QUALITY ASSURANCE FOR FLAT WIRE AND PROFILES

In our series of interviews, we’re now following our first blog on manufacturing expertise with a look at quality assurance. Matthias Schmitt from materials technology explains the strategy and measures that Waelzholz uses to ensure that material properties remain constant.

MR. SCHMITT, HOW IMPORTANT IS QUALITY ASSURANCE AT WAELZHOLZ?

“One thing’s for sure: nowadays, quality assurance has been integrated into every material manufacturer’s production process. But our unwillingness to accept compromises and our innovative approach to enhancing quality assurance are certainly unique to Waelzholz. One example is our ‘zero-defect-strategy,’ which often guides how we monitor our own processes, but leaves room for defects to pass through the preliminary stages. Waelzholz now uses eddy current technology throughout the company that allows us to detect surface quality during production.

Our company’s mission is the reason for this uncompromising approach – we supply high-quality grades for demanding applications. This usually involves the tightest tolerances and extremely homogeneous materials that not only guarantee a phenomenal final product, but also reliable processing on the way there.”

CAN YOU TELL US MORE ABOUT THE EDDY CURRENT TECHNOLOGY YOU MENTIONED?

“Eddy current technology is a well-known physical process, but we’ve adapted and optimized it for flat wire technology. In this process, magnetic fields are generated in the material via induction. These magnetic fields can, in turn, be easily detected. The key here is that deviations in the material properties influence the magnetic field. In other words, we make the material properties visible via the magnetic field. We’ve made advancements to the process so that this measurement can be carried out during ongoing production. This allows us to implement targeted corrective measures and ensures that the material has completely homogeneous properties. For our customers, this translates into a high degree of reliability, like when our grades are used in safety-relevant components in automobiles.”

HOW DO YOU CONDUCT QUALITY INSPECTIONS?

“In general, our quality inspections are carried out according to defined processes that we strictly adhere to and permanently document during the development process. Our primary goal is always to achieve maximum quality during production, which is why we’ve invested extensively in measurement and control technology for our systems like eddy current testing, for example. Our systems can even detect when a parameter merely begins to move in the direction of a tolerance limit, and then make adjustments at an early stage. In addition, we also regularly test samples from production in our materials technology laboratories.”

HOW EXTENSIVELY CAN YOU PERFORM IN-HOUSE TESTING AT WAELZHOLZ?

“First of all, I’d like to point out that we keep all of the relevant testing and inspection equipment available in house. The scope of equipment we have is definitely unique in the cold rolling industry. This includes, for example, a scanning electron microscope and 3D coordinate-measuring stations for profile measurement. The scanning electron microscope has an extremely high resolution of 2 – 3 nanometers. In comparison, a single hydrogen atom has a diameter of 0.1 nanometers, a human hair is about 100,000 nanometers thick. This device features exceptional depth of field and outstanding contrast. It allows you to view the topography of a material with absolute precision, which is really quite impressive to look at. This equipment not only helps us with quality assurance, but also with product development. Thanks to the short distances the material travels at our company, we can move extremely fast and also significantly reduce the time to market of our customers’ products. This is a real advantage.”