Application of RFID in Printing and Its Printing Technology

In the field of packaging and anti-counterfeiting, traditional bar code labels have been widely used. However, as people have higher and more complete information requirements in many aspects such as production, storage and transportation, quality assurance, anti-counterfeiting, and management, such bar code labels have apparently become ineffective. , It can not only provide information on product production, management and other information, can not warn of the need for information on the quality of goods such as the temperature, in the anti-counterfeiting effect, but also because of its single printing, easy to counterfeit and gradually lose the effectiveness of the product. With the advancement of technology and application in the field of label making, a brand-new, multi-functional, smart label with good anti-counterfeiting effect has begun to be widely used, and it will bring new vitality and vitality to label printing.

The main features of RFID

RFID (Radio Frequency Identification) is a radio frequency identification system, also known as a wireless IC tag, an electronic tag, an inductive electronic chip, a proximity card, a contactless card, etc. It is a kind of radio wave to achieve non-contact. Data access technology can be combined with data access technology through wireless communication, linking the underlying database system to form a large and connected system. A complete RFID system includes readers, sensors or chips, antennas, hardware and software systems, and the like. The basic principle is that when a tag enters a magnetic field region, a signal sent by a reader is received, and energy stored in the chip is sent out by virtue of the energy obtained by the induced current, or a signal of a certain frequency is actively sent. After reading the information and decoding it, it is sent to the central information system for processing.

RFID tags can be classified into passive tags: they do not send out information waves by themselves. The reader sends out signals to generate signals. The RFID tag's antenna receives the induced current generated by the magnetic field, and then sends the information stored in the chip to the reader. Interpretation. Active tag: In addition to the chip and the antenna, the tag has an increased power supply. It can continuously send out data signals and receive readings from the reader.

To sum up, RFID mainly has the following characteristics:

(1) Data read/write function: As long as the RFID can be accessed without touching, the message can be read directly into the database, and multiple tags can be processed at one time, and the status of the logistics process can be written as a tag for the next stage of logistics processing. The use of reading judgments.

(2) Easy to miniaturize and diversify shape: RFID is not limited by size and shape in reading, and does not need to match the fixed size and print quality of the paper for reading accuracy. In addition, RFID can be more compact and diverse in form to apply to different products.

(3) Environmental resistance: The information on the paper will be invisible once it is contaminated, but RFID has strong anti-fouling properties for water, oil, and pharmaceuticals. RFID can also read data in dark or dirty environments.

(4) Reusable: Since RFID is electronic data, it can be overwritten repeatedly, so it can be recycled for reuse. Such as passive RFID, you can use without batteries, there is no need for maintenance.

(5) Penetration: RFID can also be used for penetrating communication if it is coated with non-metallic or non-transparent materials such as paper, wood and plastic. However, if it is iron metal, it cannot communicate.

(6) The data storage capacity is large: the data capacity will expand with the development of memory specifications, and the amount of data required to carry items in the future will increase. The demand for the capacity of the label can also increase, and RFID does not Will be limited.

The main application of RFID in printing

In fact, RFID technology began its research and application as early as World War II. At that time, the United Kingdom had used RFID to confirm whether it was its own aircraft to avoid accidental attacks. RFID is a tag that can read the above information without contact, so the scope of application is very wide, for example, access control (personnel out of internship monitoring, control and commuting personnel management); asset addition and waste management (stack Recyclable container management for boards, containers, trolleys, cages, etc.; waste recycling, waste management and control systems, etc.); cargo management and storage material handling (baggage identification for air transport, inventory, logistics and transportation management; stock inventory inventory , material control systems); medical applications (hospital history systems, hazardous or controlled biochemical item management); transportation (freeway charging systems); anti-theft applications (supermarket theft prevention, library or bookstore theft management); Surveillance (animal husbandry animal management, pet identification, wildlife ecology tracking); automated control (assembly and production of automobiles, home appliances, and electronics); joint ticketing (combination of versatile smart card and bonus card) Many aspects.

In the printing field, RFID will gradually replace the traditional bar code labels. Experts predict that RFID technology will have a significant impact on packaging, security printing, and paper in the coming years. For the printing industry, in RFID production, printing technology can be used to produce RFID antennas, which brings new opportunities for the printing industry.

The application of RFID in logistics and management has been more and more. In foreign countries, Wal-Mart, the largest retailer in the United States, began requesting major upstream suppliers in January 2005 to add RFID to its supply warehouses, and to fully use RFID at the end of 2006.

