Abstract

In may 2011 Tetra Pak launched the world's first aseptic carton bottle, a completely new package and filling machine. For the development of the aseptic process, simulation driven product development was employed, in all stages of the product cycle. This presentation is about Tetra Pak's first full scale deployment of simulation driven product development with CFD.
This new filling machine is relying on the classic concept, introduced by Tetra Pak, of sterilise the product stream and sterilise the packaging material stream separately, but instead of a tube concept (as traditional Tetra Pak filler), a linear filler must be developed in which the package is premade, turned upside down with an open bottom and closed top. The package needs to be heated enabled by fluid jets, sterilised by hydrogen peroxide gas, filled with milk and sealed. From a fluid dynamic point of view this is an application of a confined jet into a dead end –a classical difficult case for turbulence modelling. A further challenge was to define the aseptic zone. The transport conveyor band cannot be completely sterilised so in the filling machine a plane needs to be defined in which there is a unidirectional flow, necessary to protect the aseptic zone. How to combine a fluid dynamics jet environment capable of managing all the processes in the package while defining a plane with a unidirectional flow?
A simulation model of the complete filling machine was gradually evolved, capable of asking more and more refined questions, always being one step ahead of the evolving real product. This way of working meant e.g. that well before the first physical prototype the aseptic performance could be evaluated, “what if” scenarios tested, and all sequences of the filling machine simulated.
Another challenge was the time to market. Our response, beside working with simulations, was to build a fast workflow and extensive usage of High Performance Computing.