Solving critical issues in the automatic filter packaging process for single-use infusion sachets.


The packaging process for single-use sachets is delicate: the automatic handling is managed by precision mechanics that dictate the fast pace of production, which can be summarised as several hundreds of operations per minute, always precise and constant. Once it has been filled with raw material, the container/filter undergoes a second processing step as it is placed in a further paper package.

It is at this stage of the process that the heating elements used in sealing the sachets make a series of seals around their perimeter. While one side of the pack is folded in on itself, the remaining three sides are heat-sealed by a mechanism powered by two cartridge heaters.

The solution used by the customer did not allow a sufficiently uniform heat distribution to achieve optimal sealing. The temperature difference between one soldering point and the next was a gap of 30°C.

CREI's Solution 

Our many years of experience in the field of heaters with differentiated distribution has enabled a specific placement of power on specially manufactured cartridge elements. In this way, we achieved a distribution of heat over the soldering body and drastically reduced the temperature gap.


  • Increased efficiency, fluidity and speed in the packaging cycle
  • Temperature gap reduction from 30°C to 2°C, so -93%
  • Increased welding speed/minute: +67%
  • Optimisation of energy efficiency with the same nominal power rating
  • Decreased active heating time
Temperature gap reduction
Increased welding speed/minute

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