Laser marking is, by nature, an ideal match for automated assembly lines. Lasers are capable to individually identify a wide array of material at high speeds. Lasers can mark serial numbers, batch numbers, logos, texts and Data Matrix Codes (DMC). In this interview, Alex Fraser reveals insights into some of Laserax’s most interesting laser integration projects.
Mr. Alex Fraser is Vice-President and CTO of Laserax. He cofounded the company in 2010 with Xavier Godmaire. Alex has a Master’s Degree and a PhD in Physics from Université Laval in Québec City. He is specialized in industrial laser marking. Alex takes great pride in the company’s success; over the past few years, it has grown from 0 to 20 employees. Providing good employment to these people gives him a lot of satisfaction.
Alex is a proficient moose hunter. He is also the president of the “Comité Patrimonial de l’Isle Verte” that has organized “Le sentier de la bouette.” Every year for the past 30 years, up to 500 participants cross the St-Lawrence river at low tide between the village of l’Isle Verte to the island bearing the same name.
What is the first thing to consider when integrating a laser marking system to an existing assembly line?
Alex Fraser - One of the first things we must make sure our clients understand is that high-power lasers are dangerous even at 10 m or 20 m. It runs counter to common safety procedures in the manufacturing sector.
For example, if you are out of reach of a robot, you are certain to be safe. And even then, robots are often safeguarded within a cage.
In order to make high-power laser 100% safe, (class 1) international standards, such as IEC 6082 and ANSI Z136 (more information on laser safety class) recommend that they be embedded in a safety enclosure. Properly embedded high-power lasers are just as safe as an industrial robot inside its cage or a welding station behind its curtain. There is no need for additional safety equipment.
Laserax has developed three types of laser enclosures. First, we have inline through-conveyor enclosures. Second, we have a standalone enclosures and third, open-air enclosures.
There are different technologies that can be used to uniquely identify products. What are the main advantages of laser direct part marking?
A. F. - Laser markings are very rugged. Contrary to ink markings, laser marking will never fade and it is impervious to UV light. Laser markings make no use of labels of any kinds, meaning there is no consumables; you’ll never lose the information printed on a flimsy label.
Peen marking is another technology that is often used in marking metals, but it tends to generate marks that have very little contrasts. Such little contrasts make the use of scanner and imager problematic at best.
Dot peen markers have lots of moving parts. They need to make contact with the surface to be marked. In addition, they are slower and will require more maintenance than your typical laser marking system. For a comparison between laser marking and dot peen marking read this blog.
You had a lot of successes integrating laser marking systems in plants. Can you give us some examples of such laser integrations?
A. F. - I am thinking of a complete integration that we have done on an assembly line. We developed a safety enclosure that resides on the client’s conveyor. It had a guillotine door that allowed the parts to enter the enclosure and another allowing the parts to exit after having been marked by the laser.
Figure 1 - Inline through-conveyor laser enclosure with up and down door
We used an A/C cabinet for the laser sources and controllers. It kept everything clean and tidy as well as free of dust and moisture in a temperature-controlled environment.
We installed our HMI and it allowed the client to control the laser marking parameters, at the laser marking station. Whenever a new batch was to be marked, the operator would go to the HMI enter all the relevant information, such as: lot number, alloy identification number and starting serial number.
We added a sensor that gave the distance the bundle was from the laser aperture. It gave the laser system the information it needed to focus on the surface to be marked. The laser was then able to mark the required information on every bundle of that batch.
In Indiana, we installed a similar system. We were asked to add a fume and dust extraction device. Because the parts’ positions were less controlled, we had to use three sensors to locate the distance and both tilt angles of the surface to be marked.
Another feature that was installed in the enclosure is a camera that captured the markings; the image was sent to to the supervisor’s office who could verify that everything went smoothly at all times.
Any other fun applications you can share?
A. F. - In a standalone enclosure, we installed a high-power laser, thereby creating a 100% safe, Class 1 laser system. The most interesting part of that project was the use of a revolving door.
On each side of the door, a jig was installed that could hold a part. In that specific instance, a robot was used to load the first jig. The door turned 180o, bringing the first part inside the enclosure and giving access to the second jig. While the laser marks the first part, the robot installs a second part on the second jig.
Figure 2 - Video demonstration of laser marking in a standalone enclosure with revolving door
And as the laser finishes marking, the robot can service other machines. In that case, it showed the part to a vision system for quality control purposes. It quenched the part and brought it to another machine to get it trimmed.
Everything is done in hidden time; the only instance the robot is waiting is when the revolving door turns.
You talked earlier about an open-air enclosure, can you give us an example of such an enclosure and how it is used in the field?
A. F. - Open-air enclosures are typically used for parts that are so big that it would be impractical to make an enclosure big enough to make them fit inside. We’ve been using open-air enclosures to mark aluminum billets and slabs as well as for die casting of smaller dimensions.
Figure 4 - Details of an open air safety enclosure
In a nutshell, an open-air enclosure is made of three components: an inner enclosure, an outer enclosure and human access barrier. These three measures, combined with other apparatuses, are just as good as a sealed enclosure for ensuring workers’ safety.
The open-air enclosure is brought in contact with the part to be marked. There are mechanisms included to make sure that the seal between the enclosure and the part is perfect.
The whole thing is designed to make sure that no beams, either incident, reflected or diffused, can make it out of the enclosure when the laser is operating. Once the marking is done, the enclosure is withdrawn. The identified part can move on to the next manufacturing steps.