automatic monitoring system has three usages:
1. As an early warning device, for some tiny tricks that can be accepted by the client, it only sends an amber light signal and shows the flaw on the display screen. However, no marks are made on the actual printed matter. Or to be removed, only to remind the operator should be taken care of or whether to take any relevant measures.
2. Marking and even rejecting defective scraps Continuous quality automatic monitoring systems can be connected to marking devices such as inkjets or labellers, so that it can not only monitor defects but also occur Marks are printed on the prints, or a label is attached to the edge of the printed product at the winder and the finished product inspector is removed. Under normal circumstances, the automatic monitoring system used for the elimination of defective scraps is more controlled than the aforementioned warning system. In many cases, both warnings and rejections must be combined. Therefore, four calculation programs can be used. Two of them are coarser and are used to reject scraps, while the other two are adjusted more precisely. As an early warning. This can be easily adjusted by the operator on the console.
3. Quality data collection and summary report In addition to the above two functions, the continuous quality automatic monitoring system can also provide all the information for quality statistics and analysis, deposit it into the database, and connect it with the computer of the quality inspection department or other management departments for inspection. .
Suitable for flexo printing
The automatic quality monitoring system for print products has been used for a long time in roller type gravure printing machines and cylinder type offset printing machines. In recent years, due to the development of flexographic printing, many people are interested in asking whether the automatic quality monitoring system for printing products is also applicable to flexographic printing presses. Of course, this answer is affirmative.
However, there are some special cases of flexographic printing that should be noted, including:
1. The format of the flexographic print has changed greatly. In terms of width, the change from the narrowest centimeter to more than two meters wide is very large. However, this can only be solved by adding more cameras in the continuous monitoring system. However, if the longitudinal length is longer, omissions may also increase in the pumping style monitoring. In continuous monitoring, there is no problem at all, just enter a print length data in the computer. Therefore, in general, in a flexographic printing press, an automatic quality monitoring system is adopted, and continuous type is suitable. The following is also the same.
2. Flexographic printing materials change. Different papers, cardboards, foils, plastic films and composite materials, for example, have different transparency or light reflectance in terms of paper and film, and must be adjusted accordingly in the monitoring system. For example, the illumination system must have reflected light and transmitted light. In the diffuse lighting, two fluorescent lamps are installed on the two sides of the camera. The camera receives the light reflected indirectly by the paper roll, and the directly diffused light does not enter the camera, so that the printed information on the roll is line by line. Sweep into the computer and compare it with the standard sample information. If the printed transparent or semi-transparent material is encountered, the third fluorescent lamp installed under the scroll must be activated, just facing the position of the scan line of the camera, allowing the camera to scan line by line.
3. Changes in press speeds The speed of modern presses is extremely common and commonplace in any type of printing process, as is flexographic printing. From high speed to high speeds of 365 meters per minute or more, the higher the speed, the more important the automatic monitoring system is, and the more significant it is. And it turns out that because of the use of an automatic monitoring system, operators can confidently increase the speed of the vehicle, and can do other things during the high-speed operation of the machine, as long as the indicator light on the console turns from green to red. Go back to the console to handle it.
If you want to ask whether the use of automatic monitoring system speed limit? In fact, the speed of the vehicle should be limited only if the scanning signal of the ingestion is difficult to identify the defect.
4. Pattern changes in printing There are many variations in the pattern of flexographic prints, and the differences are quite large. Such as decorative paper, artificial fiberboard wood grain, etc., was the problem of automatic monitoring systems for many years. However, in recent years, the technical level of the automatic monitoring system has been able to cope with any fine and complex patterns.
5. What are the flaws or defects that can be detected?
The continuous automatic monitoring system can detect various flaws or defects. In flexographic printing, such as: paper, knife marks, dust embedded stripes, bubbles, trachoma, misprints, stains, and stripes.
For more demanding prints, such as securities or medical prints, cameras with higher resolution can also be installed so that finer stripes or smaller paper can be inspected. When purchasing an automatic monitoring system, the person wishing to purchase can also provide proofs for defects or defects that can be checked out for testing. Think to meet the requirements and purchase again...
Obviously, the continuous quality automatic monitoring system can make the quality of printed products stable, the rate of defective rejects decrease, and the loss reduced. At the same time, it also improves the level of production management and quality management supervision, improves the image and credit of printing companies, and improves competition. Force to expand business sources. Its role and benefits are many and huge. The same applies to flexographic printing, in which a large variety of factors such as the printing format and the material variety change. (China Packaging News)
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