![[Translate to English:]](/fileadmin/_processed_/a/c/csm_buehler_multitherm_1200x800_31c5b434de.jpg "[Translate to English:]")
Quality comes at a price and requires constant control. With its innovative MultiTherm cocoa butter analyzer, Bühler AG enables international chocolate producers to test their raw materials. With around 12,500 employees, the international Swiss company with headquarters in Uzwil is one of the market leaders in technologies and processes for the processing of flour, rice, pasta, animal feed, and chocolate. The highest quality is therefore not only required for the cocoa butter itself, but also for the processing equipment.
With meticulous quality assurance, the technology professionals at 1zu1 made it possible to manufacture the high-quality MultiTherm in series using vacuum casting. Printing, assembly, and packaging were also left in the capable hands of 1zu1.
We talked to Simon Göldi of Bühler AG and 1zu1 project manager Sebastian Fink about this successful long-term project.
Mr. Göldi, what exactly does the MultiTherm do?
Simon Göldi: The device measures the crystallization properties of cocoa butter and cocoa mass and provides detailed information on the quality of the resulting chocolate via the Bühler Crystallization Index, BCI. The precise forecast is completed in less than one hour. This allows defective ingredients to be identified at an early stage, which in turn reduces the risk of rejects. The MultiTherm is therefore an indispensable tool for chocolate producers. It earned Bühler the iF Design Award in 2021 thanks to its unique measuring method, user-friendly design, and ease of operation.
How did the vacuum casting project come about?
Sebastian Fink: Bühler was looking for a supplier for the housing – but had not yet decided on the production method. The basis for this was a comparison of vacuum casting, injection molding, and deep drawing technologies in the fall of 2019. As specialists in vacuum casting, we were asked to provide an indicative quotation. Our many years of expertise in the manufacturing process came to the fore here. Bühler chose us and we started optimizing the design for vacuum casting. We made the first sample molds shortly thereafter. Series production has been underway since March 2021.
From Bühler’s point of view, what were the key factors for the housing?
Simon Göldi: Quality and functionality. Open the lid, fill the sample container with cocoa butter, insert, close, and measure. Everything else is done on the touch display. When opening and closing the lid, residues from previous measurements must be avoided at all costs. Since we also offer another lid variant, the lid-change process must be simple and tool-free. Together with 1zu1 we developed an optimal solution.
How did 1zu1 put this assignment into practice?
Sebastian Fink: The lid consists of three components. Firstly, it is cast, then components are inserted, and then another layer is cast over it. This makes it possible to connect the elements without screws or pins. This solution can only be implemented with vacuum casting. Some elements were encapsulated with hard polyurethane (PUR), and others – such as the sensor – with soft PUR.
Were there also other challenges?
Sebastian Fink: The MultiTherm is an absolute premium product with sky-high demands in terms of the surface finish. This begins with the production of the 3D printed model for the silicone mold and includes post-processing, painting and printing, as well as quality assurance. The size and curved shape of the parts also required a great deal of expertise.
Thinking about quality assurance – what did the challenging requirements mean in terms of the collaboration?
Sebastian Fink: The individual elements must fit together perfectly – only minimal deviations are allowed. This means managing the interplay of different parts and tolerances. It also applies to the lids. Each one must be an exact fit for every housing in the world. Due to the growing use of silicone molds in vacuum casting, ensuring this is far from easy.
Simon Göldi: 1zu1 created numerous detailed work instructions, measuring gauges, and assembly jigs, which they coordinated with us in each case. This not only involves defining the tolerances; the sensors are also checked before each subsequent vacuum casting. 1zu1 also handles the printing, assembly, and packaging. This means we get the completely finished housing and can start installing the technology right away – a big win.
How was 1zu1 able to apply its vacuum casting expertise during production?
Sebastian Fink: We suggested some design optimizations. As 3D printing specialists, we were able to exploit the technology’s full potential and, for example, create the screw fastenings on the main piece, which were not ideally located for casting, as individual 3D printed parts. Thanks to our know-how, even the first silicone molds produced results that were ready for series production.
Our interviewees: Simon Göldi is the project manager responsible for the development of new equipment in the Chocolate & Coffee division at Bühler AG in Uzwil. Sebastian Fink is the area manager for Switzerland at 1zu1 and has been involved in the project since day one. The interview was conducted by Joshua Köb, photos by Darko Todorovic.
