Are you looking for an alternative weld fume source capture option for robotic welding? If your processes involve large weldments that cannot be easily hooded – as is often the case when welding heavy agricultural or transportation equipment – robotic tip extraction may be the solution you’re looking for.
To get a closer look at what robotic tip extraction is, how it works and how you know if it is right for your facility, the answers to eight frequently asked questions are presented.
What is robotic tip extraction?
Robotic tip extraction is a fume source capture method for robotic welding applications. You can think of it as the robotic equivalent of a fume gun used for manual welding. Unlike hoods, which enclose the entire weld cell to contain fumes for collection, tip extraction collects weld fumes right at the weld seam to keep them out of the ambient air.
How does tip extraction work?
Robotic tip extraction uses a specialized fume extractor that is connected right to the robot arm. The tip of the extractor is positioned just behind the weld torch head. A special bracket holds the tip in position so that it can collect weld fumes without interfering with the robot’s motion.
The extractor tip is connected to a hose attached to the robot arm. The hose must be lightweight and flexible so that it is able to follow the movement of the robot arm without impeding or obstructing its operations.
The extraction hose is hooked up to a high-vacuum (hi-vac) dust collector, such as a model from the RoboVent FlexPro Series. The dust collector needs to have high vacuum power to overcome the high static pressure created by sucking weld fumes through a small tube rather than a large duct.
What welding applications is it suitable for?
Robotic tip extraction works best for MIG welding. In MIG welding, fumes can be efficiently collected as welding takes place.
In terms of industry applications, tip extraction is a great solution for the robotic welding of tractor-trailers, agricultural equipment, large infrastructure components and other large weldments that are difficult or impossible to put under a hood. It also works well in environments where cranes and other overhead equipment make hooded enclosures impractical.
However, it’s not the right option for every application. Robotic tip extraction should not be used for:
- Resistance welding, which can create a large number of sparks and leaves parts smoking long after the robot arm has moved on.
- Welding parts covered in oil, lubricants or surface coatings that produce smoke during the cooling process.
What are the benefits?
Robotic tip extraction provides many benefits for facilities. In particular, tip extraction:
- Provides an effective fume source capture alternative for applications that cannot be easily hooded.
- Does not interfere with overhead cranes and equipment.
- Reduces space and layout concerns related to weld cell hoods.
- Keeps weld fumes out of the ambient air, creating a healthier environment.
- Reduces the need for expensive ambient air-quality systems.
How effective is robotic tip extraction?
A properly designed robotic tip extraction system can collect between 80 and 95 percent of weld fumes, depending on the exact application and the way the robot moves. The extractor tip must be close to the source of weld fumes or smoke in order to collect them. It does not collect weld smoke that continues to be generated by cooling parts after the robot arm has moved on.
Robotic tip extraction is not a one-size-fits-all solution. Optimal weld fume capture requires custom fitting of the extractor tip to the robot arm and proper sizing of the hi-vac dust collector.
Will it interfere with robot operation?
A properly fitted extractor tip will not interfere with robot motion or weld seam quality. However, care must be taken when installing the extraction system. Improper fitting of the extractor hose and tip will significantly reduce the effectiveness and could interfere with robot arm movement.
Some robotic welding applications may not be well suited for tip extraction because of the way the robot arm needs to move during the welding process. Complicated motion paths, tight angles or deep recesses can make tip extraction challenging (though not always impossible).
At RoboVent, each tip extraction system is manufactured specifically to the exact geometry of the robotic weld torch. First, a 3-D model is created of the weld torch. Designers use CAD and 3-D printing to create a hood that fits the weld torch like a glove. Once the part is fitted, the system engineer conducts a series of calibration tests to ensure that the mass of the extraction hose and the bracket that holds the tip in place do not disrupt the operation of the robot arm and weld torch.
Are there cost savings?
Possibly. Source capture is always more efficient than ambient air-quality control. The closer you are able to collect weld fumes at the source, the smaller the volume of air that you need to move. While dust collectors for a hooded application may need to move 4,000 to 6,000 cfm, robotic tip extraction typically only requires 100 to 150 cfm for effective weld fume collection.
This can translate into big savings in equipment and energy consumption. A compact hi-vac dust collector with a 3-hp to 4-hp motor provides sufficient extraction power for a robot equipped with a robotic tip extraction system. The same robot under a hood may require a dust collector with a 10-hp or 15-hp motor to compensate for the higher volume of air to be moved. Smaller motors and lower cubic feet of air per minute translate into lower equipment costs up front as well as lower energy and operating costs. Facilities also save on expensive ductwork, which is required for hooded applications.
Is ambient air-quality control still necessary?
It depends. If 100 percent capture of weld fumes is critical – due to their toxicity or their potential to interfere with other processes in the facility – you may still need an ambient system to collect the remaining 10 to 20 percent of weld fumes that escape from the extractor tip. The necessity of an ambient system depends on the capture efficiency that can be achieved for your specific process and your specific air-quality goals.
However, when the majority of weld fumes are collected via source capture, facilities can generally use a smaller ambient system that is more cost and energy efficient. Pairing robotic tip extraction with an ambient air filtration system provides an optimal solution for many facilities.
A qualified air-quality systems engineer can help you determine if robotic tip extraction is the right solution for your application. They can also help you weigh the costs and benefits of different configurations, including hybrid source capture and ambient solutions. An effective system design maximizes weld fume capture efficiency and minimizes your equipment and operating costs.
