For years, steel components used in angle-bar transmission tower structures have not been manufactured in Finland on a large scale. Instead, they have been sourced from countries with lower labour costs. Proxocon Oy, founded in 2006, has focused on the steel and fastener business. Its current majority owner is Aurajoki Oy. In Finland, Aurajoki Group / Proxocon Oy operates in Aura, Pirkkala and Kannonkoski, where it manufactures, among other products, power line structures, railway electrification structures and switchyards. In practice, all tower components are hot-dip galvanised, and some of them are also painted at Aurajoki Group’s Finnish plants.
Cam-controlled French angle steel processing machines, among others, were already used in Finland in the 1970s. Today’s machines are, of course, numerically controlled and otherwise more advanced. Proxocon’s choice was the Italian Ficep, represented in Finland by Fredko. Managing Director Tommi Kivinen says that L-shaped bars are fed into the line. The equipment is also prepared to process flat bar and U profiles. The required holes are punched or drilled into the bar being fed through the line. There are 3 + 3 punching tools. Regulations require drilling for material thicknesses above 12 mm. There are six drilling units. Lower-end milling is carried out during drilling. The processing range for L profiles is 40 × 40 / 4 … 200 × 200 / 25, for U profiles 80 … 200, and for flat bars 50 / 4 … 200 / 20. The maximum bar feed speed is 60 m/min. The bar is cut to the required length with a shear blade. Mitre cuts can be produced when required. If needed, parts are marked using an indent marking device that penetrates the material, ensuring that the markings remain readable even after surface treatment. The machine control has seven numerical axes.
Programming is easy to carry out either externally or directly on the machine. When the customer’s up-to-date drawings are available, programming work can be avoided completely. The line located at Aurajoki Group / Proxocon Oy’s Pirkkala factory also supports production at the Kannonkoski plant. In two-shift operation, the line has an annual capacity of 2,000 tonnes. The line is still in its run-in phase, after which capacity can be increased if necessary, says Kivinen. He adds that the installation and commissioning of the line in spring 2014 went well, considering the tight schedule.
Further information: Proxocon, Managing Director Tommi Kivinen, e-mail: tommi.kivinen@aurajoki.com or Fredko, Jonas Fredriksson, e-mail: jonas.fredriksson@fredko.com
Edited by Veijo Kauppinen
