+49 (0) 211 50 66 83 - 0

DON’T SPOIL THE COIL!

Significantly less laminar imperfections thanks to CENTRICORE 4.

CENTRICORE 4 spools offer numerous benefits, one of the main being that the enormous mechanical and thermal stresses applied during coil handling do not lead to any permanent deformations. This reduces the reject rate caused by laminar imperfections, such as creases and overlaps of the metal foil to below one per cent, and also eliminates the need for expensive repairs. Consequently, these spools have a significantly longer lifecycle than conventional ones. Currently, more than 7,000 CENTRICORE 4 spools are in use worldwide.


Get in contact with us
Learn more about CENTRICORE 4

CENTRICORE 4 SPOOLS:
BROUGHT TO YOU BY BRONCKHORST

Sophisticated applications

CENTRICORE is a group of materials used to make spools in a centrifugal casting process. Spools, also known as winding spools or occasionally rolling mill sleeves, are thick-walled tubes used for winding thin aluminium strips, aluminium foil or stainless steel thin sheet metal for transportation in the manufacturing process and storage. The wound metal is called a coil.

If the coil requires thermal treatment in an oven prior to the next rolling or winding process, the spool has to withstand enormous mechanical and thermal stress. Otherwise permanent distortions may occur that would affect every consequent coiling process with that spool.

Spools endure heavy stress

When CENTRICORE 4 was developed for spools for winding thin aluminium strips and aluminium foil in the 1980s, it was necessary to find out the stress levels they would need to withstand from the belt tension and coil weight on the one hand, and from the 24-hour oven heat of around 480° C, on the other.

The St-52 or nodular cast iron (GGG) spools in use up to then were problematic, with many cases of permanent deformation, causing damage to the coils within a short time on account of the high mechanical and thermal stresses. It was not uncommon for the middle part of a spool to contract after just a few months because the materials used were unable to withstand the thermal expansion of the wound metal. As a result, the beginning of every wound metal coil would crease and overlap, making it unfit for use.

In some cases, up to eight per cent of a coil was then reject material, and the deformations had to be mechanically corrected at considerate expense. For this reason, the former spools were made with very thick walls to ensure sufficient stability after repeated mechanical reworking.

Benefits of CENTRICORE 4

CENTRICORE 4 was developed and optimised in a series of complex tests. It is a Cr-Mo-V (chromium molybdenum vanadium) alloy steel that is manufactured in a centrifugal casting process. A special chemical analysis with ensuing thermal treatment guarantees the necessary mechanical properties.

The spool geometry was computed with a customised application to achieve optimal wall thickness. The inner diameter was not changed so as to emulate the existing technical circumstances of the winding and rolling equipment.

In the final manufacturing stage, each CENTRICORE 4 spool is processed entirely mechanically according to supplied drawings, checked for internal and external imperfections, and the unbalance is measured dynamically. This is the only way to ensure the high quality and long life cycle of our spools - for the multiple benefit of our customers: creases and overlaps of the thin aluminium strips, aluminium foil or the stainless steel thin sheet metal are reduced to less than one percent, cost-intensive repairs of major spool deformations are now a thing of the past.

Small wonder, then, that more than 7,000 CENTRICORE 4 spools are in everyday use across the entire world.

Please visit our websites for further information about our range of services.
Gain an insight into our capabilities and many of the components we have created.
Gather inspiration!
We look forward to receiving your requests.