Options for Automating Industrial Laser Marking

Summary

Today’s industrial manufacturers increasingly require parts traceability. Whether they are in the medical, automotive, or electronics field; using plastics or metals; or producing devices, tools, or molds, they benefit from each part being uniquely identifiable. Laser marking achieves this with the best quality while saving time and production costs. Further, there are a variety of customizations that can be used in conjunction with laser marking workstations that can make them even more efficient for specific applications. Below, we explore these technologies, and provide solutions for laser marking any kind of part.

Consider all the variables

Choosing the appropriate marking system and possible automation depends on the type, quantity, and material of the workpieces, as well as the required size of the marking field. The desired visual inspection before, during, and after marking must also be taken into consideration. Then there are the actual automation processes: loading and unloading, pick and place operations, stacking, sorting, packaging, and cleaning. Finally comes the choice between a semi-automated or fully automated system.  

Process control through camera and software features

The priority of the process will, of course, be the ability to exactly position the laser mark where it is intended on the product. With the help of an integrated camera and corresponding software, it is possible not only to automate this function, but also to make it repeatable with consistent accuracy. Mark alignment through automated optical part recognition, for example, enables precise mark placement, as well as software-controlled inspection throughout the entire process.
 
The right software can drastically reduce the time and effort spent on manually aligning parts to the laser, as well as the considerable cost of designing, manufacturing, validating, and maintaining production fixtures. Mosaic™, a patented component of FOBA MarkUS marking software, uses the laser’s internal camera to capture multiple small images of  one or more parts in the marking field and create one large, undistorted image. This allows fixtureless alignment of parts, which can be loosely placed anywhere in the marking field.
 
This is especially useful in medical device manufacturing, where there is a significant variation in types, materials and shapes of products. The large numbers of Stock Keeping Units (SKUs) combined with small batch sizes also result in a great variety of requirements for marking. With various possible degrees and ways of automation The technical integration of  a laser marking  system and  an automation system, or even a robot, also requires smooth interfaces. Notably, the integrated camera solution from FOBA requires no additional validation with separate camera software for medical device part marking. All elements of the marking process, including the camera and illumination, are controlled by a single software. Taking into account the demands of loading and unloadingwe’ll next explore several options with varying degrees of autonomy for addressing this onerous task.

Semi-automated loading with robotics

It may be helpful to first look at the example of direct part laser marking specialist add'n solutions utilizing the industrial robot “Horst” from fruitcore robotics. This case study shows what a robot-assisted semi-automated laser marking solution can look like: The marking software directs the robot to remove a tray containing one type of medical instrument or implant at a time from a cart. Horst then places it in the spacious protective cabin of a FOBA M3000-P laser marking station (Figure 1). The integrated camera provides automated inspection of the parts and ensures precise alignment before marking them with permanent unique device identification (UDI) codes. 
 
Says Product Manager Markus Vetter, “The marking software can identify the outline (or contour perimeter), size, or incorrect assignments and, if necessary, distinguish individual parts to be excluded from the marking. After laser marking, the station access door opens, the robot removes the tray and reassigns it to the original insertion location in the service cart.”

Fully automated loading with docking modules

For a fully automated marking solution, and one that is particularly flexible, a docking module can be connected to a FOBA M-Series marking workstation, M2000 or M3000, depending on batch size. WeStore modules by Swiss automation specialist Wenger are also available in two sizes and offer seamless integration (Figure 2), as the docked cell is adapted in format and appearance to the marking workstation. It can be loaded with up to 20 pallets, which are individually drawn into the marking unit via linear kinematics.

Autonomous stack loading

More common solutions are special machines developed inhouse for automated stack tray loading. One application in which this is useful is so-called “day/night marking,” which involves lasering paint off plastic to create a word or symbol that is illuminated in both light and darkness—vehicle and aircraft dashboards and controls or displays of household appliances are typical examples. For this, FOBA has developed a solution whereby autonomous gripping and loading systems continuously feed trays from a stack to the marking workstation, enabling hours of operator-free, large-batch production.

Custom solutions

Marking systems can also be configured on a case-by-case basis. For applications involving small batch sizes or parts that are particularly delicate or challenging to mark, such as a cylindrical bone screw, a robot would be a poor substitute for a human. Still, the marking process can be streamlined with additional customization.
 
U.S.-based Centex Machining did just that with a rotary unit (featured photo above) and an M3000, a combination that greatly simplified its manufacturing. The company says it has integrated a process that previously required 12 individual steps and 18 hours of marking time; it now takes just three hours—two hours for setup and one hour for marking.

The addition of a laser marking workstation and its various customizations (Figure 3) can both radically upgrade manufacturers’ operations and ensure that they are poised to handle new challenges and opportunities in their rapidly changing industries.

Also, for a deeper look at laser marking in the medical industry, a free on-demand webinar is available featuring Dr. Faycal Benayad-Cherif of FOBA Laser Marking + Engraving. Dr. Benayad-Cherif is an expert in laser marking automation and the developer of several patented laser marking solutions.