Unravelling rope manufacturing

Visiting Casar’s facility in Kirkel, in the southwest of Germany towards France and Luxembourg, offers a fascinating tour through the process of manufacturing wire rope, and in particular the range of equipment used. The company combines some of the very latest, cutting-edge technology with machines that were built by the company according to their own design specifications and which are still running perfectly today— and Casar will celebrate its 70th birthday in the coming year.

Pascal Ignor, mechanical engineer and product manager at Casar, talks me through the process.

“When coils of wire arrive, they need to be re-spooled, as the spools they are supplied on are not compatible with our rope manufacturing equipment,” says Ignor. “In 2016 we invested €2.2m in a highspeed spooling centre, featuring eight high-speed spooling machines. They have increased operational speed by 400–600%, even though before we were using 40 machines.”

The new spooling machines incorporate a laser measurement system to check the length of each wire during the spooling process, as well as automatic re-tensioning to maintain the correct tension. Casar keeps a permanent stock of around 2,800t of wire, says Ignor, with various specifications and diameters, increasing in increments from 0.4mm to 4mm.

The wire is typically supplied is three different tensile grades, and can be galvanised or ungalvanised. Special diameters, higher tensile grades and extraordinary wire coatings are also available but the company only buys such material for specific orders, so it is not part of the permanent stock.

All of the incoming material is tested—a small piece of each spool of wire is taken for testing, and the company won’t use any wire until the quality department gives the green light. The department uses a twin labelling system, enabling Casar to trace every single wire inside each rope, to assist with identifying any issues.

The testing department provides an interesting insight into the quality control process, with both manual and digital systems employed. The wires are tested according to the European standard EN 10264, but on a higher quality level. The diameter and the tensile strength are tested digitally and the data is transferred directly to a computer system. The tension and the torsion are tested manually. To measure the quantity of zinc on the rope surface, a chemical method called ‘gaseous volumetric method’ is used.