196

MODERN PAPER-MAKING

The Dual Press (Figs. 74 and 75), which is now being taken up in this country,
has actually been in use for some years in America.

It consists of three press rolls, two of which may be suction rolls, with a
plain roll in between, as clearly shown in the photograph and drawing.

There is a great saving in space with this arrangement, but there are also
many other advantages claimed by those who are using this design.

The pressure is applied laterally by levers, instead of vertically, and much
greater felt life is being obtained.

ftc. 74.—Duax PKBSS ARRANGEMENT, SHOWING ONE SUCTION ROLL AND Two PLAIN

ROLLS ARRANGED TOGETHER

The third roll can be arranged for suction if necessary

[Wdmsleys

A doctor blade should be made to move from side to side by traversing
gear; the purpose of this is to prevent pencilling or scoring of the roll by
any partkle of grit becoming embedded between the doctor blade and
die roll The doctor is hung on pivots to enable it to be cleaned and
refitted.
Tlae felts' are pure wool fabrics and may be obtained from the makers in
many degrees of fineness and quality. Nevertheless, it is sometimes very
difficult to find a kind that is bodh efficient and economical to run, owing to