When a dental laboratory commissioned special-purpose machinery manufacturer, Jonas & Redmann, to design and build a highly automated production cell capable of producing and testing five million mixing nozzles per year the company’s 30 years mechanical engineering experience was up to the task but the short cycle time of 1.5 seconds was a problem when it came to the essential 100% final testing.
Kistler Group
The mixing nozzles, used to produce the casting compounds used by dentists, are made of four separate parts and are assembled in the production cell and, like many medtech products, are disposable, use once items. Final testing, a mission critical part of the production process, had to be based on a friction coefficient test (< 0.5 Nm) on the mixing mechanism of the assembled nozzle. Having worked successfully with Kistler on other projects, Jonas & Redmann looked to the sensor company for a solution.
The solution Kistler proposed used a combination of a type 4502A torque sensor and the maXYmos BL evaluation system to check the torque curve for each individual product. The measurement value produced by the torque sensor is used to generate an OK/NOK signal transmitted directly to the control system so that any product with an out of spec torque curve is automatically rejected. This 100% testing ensures that only perfect products are delivered by the production cell.
One important factor in the successful outcome was the close collaboration of Kistler and the consulting engineers who were executing the project. The two teams quickly devised a test rig to verify the solution which, at the first attempt, confirmed that the transducer produced values for frictional torque that were within the tolerances allowed by the system specifications.
The 30 years mechanical engineering experience plus Kistler’s measurement solutions created a successful end product.
