Welding is the process of heating, melting and joining materials such as metals and plastics to create a single part. It is performed in all major manufacturing industries including automotive, aviation, construction, oil and gas, and computers.
These joints might experience fatigue and exposure to loads, so it is critical that welds are done properly and to specification to prevent future failure.
The Axium Group, headquartered in Montréal, designs, builds and implements high-speed, automated assembly systems for manufacturing. These include solutions for welding and assembling components on plastic fuel tanks.
The company is composed of several entities: Axium, Lupar, Enico and SPG. Axium was founded in Montréal in 1998 by Robert Jodoin, an electrical engineer with a specialty in robotics, and mechanical engineer Sylvain-Paul Morency. Later, mechanical engineer Marc Ducharme joined them. Since the beginning, Axium grew at a constant rate through three main business units: process and integration, factory automation and material handling (picking, packing, palletizing and warehouse automation). As the company grew, Axium focused on robotic material handling and assembly lines and acquired other competences to become the Axium Group. It is now comprised of an electrical division (Lupar), a specialist in process and automation (Enico), and a vision entity specialized in 3D application for inspection in high-precision applications (SPG). Axium also started its activities in Europe and created Axium Europe in Croatia.
Naturally, Axium and SPG work together on all projects that include vision and robotics. Axium is a seasoned veteran in the field of assembly automation. Axium designs, builds, implements and supports innovative, high-speed automated assembly systems that deliver what we believe is unmatched reliability and repeatability for the manufacturing industry. Axium has a vast experience in assembly automation, having supplied non-robotic (hard automation) systems and robotic systems ranging from two to 15 robots and cycle times down to 48 seconds.
The company's robotic welding line performs all the operations required in the welding process using automatic or manual tank loading and unloading (Figure 1). Operations include hot plate welding, IR welding, internal welding, spin welding, cutting, manual operations and 3D vision inspection.
Safety requirements and environmental regulations make it critical to ensure the weld quality of every tank. SPG Vision and Robotics, a member of the Axium Group, manufactures digital 2D and 3D vision solutions for automated inspection, quality assurance and intelligent robot guidance.
Axium provides completely automated plastic fuel-tank welding and finishing lines. Just downstream of the blow-molding machine, the Axium system takes charge of the tank. First, the tank and flashes are individually weighed, and then a 1D or 2D bar code is laser etched on the tank while the flashes are removed. A robot takes each tank and properly inserts and retrieves it from the water cooling bath. The tank is placed on an exit conveyor and goes through an air-drying station to remove excess water. From there, tanks move to an automated storage and retrieval system (ASRS) and then to the welding line.
In the welding line, robots perform numerous tasks, including 3D vision inspection, cutting of holes for valves and components, and finally the welding of said valves and components (Figure 2) using the information from the vision system(s).
Finally, tanks move to a semi-automated line, where operators perform the final dress-out of a fuel tank before it leaves the factory. The line regroups all necessary features to complete a finished product that's ready to deliver to a customer.
Before the Welding Begins
"Prior to the welding steps, the system scans a region of interest (ROI), in this case, a weld pad—the surface feature on the tank where a component is welded or a hole is cut—that can vary in size and geometry—and dynamically adjusts the position and orientation of the welding tool," says Robert Battaglia, Axium supervisor—mechanical design. "This step has to be highly accurate and precise to ensure a minimum of off-quality scrapped tanks, since the components to be welded have to be centered and parallel to the weld pad, while minimizing the weld cycle time."