Wednesday, July 20, 2016

Offset plate (part 1)

Offset plate (part 1)

Paper Offset Plates:

Mr. Halpern even in the late 1940’s realized that offset would take over the stencil market. He hired Bob Teichner, who had worked for Remington Rand, the typewriter company that had made stencils and paper offset plates. He brought the Remington Rand stencil formula which was based on cellulose acetate, not nitrocellulose. We set up a pilot coater to evaluate it. They were not as good as ours. He gave us a formula for stencil duplicating inks base on derivatives of castor oil made by Hercules, which we manufactured.

He also had a formula for paper offset plates. Addressograph-Multigraph had patented casein coated direct image offset plates. The plate Bob Teichner developed was based on starch carbonate. We installed two coating machines with gas heated drying tunnels, which were built by Pot Devin in the space where the stencil finishing operation had been. The first tunnel was used for applying a ureaformaldehyde base coat on paper bought from Crocker Burbank, a paper mill in Fitchburg, Massachusetts, which I visited several times. The second coater applied the pigmented starch carbonate coating. The time between the two coats was critical. It had to be between two and seven days for the urea formaldehyde resin to cure, but before it became hydrophobic. We started to sell the direct image offset plates in 1950. Our largest customer for these plates was a company in Massachusetts that printed telephone directories. They set type in a proof press and printed it on our plates, which were then run on an offset press.