How to check and control the printing quality of barcode barcodes (1)

With the vigorous development of the market economy, bar codes [barcode printers] play an increasingly important role in the sales and circulation of commodities, especially the rapid development of computers and network technologies. Bar codes [barcode printers] are providing for product sales and management. More and more convenient and fast, so grasp the type of bar code [bar code printer], application and quality control for printing companies and production of product manufacturers are urgent and important. The author summarizes some experiences and opinions on how to check and control the printing quality of bar code [barcode printer].

This article by the bar code printer: to provide, related to the equipment mentioned in the article: bar code printers, bar code scanners, bar code knowledge can ask the company!

First, the application of the bar code and printing method

As we all know, bar codes have been applied to almost all product packaging, some even directly printed on the product. The product packaging methods vary widely. There are paper products, plastic packaging, metal packaging, etc. The product shape and surface materials are also different, so the way of printing bar codes is also different. In fact, all printing methods can print barcodes, such as offset printing, letterpress/flexographic printing, gravure printing, screen printing, and inkjet printing. [Generally printed by professional bar code printers]. There are different methods of controlling different bar code printing methods, but the inspection method is the same.

Second, the basic quality requirements of bar codes;

1. Exterior:

The bar code symbol is neat and clean, with no obvious dirt, wrinkles, damage or perforation.

• The numbers, letters, and special symbols in the bar code symbol are printed in a clear, unambiguous manner.

Bar code symbols have no significant deinking, smearing, or broken lines; the edges of the bar are neat, with no significant bending deformation.

• The ink color of the bar code symbol is uniform and there is no significant difference.

2. skills requirement:

In accordance with the bar code national standards adopted by the sample, for these technical requirements, the national bar code standard has detailed quantitative indicators. The specific items include:

Bar (empty) reflectivity, print contrast (PCS value / Print Contrast Signal):

PCS = (Rl-Rd)/Rl, where Rl represents the reflectivity of the bar code symbol, and Rd represents the reflectivity of the bar code symbol. In fact, most barcode readers (like QUICKCHECK 400, XAMINER 6500, etc.) can automatically calculate PCS values. If you want to calculate by yourself, you need to measure the reflectance of the null and bar separately with the bar code reading pen (demonstration equipment and operation method), and then substitute the above formula to obtain the PCS value. The PCS value needs to meet the technical specifications specified in the national standard GB12904-1998. . In principle, the color of the selection bar and the blank should be appropriate, and the bar and the empty reflection density value should be pulled as far as possible. The PCS value will not be a problem. So the main requirement of this item is to choose the right color at design time and control the color in the printing process.

• Bar (empty) size error, can be measured with a length measuring accuracy of more than 0.01mm. However, this is also a test project in the main design process. In the actual process if the bar or empty size is wrong, the bar code will not be readable. The national standard has strict regulations on the deviations of the original film and printed material. If necessary, relevant standards can be found. Now, special software has been used to generate bar codes automatically, like the MBC software of the Mac, so now the size of the bar and the space is not very common.

• The size of the Quiet Zone is quite common because it is sometimes easy for designers to ignore this requirement when space is limited. The measurement method is relatively simple, and a length measuring instrument with an accuracy of 0.5 mm can be used.

· The bar height refers to the bar height, which should not be less than the integer value of the standard bar high size. This item is more flexible, so the amount is relatively simple, but this item cannot be directly measured by the bar code reader. , so be careful when designing.

· Numbers and letters should use OCR B character set (GB/T12508). These human-readable characters or letters should be printed on the bottom of the bar code and correspond to the corresponding bar code character. Its size should comply with national standards and be in accordance with the bar code. The same magnification is enlarged or reduced. This item is also not directly measured by a bar code reader, so care must be taken when designing.

·Check codes can be checked according to the calculation method specified by the state.

• The correctness of the decoding, ie, the readability of the bar code, is very important and must be judged by means of a bar code reader.

• The magnification factor is the ratio of the length dimension of the bar code symbol to the standard size. The general magnification factor is 0.80-2.00, as long as a pair of standard bar code film is known.

• Printed thickness refers to the difference in thickness between bars and spaces in the bar code symbol. The difference must be less than 0.1 mm. In other words, the printing must be as even and smooth as possible, as long as the accuracy is 0.01 mm.

· The printing position should be visually measured according to the provisions of GB/T14257. The above technical specifications require the consideration of factors and inspection items in the design of the barcode.