Inspection Standards for the Print Quality of Bar Code Symbols

I. Subject matter and scope of application

This standard specifies the inspection method for the printing quality of bar code symbols.

This standard applies to the inspection of the printing quality of various bar code symbols.

II. Normative references

GB2828 Sampling procedures and tables for inspection by attributes (applicable to inspection of successive lots)

GB7705 Lithographic decorative printed matter GB12053 Alphanumeric character sets for optical recognition - Part: OCR-A character set - Shapes and dimensions of printed images

GB12508 Alphanumeric character sets for optical recognition - Part: OCR-B character set - Shapes and dimensions of printed images

GB12904 Universal product bar code

GB12905 General terminology for bar code systems - Terminology for bar code symbols

GB12906 Bar code for China standard book number (ISBN part)

GB12907 Codabar

GB12908 Code 39 bar code

GB/T14257 Symbol positions for universal product bar codes

3.1 Void: a printing defect in the bars of a bar code symbol, whose reflectance is close to the reflectance of the spaces.

3.2 Spot: a printing defect within the spaces or the quiet zone of a bar code symbol, whose reflectance is close to the reflectance.

3.3 Print thickness: the difference in coating thickness between the bars and the spaces of a bar code symbol.

3.4 Magnification factor: the ratio of the length dimension of a bar code symbol to the standard dimension

IV. Inspection items

4.2 Bar (space) reflectance, print contrast (PCS value)

4.3 Bar (space) dimensional deviation

4.4 Quiet zone dimension

4.6 Dimensions of digits and letters

4.7 Check character

4.8 Decoding correctness

4.9 Magnification factor

4.10 Print thickness

4.11 Print position

V. Technical requirements

5.1.1 The surface of the bar code symbol shall be clean, with no obvious dirt, wrinkles, damage or perforations

5.1.2 The digits, letters and special symbols in the bar code symbol shall be printed completely and clearly, with no ambiguity

5.1.3 The bar code characters shall show no obvious voids, spots or broken lines; the edges of the bars shall be neat, with no obvious bending or deformation

5.1.4 The ink colour of the bar code characters shall be uniform, with no obvious differences

5.2 The technical requirements of clauses 4.2 to 4.11 shall comply with the national bar code standard adopted for the sample

VI. Inspection methods

6.1 Environmental requirements: inspection room temperature 23±2℃, relative humidity 50%±5%

6.2 Sample handling

6.2.1 The sample shall be flat, free of wrinkles and undeformed

6.2.2 When inspecting bar code symbols on labels, label paper and packaging, sufficient fixing dimensions shall be left around the sample

6.2.3 When inspecting bar code symbols on actual packaged goods, the sample requires no handling

6.3.1 Visual inspection: place the sample under a D65 standard light source with a colour temperature of 5500-6500K and carry out a visual inspection in accordance with clause 5.1

6.3.2 Instrumental inspection 6.3.2.1 Measuring instruments A microscope and a grid eyepiece micrometer shall be used

6.3.2.2 Measurement procedure

a. Use a microscope and a grid eyepiece micrometer to magnify and divide the spot or void, and determine its area from the number of grid squares the spot or void occupies

b. Compare the area value obtained in a with the area value specified in the national bar code standard adopted for the sample

6.4 Bar (space) reflectance

6.4.1 Measurement conditions The measurement conditions shall comply with the national bar code standard adopted for the sample under inspection

6.4.2 Measuring instruments The measuring instruments shall be those meeting

the requirements of clause 6.4.1

6.4.3 Measurement procedure

6.4.3.1 Instrument calibration

6.4.3.2 Place a backing under the sample; the backing shall be a spectrally non-selective diffuse reflecting material with a reflection density of 1.50 or above

6.4.3.3 Take five measurement positions evenly along the longitudinal direction of the bars of the bar code characters, and measure the reflectance of each bar (space) one by one from the start character to the stop character, repeating the above procedure for each height position

6.4.4 Data processing

6.4.4.1 Take the maximum value among the reflectances of the bars and the minimum value among the reflectances of the spaces at the same height position as the bar (space) reflectance at that height position

6.4.4.2 Take the maximum value among the bar reflectances and the minimum value among the space reflectances at five different height positions as the bar (space) reflectance of the bar code symbol

6.5 Print contrast (PCS value)

The print contrast (PCS value) is calculated according to formula (1). PCS=RL-RD RL where: RL - the reflectance of the spaces in the bar code; RD - the reflectance of the bars in the bar code

6.6 Bar (space) dimensional deviation

6.6.1 The measurement conditions are the same as those of clause 6.3.1

6.6.2 Measuring instruments A length measuring instrument with a smallest division of 0.01mm

6.6.3 Measurement procedure Take five measurement positions evenly along the longitudinal direction of the bars of the bar code characters, and measure the dimensions of each bar (space) one by one from the start character to the stop character, repeating the above procedure for each height position

6.6.4 Data processing 6.6.4.1 Take the maximum value of the dimensional deviations of the bars (spaces) at the same height as the maximum and minimum values of the bar (space) dimensional deviation at that height

6.6.4.2 Take the maximum and minimum values of the dimensional deviations of the bars (spaces) at five different height positions as the bar (space) dimensional deviation of the bar code symbol

6.7 Quiet zone dimension

Under the light source specified in clause 6.3.1, measure with a steel rule with a smallest division of 0.5mm

6.8 Bar height The measurement method is the same as that of clause 6.7

6.9 Dimensions of digits and letters The measurement method is the same as that of clause 6.7

6.10 Check character Check in accordance with the calculation method specified in the national bar code standard adopted for the sample

6.11 Decoding correctness Check the result of reading the bar code symbol with bar code reading equipment against the visually inspected characters

6.12 Magnification factor The measurement method for the bar code length dimension is the same as that of clause 6.7, and the magnification factor is calculated according to the definition in clause 3.4

6.13 Print thickness Under the light source specified in clause 6.3.1, measure with a thickness gauge with a smallest division of 0.01mm or an instrument of equivalent accuracy

6.14 Print position Carry out a visual inspection in accordance with the provisions of GB/T14257.

VII. Inspection report

The inspection report depends on the inspection content of the sample

Sampling for this standard is carried out in accordance with the national standard GB2828.

This standard was proposed by the China Article Numbering Centre.

This standard is under the jurisdiction of the China Article Numbering Centre, which is also responsible for drafting it.

The principal drafters of this standard are Wu Hailian and Zhou Gang.

——This article is reprinted from China Packaging Network (pack.cn), original link: http://news.pack.cn/show-362273.html