Most drinks containing solid pieces available on the market are filled into bottles or cans using a hot fill technique or are sterilized, after filling, in an autoclave. However this has a number of problems: the heat treatment – which has to be at a higher level to penetrate the solid pieces – can affect the taste and the nutritional efficacy of the drink; containers must be sufficiently robust to stand the temperatures and pressures involved in the process without distortion; and the whole process is extremely wasteful in energy.
The aseptic Dual Filling developed by GEA is believed to be the first process that can be used to fill PET and HDPE bottles, in a cold-fill environment, with the required high level of accuracy.
The aseptic Dual Fill system has two separate filling carrousels, both located inside a microbiological isolator: the aseptic Piston Doser Fillstar PX for solid particles with set volume from 30 to 150 ml; and a volumetric electronic filler, an industry standard for still aseptic beverage filling.
Bottle filling takes place in two operations: first the dosing of the solid particles, then the addition of the liquid phase. The aseptic Piston Doser Fillstar PX is simple but effective: a cam-driven piston first draws the prescribed volume of solid particles into a cylinder, before injecting it into the awaiting PET bottle. The bottle then moves on to the filler to add the liquid juice and complete the aseptic filling process.
The dual fill system requires a two-stream process line: one dedicated to the thermal treatment of the pieces and the other to the thermal treatment of the clear liquid.