KUKA robots enable efficiency in the injection molding of plastics at Gebrüder Schwarz GmbH
Gebrüder Schwarz GmbH, based in Rottweil-Neukirch and with a workforce of 200, is one of the technological leaders in the fields of injection molding, tool development and system components
In order to be able to offer optimal solutions to customers in the medical technology sector, the automotive industry, the measuring technology, electrical engineering and hardware technology sectors and in the fields of environmental technology and power engineering, the company ensures that its modern injection molding machines, drying systems, peripheral devices and robot systems correspond to the state of the art at all times and are operated exclusively by an experienced, highly qualified team of Spezialist. Since February 2015, in addition to the two automation solutions from KUKA already in operation, the company has also been using two six-axis robots of types KR AGILUS and KR 16.
Automation solution for the production of fans
An automation solution was required for the production of fans for ebm-papst, a specialist for ventilators and motors in the fields of ventilation and drive engineering. As the task was too complex for a linear gantry, this alternative was rejected early on in consultations with Zimmern-based integrator Barth Mechanik GmbH. A pioneering automation approach was required in order to be able to meet all customer requirements in terms of cost-effectiveness and high quality. The manufacture of the complex injection-molded plastic components requires a combination of the utmost precision and reproducibility and short cycle times. The specified cycle time and process reliability also had to be ensured.
Two KUKA robots work as a team
For the production of the fans, four shafts are fed to the KR 16 which loads them into the tool. The very small components, with a diameter of just 1.2 mm and a length of 1.5 cm, must be loaded with absolute positional accuracy. For this purpose, a laser measures the exact position. Following injection molding, the robot removes the four molded fans from the tool and transfers them to the inspection station where they are inspected using a camera. The KUKA small robot from the KR AGILUS series (KR 6 R900) then takes the finished parts from the inspection station and sets them down on palletized trays.
Only a robot can perform these process steps reliably. The human hand would cause corrosion on the component and must therefore not touch it. And with gloves it is no longer possible to grip the very small shafts.
Flexibility and precision through synchronized robot systems
The KUKA robots used at Gebrüder Schwarz GmbH have made a great impression, not only in terms of quality, but also for their robustness and high availability of 99.995 percent. They have an ideal combination of reach, weight, speed and energy consumption. Their functional versatility makes them highly flexible, thereby simplifying the synchronization of the two robot systems in the specified production cycle at Gebrüder Schwarz. While the KR 16-2 stands out for its flexibility and precision when removing parts from the injection molding machine, the KR AGILUS 6 R900 scores high in top precision at the highest of speeds.
Marked increase in productivity and high quality
With the robotic solution, the company has seen a marked increase in productivity – with consistently high quality. Furthermore, the solution is also serving as a pilot project for similar challenges in the future. In the medium and long term, Gebrüder Schwarz GmbH will be able to build on the new automation system, based on six-axis robots, as well as on the acquired expertise.