in Vol. 17 - January Issue - Year 2016
Descaling Wire And Rod In High-Speed Drawing Lines
FL blast machine for wire and rod
Wheelabrator Group is a global provider of surface preparation and finishing solutions. Committed to offering the broadest array of technologies, products, replacement parts, services and technical expertise, the Wheelabrator Group works closely with customers to deliver the best solutions for their specific requirements. The company's strategically located and electronically linked offices allow Wheelabrator Group to provide unrivalled customer service and support worldwide.
Steeltec Group, a Schmolz + Bickenbach Group company, is one of the leading producers of special steels in Europe, with 620 employees and manufacturing locations in Denmark, Germany, Sweden, Switzerland and Turkey. At its two sites in Emmenbrücke, Switzerland, the company draws wire rod and bar stock into bright steel rods.
Originally Steeltec used chemical descaling to clean the wire rod and bars before drawing. They installed their first high-performance single-strand shot blast machines in the 1970s, and over time, mechanical descaling using Wheelabrator's shot blast machines has gradually replaced chemical descaling (in immersion baths).
In 2008, the last pickling bath was decommissioned in Emmenbrücke. All high-speed drawing lines at the two sites now feature an integrated Wheelabrator FL shot blast machine, spanning several generations of the tried and tested FL-concept.
The FL range (F from the French word 'fil' - wire' - and L from 'longitudinal') has been treating wire or rod-shaped workpieces for decades. FL machines are designed to focus the blast media onto narrow workpieces using guide plates, which can be adjusted to suit individual workpiece diameters.
The latest blast machine to join the fleet at Steeltec is an FL-4-37/55, which has been integrated into the most powerful drawing line on site. Due to its high blast power and new blast wheel arrangement, the machine can keep up with highest drawing speeds, even when processing demanding new materials.
For the first time, this latest machine adjusts guide plates automatically to the correct wire diameter, making the overall drawing line more efficient.
The three generations of FL machines currently in operation at Steeltec go back to 1970, starting with a WFL-383. A second WFL-383 followed in 1972. A WFL-3-37/55 was installed in 1987 and has since been replaced with the next-generation model, a WFL-4-37/55.
The biggest change in descaling operations in Emmenbrücke to date came in 2008, when several FL-3-22(30)/38 were commissioned at once, bringing to an end the era of chemical descaling at Steeltec.
Andreas Sieber, Head of Operations, Plant 1, at Steeltec: "The transition from chemical treatment to mechanical descaling had a range of positive effects on operations here in Emmenbrücke. In addition to much more straightforward waste disposal, we've also noticed the wire surface is now much better prepared for the drawing process. Depending on blast media type and size, the blast process creates little pockets on the surface, which improves adhesion and distribution of the drawing oil. This is incredibly important in order to achieve the desired drawing quality and to extend the life of drawing dies. Compared to immersion baths, blast machines also take up less room and fit snugly into the drawing line."
Depending on drawing speed, wire or rod diameter, material and desired surface cleanliness, FL machines can be equipped with three, four or six blast wheel units with a range of motor capacities. The machines are slotted into the line ahead of the drawing machines and fetch relevant settings and parameters from the latter.
Dirk Meyer, Project Engineer, Plant 1: "Over the years, the FL machines have proven their reliability, sturdiness and, not least, their high performance. We continuously modernise, renew and upgrade our drawing technology and know that there'll always be a Wheelabrator machine that can keep up with latest requirements."
More than 600 FL blast machines have been manufactured to date and are in operation in wire and rod production around the world.
DISA Industrie AG (Wheelabrator Group)
8184 Bachenbülach, Switzerland
Tel. +41.44.815 4000
Fax +41.44.815 4001