Since the birth of the world's first automobile "Mercedes-Benz 1" 121 years ago, the automobile industry has been developing rapidly. Along with the increasing speed of automobiles, the safety issue has also been increasingly emphasized.
In the sixties of last century, the United States promulgated the first National Traffic and Motor Vehicle Safety Act on automobile recall system, and put forward strict requirements on the traceability of automobile parts and components, and the development of automobile parts marking technology has also opened the prelude.
At present, the common auto parts marking methods are: mold casting, electric corrosion marking, stickers, screen printing, pneumatic marking and laser marking. Laser marking technology, although the birth of the latest, but since its inception to mark the indelible nature received widespread attention.
The main advantage of using laser for marking automotive parts is that it is a fast, programmable, non-contact process that is long-lasting and is usually unaffected by the steps required in the production process or by the harsh on-site environment it endures. Of course, it also has drawbacks, such as the high initial cost of laser marking equipment and the lack of contrast in marking in certain applications (e.g., marking plastic products).
Laser Selection
Typically, there are two main types of lasers used when marking automotive parts:
- CO2 lasers, as the name suggests, this is the use of carbon dioxide gas to generate monochromatic light to form a mark at a wavelength of 10640nm. It is suitable for marking non-metallic materials and metal surface paint layers.
- Nd3+:YAG laser, which uses diamond-doped crystalline material as a medium to generate a near- and far-infrared beam at a wavelength of 1064nm. It is suitable for marking metallic and some non-metallic materials.
- New developments in the field of Nd3+:YAG lasers, the use of plastic additives for laser marking have essentially eradicated the problem of contrast. Even on the surface of some plastic materials that have a hard time absorbing the 1064nm wavelength, very clear markings can be obtained with the Nd3+:YAG laser (Figure I).
Lasers, Barcodes and 2D Codes
Barcodes and 2D codes are today's popular technologies for all forms of product traceability and are perfectly suited for all types of automotive parts.
Early automotive parts marking mainly by marking the serial number on the product to meet the requirements of traceability, the birth of the bar code was quickly applied to the identification of automotive parts (Figure 2), but its small amount of information, poor fault tolerance so that it has not been fully popularized. This problem was not solved until the birth of QR code technology.
A QR code is a 2D graphic similar to a checkerboard shape that can hold a large amount of information in a very small area. Because QR code 2D graphics only require readout performance at a contrast ratio of 50% or even less, the use of QR code graphics has greatly increased the number of laser applications.
QR codes are also encoded with built-in corrections so that even if for some reason part of the code is corrupted, the code is still readable. QR codes can also be encrypted with several different forms of decoding and protection devices can be placed in the data, making this type of marking even more valuable to proprietary components. Huagong Laser's LSY50F laser marking system, for example, the marking software not only has the ability to automatically generate barcodes, but also supports DataMatrix, PDF417, QR Code and other two-dimensional code technologies.
The Importance of Database and Network Support
Automotive parts traceability is realized through the product marking database, before the birth of the computer, the database using manual entry and retrieval methods, requiring a lot of manpower, the increasingly large database also brings a huge test of retrieval work. The birth of the computer and the network for this work has brought a new model.
The laser marking system adopts the computer control method, which makes the automatic generation and retrieval of database a very easy task. As the earliest laser company focusing on the automobile industry in China - "Huagong Laser", in response to the needs of auto parts enterprises, very early in the marking software implanted in a strong database support and networking capabilities, and automobile machine and parts manufacturers can be seamlessly linked to the database network, and can be used for the automobile machine and parts manufacturers. It can realize seamless linkage with the database network of automobile machine and parts manufacturers, and can automatically complete the establishment of marking information database, communicate with upstream and downstream databases and other functions, so as to realize the whole process of product tracking.
How much does it cost?
The initial investment in a stand-alone or in-line laser marking system is generally higher than that of most traditional marking systems.
Importantly, when compared on a cost of ownership basis, a laser marking system is actually a better investment over time because there are no overly important consumables, no recurring process costs, or costs of delivering, stocking, or adding new products on an order-by-order basis. Long-life, gas-tight CO2 configurations and diode, solid-state laser marking systems require very little service maintenance. What's more, laser marking systems have moved toward automation in most automotive parts production processes, where operation requires no special attention and is little or largely operator-independent.
Conclusion
The implementation of the automotive recall system in China since October 1, 2004 means that the requirement for traceability of automotive parts has been further improved. In the event of a batch problem with the quality of an automotive component, a company's reputation, liability and future business depend on fault resolution and corrective measures. The use of laser marking based on QR code technology can easily realize the traceability of products throughout their life cycle.
Flexible Labeling Laser Marking Systems
The use of labels is ubiquitous in the modern manufacturing industry. There is also a never-ending demand for improved product marking in all industries. The entire marking industry is moving toward information traceability, and flexible label laser marking systems using industrial PC control are bound to receive more and more attention due to the extensive database support of the marking software.
Flexible labels mainly refers to TESA, 3M and other companies produce special labeling materials produced by the label. Typical materials for this type of labeling are Tesa-6930 and 3M-7846. taking Tesa- 6 9 3 0 as an example, the thickness of the material is about 1.18mm, a total of four layers, of which: the first layer is a black PU acrylic, the second layer is a white PU acrylic, the third layer of the special adhesive and the fourth layer of the protective layer.
The material has the following characteristics:
- The use temperature is from - 50℃ to 300℃.
- Non-combustible material, anti-corrosion, wear-resistant.
- The service life is more than 20 years (under normal use conditions).
Once pasted onto the surface of an object, it cannot be removed from the pasted position after 8h. If the label is forcibly removed, the moved label will become fragments and cannot be used again. This feature makes the label difficult to duplicate and makes it easy to recognize the authenticity of cars and parts from the label.
A precisely controlled laser beam is scanned over the above special four-layer label material, and depending on the information required by the user, the first color layer (black) on the surface is removed to reveal the second layer (white) by precisely controlling the laser energy output and scanning speed, thus completing the laser marking of the user's pattern or text information. In order to facilitate the paste, through the precision control of the laser beam in the closed periphery of the desired label pattern, remove the labeling material of the first, second and third layer, so as to facilitate the desired labeling from the whole roll of material peeled off. Since the peeled label is covered with adhesive, it can be easily attached to the desired position on the vehicle. We call the process of removing the first layer by the laser the process of marking the label material by the laser, and the process of removing the first, second and third layers by the laser the process of cutting the label material by the laser.
