Handheld laser welding made its market debut a mere few years ago. Since then, the cutting-edge technology is proving to be an incredibly useful tool in industrial settings of all types as exemplified in Miller’s OptX 2-kW handheld laser welding system. As the new welding process inevitably gains in popularity, however, the industry will need to ingrain the relative safety practices into its DNA just as it did with traditional arc welding safety decades ago.
To understand the nuances of handheld laser welding safety, the team at FAB Shop Magazine got the opportunity to speak with Andrew Pfaller, segment manager for Miller Electric Mfg. LLC, to discuss the tools and PPE that handheld laser welding requires as well as the protocols and procedures specific to laser welding.
FSM: What is the first thing users should know about handheld laser welding safety?
Pfaller: If you’re using a Class 4 laser, regardless of what you’re welding, you must have an enclosure, which is referred to as a laser-controlled area or LCA. That requirement is laid out in the various industry standards that cover the use of Class 4 lasers, including ANSI Z 136.1, Z 136.9, the IEC standard or whichever standard your company will be required to follow.
Miller’s OptX 2-kW system has a laser reach of about 755 ft.; in the context of a manufacturing environment, that would be the size of three football fields in all directions. Requiring everyone inside the building to wear PPE isn’t reasonable. That’s why you must create an LCA or install some sort of barrier system. Anyone inside of the LCA must have on the proper PPE to protect their eyes and skin – anyone outside of the area doesn’t.
As an alternative to purchasing a barrier system, you can repurpose a cinder block room as an LCA where the entryways are controlled with interlocks. If the door is open, harmful laser light can escape, so a proximity sensor must be placed on the door in the case of a breach. If the door is open, the laser doesn’t work.
For laser welding much larger assemblies where it isn’t feasible to put up guarding around a particular assembly, there are various options. As an example, one of our customers chose to limit laser welding to the second shift. In that scenario, their entire building becomes the LCA where everyone working is required to wear the appropriate PPE.
One important item to note is that traditional weld screens won’t stop the laser beam, which is invisible light energy. So again, you will need to establish an LCA. Fortunately, there are multiple options for doing that.
Can users wear regular welding helmets when handheld laser welding?
The short answer, unfortunately, is no. Our eyes refocus laser energy almost like a magnifying glass, meaning the laser can do great harm if dedicated protection isn’t being used. That’s why we supply the appropriate laser safety glasses with all of our systems. For users that need corrective lenses, we have a version of the safety glasses that fit over prescription glasses, as well.
Back to the welding helmet, we developed one specifically for laser welding that’s constructed of a carbon fiber and features special light-filtering glass. The typical polycarbonate or plastic used for traditional welding helmets can be pierced through with laser light, so we made sure to construct ours with durable material that can withstand an immense amount of laser energy.
What additional PPE should users be aware of?
Whether it’s traditional or handheld laser welding, you’re dealing with hot molten metal, so it’s necessary to wear skin protection like gloves, long sleeves and pants. Unlike MIG or stick welding, there isn’t a lot of spatter if the laser welding is being done properly.
It’s important to remember, however, that there’s still a small amount of UV light that’s generated at the end of the nozzle where the welding is taking place, often referred to as the plasma plume. With extended exposure, it’s possible to experience sunburn from the UV light. That’s also the case with traditional welding, which is why you always want to cover any exposed skin – not just to protect yourself from the UV light, but also any spatter that could be produced.
Does laser welding produce harmful fumes like traditional arc welding?
Despite the fact that laser welding doesn’t generate as much visible fumes as traditional welding, we still receive a lot of inquiries about fume mitigation. Questions surround the size of the invisible particulates and whether something special is required to filter them.
Fortunately, the team here at Miller has conducted various studies that determined our FiltAir products adequately capture any harmful fumes and particulates. It’s always recommended, however, to have an industrial hygienist evaluate your operations to ensure that what you’re doing is adequate for the processes you perform.
What should users know about local and federal safety regulations and guidelines?
For the OptX, you must scan a built-in activation QR code. From both a safety and industry knowledge standpoint, the product can’t be used until you register it. The QR code takes you to a resource page with videos that outline maintenance, inspections, safety checks and how to set up your first weld.
As part of registration, we inform you of some of the applicable ANSI standards. This is to ensure you’re aware of the industry safety standards with which you need to comply, including the need for an LCA as well as a laser safety officer or LSO. Establishing an LSO is an industry requirement that goes back to the ANSI standard. If you have an incident on-site and don’t have an LSO, the first question will be: “What other industry standards aren’t you complying with?”
In terms of local regulations, every municipality is going to be a little bit different, so it’s important to be mindful of the specific local guidelines. Because of those differences, we’re communicating the bigger industry guidelines, such as the ANSI and OSHA standards.
We also have regional district managers all over the country that can be a great resource if you have particular questions about regulations in your local geography. Whether a local municipality requires you to register it or not, it shouldn’t change your behavior and how you interact with the product. It should always be used safely.
Is there any specific safety training involved with using the OptX?
When we sell the product, we inform customers of the industry requirements and the need to have an LSO. In terms of training, every company is different. Using our own company as an example, Miller has more than 1,000 employees, so it isn’t feasible or necessary for everyone to be trained on every new technology.
But there are different ways that you can control the safety of your entire workforce. As one example, access to Miller’s development lab is badge-restricted. Anyone who doesn’t have access or doesn’t understand what’s going on inside can’t just walk in. There’s also a key switch on the actual product, which is an industry requirement that keeps unauthorized users from interacting with the product. The LSO will determine where the key is located to ensure that only the appropriate people have access to it.
It’s never a bad idea, though, to have a broader education within a company about new on-site technologies. But ultimately, it’s up to the LSO to determine who needs training and who doesn’t.
What other built-in safety features are there for the OptX?
There are multiple built-in safety mechanisms. The main ones are industry standards: the key to prevent unauthorized use of the product, an E-stop switch to stop the laser emission and a terminal strip to protect people outside the LCA that connects with the interlocks on the door. We also incorporated a sensing circuit that ensures the nozzle has contact with the conductive part. A work clamp is clipped to the table or part to complete the circuit, so if you point the torch into the air, it isn’t going to fire.
We also have a two-stage trigger, which requires a positive grip on the torch to use it, assuming all the other safety circuits, door interlocks and nozzle connections are satisfied. You must squeeze the first and second stage triggers for it to work. If you let go for any reason, it shuts off. This also ensures that if you set it down, the trigger can’t engage.
For reflective metals, there are also additional features to keep the laser energy from absorbing into the material too fast. As an example, if you don’t have the proper torch angle, the energy can come back toward the torch, which can damage the system and potentially harm you.
Another safety algorithm that we’ve incorporated measures the plasma plume being created when you’re welding across a piece of material that has an open hole or profile. To keep the laser from shooting through the hole onto the floor or whatever is below the part, the system recognizes when there’s no plasma plume and stops the laser output.
What other factors should users consider regarding handheld laser welding?
The main thing to highlight is why somebody would even consider this technology in the first place. Many customers that have taken the leap into the handheld laser welding space are looking to accomplish something that they can’t with traditional welding.
A lot of it also comes down to the workforce. Even when there’s a skilled welder to do the work, we’ve heard that customers are designing products in ways that can’t be made with TIG or MIG welding – be it because of material thicknesses, perforated materials or alloys prone to heat signatures on parts.
Beyond that, laser welding removes or eliminates post-welding operations – all of the straightening, bending and grinding required to fix the distortion caused by traditional welding. This adds up to a lot of labor savings. There are so many benefits that are driving companies to consider handheld laser welding. It’s not right for every application, but there are plenty of applications where it can shine.
