One concept – several possibilities to assure quality; Online and offline analysis of Pellets, Flakes and Films/Tapes
December 31, 2015
SIKORA presents at the Wire 2016 in Düsseldorf (booth 9A41) its new and pioneering models of the PURITY CONCEPT Systems. With that, the company offers an outlook on the varied potential of its systems for online and offline inspection and analysis of plastic material. According to the application, the systems are equipped with X-ray technology (X), infrared technology (IR) or optical sensors (V) and can be used for samples during the production in order to find impurities from 50 μm.
Especially interesting are the systems for the production of high voltage cables. An essential criterion of high voltage cables is the production over long distances with as few joints as possible. Various reasons make the production of a cable in one length sometimes impossible to realize. In this case two cable ends have to be connected to each other in order to cover larger distances.
Weak point: Joint
In order to connect two cables with each other, the ends have to be stripped first. Both blank conductors are welded together. The occurring gap in the insulation is being closed by manually applied layers of tape. Thereby, it is essential that the tape does not contain any contamination, which might later cause breakdowns of the cable. But for all the care, there might be contamination that are not visible with the naked eye – metallic and organic contamination from 50 μm in the tape.
The PURITY CONCEPT Systems with optical sensors are suitable for the inspection and analysis of thin, transparent films/tapes, the systems with X-ray technology are appropriate for e.g. thick, black tapes1. In this way, it can be ensured that the same quality, as used for the main insulation, is used during the production of the tapes.
Production films/tapes
Films and tapes for the insulation of joints in the high-voltage cable area are produced by using the same high quality XLPE2 material that is used for the insulation of the cable. This brings some logistic challenges with it: Tapes are coiled when they are sent out by the manufacturer and need therefore to be delivered and used before they get cross linked by environmental circumstances. Therefore, a stockpiling order is just as problematic as possible delivery delays.
A possible solution is the independent production of films/tapes at the own manufacturing site. By using an extruder, the tapes can be extruded. The used XLPE material can either be inspected for contamination from 50 μm prior to entering the extruder by the PURITY SCANNER or after the extrusion by the according PURITY CONCEPT System.
1 Used films/tapes are often thin enough that they can be inspected with both the X-ray technology and the optical sensors
2 XLPE: Cross-linked Polyethylene
