Lasers create high-quality markings that enable manufacturers in many industries to meet increasingly stringent standards for product traceability.
Manufacturers in nearly every industry worldwide face increasing government requirements to provide detailed traceability and compliance data for their products. In addition, traceability has benefits for manufacturers and distributors themselves. It can help in quality assurance, improve production yields, help maintain brand standards and assist in resolving quality disputes.
What is product traceability?
Product traceability is the ability to identify and track the various components of products as they move through the supply chain from raw materials to finished products. For industrial goods (as opposed to food, natural materials, etc.), the most basic traceability information includes the name and location of the manufacturer and a unique identifier (such as a part number or SKU) for the product.
Traceability may also include information on the conditions under which different batches of the product or even individual parts were produced. For example, it may include details of the specific equipment that was used to manufacture the item and even their exact operating parameters at the time. It may also contain information on how the product was inspected or tested.
Marking is a key tool for traceability. Specifically, this means placing unique tags on each individual unit, providing data or linking it to a manufacturer's database containing the types of information mentioned above.
The simplest mark can be simply a part number or serial number of the product in the form of alphanumeric text or a traditional 2D barcode. More complex tags can contain web links, MAC IDs, and even features to prevent product counterfeiting.
Laser marking solutions
For materials that can be laser marked - and there are very few that can't - this technology is the best way to introduce traceability marking into a manufacturing environment. There are several reasons for this.
First, laser marking is capable of creating complex marks that contain large amounts of data. And laser marks can also be relatively small in size. This is because in most laser marking applications, the beam is focused on a point with a diameter on the order of micrometers or tens of micrometers. Marking with such a small "tool" makes it easier to render fine details and create complex patterns even at very small scales.
Laser marking also easily adapts to changes in position, orientation or even shape of the part, so that marks can be consistently placed in the right place. Laser marking can accomplish this because it is usually accomplished using some type of scanning - usually based on galvanometric mirrors. Two-dimensional scanning allows the beam to be quickly moved to any point on the surface to create a mark. In practice, a machine vision system is often used in addition, which can compare the actual position of the part to be marked and its orientation, after which the system's software automatically adjusts to place the mark in the right place every time.
Adding dynamic focusing capability to a two-dimensional scanner allows marking on curved or multi-level flat surfaces. This so-called "3D scanning" significantly expands the utility of laser marking technology.
Another advantage of laser marking is that it produces attractive marks on almost any material. This can be particularly important on consumer products. In addition, a laser mark is very durable and will not smudge, stain or rub off.
Although the laser heats the material when creating the mark, the process can also be performed on delicate or heat-sensitive components such as integrated circuits. The laser wavelength and pulse length can be selected to minimize the area affected by heat. For example, the nanosecond pulse duration of Q-switched lasers (e.g., Coherent PowerLine E and PowerLine Fseries ) limits the thermal exposure during marking to a few tenths of a millimeter. The temperature of the part beyond this limit remains essentially unchanged.
Laser marking is also fast. The entire laser marking process can take just a few seconds. And that includes the machine vision tasks of measuring and correcting part position, the marking process itself, and the post-process inspection and verification steps.
No other marking technology involving printing or other mechanical methods offers the same combination of benefits. In addition, laser marking requires no consumables, whereas ink costs for traditional printing methods can be a significant factor in high-volume applications. For these reasons, laser marking has become extremely popular in a wide range of industries.
A framework for traceability marking
In the most advanced production environments - so-called "digital factories" - laser marking is fully integrated with the enterprise-wide production automation system. This allows it to work seamlessly with other production equipment and also provide all the functions needed for complete traceability.
For example, the marking system can communicate with the parts handling equipment to indicate when it is ready to accept a part. It can then visually inspect the part using embedded vision and let the system know that it has verified that the correct part has been delivered.
It can also interface with the production control system to obtain serial numbers and other part-specific data. It can feed back process information after marking. This information may include process parameters, indications that the marking has been verified, mark quality ratings, etc.
Coherent has developed a software package, Laser FrameWork, that fully supports this kind of digital manufacturing environment. It provides all the capabilities for creating new laser marking jobs, including vision, and then executing them in production. And it provides the "framework" (software platform) for developing and implementing the specific routines needed to interface with other manufacturing automation systems. Coherent Laser FrameWork ships ready to make laser marking part of the digital factory right out of the box.
Traceability has the power to make products safer and enable manufacturers to reduce costs and improve quality. Laser product marking is the foundation for many manufacturers to implement traceability. And laser marking powered by Coherent Laser FrameWork provides an easy path to its adoption in a digital manufacturing environment.
Source: coherent.com
