WHY SHOULD YOU PREFER MECHANICAL DESCALING OVER CHEMICAL PICKLING FOR WIRE ROD PREPARATION?

Wire rod preparation is a crucial step in achieving high-quality wire products and ensuring efficient production.??

The steel wire rod is coated with an oxide scale layer that must be removed before the drawing process. If this layer is not removed, it can result in the embedding of hard oxides into the wire surface, leading to a lower surface quality.??

Having an effective wire rod preparation line in place before the drawing line ensures that you have a superior wire product and higher production speeds.?

Two of the most common rod treatment methods are mechanical descaling and chemical pickling. Chemical pickling systems consist of the passage of the rod inside acid, which is almost sulfuric acid or hydrochloric acid.??

Mechanical Descaling uses mechanical means to remove surface contaminants and it is increasingly becoming the preferred method for wire rod preparation.?

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MECHANICAL DESCALING: THE PROCESS?

Back in the early 2000s, mechanical descaling and electrolytic phosphating processes were considered disruptive technologies for low carbon rods due to their particular qualities. However, for other types of wires, the easiest and most commonly used method of descaling has been acid pickling using either HCl or H2SO4 technology. Despite the high efficiency and ease of operation of HCl, its use has had a significant ecological impact, especially in areas with poor wastewater treatment facilities.?

However, in response to growing ecological concerns in Europe and the USA, they are moving up and challenging the incumbents for higher-value products such as Bead Wire, Steel Cord, Spring and Roping Wire, Induction and Oil Tempered Wire, MIG-TIG Welding Wires, PC Wire, and Strand, among others.??

The process for this application can be set up in-line with the drawing process or off-line, depending on factors such as space availability, handling procedures, and labour costs.?

In the mechanical descaling, the wire passes through rollers, and as the calamine bends, it breaks and detaches the layer of oxide. After that, the wire passes through a double head sand belt cleaner to reach the desired rod surface finishing.?

As an alternative to double head sand belt cleaner, a wire brush system can be used to remove the remaining thin layer of calamine from the wire. The brush rotates around the wire, allowing it to clean the wire rod completely and remove any remaining calamine. This system can remove some rust as well, as long as it has not penetrated too deeply into the wire's surface.?

Then, the rod is washed under high-pressure water, possibly subjected to electrolytic phosphating and salted. Electro-Phosphating is used to increase the drawability or to protect the wire from oxidation.?

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FOUR REASONS TO CHOOSE MECHANICAL DESCALING?

Mechanical descaling and chemical pickling are two common methods used for treating rods in industrial settings. While both methods can be effective, there are several reasons why mechanical descaling may be a better choice for rod treatment:?

• Environmentally friendly: chemical pickling systems use strong acids, whereas mechanical descaling does not. In addition, stricter pollution regulations are incentivizing replacing chemical pickling with greener solutions.?

• Lower OPEX and CAPEX: Mechanical descaling is less expensive than chemical pickling, due to the higher cost of the equipment, chemicals, and disposal of waste materials of chemical pickling.?
• Lower energy consumption.?
• Increased productivity due to an optimized wire rod pre-processing with the consequent increase of the drawing speed?

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MFL GROUP SOLUTIONS FOR MECHANICAL DESCALING??

MFL is now capable of providing the appropriate combination of machines and tools for every product (low carbon, high carbon), ensuring efficient and effective scale removal and leaving the wire surface suitable for downstream drawing processes and meeting final product requirements.?

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In light of this, MFL has in its portfolio also the electro-phosphating line by Coseco in order to improve wire drawability and protect against corrosion. Pre-stressed concrete wire and strand, for example, require such a coating.

Mario Frigerio Draweasy is one of the most efficient, economical, and ecological solutions for rod treatment. It not only increases productivity, but also achieves higher quality standards than other mechanical descaling equipment on the market.?

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Contact us to know more about our green solutions https://bit.ly/3eFfSby