The challenge
Italian manufacturer Fedegari Group wanted to cut the time needed to produce large autoclave pressure vessels for the pharmaceutical industry. Strict international standards preventing alterations to the welding process speed or voltage meant that the efficiency of the process itself needed to be enhanced.
The solution
ABB supplied two flexible welding cells based on ABB gantry mounted robots, together with its RobotStudio® offline programming tool to design new set-ups and reduce programming and changeover times.
The application
The two cells can weld both inside and outside large autoclave vessels, with handling equipment that allows loading one vessel while the robot works on another. Offline programming using ABB RobotStudio® means the next job can be prepared while the current one is in progress, avoiding unnecessary down time.
Italian engineering company Fedegari Group has reduced the time to produce specialised autoclave pressure vessels for the pharmaceutical industry by 50 percent following the introduction of ABB industrial robots and RobotStudio® offline programming tool.
The company produces customised welded pressure vessels for autoclave manufacturers, who supply bespoke products to meet the specific needs of their own customers. This means that very few of the pressure vessels are the same, requiring a highly flexible production system that can produce precision joints and handle the widely varying sizes and geometry of the vessels.
Although Fedegari was already using a robotic system of another maker, it was aging and not very efficient. Some operations also needed to be handled manually.
To meet growing demand for its pressure vessels from pharmaceutical manufacturers, the company needed to speed up its production times. However, with welding parameters fixed by international standards, it was not possible to achieve this by altering aspects such as the speed of the welding head or the weld voltage.
Instead, the company needed to find a way to improve the overall efficiency of the production process. This meant that Fedegari needed an automated process that could switch to producing a new vessel rapidly with almost zero changeover time. This demanded not only robots with the flexibility to handle different processes, but also an offline programming system that could alter a program ready for the next vessel while the welding cell was working on the current product.
Such a system would enable a library of pre-compiled programs to be built, allowing suitable programs to be adapted to meet the needs of each new customised vessel and then sent to the machine. This rapid programming would discourage welders from making their own welding programs manually by positioning the robot at each point, a practice that had led to delays.
As well as a flexible programming system, Fedegari also wanted a highly adaptable cell that could accommodate vessels of different sizes – it also needed to perform all the welding operations without the need to stop and move the autoclaves.
Autoclave vessels usually have two doors, and it was a challenge to develop a solution that ensures all the required welding processes can be performed without a changeover. The production process entails handling a combination of bent sheet metal, pressure cover and door frames, with both stainless steel and carbon steel being used. The process uses three different welding materials, with the robot needing to change its welding torch up to three times depending on the product being made.
Both interior and exterior welding operations in and around the vessel needed to be performed.
The flexibility provided by the robots enabled the final cell design to be optimized to cover 83 percent of the various pressure vessel sizes available in Fedegari’s product range.
The ABB solution
For Fedegari, a key attraction of working with ABB was its ability to act as a general contractor, giving it just one party to deal with.
Through its Italian global solution center for welding and cutting, ABB assumed responsibility for the entire project from the concept study to the start of production, working in collaboration with its system integrator partner PRSE S.r.l.
“ABB’s technical solution was the best one,” says Marco Gonnella, Fedegari’s Plant & Operations Director. “The combination of automation from ABB and the collaboration between robot and the gear and equipment of Fedegari was the main factor in our choice.”
ABB provided a complete solution for robotized welding consisting of two welding cells.
The first cell consists of an ABB XYZ Gantry system for the production of vessel bodies. This is equipped with an ABB IRB 2600 robot, three ABB-PRSE flexible positioners for welding different sized vessels and one multi process welding tool complete with searching and tracking sensors.
The other cell is designed for the production of vessel doors and has an ABB XYZ Gantry system, an IRB 2600 robot, two ABB IRBP 2000 positioners for welding different sized doors and one multi process welding tool.
Offline programming was conducted using ABB’s RobotStudio® offline and Arc Welding Power Pack software tools.
“The simulations by RobotStudio were the most important tool both during the concept development phase, the cycle time analysis and in the execution checks for the special components,” says Gonnella. “Moreover, by using a virtual production welding program, the cell final test is reduced to a simple optimization on the real cell.”
Production capacity raised by a third
The flexibility and speed of programming of the cells has led to major production gains for Fedegari, with the overall cycle time reduced by 50 percent. The cells allow mounting of two different vessels in two different positions, enabling the company to prepare one product while the robot is working on another, gaining time and efficiency.
“Thanks to the ABB solution, we have achieved a 35 percent improvement in production capability,” says Gonnella. “The cells are used on three shifts, with the third one being completely unmanned. At the moment, we use the cells at up to 60 percent of their potential, which is very fast for the dimensions for which they were designed.
“The best part of the project is not the welding; it is the collaboration between the welding system and the positioning system of the machine and the flexibility it offers. We are so pleased with the results that we are considering investing in a further project to use robots for our circular vessel production.”, says Gonnella.
