Coperion at the WIRE exhibition: flexibility in the production of cable compounds Kombiplast hybrid: for PVC and HFFR compounds

Stuttgart/Germany, March 2010. – At the WIRE exhibition in Düsseldorf (April 12-16, 2010) Coperion GmbH, formerly Werner & Pfleiderer, will be presenting the hybrid concept of its well-established Kombiplast compounding lines for the production of cable compounds. The Kombiplast PVC/HFFR hybrid permits the economically efficient production of either PVC compounds or HFFR (halogen-free flame-retardant) compounds for the cable industry. The advantages of the Kombiplast PVC/HFFR hybrid are as follows:
· Small and medium-sized compound suppliers to the cable industry can supply high-grade compounds both to the innovative, rapidly growing HFFR market and to the conventional, long-established PVC market.
· Companies just starting up in business, or existing compound manufacturers that are setting up a new production facility, can commence production with just one compounding line and still exploit the respective potentials of both markets.
· Relatively large compound manufacturers can gradually increase their production of HFFR compounds in pace with corresponding market developments.
· Cable manufacturers equipped with their own compounding facilities can increase their production of HFFR cables in pace with the growth in market demand.
Coperion also offers the Kombiplast PVC/HFFR hybrid concept as a turnkey production line – from raw materials arrival to the compounding process to the bagging of the finished product, all units being designed for hybrid operation.

As regards the actual compounding process, the Kombiplast hybrid differs from a PVC-only line in that the ZSK MEGAvolume PLUS compounding unit is not only longer but also equipped with a second twin screw side feeder ZS-B. No matter whether PVC or HFFR is being compounded, the barrel of the ZSK MEGAvolume PLUS ensures absolute homogeneity of the melt. The single discharge screw ESA then gently builds up the pressure of the melt for subsequent eccentric pelletizing in air.

Only a few changes to the Kombiplast PVC/HFFR hybrid are necessary for switching over from PVC to HFFR or vice versa. Changeover can be effected within 2 hours depending on the actual equipment and size of machine, the main task consisting in the changing of the twin screws in the extruder barrel. This is quickly and easily done: the twin screws are directly accessible via the transition chute between the ZSK MEGAvolume PLUS and the single screw extruder. They can be withdrawn from the barrel towards the front. This screw change is absolutely necessary on account of the fact that the processing requirements for PVC are completely different to those for HFFR. A dryblend without adding any further raw material is used for the production of PVC compounds, gentle compounding being absolutely imperative, while for the production of HFFR compounds over 60% powdered filler is mixed and dispersed into the polymer matrix.

Several Kombiplast PVC/HFFR hybrid compounding lines have now been giving successful service in the cable industry for almost ten years, and in both applications – the production of PVC compounds and HFFR compounds – they have distinguished themselves through their flexible and economical mode of operation and their extremely high quality of product. Output rates of up to 2,500 kg/hour are possible when producing HFFR compounds. The flame retardants Al(OH)3 or Mg(OH)2 are processed very gently, ensuring full compliance with all relevant UL and VDE fire safety requirements.