Düsseldorf, October 09, 2017

Advanced design for scrap chopper knife heads

Twinblade scrap chopper knife heads

Side trimmers in strip processing lines trim endless steel strip to a defined width with high accuracy. Thus, at first an also endless seam is trimmed off both strip edges. In order to enable easy handling of the high quality scrap, the scrap chopper cuts the seam into short pieces. The scrap chopper is an integral part of SMS group’s ASC (Automatic Scrap Chopper) side trimmers.

The product management of the divisions strip processing lines and technical service have jointly developed an advanced design for the proven SMS group scrap chopper knife heads. The goal is a substantial handling and machining time reduction for re-sharpening scrap chopper knives.

The improved knife heads contain knives with two instead of only one cutting edge. The knife edge not in use is protected by the knife clamping piece. When one edge is worn, the knife can be rotated by 180 degrees and refitted immediately.

The knives can quickly be re-ground separately on a flatbed grinding machine. Thus, a knife reconditioning time reduction of up to 90% is possible. Ronald Genßler, Product Manager Technical Service, at SMS group

In contrast to the conventional knife head concept, knife replacement or knife rotation requires no head dismounting. The Twinblade knife head also requires no shimming for enabling the re-sharpening of worn knives. “The knives can quickly be re-ground separately on a flatbed grinding machine. Thus, a knife reconditioning time reduction of up to 90% is possible”, says Ronald Genßler, Productmanager Technical Service, at SMS group.

Twinblade knife heads will be made available in the diameters 250 mm (four knives) and 350 mm (six knives). The modified outer geometry also facilitates the fabrication. The identical fitting geometry enables installation at all ASC scrap choppers produced so far. Retrofitting Twinblade knife heads only requires a minor machining of the scrap guiding channels between side trimmer (circular knives) and scrap chopper.

The first test set comprises four complete 250 mm knife heads with spare knives. It was developed in close cooperation with WUPPERMANN Moerdijk (NL). After the order placement in August 2017, its installation, commissioning and test run are now planned for end of 2017 in Moerdijk.