TPT July 2007

P lastic & C omposite T ube: P roducts & M anufacture

Developed flow simulation, Battenfeld Extrusionstechnik’s new side-fed die allows – by non-centrical melt injection – a quick and optimal melt distribution into a circular ring geometry for further distribution. A geometry of twin centre sleeves preceded by a coathanger manifold ensures symmetrical distribution of pressure inside the die. This causes the majority of mechanical forces generated to cancel each other out, and ensures automatic centring of the mandrel. The design includes the option of modular, consecutive connection of several distributors, and thus a facility for thermal isolation of each individual layer of melt from the other layers. To further optimise melt homogeneity, the side-fed distributor is followed by a brake-up plate, the geometry of which has also been optimised using 3D flow simulation. Battenfeld Extrusionstechnik GmbH – Germany Fax : +49 5731 27 124 Email : welcome@bex.battenfeld.com Website : www.bex.battenfeld.com using CFD-based

High-precision manufacturing of multi-layer pipes

As a response to increasing resin prices and the demand for more functional pipes, Battenfeld Extrusionstechnik, Germany, has developed an innovative side-fed multi- layer die. The die allows the processing of materials with high residence time and temperatures, even at low mass flow rates,

and ensures an accurate wall thickness distribution. In-demand plastic pipe attributes, such as acoustic insulation, oxygen barrier, and special optical, mechanical or thermal properties, can be achieved in multi-layer

products consisting of special materials that fulfil different functions. materials, however, are often highly sensitive to thermal and mechanical stress and, compared with basic materials, require special process parameters. With conventional die concepts, such as spiral mandrel dies, these materials can be processed only with difficulty, if at all. Such

fi The new twin centre sleeves (with break-up plate) from Battenfeld Extrusionstechnik

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J uly /A ugust 2007