What are Wiper Blocks?

Wiper blocks, also referred to as wiping pads are used in the steel wire “continuous hot-dip” galvanization process. Steel wires are immersed in molten zinc to render them corrosion resistant. Small amounts of aluminium are also sometimes added. Galvanized wires are being used in a wide range of industries and manufacturing applications.

The continuous hot-dip process requires to wipe excess molten zinc and leave a smooth, bright coating onto ASTM Class I or III wires. As they exit the galvanizer, each wire passes longitudinally between a set of rectangular pads called wiper blocks. A screw mechanism compresses each set of wiper blocks together to tightly wipe the wire before it enters the quench tubes designed to cool off the wire.

Wiper blocks are available in a variety of sizes to suit various wiping systems and wire diameters. They are manufactured from high temperature resistant materials known for their abrasion resistance and moulded into rectangular pads, rolled into a thick block saturated with rubber or from spun yarns braided around a core filler and impregnated with high temperature lubricants. Some blocks are pre-moulded with a groove so larger caliber wires can benefit from an even wiping pressure all around.

Quality and pricing vary greatly on the market, but so does the production efficiency. Wiper blocks represent a small part of the overall production costs, but sturdy wiper blocks, engineered with well-established know-how, will result in increased wire quality, better finish and longer production runs before requiring to rotate or replace the blocks.

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