Output rates have been dramatically increased using a wide-slot die and a post forming device

Battenfeld Extrusion Technology, together with B-Tec of Consandolo, Italy, has developed a new post-forming extrusion line that more than triples the output speed of rain gutter profiles. The line uses a wide slot die to extrude the PVC as a strip, which is then smoothed with a roller calendar and passed while still hot through a post-forming device. This forming device is a simple piece of fibre-reinforced laminate with a cut-out to shape the strip into the gutter profile contour.

Wolfgang Zimmermann, design manager at the Kempen plant, told Prw.com that while post-forming is already an established technique for extruded products such as sidings and cable channels, it has not before been applied to a household rain gutter application. Two extruders with material consumption of 600kg per hour were used to feed the outer UV-protected layer and the inner (top) unprotected PVC layers of the gutter.

The first line of this type, which has been sold to a customer in Poland, was demonstrated at the BEX downstream equipment plant at Kempen, in Germany, running at 17metres per minute. However, BEX believes linear speeds as high as 30metres per minute can be achieved with the post-forming technique. Output would be limited to around 5-6metres per minute with conventional extrusion methods.