The bar code is provided by N. T. Woodland first proposed it in 1949. In recent years, with the continuous popularization of computer applications, the application of barcodes has been greatly developed. The bar code can indicate the country of manufacture, manufacturer, product name, production date, book classification number, mail start and end location, category, date and other information of the product, so it is obtained in many fields such as product circulation, library management, post and telecommunications management, banking system, etc It has been widely used. The bar code is composed of lines of a certain length, width and width and digital symbols. It is a computer graphics language that is printed by ordinary printing methods and read by photoelectric scanning reading devices. Bar code is a data input technology and automatic identification technology researched and developed in recent decades. It can reflect a lot of information such as the type of goods, manufacturer, weight, amount, date of manufacture and circulation time. 5. When scanning barcodes, the scanner must have a low-level reset signal of a certain width to determine the start and end of scanning the barcode. Therefore, the left and right blank areas should be of sufficient size according to the four corner marks of the film, otherwise the barcode will It is difficult or impossible to read. 6. Printing materials When printing bar code symbols on transparent materials (such as plastic, glass, etc.), you can't just print the color of the bar without printing the background color (empty color). Otherwise, the scanner cannot collect the empty reflection signal and cannot read it. Therefore, when printing barcodes on transparent materials, the background color must be preprinted first. 8. The requirements of the substrates: when the barcode is read, the scanning light source is incident at a 45 ° angle, and the reflected light collection angle is 15 °. When the reflected light exceeds 15 °, the reflected light signal cannot be collected, which is equivalent Due to the black effect. Therefore, in order to meet the characteristics of barcode scanning, the substrate must have good light scattering characteristics, and no specular reflection can occur. Therefore, the white matter, opacity and gloss of the paper have a certain influence on the reading of the barcode. In addition, materials with good weather resistance, dimensional stability after stress, good coloring, small ink permeability, moderate smoothness and smoothness should also be considered. Kn95 Mask can be used to protect you from harmful dust,PM2.5, car exhaust, wood products, pollen allergies, and smog, is to maintain your health and life. This masks are soft and reliable - not easy to drop, no need to adjust it when you work. A flexible Nose bar is adopted at the bridge of nose; The four sides join flatly and tightly to the face; Hence, it avoids unfiltered air directly entering into and thus make breathe safely. Recommendations - Only be worn for a maximum of four hours and it is best to change them regularly so they can remain effective. Protective Medical Mask,Mask For Prevent Tuberculosis,Civilian Medical Mask,Kn95 Mask Can Prevent Flu, Surgical Mask GUANGZHOU T.WING-PAK MFG.CO.,LTD , https://www.watch-winder-factory.com
The barcode has a one-dimensional barcode and a two-dimensional barcode. There are many bar code systems, such as one-dimensional bar codes, including UPC code, EAN code, 39 code, ISBN code, etc. The two-dimensional bar code is developed in response to the shortcomings of the one-dimensional bar code information capacity and the reduction of the bar code area to improve the ability to resist pollution. The difference between the two-dimensional bar code and the one-dimensional bar code is that the text information can also be bar coded, and the information is not only applicable It can be processed in English, numbers, Chinese characters, symbols, fonts and even blanks, and the information storage capacity can reach 1100 digits (one-dimensional barcode has only 15 digits). In addition, the two-dimensional bar code can also use encryption technology, which greatly improves the anti-counterfeiting performance of goods.
In addition to conventional barcodes, there are some new types of barcodes, such as:
(1) Invisible barcode. There are three types of invisible barcodes: cover-type invisible barcodes, photochemically processed invisible barcodes and invisible ink printed invisible barcodes.
(2) Watermark magnetic code. The watermark magnetic code is the binary interval of the pattern generated by the computer while it is wet coated in the production process. After drying, it stays in the magnetic oxide to produce a unique 12-digit number that cannot be changed. The ordinary magnetic head is added with a special Watermark magnetic verification track to read. The watermark magnetic code can be combined with the hologram to form a holographic magnetic strip anti-counterfeiting technology to form a better anti-counterfeiting effect.
(3) Metal barcode. Compared with ordinary bar codes, it has the characteristics of not afraid of stains on the surface, strong anti-aging ability, and can also be made into invisible bar codes. There are also new two-dimensional metal bar codes.
The method of editing this paragraph of barcodes can be printed in a variety of ways, such as lithography, letterpress, intaglio, screen, and plateless (inkjet). No matter which method is used, the printing quality is required to be good. In summary, there are mainly the following aspects :
(1) In order to ensure correct scanning and reading, the printed barcodes should be neat and clear and the barcodes have no obvious defects (defects), and the blank characters have no extra black spots (spots). Usually the maximum diameter of defects and stains should be ≤ the narrowest barcode 0.4 times nominal.
