Pa′per Wa′ter-proof′ing Machine′.
A machine for impregnating or surfacing paper with a water-resisting material.
Hudson's process of water-proofing paper passes it through a number of troughs containing chemical agents, by which it is acted upon successively.
Fig. 3543 shows a series of tanks used for this purpose.
a contains a solution of sulphuric acid and water.
To maintain this at a proper temperature,— about 60°,— a tank of ice
b is placed underneath.
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Hudson's paper water-proofing machine |
From the tank
a the roll of paper is fed over a cylinder, passes between a pair of pressing-rollers, and down into tank
c, filled with clear water.
It then goes over another roller, and down into tank
d, filled with dilute ammonia.
It then passes over another roller, is again pressed, and goes through the vat of water
e, where it is again washed.
g contains lime-water, and after the roll of paper has passed through this, and been again washed in
h, it is finally treated with glycerine in the vat
i.
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Paper-coating machine |
A machine for coating paper with tar or asphaltum is shown in
Fig. 3544.
a is a tar vat.
b is a roll of paper, which is fed down into the tar, and is drawn out over the scrapers
d e, and is wound upon the roll
c 
