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.