Electronic label printing

The Chinese name of RFID (Radio Frequency Identification) is radio frequency identification technology. This technology was first proposed and researched by the US Department of Defense and the world’s largest retailer, Wal-Mart, in the early 1980s. The purpose is to allow people to adopt advanced technology to achieve automatic identification and management of various targets (people or things) in different states (static, mobile, or even harsh environments), so as to achieve control in the production process of goods. Improve production efficiency: achieve control in the process of goods flow, improve circulation efficiency, reduce the phenomenon of loss of goods: In the security inspection department can achieve contactless security inspection: in the traffic department can realize real-time monitoring of vehicles and so on.

1. Radio frequency identification technology

Radio frequency identification technology is a technology that uses radio frequency signals to achieve non-contact information transmission through space coupling (alternating magnetic field or electromagnetic field) and achieves the purpose of identification through the transmitted information. RFID systems are usually composed of electronic tags and readers.

The reader sends an inquiry signal of a certain frequency to the RFID tag. After the tag gets the signal, it sends a feedback signal. The reader processes the signal and sends it to the computer network. The RFID electronic tag also consists of two parts. The RFID electronic tag is composed of a coupling element (dedicated antenna) and a chip integrated on the thin film to complete the data storage, transmission and data collection. After years of research, the thickness of electronic tag chips is becoming thinner and thinner, which is enough to be used in some flexible materials of packaged products.

With its unique advantages, e-tags have gradually been widely used in industrial automation, commercial automation and transportation control management, automotive, train and other traffic monitoring; highway automatic toll collection system; parking management system; article management; assembly line production automation; security Check in and out; warehousing management; animal management; vehicle security and so on.

The most successful application of e-label at present is logistics management and commodity circulation. For example, if a certain supermarket wants to track the sales status of a certain brand of toothpaste, the usual practice is for supermarket managers to directly read the bar code of the product with a scanner. For dozens of products, scanning barcodes on toothpaste can take a lot of time. If we use RFID technology, we can automate the collection of all toothpaste information within seconds. Furthermore, once a new product is filled on the shelf, the system will automatically update the catalog and automatically place orders when it is out of stock. . RFID technology can also quickly register products, solve the supermarket payment queue waiting for and stolen goods and other issues.

Having said this, you may be tempted to ask how the development of radio frequency identification (RFID) technology has anything to do with the traditional printing used today. At present, the relationship between them is indeed not close, but it is certain that in the near future RFID systems will be promoted by means of printing technology. Traditional printing technology will give advanced RFID technology a new vitality. RFID tags will bring the printing industry and electronics industry closer together. Although the relationship between traditional circuit boards and the traditional printing industry is not great, the importance of printing after the emergence of smart labels is very important.

2. Electronic tag antenna printing
In the past, the antennas in RFID tags were usually made by copper etching. Since etching copper to make antennas is not only unfavorable for environmental protection, but also the production cost is relatively expensive. For those high-end products, the cost of several dollars increase may be able to be used by manufacturers. And consumer acceptance, and for the low-end consumer goods, RFID tags are not easy to accept, because no one is willing to accept an ordinary toothpaste because of the use of RFID tags rose a few dollars. Therefore, many large companies are actively looking for ways to reduce the cost of RFID tags. People envisage using printed methods to make conductive antennas instead of etching the antenna. This technology is considered to be a major innovation in reducing the cost of RFID tag production. At the same time, RFID tags bring business opportunities to the printing industry.

The most common process for printing electronic tags at home and abroad is screen printing, but it is not the most ideal process. The thickness of an electronic label printed antenna is generally 0.01 to 0.04 mm, which requires that the screen printer must be able to print fine thin lines, and the gap between two adjacent fine lines is as small as possible. Make sure that the electronic label is compact, however, it is very difficult to make the gap very small in the usual screen printer. In addition, in order to ensure the conductive properties of the antenna, the printing thickness of the screen printing machine is also required to be uniform when printing the electronic tag, otherwise if there are some tiny cracks or depressions in the printing of the antenna, the conductive performance will be affected. The environment of the antenna printing process is very demanding, because if there is dust in the environment during the printing process, it will also affect the conductive properties between the wires.

The Institute of Printing and Media Technology at Chemnitz University of Technology in Germany is currently conducting research projects on polymer electronic printing. The aim is to develop a new type of printing method suitable for industrial production of polymer electronic products. Some offset printing machines superimpose conductive ink on a wide web of material. According to the Institute, a high-efficiency printing press can produce the output of a traditional electronic label factory for one year in 40 minutes, and the production price has also dropped below 1 euro cent per unit.

The development of RFID electronic tags will effectively promote the future of printing technology innovation, because RFID electronic tags are a kind of microstructured printing technology, and the ordinary offset printing press is not suitable for printing of this kind of microstructure, but in order to be able to make conductive ink Uniform and extremely thin coating on very thin substrates. There are two issues that must be addressed here. One is the development of conductive inks. The second is that printing equipment providers can provide an ideal solution for printing RFID tags, such as: hybrid printing technology.

3. Conductive ink
Conductive ink is a special ink that allows current to flow. It is composed of dispersed fine conductive particles and conductive polymers. After printing on the substrate, it can function as a wire, antenna, and resistor. This ink is printed on a flexible or rigid substrate to make a printed circuit, and an antenna printed with conductive ink can receive radio signals from a dedicated RFID computer. But what exactly is the acceptance effect? Some people have used different kinds of emission frequency inspection conductive inks instead of corrosive metals as the RFID tag antenna effect. Experiments have proved that both have the same function at UHF (860-950 MHz) and microwave (2450 MHz) emission frequencies. : If the frequency is around 13.56MHz, add some additional processing, such as high temperature or electroplating, to make the antenna printed by the conductive ink work like a copper coil antenna. In the past, conductive inks were mostly used for screen printing, but now it can be applied not only to screen printing but also to various printing processes such as offset printing, gravure printing, and flexographic printing, thereby greatly broadening the range of applications.

4. Printing prospects of electronic labels
Today, about 40 billion barcodes are printed every day. If 1% of the 400 billion barcodes are printed with electronic labels, this is undoubtedly a huge market for printing companies! However, bar codes and electronic tags will also exist for a long period of time. According to incomplete statistics, the global RFID tag market reached 4 billion U.S. dollars in 2004 and is expected to exceed 7 billion U.S. dollars in 2006. At the RFID seminar held in Shanghai in 2005, experts estimated that the global RFID market will reach 300 billion US dollars in 2010.

At present, the application field of electronic tags is mainly containers or large-packaged goods or items with higher value. In this area, electronic labels can integrate all aspects of the supply chain into an organic whole. They have significant advantages in improving logistics efficiency, reducing logistics costs, and tracking product quality and product information, and have shown strong development momentum. .

However, it is too early for the electronic label to be used as a code mark for daily consumer goods. The most direct reason is the cost. It can be believed that as the printing cost of electronic labels decreases, the market for electronic labels will increase.