Quality Issues With Cigarette Packaging Coding Are Frequent, And Well-Known Cigarette Packaging Printing Companies Are Taking Measures

At the end of 2022, the National Tobacco Monopoly Administration decided to fully print QR codes on all brand cigarette packs, achieving one item, one code. From January to April 2023, various cigarette pack companies will gradually print QR codes on their own brand cigarette packs, revise and sample them. In May 2023, cigarette pack products with QR code logos will be launched on the market, marking the official start of the cigarette pack coding operation. Nowadays, various cigarette packaging printing companies have been implementing cigarette packaging coding operations for more than a year. During the cigarette packaging coding process, they have encountered numerous quality problems such as white spots, black spots, white lines, black lines, deviation, duplicate coding, and incorrect coding. Our company has accumulated some experience and explored some methods in the process of solving these problems. Now, we summarize our past experience and coding process and discuss and exchange ideas with colleagues in the industry.
Equipment adjustment
01
Trigger electric eye and digital dynamic positioning lens adjustment
Test paper and select color blocks with obvious contrast and no interference on the printed product based on product characteristics (mostly using color blocks specially printed for coding operations, such as circular, square, rectangular, or other shapes set according to rules, such as 8-4 marks, which are 8mm color blocks+4mm empty+4mm color blocks, as trigger color blocks, and move the trigger eye to the corresponding position.
Select the pattern position with obvious contrast on the printed product as the correction positioning point based on its characteristics, and move the digital dynamic positioning lens to the corresponding position.
02
Adjustment of nozzle position and height
Try walking the paper, adjust the nozzle position according to the reserved coding position on the printed product, and adjust the nozzle height to about 3 sheets of paper thickness from the platform.
03
UV curing lamp position adjustment
Test the paper and adjust the UV curing lamp to the corresponding position according to the reserved coding position on the printed product.
Print adjustment
01
Template drawing
The new product needs to redraw the template, and the layout height should be set to include the printed QR code in the template. Draw the QR code at the corresponding layout position based on the actual production situation, and set the data of the QR code (basic attributes, data source, QR code attributes, and calibration information). When setting basic attributes, it is prohibited to use the mirroring function, otherwise it will cause the code to be unrecognizable when receiving. The QR code attributes include error correction level and version number, which should comply with technical standard requirements, and the direction and starting position should match the standard sample.

02
Template call
Old products need to call templates. Open the printing software in the printing computer, open the template list, click to open the template, select the desired work template, and click to save the template.
03
Spray code parameter settings
(1) Waveform voltage setting: The waveform voltage mainly affects the ink volume and blackness of the printing. The higher the voltage, the larger the ink volume and the blackness of the QR code. There are two types of waveforms: single wave and double wave. Single wave uses one of the two components in the selected nozzle to spray the code; Double wave uses two sets of components from the selected nozzle for coding. It should be noted that in the early days of inkjet printers, there was only one set of components in one nozzle, so the sprayed patterns were prone to quality issues such as white spots and white lines. To solve such problems, most of the later inkjet printers have changed their nozzles to dual components, which means that one nozzle has two sets of components for inkjet printing. If one component is slightly blocked and causes quality problems such as white spots or lines, the other component can be used for inkjet printing to make up for it.
(2) Color matching setting: Adjust the position of the QR code in the QR code box or the overlap of the inkjet positions of two components on a nozzle.
(3) Trigger setting: Generally set to read label printing, using custom labels (8-4 labels).
(4) The resolution of QR code printing is generally set to 400dpi to 480dpi.
(5) Anti duplication code printing: The anti duplication code function that comes with the coding software must be set to stop printing with a duplication code alarm.
Sample setting
01
Template creation
A template needs to be created for the new product, and a complete printed image is required for image capture. The actual height value of the product should be smaller than the height value of the captured image; When setting the small opening (machines without this option can ignore it), the selection of the small opening Mark positioning must be in the same position where each single version of the product exists. The location of the Mark point selection should be in a position with high image contrast, and the codeword window is the most important step in setting up the detection QR code. After the template is built, it is necessary to check whether the entire product's QR code area has been selected.
The modification of QR code parameters mainly includes areas for missing prints, dirty versions, quality, layout, and advanced parameter settings. Corresponding settings can be made according to the customer's quality requirements.
02
Template call
Old products need to call templates. Open the detection software on the detection computer, open the template management, and select the required work template to load.

03

Inspection parameter settings
Implement real-time comparison with the data center for the machine. In the "Detection Accuracy" option, select "Data Center Comparison" as the priority for the code setting. Enter the work order number according to the code notification and start the work order detection.
For machines that have not achieved real-time comparison with the data center, first confirm whether the database memory of the spray code detection software has enough storage space to load all code packages in this batch. If it is not enough, clean up the number pool in a timely manner, and then add the code packages that need to be detected to the number pool according to the notification work order number. To prevent the problem of duplicate codes between different code packages within a batch, it is strictly prohibited to delete any code package of the batch in the number pool before all products in each batch are produced. If the capacity of the number pool is insufficient, the code package data that completes printing first shall be deleted in chronological order.
Self written invalid code trial spraying
Use self-made invalid codes for trial spraying, adjust the nozzle position, temperature, waveform voltage, resolution and other parameters based on the trial spraying effect until the spraying effect meets the standard requirements. After the invalid code trial spray is qualified, the site should be cleaned up as soon as possible to prevent invalid code products from mixing into genuine products.
Formal printing process improvement
(1) Log in to the QR code data management system on the printing computer, open the spray code management option, and download the required code package for production corresponding to the code notification. The code package can only be downloaded once and cannot be downloaded repeatedly. If the downloaded code package is deleted due to misoperation and needs to be downloaded again, the data center administrator must be notified to redistribute it. After completing the coding of each downloaded code package, another code package can be downloaded, and the already printed code package must be deleted immediately after importing the new downloaded code package.
(2) When importing data, be sure to check the anti duplication code import option and confirm the accuracy of the imported code package data again by comparing it with the code notification.
(3) Select the downloaded code package information for the data source option of the printing software, and check the decryption option (machines without this option can ignore it) by selecting "When a QR code contains two pieces of information, select the delimiter to separate them".
(4) During normal printing, it is necessary to confirm that the printing data method is "stop printing due to duplicate code alarm". Confirm that the number of lines in the first printed code packet starts from 0. After normal printing, use a scanning device to scan and verify the code immediately to confirm whether it is the code packet that needs to be printed, avoid duplicate code problems, and check whether the direction, size, and appearance quality of the QR code are consistent with the standard sample.
(5) During the coding process, check in a timely manner whether the QR code is the code segment that needs to be produced, observe in real time whether the QR code upload data on the data management platform is updated in real time, and whether the printing quantity corresponds to the upload quantity on the data management platform.
(6) After the printing of this batch of products is completed, the code packages that have not been downloaded should be contacted to the data center for recycling. The code packages that have been completed with coding should have their data deleted and the data folder cleared.
Code package replacement and shift handover

(1) Confirm that the code package has been sprayed, record the spraying situation and quantity in the shift handover record, delete the printed code packages in the printing computer, and clean up the site to prevent confusion between the products of the two code packages.
(2) During the shift handover, it is necessary to carefully check the printing and testing of various parameter settings to ensure that the status is normal. When shutting down after work, it is necessary to record in detail the current code packet's printing line and code, as well as the last four digits of the code data, to prevent inputting the wrong line number when restarting.
(3) Turn on the backup power before starting up, and turn off the backup power after shutting down to prevent data loss caused by abnormal power outages.