New pipehead cuts material costs for foamcore pipe production

Raw material costs account for up to 80 percent of the total manufacturing cost for plastic pipe. With rising material prices, this share is inevitably set to increase. This situation has been a strong motivation for KraussMaffei Berstorff to develop machines and systems for pipe extrusion that will counteract the trend by minimizing material consumption. The most recent example is the new, large KM 3 LRK 43 multilayer pipehead. It is used to produce PVC foamcore pipe in the diameter range between 200 and 500 mm with wall thicknesses between 3.9 and 14.6 mm. Maximum output is 1500 kg/h.

Foaming reduces the density of the pipe core layer to as low as 0.6 g/cm3. This means that, compared with comparable compact PVC pipe, the density of the whole composite pipe can reduced by as much as 30%. It’s possible to produce three-layer pipe – with a foam core and compact inner and outer layers – with a total density of under 1.0 g/cm3.

One of the new large pipeheads was recently supplied to a customer in Russia together with two KraussMaffei Berstorff KMD 90-36/R extruders. One of the two extruders produces the compact inner and outer layers, while the other produces the foamed core layer. The pipehead can also be operated with three extruders. In this configuration, the inner and outer layers can be made of different materials or in different colours.

The new pipehead for large pipe diameters completes KraussMaffei Berstorff’s range of PVC multilayer pipeheads at the upper end of the diameter range. Together, the three KraussMaffei Berstorff pipeheads – the KM 3 LRK 41, KM 3 LRK 42 and the new KM 3 LRK 43 – cover the diameter range from 32 to 500 mm. Since this multilayer pipehead range was launched, over 50 have been shipped.

KraussMaffei Berstorff foamcore pipeheads are engineered for very tight layer thickness distribution and very low densities. This maximizes their potential for cutting material costs. Once the three layers have joined up in the pipehead, there are no crosspieces to break the flow of the melt. The pressure-optimized design of the flow paths makes it possible to process cost-competitive formulations without problems.

The pipehead is extremely easy to operate during production start-up and stoppage. The dieset can be changed without tilting the pipehead in the mounting carriage. The pipehead can be tilted 90° in the carriage to simplify complete disassembly or to clean individual components.