WCA September 2010

Technology news

Monitoring melt temperature

Ultratemp 6000 is Sikora’s latest development for the power cable sector. It is a non-contact polyethylene melt temperature measurement system, based on non-invasive ultrasonic technology. It is specifically tailored to the production of medium voltage (MV) and high voltage (HV) XLPE insulated power cables. The system precisely measures the melt temperature during production without influencing the melt flow properties, as the ultrasonic sensors are positioned outside of the flow channel. Melt shear heating effects do not occur. Besides temperature measurement, the Ultratemp 6000 detects discontinuities in the melt. Early cross-linking after screens which may lead to ambers and scorches in the polyethylene material is avoided. The extremely high measuring rate allows a fast response time as well as the registration of small temperature variations. Ultratemp 6000 is described as an important step for further process

Ultratemp 6000 measures the melt m m

temperature and detects discontinuities

optimisation and costs reduction during the production of MV and HV cables.

Sikora AG – Germany Fax : +49 421 48900 90 Email : sales@sikora.net Website : www.sikora.net

In wire manufacturing, salt carriers are frequently part of the coating system that is applied before drawing. On high carbon wire salt carriers are used as a basis for the drawing process, on top of conversion coatings or on a bare surface. Their function is the separation of die and wire, and transfer of lubricant into the forming die. The sophisticated composition of the products gives a reduced sensitivity against humidity and so low water pick up on the coated wire. This provides a good corrosion protection even during long storage periods. Traditionally borax, or formulations containing borax, are used for this application. Recent investigation of the toxicology of borax and boric acid initiated by the European Union has shown that borax acts as a reproduction-toxic substance. Borax has since been classified as a toxic substance with a Reprotox category 2 (or according to the GHS System: Repr. 1B). This reclassification presents a new situation for the wire drawing industry. New handling techniques are required for these toxic substances and stricter environmental regulations have to be applied in the production plants. Reducing borax content in salt carriers below the limit of declaration could, perhaps, be an interim solution. However, such a measure is questionable, not only because future legal regulations can hardly be predicted. The challenge for Chemetall was to formulate salt carrier coating products completely free of boron. The result of Chemtall’s R&D efforts is a range of new boron-free carrier coatings for different applications. First formulations have been tested successfully in industrial applications in Europe. Among the newly developed and tested products is Gardolube ® SC 6226. Its properties are at least comparable to carriers containing borax that are still in use in the market. Boron-free salt carrier coatings

Chemetall GmbH – Germany Website : www.chemetall.com

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Wire & Cable ASIA – September/October 2010