Oceplast, a well-known processor based in France, has commissioned a complete WPC direct extrusion line from KraussMaffei Berstorff at the end of 2012. The company is one of the leading PVC processors in France and produces various WPC decking profiles using the direct extrusion process at its plant in Alzenay (northern France).
“Oceplast, a long-standing customer of KraussMaffei Berstorff and founder of the OCEWOOD trademark that is renowned in France and Europe, chose our WPC concept since the twin-screw extruders have very high wear resistance”, said Michael Finkenzeller, Product Manager for WPC extrusion at KraussMaffei Berstorff. “The screws have tungsten carbide armor plating while the barrels are lined with a bi-metal bushing. Wear resistance is very important, especially in WPC processing, since this is the only way to attain the machine service lives demanded by processors and minimise standstill phases and maintenance costs”, continued Finkenzeller. The core component of the line is the KMD 75-32/WPC twin-screw extruder with a maximum output of up to 200kg per hour. Other line components, for example the calibration table, the haul-off/saw combination and the tilting table, were designed to meet the customer's requirements. The line is therefore extremely compact and is designed for processing extra wide profiles.
The line features a single-step process which permits direct metering of the two components, i.e. wood and PVC. A two-component gravimetric system transports wood flour and PVC dryblend into a dynamic mixer which feeds the homogenised material mixture directly into the extruder. The complex compounding process using a heating-cooling mixer is therefore not required; the processor saves valuable production space and energy as the wood flour is already pre-dried.