Silicone valve keeps liquid in place where it belongs

starlim//sterner develops and produces high-performance metering valve for American customer.

The starlim//sterner group with headquarters in Marchtrenk/Austria regularly shows its unique competence in producing customized components from liquid silicone. For their American customer International Dispensing Corporation (IDC), New York, they have recently developed a high-performance metering valve made from a special type of silicone. The new valve allows to meter liquids with high precision, without subsequent dripping, an absolutely clean process.

Metering valves are increasingly used not only in gastronomy: they are indispensable in the composition of mixed drinks from concentrate or for filling cans from bulk packs. Such valves sometimes fail to fulfill the demands of their user with respect to metering precision and cleanness or the absence of subsequent dripping. In order to solve these problems, IDC turned to starlim//sterner.

Leopold Pühringer is responsible at starlim//sterner for product engineering. "We had to modify an already existing metering system. The existing silicone valve contained parts made from food-grade thermoplastics with a given geometry. It was our task to optimize the silicone in such a manner that no subsequent dripping would occur" he says.

Combining great experience in silicone-processing with the latest analysis and simulation processes starlim//sterner could work out an optimized solution. A computer tomograph was used to determine the existing external geometry dimensions of the parts. "This method is important, it is the only way to determine the exact internal dimensions inside the dispenser" Pühringer emphasizes. On the basis of the virtual model the correct geometry of the inner umbrella valve was determined and then we built the tool to fit the process. We also took into consideration the use of another type of silicone with a Shore A value of 80. That material is harder to work with than the previous type, which had a lower viscosity. But because it is harder it is better suited to fulfill the mechanical demands. "We chose a harder type of silicone and made minor alterations to its geometry, this way we could meet the client's specifications", Pühringer is glad to say. The metering valve aseptically seals off the bulk pack. That makes it possible to use it also for milk products.

The client also benefitted from starlim//sterner's global networking: the development of the product took place in the well-equipped center in Austria while at the same time the client had his contact persons directly on his site in North America. Mass production has been taking place for the past few months.