EuroWire November 2014

Technical article

Green technology for higher productivity of the production line As explained at the start, green technologies have to provide both an environmental and financial benefit to the market. The following gives an example of how the green system also increases the productivity of the line. A very important aspect is always the cable joint, specifically with regard to power cables for offshore applications. The joints where the cables are connected together are critical as each joint contains a potential risk for breakdowns. Therefore, energy suppliers expect cable manufacturers to deliver large cable lengths in one piece with a minimum amount of joints. Consequently, the aim is to produce energy cables with long lengths with only a few joints while using highly pure raw material. One solution is to omit the screens. However, this is not a suitable alternative for all cable manufacturers. But, even with the screens remaining in the production, the application of the newly developed inspection and sorting system will give manufacturers the benefit of keeping the screens clean for decisive longer production runs. In order to catch possible impurities in the XLPE compound before they get into the cable, manufacturers use screens, which are positioned directly in the melt flow after the extruder, before the crosshead, and thus prevent contamination from entering the product. But degraded XLPE, ie scorches or excessive amounts of contaminants after a certain run time, can clog these screens. Then the melt pressure in the extruder may increase significantly. Finally, production has to be stopped in order to change the screens, which in turn means that later a joint is required at that position. Therefore, the system supports cable manufacturers to produce long cable lengths in one piece to avoid cable joints which are the weakest link of the cable. It assures that contamination that would clog the screens is detected and separated before it enters the production process. As a result, longer production cycles can be run and fewer cable joints are required. Thus, there is a minimised risk of breakdown as only pure material is used for the insulation.

Conclusion The introduced system for online inspection and sorting of material represents an innovative solution of green technology for power cables. By assuring clean material for the production process, plastic material and thus crude oil can be saved, the productivity of the production line improved and the lifetime of the cable extended. The short payback period of the technology also positively contributes towards consolidated earnings for the company. With this system the quality and functionality of end products in the cable industry is increased significantly. n

Sikora AG Bruchweide 2 28307 Bremen Germany Tel : +49 421 489 000 Email : sales@sikora.net Website : www.sikora.net

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November 2014