Angled Pad Wiping (Commercial Coatings)

The QED Pad Wiping Systems are designed to wipe excess zinc and to apply a smooth bright coating to the wires. As they exit the galvanizer, each wire passes longitudinally between a set of two rectangular pads. Individual screw clamping mechanisms compress each set of pads together to tightly wipe the wire. The wires exit the back side of the pads directly into individual quench tubes that cool the wires to ambient temperature.

An axial clamping mechanism presses the quench tube into the back face of the pad set to provide a water tight seal. Fresh water is supplied to the front end of each quench tube through a flexible hose and flow control valve from a common supply header. The water exits the back end of the tube with the wire and falls into a special catch basin integrated into the structure. The system is designed to permit easy access for operation and wire threading.

The Pad Wiping Systems are precision made of laser-cut stainless steel sections and are custom designed to suit the wire diameters, wire pitch and galvanizer exit configuration.

Stainless Steel Construction

QED’s Angled Pad Wiping Systems are optimized for smaller production galvanizing lines requiring only commercial zinc coating on the wires. The wires exit the galvanizer at an angle of about 25° from the horizontal into the pad set and quench tube. A rapid quench of cool water ensures a bright zinc surface. The wires then generally enter an angled wax tank for a final protective coating.

Commercial Coating Weights

The zinc coating weight obtained in our pad wiping systems is a function of several factors including; wire diameter, wire tensile, pad pressure, pad type (softness), immersion time, bath temperature and wire chemistry (silicone content). However within a wire diameter range of 2mm to 4mm and with constant pad pressure, the primary variable is immersion time and coating weight can be estimated by the graph.

Zinc coating weights are about 20% to 40% pure zinc with the balance zinc-iron alloy layers.

With a modern high speed galvanizing line a typical immersion time would be 6 seconds (DV=150, 2.5mm Ø, 6m bath length).

Alloy layer coatings can be decreased by the practice of “short dipping” in the galvanizing bath.