At IKO Polymeric's production facility in Chesterfield/UK, the new extrusion system is being used for the plasticizing and compounding of soft PVC destined for the production of multilayer roofing membranes for the waterproofing of flat roofs. IKO PLC is a member company of the international IKO Group, which specializes in high-quality roofing systems for both private and commercial buildings.
The Coperion Kombiplast has been developed specially for the gentle compounding of temperature and shear sensitive polymers such as PVC, cable and other special-purpose compounds. Operating in two stages, the Kombiplast from Coperion consists of a ZSK twin screw extruder, into which the starting materials are metered via a ZS-B side feeder and then plasticized, mixed and homogenized. The downstream ES-A single screw discharge unit gently builds up enough melt pressure for the subsequent pelletizing in the EGR eccentric pelletizer. IKO’s Kombiplast KP 62 Mv PLUS/200 features a screw diameter of 200 mm. Andrew Salmon, General Manager at IKO's site in Chesterfield, says: “Whilst Coperion guaranteed us a throughput as high as 2,400 kg/hour, we can in fact operate the machine at up to 2,700 kg/hour with no loss of process stability while maintaining exactly the same high quality of compound.”
What is particularly special about IKO's new compounding line is that it is being operated without the cold mixer that is frequently required upstream when compounding soft PVC, as the preheated pre-blend must normally be cooled down again prior to plastification. With Coperion's Kombiplast, IKO can meter the hot pre-blend straight into the extruder, thus maintaining high energy efficiency and, by the same token, keeping down the production costs.
After only a few months' practical experience with the new compounding system, Andrew Salmon can already say: “As our products must not show any fluctuations in colour whatsoever, the extrusion system we were looking for obviously had to produce a particularly high quality of product. Many users advised us to invest in a Kombiplast from Coperion, especially as it is also distinguished by its gentle product handling. Today we are pleased to say that we made absolutely the right decision.”