Thermal imaging cameras for quality control

Today's production facilities are planned with a high degree of automation and a particular focus on cost efficiency. Because a high throughput is ideal for this, production often runs very quickly around the clock and preferably without interruption. For quality control, this means that in order to avoid motion blur in the thermal images, a high-quality, fast thermal imaging camera must be used - in other words, a cooled system.

In contrast to an uncooled thermal imaging camera, however, a cooled camera design with its cryocooler is significantly more complex and maintenance-intensive. Flir has responded to this by launching the cooled MWIR thermal imaging camera A6301 in 2024, a model that can be used continuously for an average of around 27,000 operating hours - i.e. more than 3 years - before it needs to be serviced. Inductive sealing of caps is essentially based on the same technology as wireless charging of cell phones, but instead of charging a phone, an adhesive-coated foil element in the bottle cap is heated without contact. The heat melts the adhesive and the film creates the desired airtight seal. The Californian company Movitherm specializes in turnkey thermographic testing solutions and uses thermal imaging cameras from Flir, among others.

Tae Moon, Application Engineer at Movitherm, explains how the quality control works: "Thanks to various sensors and thermal imaging cameras, our TSI system is able to determine whether the seal is intact. By analyzing various aspects of the thermal image we receive of the bottle seals, the algorithm is able to determine whether the seal is good, too weak or too strong, or whether there is a faulty connection due to folding of the film. We can therefore draw a lot of conclusions from a single thermal image. That's why it's extremely important to have a very sharp and good IR image."

100 percent inspection rate

What is important to application engineer Tae Moon is a 100 percent inspection rate, in which every product produced is really inspected, which is still not standard in production processes: "If it's a very fast production line, an uncooled camera will deliver blurred images. The Flir A6301, on the other hand, has really good thermal contrast and works very quickly, so there is no motion blur. Even in the fastest inspection series I've seen, the A6301 takes crisp, really good images without the image quality suffering from the fast throughput. But the most important thing for me is that the camera only needs servicing after 27,000 hours of operation on average, which is really impressive, as the next best comparable camera I know only reaches 8,000 hours."