NEWSPRINT

271

ing up the remainder of the sheet thickness is governed by the height of the
projecting slice 'lip* above the wire. This slice is being found especially useful
for very free stock.

The Wire Part.—The wire part of a news machine is different from that
of slower-running machines in that there is usually no shake fitted, the section
is removable as a whole to facilitate wire changing, and it has fewer table, or
tube, rolls.

When the stock flows on to the machine wire, drainage of the water com-
mences right away, but only a small proportion is removed by the effect of
gravity alone. Most of the water which is removed before the suction boxes

tW VV

[Millspaugh, Ltd., Sheffield
FIG. 117.—ARRANGEMENT OF MHXSPAUGH DUPLEX VACUUM-FORMING MACHINE WITH STACKED SUCTION PRESS

This machine has no slice, the wires are very short, and the duplex sheet is made hy combining the under sides of the

two webs, thus giving finished paper having two top sides

are reached is withdrawn, by the effect of the contact of the table rolls with the
underside of the wire, and by the suction produced as they revolve rapidly
round. This can be seen by observing what is happening under the wire»
and also to some extent the action is indicated by the appearance of the stock
on top of the wire.
The very large volume of water handled at the wet end of a news machine
makes it necessary for the table rolls to be rather large in diameter. On a
220-inch machine the diameter would be n or 12 inches, while on a 300-inch
machine the diameter is 15 inches. This large size is also needed to prevent
whip at the high speeds at which the table rolls rotate.
Some of the water drained from the stock tends to be flung back on the
underside of the wire by the centrifugal action of the rolls. This can spoil die
formation of the sheet, and in order to prevent the trouble the practice is very
often adopted of fitting baffles between the rolls, especially near the breast
roll. Alternatively it is helpful to space the rolls fairly far apart.