TPT July 2016

T E CHNOLOG Y

Areas of application of technology The millimetre wave technology is suitable for the measurement of any kind of plastic tubes with a diameter from 120 to 2,500mm that are, for example, used for conducting water, gas, chemicals and oil. Particularly interesting is the application of tubes made of all common plastics, such as PE, HDPE, PP, PA6, PVC, etc. Here the system provides precise measuring values, even for tubes with wall thicknesses of 200mm. Another area of application is the measurement of single- and multi-layer tubes. During production, there is the risk that the melt that leaves the tube tool flows down as a result of gravity and thus negatively influences the tube wall thickness distribution. This so-called sagging is identified by the millimetre wave measuring method. Conclusion and outlook Quality demands when manufacturing large plastic tubes are increasing. Norms precisely define the dimensions of the products to be produced. The precise and reliable quality assurance of plastic tubes during extrusion is gaining importance. By the use of a new system on the basis

a special challenge. As a result of the temperature dependence of ultrasonic, a temperature compensation is required. But the goal is to achieve, as early as possible in the production process, reliable and precise information about tube dimensions in order to take action if necessary and to avoid failure deliveries. Moreover, it is necessary to approach early in the production process the minimum permissible tube dimensions to produce a minimum metre weight. Cost savings resulting from the low metre weight are often decisive in competition. Material costs of extruded plastic tubes account for up to 90 per cent of the total manufacturing costs. Depending on throughput of the line, used material type and underlying norm, between the minimum and maximum permissible tube dimensions there is an annual savings potential in the single-digit millions range. In addition, the production of standardised plastic tubes assures a flawless processing of the tubes. For example, quality tubes can be welded easily. Thus, the use of a millimetre wave measuring system leads to significant time and material savings, as well as to a high quality end product.

Evaluation of the received signals and determination of the tube dimensions

of millimetre wave technology for hot measurement and at the cold measuring end for final quality control, the product parameters of inner and outer diameter, ovality, wall thickness and sagging are continuously monitored online. The introduced millimetre wave technology, in combination with processor systems, increases quality, minimises material consumption, and contributes to time and cost saving.

Sikora AG – Germany Email: sales@sikora.net Website: www.sikora.net

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J uly 2016