Ways and Methods to Improve the Quality of Tobacco Label Printing

Product bar code is an open global information system. It gives each product a globally unique code to ensure the uniqueness, standardization, versatility, and internationality of the product.

Yunnan is a major province of tobacco. Cigarettes are a major economic pillar and enjoy a good reputation both at home and abroad. Bar codes with the role of “passes for commodities” have a direct bearing on the circulation of cigarettes to domestic and foreign markets. The quality of barcodes is affected by cigarette companies and printing companies. Highly valued. Combining the practical experience of solving bar code printing quality problems for many years, the author carried out the quality of the bar coded product bar code that was sent for sample inspection in the past year after the implementation of the new national standard in accordance with the quality requirements of GB12904-2003 "Commodity Bar Code" (hereinafter referred to as the new national standard). Organize and analyze, and propose methods and approaches to solve quality problems, designed to help printers control and improve the quality of product barcodes.

The mandatory requirements for the printing quality of bar code symbols in the new national standard are: (1) The symbol level is not less than 1.5/06/670; (2) The bar code symbolizes the same product identification code as the one provided for human identification; (3) Blank The width of the area is not smaller than the minimum width of the blank area specified by the standard (unit is mm). One decimal place is reserved. The symbol level is determined on the premise of error-free decoding, and the ten scanning reflectance levels obtained from a total of ten scans at ten positions evenly distributed on the height direction of the bar code symbol of the product to be tested are decoded. The average of the seven parameters of correctness, minimum reflectivity, symbol contrast, minimum edge contrast, degree of modulation, degree of defect, and decodability. The problems with the quality of the smoke bar code and solutions are as follows:

1. Among the problems with the quality of the smoke bar code, the bar cuts accounted for 81.8% of the problems. Although the bar height and magnification factor are not included in the new standard, this does not mean that the bar code symbol height can be arbitrarily shortened. The smaller the height of the bar code, the higher the requirement for the scanning line to aim at the bar code symbol, and the lower the first reading success rate (first reading rate), which reduces the operating efficiency of the POS system.

The box cigarette label has a large packaging area, and the barcode height can meet the requirements of the standard. If the article does not meet the requirements, it all occurs on small box cigarette labels (trademarks). Some small box cigarette labels have a height of only 9 mm, causing difficulties in reading and writing. .
The printing company should strictly control the sample inspection. The height of the side bar code on the small box should not be less than 12.5mm. The ideal reading rate can be achieved at this height.

2. Defects: Defects are the ratio of the maximum unit reflectance non-uniformity (ERNmax) to the sign contrast (SC), ie Defects=ERN-max/SC.

The defect accounted for 10.6% of the problem, which is a technical parameter related to the reflectance of the deinking/blot size, the measurement of the optical aperture, and the sign contrast. The unit reflectance non-uniformity (ERN) reflects the effect of defects such as de-inking and smearing on bar code symbols on the reflectivity of the bar/space locality. When the diameter of the measurement aperture is fixed, the larger the deinking/staining diameter, the higher the de-inking reflectance and the lower the stain reflectance, the smaller the symbol contrast, and the greater the defect degree, the greater the influence on the scanning reading. Caused by the degree of defect of barcode symbol does not meet the requirements of the national standards are: (1) improper color matching of the barcode symbol; (2) high brightness of the printing carrier, such as gold or silver; (3) ink color is not satisfied ( Empty) reflectivity requirements; (4) rough print quality, deinking, blemishes are serious.

For the pursuit of high-end packaging, companies often use higher brightness packaging materials, bar code symbols printed on such materials, the optical characteristics can not meet the national standards, the specular reflection to reduce the empty reflectivity, resulting in refusal to read, should be taken in use The following measures: First, to ensure that the back of the printing carrier (empty) has enough reflective ability, it should be diffuse reflection capabilities, rather than specular reflection, such as gold or silver when empty, should be coated on the back, the coating thickness should be The printing carrier can be completely evenly covered, otherwise the poorly covered areas will be mistaken for stains and the non-uniformity of the unit reflectance will increase, leading to an increase in the degree of defects. Second, select the appropriate printing ink, and perform trial and error, and check whether the color of the ink can meet the requirement of strip (empty) reflectivity by means of a barcode detector.

3. Symbol contrast (SC): The symbol contrast is the difference between the highest reflectivity and the lowest reflectance of the scanned reflectance curve, ie, SC = Rmax - Rmin, and the sign contrast accounts for 1.5% of the problem. Caused by the unqualified reasons are: bar code symbol strips, empty color with improper; reflectance of printing materials can not meet the standard requirements; ink reflectivity can not meet the standard requirements.

The main reason for the unsatisfactory sign contrast in the smoke sign is that the ink reflectance cannot meet the standard requirements. The printing company shall, in the proofing test phase, aim at the characteristics of the use of the ink, combined with the printing process, and find the printing conditions satisfying the quality requirements through trial and error.

4. Decodability: The minimum of the ratio of the unoccupied offsets in the available tolerances of the individual unit or cell combination sizes associated with the reference decoding algorithm to the available tolerances. value. That is: Decodability = Residual Tolerance / Total Tolerance = (RT-M)/(RT-A).

The decipherability accounts for 1.5% of the existing problems. The higher the decodability, the smaller the printing deviation, the farther the barcode size is from the maximum allowable threshold specified by the decoding algorithm, and the larger the error space left for the barcode reading device, the higher the reading rate of the reading device is. . The main reason that the decodability does not meet the requirements of the standard is due to the fact that the stripe size is out of tolerance, the stripe size is related to the plate making deviation, the printing gain and the printing conditions. An effective way to control the empty size of a bar is to do a good job of bar code testing. Suitability test refers to the ability of a printing system to adapt to the print quality requirements of bar code symbols under different printing conditions. The suitability test solves two problems. First, it determines the size of the print gain (generally increasing the overall bar size) when printing a bar code symbol. Second, it determines the printing bar code symbol accuracy (abbreviation ).

The print gain is a systematic error, which is caused by the ink spreading on the paper or the ink spillage during printing. For each printing condition, the printing gain and the printing accuracy cannot be exactly the same, which requires a suitability test for each printing condition.

5. Blank space width: Blank space refers to the area with the same reflectivity as the blank on the leftmost (rightmost) side of the bar code symbol. The blank area accounted for 3.7% of the existing problems. The function of the blank area is to provide "start data collection" or "end data collection" information for the reading device. The width of the blank area is not enough to cause the barcode symbol to be unreadable or even misunderstood. The new national standard imposes a mandatory requirement on the width of the blank area. The blank area width of the product barcode symbol does not meet the requirements. The barcode symbol is judged as unqualified. The reason why the width of the blank area is not enough is that the width of the blank area selected by the design does not match with the enlargement factor or the overlay error in the printing process.

Whether the blank area width can meet the standard requirements, in addition to the design of the review strictly in accordance with the standard requirements to measure the size of the blank area, it should also control the overlay error during the printing process. When there is a dark color around the bar code symbol, the size of the blank area should be increased to avoid the influence on the reading device.

6. Refused to read: The barcode symbol cannot be read by the scanner.

The reasons for the refusal to read are: (1) the bar code symbol can not meet the quality requirements in terms of optical characteristics; (2) the size of each bar or space in the bar code symbol is too bad; (3) the width of the blank area is not enough. There are many reasons for the refusal to read, such as the optical characteristics of five technical parameters.