Household technology case study: Mould technology with conformal cooling at Rowenta

At a glance:
Development of 3-component moulds with conformal cooling for the production of distortion-free parts for a new series of clothes irons from Rowenta.

The customer:
Rowenta Werke GmbH, located in Erbach in the Odenwald region of Hesse, Germany, is a manufacturer of kitchen and household appliances. Since 1909, this German brand has thrilled demanding consumers with high-quality products guaranteeing perfect results. In 1988, it was integrated into the globally operating Groupe SEB based in France, which includes more than 20 renowned brands and is present in many other product families.

The task:
Hofmann – Ihr Impulsgeber had to develop 3-component injection moulding tools for a new series of clothes iron which, thanks to conformal cooling, guarantee improvements in cycle time and a reduction in distortion.

The solution:
Essential to the development of the 3-component parts is the resulting freedom from distortion. It’s also responsible for positive “assembly behaviour,” i.e. high dimensional stability. In developing the cooling concept, Hofmann –Ihr Impulsgeber fell back on the Moldex3D simulation software, enabling the designer to get a virtual view of the inside of the mould. This makes it possible to make qualified statements on the flow behaviour, temperature distributions, pressure losses and flow speeds. This is especially crucial when temperature-control channels, such as those created using the 3D metal printing process, become so complex that the flow can no longer be evaluated using conventional methods. As an innovative partner, it goes without saying that Hofmann – Ihr Impulsgeber uses simulations for cooling channel design and testing.

The development goal of 3-component injection moulding tools, i.e. to reduce the tendency toward distortion in the front section of the part, was implemented thanks to the most even temperature distribution possible in the cooling phase of the injection process. Three-dimensional presentation results and animations of the distortion demonstrated the behaviour of the end product and helped design and optimise conformal temperature control. It was also possible to precisely analyse the interplay of the various different components, materials and geometries. Both aspects – transparency and optimisation – led to a high-quality component. This made it possible to shorten overall cycle times, reduce production costs, decrease mould post-processing to a minimum and achieve a considerably shorter development process.