High mechanical quality is mandatory in an electric toothbrush, but the market--especially the US market--also requires variety in color and design. A major manufacturer of electric toothbrushes has chosen to meet the demand for rapidly changing color schemes for molded plastic toothbrush shells by installing a machine-vision system developed by Wolf Systeme (Neulingen-Göbrichen, Germany; www.wolfsysteme.de).
The major challenge was inspecting for color changes to existing products. Given the small batches produced of each color and the fact that each shell consists of two or three injection-molded pieces, it is difficult to ensure that the colored parts are properly matched. While the geometrical forms of the plastic shells remain the same, the color combinations continually change. And, to enhance appearance, glittering metal may be added to the components, which increases the challenge of surface inspection.
To meet the complex demands for sorting out mismatches and defects, Wolf Systeme modified its flexible MVplus machine-vision system. "We were increasingly faced with the problem that we always had to adopt common software products for every new customer application and every new product," says Markus Wolf, CEO of the company. He says MVplus now uses HALCON software from MVTec Software (Munich, Germany; www.mvtec.com) because it is an object-oriented, flexible software with a standard library that runs on parallel processors.
MVplus allows fully automated training of new color combinations without additional programming. This automated teaching takes only 30 minutes before new color types of tool holders can be controlled. Without MVplus, programming took several days. There are more than 25 different color combinations, and thus the automated teaching reduced costs about 100,000 euros.
Furthermore, MVPlus provides user management and, thus, with a Web interface remote control is possible. If a problem occurs or application enlargements must be integrated, complete simulations can be operated with real data and images transferred in the Wolf lab. "This saves customer costs," says Gerhard Hauser, sales manager at Wolf Systeme.