RFID printing technology

There is a big difference between RFID production and traditional label printing. At present, China's traditional label printing technology has a very high level. There is no lack of experienced companies in the trademark printing industry, but also produces many beautifully designed and high-quality products. , But for RFID, some people think that it has nothing special, as long as it is covered with a plain label on a beautiful coat, which is not difficult for high-quality label printing companies, but simply adding a beautiful coat RFID, for its high added value will cause significant losses. So, what are the characteristics of RFID printing compared to traditional label printing? First of all, from the definition of RFID, intelligence refers to radio frequency circuits made up of chips, antennas, etc., while labels are printed by the label printing process to make commercially available coats of radio frequency circuits. From a printing point of view, the emergence of RFID will bring higher gold content to traditional label printing. The chip layer of RFID can be packaged and printed with materials such as paper, PE, PET and even textiles to make self-adhesive stickers, paper cards, hanging labels or other types of labels. The chip is the key to RFID and is determined by its special structure. Can not withstand the pressure of the printing press, so, in addition to inkjet printing, it is generally used to print the surface layer, and then with the chip layer composite, die-cutting process.

(1) Printing method. Printing is mainly based on screen printing. This is mainly because the printing quality of screen printing in integrated circuit boards, membrane switches, etc. cannot be matched by other printing methods. In RFID printing, conductive ink is used, and printed conductive The preferred screen for the ink is a nickel foil perforated screen. It is a kind of high-tech wire mesh. It is not a wire mesh woven from general metal or nylon wire, but a foil mesh drilled from nickel foil. The mesh is hexagonal and can also be formed by electrolytic forming. Hole shape. The entire mesh surface is even and thin, which can greatly improve the stability and precision of imprinting. It is effective for printing high-tech products such as conductive inks, wafers, and integrated circuits, and can resolve circuit line intervals of 0.1 mm and have high positioning accuracy. 0.01mm.

(2) The application of conductive ink. Conductive ink is a kind of special ink. It can add conductive carrier to UV ink, flexographic water-based ink or special offset ink to make the ink conductive. Conductive inks are mainly composed of conductive fillers (including metal powders, metal oxides, non-metals, and other composite powders), linkers (mainly synthetic resins, photosensitive resins, low-melting-point organic glasses, etc.), additives (mainly dispersants, and adjustments). Agents, thickeners, plasticizers, lubricants, inhibitors, etc.), solvents (mainly aromatics, alcohols, ketones, esters, alcohol ethers, etc.), conductive inks are a type of functional ink, mainly in printing. There are carbon paste, silver paste and other conductive inks. Carbon paste ink is a liquid type thermosetting ink. It has the function of protecting copper foil and conducting current after film curing. It has good conductivity and low resistance. It is not easy to oxidize, stable performance, acid, alkali and chemical solvents. The erosion; has strong wear resistance, anti-wear, good thermal shock resistance and other characteristics. Silver paste ink is a one-component type ink composed mainly of ultra-fine silver powder and thermoplastic resin. It can be used on PET, PT and PVC sheets. It has strong adhesion and hiding power, low temperature curing, and controllable conductivity. And a very low resistance value. In addition, conductive nanometer carbon ink is added to the conductive ink made of ink, and conductive ink can also be made of metal powder (such as silver powder) into nanometer silver powder. This conductive ink is not only a printed film. Thin and uniform smooth, excellent performance, but also can save a lot of material.

In RFID printing, conductive inks are mainly used to print RFID large lines, replacing traditional metal foils produced by foiling or etching. It has two main advantages. First of all, the traditional metal foil made by the foiling method or etching method has a complicated process and a long time for the production of the finished product. The application of the conductive ink to print the antenna is a high-speed printing method, which is efficient and fast, and is a printed antenna. The fastest and cheapest method of choice in the circuit. Today, conductive inks have begun to replace etched antennas in various frequency bands, such as the ultra-high frequency bands (860 MHz to 950 MHz) and the microwave frequency band (2450 MHz), and antennas printed with conductive ink can be compared to conventionally etched copper antennas. In addition, conductive inks are also used to print sensors and lines printed in RFID. Secondly, the metal antenna fabricated by the conventional foil-fed method or etching method consumes waste metal materials and has high cost, while the raw material cost of the conductive ink is lower than that of the traditional metal antenna, which is of great significance for reducing the manufacturing cost of RFID. .

(3) unique process requirements. In the RFID printing industry, there are unique requirements for the production process, and high-yield, thick-paper printing, and composite processing are mainly required.

In terms of high yield, since the value of RFID itself is many times higher than that of ordinary printed labels, it brings high profits to enterprises and high yield of printed materials is particularly important. In particular, many products require multi-color UV ink printing, glazing, and gluing. Most of the large-volume labels are also processed by roll-to-roll printing or interfaceless printing (Tunghua), due to a large number of processing operations. Big difficulty in screening the finished product.

For thick paper printing, in the paper jamming process, it must be noted that the equipment should have good printability for 350-gram-thick paperboard, and the tension of the paper-tape must be kept stable during the paper-card printing to ensure that the accumulated printing overlay error is minimized. Therefore, if each frame is overprinted, but the space between the frames has a large error, it will cause troubles for the compounding and the cutting process after RFID printing. As for composite machining, it is a key process in RFID processing. It not only requires that the size between each label does not change due to tension change, but also for film materials, it also needs to consider the degree of increase in label spacing caused by tensile deformation, and to do Appropriate adjustments.