An ideal example of the diverse advantages inherent in a silicone component is the innovative new ice cube tray that Starlim Spritzguss GmbH from Marchtrenk in Austria, the world’s largest processor of liquid silicone, recently developed as a demonstration object. In addition to its pleasant feel, it is its compatibility with food, its low temperature resistance and the option to create even difficult geometries with undercuts that primarily make silicone so interesting for a variety of different applications.
The two-part, practically spherical ice cube mold in blue and grey corporate colours has a diameter of around 6 cm. It is closed through a simple engaging mechanism and opened again by applying light pressure. This is all made possible by a slightly larger upper part and undercuts on the upper edge of each half that engage in each other during closing. Undercuts can be created without difficulty in silicone components without designing complex multi-sectional molds, as cured silicone polymers can withstand extensive elongation. These high levels of elongation permit induced demolding of the component without any damage, which is an enormous advantage when compared to thermoplastic components! The realisation of components with freely formed surfaces such as required in a baby pacifier is also possible in silicone.
And speaking of pacifiers – a further advantage of silicone components is the material itself. The processing of silicones is absolutely pure and involves no additives, so they do not contain or emit any substances that are harmful to health. This makes these flexible high-tech components particularly suitable for all applications in healthcare and both the medical and food sectors.
The high level of elasticity of silicone is not only evident in demolding, but also during use. The ice cube can be removed from the flexible mold with ease following opening. Ultimately, the trick is that, following freezing, the mold itself remains flexible in the freezer, as silicones are resistant to temperatures as low as around -120°C. Silicones are known for the fact that nothing adheres to them which, naturally enough, benefits the user when removing the ice cube, as the cube can be slipped into the cooling drink by applying mild pressure.
The ice cube container is only one example of around 50 different individual molds that starlim develops each year in its R+D department. A major customer benefit in this respect is that every component is initially a 100% virtual creation, an approach that offers both a financial and time advantage. Thanks to an enormous level of in-house know-how, molds are created rapidly after component development with little need for reworking.
Every visitor to the starlim-sterner Group tech.day on 23 June was presented with a silicone ice cube mold, allowing them to appreciate the complex geometry and pleasant feel of this innovation.
A qualified automation technician, Leopold Pühringer has been part of the 8-person R+D team at Starlim Spritzguss GmbH in Marchtrenk, Austria for 17 years. In his role as Manager R&D, he provides support for customers during product development from the initial idea to the finished product. The world’s largest processor of liquid silicone, which has been a family business since being established in 1984, produces around 14 billion high-quality silicone components each year. These components are used in areas ranging from industry and life sciences to mobility applications. This means that, in addition to being a contract manufacturer, starlim is also a B2B, tier 2 and tier 3 supplier for the mobility sector.