I98 MODERN PAPER-MAKING

Consequently, the felt will get 'dirty' in a shorter time and require more
drastic cleaning. In this case we must reckon the life of the felt on die quantity
of water extracted as well as on the weight of paper made and the time ran.
Conversely, with free beaten stuff and a heavier substance that can be well
couched, we may easily make ten times the weight of paper without being
checked by felt-crushing. Then there is the question of felt-cleaning. The
simplest plan is to run a felt until it gets dirty and replace it with a clean one.
The felt is then washed on a felt-washer and put back again in turn. The chief
objection to this system is the waste of time changing felts* Another plan is

Be. 76.—Vicsm FELT CONDITIONER WITH Two SHOES [Vtekerys
to shut the machine and clean the felt without taking it of£ This also is time-
wasting and really only saves labour in changing felts, since this latter operation
could be done almost as quickly as washing on the machine.
Felt-washers operating on the machine as the paper is being made offer a
solution of the problem, but are open to the objection that the continual washing
wears out the felt as much or more than the legitimate work does. The
usual felt-washing apparatus on the machine consists of a series of sprays
impiugmg on both sides of the felt, a pair of rubber-covered rolls to press
out d&e ifirty water, and a small suction box to dry the felt again ready for
die paper.
Tflbe Vicbsy felt conditioner (Bg. 76) is the best attempt to solve the felt
waiting'problem, and is now in general use. It may be made very drastic in
ite action and requires skMil aad cauoefcl manipulation, since, of course, any