Ventilation Considerations for Laser Welding Operations
Are you considering a switch to robotic laser welding? Laser welding offers significant advantages for manufacturers willing to make the initial investment. It also has its own unique challenges when it comes to weld fume control.
Laser welding requires specific types of ventilation to maintain safety and effectiveness. Here, we’ll explore the pros and cons of moving to laser welding and how to choose a ventilation system for your laser operations.
Laser Welding: The Fastest Growing Segment of the Welding Market
Laser welding is a small but rapidly growing segment of the total welding market. Unlike other welding methods (e.g. MIG welding, TIG welding and spot welding) laser welding does not use a filler material for the weld joint. Instead, the two surfaces of the metal are melted together to form a smooth seam.
- offers high levels of precision;
- can significantly speed up welding production; and
- eliminates the purchase of consumable rods or wires.
Because the heat from the laser is precisely applied only at the seam where it is needed, laser welding is an excellent choice for precision jobs and thinner pieces of metal where warping is a concern. For this reason, laser welding is a popular choice for the manufacture of pharmaceutical machines, medical devices, food containers, dental equipment and other applications where precision and weight are considerations. Recently, it’s been gaining ground in the automotive industry as well.
Switching to laser welding requires a large initial investment. Laser welders are more expensive to purchase than other kinds of robotic welders. In addition, companies must change all of their upstream processes—including cutting, bending and material handing—in order to meet tighter tolerances for the material to be welded. However, investing in laser equipment will pay dividends down the line through faster production.
Ventilation Challenges for Laser Welding
Ventilation concerns for laser welders are a bit different than for other types of systems. Laser welders are almost always robotic, so humans are not usually directly impacted by weld fumes. However, the laser itself requires a very clean environment in order to operate safely and efficiently.
Laser beams refract (spread out) when there are contaminants in the air. This is the same effect that you see at a laser light show when smoke is used to spread the light from laser beams to make them visible and produce special effects.
Refraction of the laser beam means that it is no longer directly focused on the weld seam, making the process both less efficient and less precise. For this reason, you need a ventilation system with a lot of airflow to pull weld fumes away from the laser as fast as they are generated.
There is another challenge to overcome with the design of laser welding equipment. Because laser welders require special light-tight enclosures to prevent the laser beams from ricocheting around the area and hurting people, weld fumes can accumulate within the weld equipment’s environment. A source-capture ventilation system is necessary to efficiently pull fumes out of each laser enclosure.
A final consideration for laser welding operations is the character of the weld fumes produced. The particles in weld fumes produced by laser welders are extremely fine—much finer than those produced in other types of welding. If you are using a system that cleans the air and returns it to the facility, using the correct filter is critical to protect workers’ health and safety.
Ventilation Options for Laser Welding
- The simplest method is to connect ducts for each laser welder to large ceiling exhaust fans and vent the fumes outside. However, in most areas environmental regulations do not permit direct venting of weld fumes to the outdoors. These systems can also result in significant loss of heat or air conditioning for the facility.
- Filtration systems pull air out of the enclosure, run it through powerful industrial filters to remove contaminants, and return it back to the plant. Filtration systems are more expensive, but deliver significant energy savings by returning air to the facility. They also minimize environmental contamination from weld fumes.
In most cases, facilities using laser welding will want to use a filtration system to ensure that they are meeting both environmental regulations and OSHA requirements for clean air.
Choosing a Ventilation System for Your Laser Welding Facility
The most critical consideration when choosing a ventilation system for laser welding is the rate at which the enclosure is cleared out. In order to keep the cabinet clean enough for laser operation, the system will need to provide a 10 to 15 second turnover rate for air at the point of welding.
Many welding ventilation systems utilize self-cleaning filters in which compressed air blows collected dust and contaminants out of the filter and into a collection bin. Filters that are not self-cleaning will need to be periodically replaced. The length of time that the system can operate before the filters need to be changed or cleaned depends on the size of the filters and the amount and character of the weld fumes produced.
- How many laser welders do you have in your manufacturing process, and how many parts will they produce per hour? The more machines you are operating and the faster they are producing, the more powerful your ventilation system needs to be.
- What is the thickness of the metal you will be joining together? The intensity of the laser will dictate the maximum thickness of the metal that the machine can handle. The thicker the metal, the more fumes will be generated.
- What type of metal are you welding? Different kinds of steel (carbon, aluminum, stainless, titanium) produce different kinds and levels of contaminants, impacting the life of the filters in your ventilation system.
- Is the metal clean or does it have preservative or lubricant oil from another process? Oil produces thick, sticky fumes that will plug up filters very quickly.
- Will operation be continuous or will there be regular breaks? If there are regular breaks built into the manufacturing process, a smaller system with self-cleaning filters will be sufficient. Continuously running machines will need larger units with heavier-duty filters to minimize maintenance down time.
Selecting the right ventilation system for the facility requires balancing the size and cost of the ventilation system against the cost of shutting down operations to clean or replace the filters. An experienced ventilation system engineer can help facilities make the right choice for the number of laser welding units, the amount and type of weld fumes produced by each, and the desired production and maintenance schedule.
RoboVent Solutions for Laser Welding
Plaser® by RoboVent is the ventilation system best suited for laser welding operations. Also used for laser and plasma cutting, Plaser is a powerful source-capture system that takes filtration technology to new levels to maximize effectiveness and reduce maintenance time. Plaser systems feature:
- powerful, consistent air flow with high air turnover rates suitable for laser welding enclosures;
- premium filters with patented filter cleaning technologies to maximize filter life; and
- dust containment options designed for easy maintenance and reduced downtime.
RoboVent systems also feature additional safety features.
- The SafeSensor® particulate monitoring system automatically shuts down equipment if a leak is detected in the filtration system.
- The RoboVent Delta3® spark suppression system quickly extinguishes sparks created in the welding process.
Contact us today to find out how RoboVent can help you improve the safety and effectiveness of your laser welding operations.