Miniaturization of codes – a persistent trend in product identification
Do you remember what the first mobile phones looked like? Heavy, large devices that were difficult to carry. Today, that is a thing of the past. For many years, the task of product developers has been their miniaturization. The mobile phones currently available on the market are the size of a credit card. How small are their parts? How does their production process work? What does their tracking and monitoring look like? The identification of small parts and components plays a major role in the production processes of many industries. A barcode helps not only in the automation of processes but also serves as an identifier in the logistics chain until the moment the product is handed over to the end recipient.
The specific requirements placed on barcodes in industries such as the production of pharmaceuticals, medical devices, cars, and mobile phones mean that the use of EAN/UPC and GS1-128 codes would not fulfill their function. Marking a component with a traditional 16-digit code on a small surface is difficult to carry out. Additionally, placing the code directly on metal or a plastic surface presents difficulties. The ideal solution here, for several important reasons, is the GS1 Data Matrix code:
– GS1 Data Matrix has extremely small dimensions
– it can encode up to 1.5 kilobytes of data, unlike the EAN-13 code, where the encoded data cannot exceed 128 bits
– alphanumeric characters can be encoded in the GS1 Data Matrix code, which is not possible with the EAN-13 code
– the specific way data is recorded ensures that even the loss of 25% of the code ensures its full readability
– the GS1 Data Matrix code enables unambiguous identification that is impossible to forge. Making changes to the code after it has been applied to an object is impossible. The code is read correctly or it is not read at all.
This property of the GS1 Data Matrix code is a factor ensuring product safety and protection against counterfeiting. The Data Matrix code technology was created in the mid-90s. Up to 3,116 numeric and 2,335 alphanumeric characters can be represented in this code. The less information is encoded, the smaller the GS1 Data Matrix code is. Depending on the amount of data, printing technique, and the material on which the code is applied, a code surface smaller than 5 x 5 mm can be achieved.
The GS1 Data Matrix code can be read using optical devices. The most common are cameras and 2D image scanners. To read a GS1 Data Matrix code, the reader must have a built-in 2D image reproduction option. Smart cameras and scanners have this, while standard cameras require a connection to a PC. In addition to optical readers, new solutions for reading codes are being developed, for example, the LocusReader, which can use an ultrasonic beam to read invisible, contrast-free codes, including codes placed, for example, under varnish.
A simple way to track parts
So that individual parts can be tracked and monitored in the production process and beyond, every part assembled in a product sub-assembly must be identified with a code. All data regarding a given sub-assembly, as well as production processes, are assigned to it and archived in a database.
One can quickly find the answer to the basic question regarding product liability: “From which production batch does part X of sub-assembly Y come?”. The ability to collect specific data and document it ensures proper quality and production flow. The use of GS1 Data Matrix codes is supported by their small size, high capacity, as well as the possibility of direct marking of the code on parts. Marking can be done in a variety of ways. This can be laser marking, chemical etching, dot peen marking, etc.
Laser marking – particularly useful for making marks on small surfaces or materials with high hardness (above 65 HRC), as well as in cases where high precision is required. The surface is not damaged or destroyed in this process. The contrast between the light and dark background, and thus the readability of the code, depends on the material used and the laser parameters.
Dot peen marking consists of indenting points into the material using a carbide needle, which is set in motion by compressed air or an electromagnet. A grouping of many points forms a matrix and creates a code. The material surface is destroyed, which means the code cannot be removed without affecting its surface.
The article comes from the magazine “Logistyka” 1/2008.