With rising material and energy costs and high functionality standards for pipes, multi-layer pipes are more and more in demand. Optimal die technology is required to produce such pipes in top quality. Battenfeld Extrusionstechnik GmbH, Bad Oeynhausen is the only machine manufacturer worldwide offering a special modular system for multi-layer dies designed to allow custom-made adaptation to each individual product.

In the production of multi-layer pipes, the correct choice of die is a vital factor in end product quality. Therefore Battenfeld Extrusionstechnik first calculates the optimal die geometry for every application by means of a specially developed, computer-aided simulation program. With the help of its modular system, which includes all known melt distribution systems for pipe extrusion such as mandrel support, spiral mandrel, lattice basket und side-fed dies, this geometry is then realized. This course of action ensures that every die is optimally laid out for the specific requirements of the individual product, utilizing the various characteristics of the different melt distribution concepts to best advantage.

Battenfeld specially designed the PO 800-2 VSI, its largest multi-layer die so far, for HDPE pipes with a protective PP layer on the outside and diameters of up to 800 mm. This particular die is a VSI sheathing die combined with a PO 800 VSI for mono-layer pipes. While a spiral mandrel die is used for the outer layer, the VSI component forms the middle layer. The complete separation of melt distribution units with this type of die is an ideal process technology feature in respect of processing temperatures and melt distribution times.