The drying cylinders are hollow and heated by steam, their
temperature being regulated according to requirements. These driers,
made from iron or steel, are usually from three to four feet in diameter
and vary in length according to the width of the machine. There are from
twelve to fifty of these cylinders, their number depending upon the
character and weight of the paper to be produced, very heavy sheets
requiring many more drying cylinders than sheets of lighter weight.
Strange, almost phenomenal, conditions come about in the transformation
from filmy pulp to finished paper. A sheet which, though formed, is at
the first press-roll too fragile to carry its own weight, becomes
possessed of a final strength and power that is almost incredible. The
myriad of minute fibers composing the sheet, upon drying uniformly,
possesses great aggregate strength. A sheet of paper yields readily to
tearing, but the same sheet, when a perfectly even tension is applied,
will demonstrate that it is possessed of wonderful resisting power.
Pages:
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123