Citing a trend to move away from single-layer standard pipe toward multilayer pipes with extra functional layers, KraussMaffei Berstorff (Stand 15B27) will use the K show to emphasize its ability to create polypropylene fiber-composite pipe and PP foam core pipe, among other capabilities. Extrusion lines enlisted for such products include single-screw extruders from the 36D Series with multilayer tooling and material-specific calibration and cooling systems. The pipe has several applications, including hot-water supply, where its backers say it has some clear advantages over conventional hot-water pipes. Among these is the fact that hot water passing through the multilayer pipes causes only minimal longitudinal expansion. This dimensional stability makes them easier to install, since plumbers needn't allow for expansion in their choice of connecting fittings. 

In other news at KraussMaffei, the company is eager to talk about changes in its QuickSwitch dimension change-on-the-fly system for pipe extrusion that allows pipe diameter to be altered on a running system. The system was introduced seven years ago [May 2003 MPW pg. 49].

Since its introduction the company has sold about 35 units, mainly for polyethylene pipe extrusion but also a few for PVC. Now the company offers a newly developed adjustable die combined with a 3L-RKW73 pipehead to produce multi-layer pipes. This has the advantage that the melt moves directly in a linear stream from the extruder into the pipehead to generate optimal pressure build-up.

Previous QuickSwitch pipeheads had a movable pin and a fixed die. The new design allows the die to be adjustable while the pin is fixed. This is said to offer cost benefits and processing advantages such as combining the adjustable die with conventional standard pipeheads. This can also simplify retrofitting.