Saturday, November 12, 2016

Presensitized Printing plate 2

Presensitized Printing plate 2                  By Mr. Bob Gumbinner

The production process was to sheet and cut 3S aluminum to the proper size for the press on which the plates were mounted and to punch the heading or two holes on top and bottom. These were then mounted on racks with stainless steel springs--30 for duplicator size plates. These racks were then moved by hand through a series of tanks: a sodium phosphate etch, rinse, a 3% each of sulfuric, chromic, and phosphoric acids, rinse; a 160oF 3% solution of sodium silicate, rinse. The plates were removed from the racks and fed first through a distilled water spray and squeeze rollers, a drying tunnel; then through squeeze rollers on which 2% solution of the formaldehyde paradiazodiphenylamine condensation product with ¼ %of citric acid and 0.1% saponin was sprayed. The plates were carried on V belts through the drying tunnels which were heated with coated infra red bulbs. The plates were inspected and wrapped in paper to which was laminated black polyethylene coated aluminum. They were then packed in cartons. We were quickly successful in selling these plates, mostly through dealers but we also set up a number of sales offices to sell directly and service the dealers.

On July 26, 1955, a patent was issued to Jewett and Case which was assigned to 3M. A few weeks later 3M sued A B Dick and Alumolith for patent infringement. Three months later, 3M brought suits against a printer in Cleveland, who was using our plates, our dealer in Wichita, Kansas and three of our salesmen in our Chicago office. Because of this suit, very few dealers continued to sell Polychrome plates. Therefore, we established more direct sales offices. Our patent attorneys, Ostrolenk and Faber, assured us that the patent was not valid. However they were not a match for the 3M attorneys. They made the mistake of controlling the case against the dealer in Kansas which 3M won. When the case went to court in Chicago, we hired Don Spille to represent us. However, the Judge ruled in December 1961 that we were bound by the Texas decision. By that time we were no longer using the 3M silicate process but my zirconium hexafluoride process. Both the patent Court of Appeals and the Kansas court had ruled that the Jewett patent could not be broadened to cover any aluminum treatment.