The Science of Doctor Blades

Furr and Benton Graphics (Trenton, N.J.) Vice President David Ritz, advise using strong magnets and ink filters in the inking system to capture blade wear particles. During a case study conducted by HarperScientific®, Furr was surprised by the drastic affect a magnet had on an enclosed chamber system. Water was simulated as ink pumping out of a five gallon bucket, and "within an hour of run time, the water in the bucket had turned completely gray," Furr said. "We then took a rare earth magnet and installed it in the bucket. Within a matter of minutes, the water turned back to its clear form. What this proved was that if a magnet is not being used within an inking system, the inks, plates, substrate, and the anilox roll will be effected." Rich Coleman, vice president of Flexo Inking Technology (Sellersville, Pa.), agrees. "Every enclosed chamber we manufacture today addresses each one of those problems. We control the pressure, not the operator. We now use less than 12 lbs. of pressure, and maintain it as the blade wears. Combined with blade clamping that ensures that even thin blades are held straight, scoring is preventable."