Oerlikon Barmag: Continual Mixing And Metering Of Liquid Dyes And Additives

Editor’s Note: Dipl.-Ing. Ulrich Helbing is manager, Research & Development, Gear Pump
Division, at Oerlikon Barmag, a business unit of Germany-based Oerlikon Textile GmbH & Co.


In the case of many production processes in the plastics-processing industry, the polymers
used require dyes or additives. Dyeing polymers frequently takes place during the manufacture of
films, pipes, profiles, etc., but also in the production of yarns. Here, it is common to use
colored master batch granulates, which are usually added to the main polymer by means of
gravimetric metering systems in the hopper zone of the extruder. The drawback of this method is
that manufacturers must warehouse a separate mast batch of each shade f the end produce, which
results in considerable warehousing and logistics costs. Furthermore, determining the pigment
ratios of each individual master batch requires comprehensive preliminary trials to be carried out,
whereby the master batch granulates must first be manufactured followed by testing of the
production process. Liquid dyes — which can be mixed continually during production — are an
extremely efficient alternative to the above-mentioned utilization of dye master batches. This
offers two decisive alternatives:

  • Manufacturers only have to stock a few basic dyes on the basis of which all final dyes are
    mixed. This substantially lowers warehousing and logistics costs.
  • The color of the end product can be corrected during on-going production, which can
    significantly reduce time and costs.

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May 31, 2011

Source: Oerlikon Barmag