Laser engraving applied to seal anti-counterfeiting
Seal anti-counterfeiting should be considered from two aspects: one is the unforgeable nature of the seal; the second is the identifiable nature of the seal. To solve the problem of unforgeableness, it is necessary to start from the aspects of seal materials, production processes, and production equipment (enhance management to discuss the subject separately); and the identifiable issues of seals must be made from ink, image recognition, establishment of seal archives, etc.
Laser technology and computer technology are the frontiers of contemporary technology. The birth of these two technologies immediately brought about the revolution in the printing industry. Laser photocopying replaced hundreds of years of movable type printing. Typesetting is almost extinct in China. Inspired by the laser illumination, these two technologies are also rapidly introducing the fields of seal manufacturing and anti-counterfeiting.
Computer typesetting has greatly improved the technical level and production speed of the seal. Laser engraving has succeeded in replacing the method of plate-making stamper, manual and tool photoelectric tracking, which has caused widespread concern of relevant departments and experts.
The advantages of laser's monochromaticity, high brightness, and good directionality are widely used in material processing such as laser heat treatment, cutting, welding, and marking. In these occasions, the laser is used as an invisible "knife" on the material, causing the material to melt, vaporize, and form a variety of processes. Advanced industrial countries have all promoted laser processing into advanced manufacturing technologies. The principle of laser engraving is that the laser beam is transmitted and focused on the surface of the material by the optical mechanism, and the material of the point of application of the laser beam with high energy density rapidly vaporizes to form pits. Using a computer to control the xy console to drive the laser head to move and control the laser switch as required, the software processed image information has been stored in the computer in a certain way. When the information is read from the computer in order, the laser head is along The scanning traces are scanned back and forth from top to bottom from left to right. Whenever a "1" point is scanned, the laser is turned on and the laser is turned off when scanning to a "0" point. We know that computer storage information is performed in binary, which coincides with the two states of the laser switch.
The current popular stamp typesetting software can be slightly modified to be used in special laser engraving equipment composed of lasers, scanning workstations, and computers. Because of this kind of apparatus laser generally has YAG and CO2 two kinds. YAG is used for metal marking and it is not easy to reach the desired depth. This cannot be used for seal engraving. The CO2 laser is suitable for engraving of non-metallic materials. In terms of the seal, rubber, horn, plexiglass, marble, jade, ink pad, wood, etc. can be carved to achieve better depth and accuracy. CO2 laser power selection 1-20 watts. Engrave a badge for 3-5 minutes and seal it for 15-30 minutes. At present, the device's laser spot is less than 0.1mm. Mechanical resolution 0.025mm repeatability 0.1mm. The stamped seal fully complies with the industry standard of the seal.
Why can laser engraving be anti-counterfeit? First, the process method is unforgeable and manual imitation is very difficult; second, it is easy to reflect many anti-counterfeiting measures in computer typesetting through laser engraving. This is the biggest advantage over other process methods. For example, engrave bar code, code, shadow, non-repeatable dots, charts, patterns, etc. Third, it is easy for the computer to archive and establish the seal archive. The printed text is easy to compare and identify with the sample chapters in the computer image recognition and archives.
Our country is a big country of seals. Seal anti-counterfeiting should be divided into two steps: At present, it is necessary to strengthen management and adopt as far as possible some of the current primary anti-counterfeiting measures. At the same time, we must vigorously strengthen the application of high technology in the seal industry. Through in-depth investigation, repeated arguments, and scientific and technological research, we studied a set of practical seal standards, seal processes, seal materials and seal equipment, and established a network of authentication and management system. Form a unified national professional system.
Seal anti-counterfeiting is a complex system project, relying on the joint efforts of government departments, research institutes and enterprises. The State Key Laboratory of Laser Technology and National Engineering Research Center for Laser Processing of Huazhong University of Science and Technology sent laser technology to the public, and also enthusiastically invited related technologies from the fraternal units to enter into a friendly and cooperative relationship. For the advancement of China's seal anti-counterfeiting technology, it will contribute to the prosperity of the seal industry.