(2) Controlling the size error of the barcode is a guarantee to improve the first reading rate of the reading device and reduce the decoding error rate. This should not only improve the quality requirements of plate making, printing or printing, but also increase the tolerance requirements for reading devices.
(3) In order to read reliably, the bars and spaces in the barcode after printing should have obvious contrast signals. The greater the contrast signal of the barcode, the better the reading performance.
(4) The printing tolerance must be strictly controlled during printing, otherwise the reading effect will be affected.
(5) There are certain requirements for the roughness of the edge of the barcode. When the roughness is too large, it cannot be read.
(6) The thickness of the ink layer in the bar and the space of the bar code should generally be controlled within 0.1mm, otherwise the correctness of the reading will be affected because the bar and the space are in different scanning planes.
Barcode printing quality requirements Barcode quality directly affects the use of barcodes. Barcodes that do not meet quality requirements will not only improve management efficiency, but will also cause confusion. Although the quality of barcodes has been improved to a certain extent in recent years, there have also been instances of products being rejected by supermarkets due to poor barcode quality. Therefore, improving the quality of barcodes is very important for manufacturers and sellers.
Bar code printing looks very simple, it does not have complex patterns and beautiful soft tones, so some companies think that its printing requirements are relatively simple, but it is not true, because the bar code combination contains specific information, and by specific reading equipment Recognition, therefore, there are strict regulations on the printing accuracy, color matching, printing position, etc. of the bar size of the barcode. details as follows:
1. Stripe color matching.
When matching stripe colors, the contrast of stripe colors must be sufficiently large. The color of the bar can be: dark blue, dark green, dark brown, black, the empty color can be red, orange, yellow, white, of which black and white is the best match, the original color of metal materials (such as gold, silver) are not suitable for bars Or empty color.
2. The printing position selects the placement position of the product barcode according to different packaging forms, and should meet the scanning requirements of the scanning device. It should be noted that the barcode must be at least 5 mm away from the edges, overlaps, folds, or corners of the package to prevent the barcode from being worn, covered, or deformed with the package, causing problems when scanning and reading. For example, dried tofu produced by an enterprise can be read when the barcode on the packaging bag is not filled with physical objects, but the physical objects are contained in the bag. After the vacuum packaging process, the barcode is not readable due to improper position due to wrinkle deformation . Therefore, enterprises should judge the barcode printing position based on the actual sales status of the goods.
3. The size of the bar code is based on the size of the outer packaging of the product and the area allowed for printing. The bar code magnification factor is selected within the range of 0.8-2.00 times the standard bar code size. (Standard barcode refers to a barcode with a magnification factor of 1.00, and its size is 37.29 * 26.26 mm).
4. Bar height of bar code The height of bar code can not be shortened in principle. If the position of the bar code is not enough, it must be shortened. Consult the relevant bar code technicians for advice.
7. Ink requirements The color matching of the ink should fully consider the color cast of the ink. The color cast of the ink also has a great influence on the accuracy of the barcode. In theory, as long as the ink is used in accordance with the color ratio, it can meet the barcode printing requirements. However, due to the defect of the impure coloring phase of the printing ink, the color cast occurs. Therefore, the color of the ink should be accurately controlled so that the ink density is uniform, the hue is saturated, and the purity is high. It is best to determine whether the reflectivity of a certain ink under red light meets the requirements before printing the barcode. The reflectivity and glossiness of gold ink will cause a specular reflection effect and affect the scanner reading, so it cannot be used to print barcodes. In addition, the concentration of the ink and the thickness of the ink layer should also be suitable for the barcode printing requirements. Since the barcode printing is solid printing, the reflection density that can be achieved by the printing is related to the optical characteristics of the ink and the thickness of the ink layer. During the printing process, the reflection density of the printing increases with the thickness of the ink. When the thickness of the ink reaches a certain value, the density reaches saturation. General ink saturation density requirements are: black ink 1.8 ~ 2.0; cyan ink 1.45 ~ 1.70; magenta ink 1.25 ~ 1.50; yellow ink 0.90 ~ 1.05; other special Color ink above 0.8. Due to the difference in printing technology, the thickness of the ink layer of the printed matter is also different. The general offset printing is 2 to 4 μm; the relief printing is 8 μm; the flexographic printing is 10 μm; the gravure printing is 12 μm; the silk printing is 30 μm.