Canadian Forestry Journal, April, ip20. 



i6i 



suction boxes with perforated tops, 

 over which the wire travels. Before 

 leaving the Avire the paper passes be- 

 tween a pair of rollers, called "couch 

 rolls" which press the fibres together 

 and squeeze out more water. In some 

 machines, a suction roll is used at 

 this point. It is this roll or the lower 

 •one of the pair, which drives the wire. 

 The paper is now made, so far as 

 the interweaving of the fibres is con- 

 cerned, and it contains about 90 per 

 cent, of moisture. In order to im- 

 prove the firmness, texture and finish 

 and to remove more water, the sheet 

 is passed through several pairs of 

 "press" rolls, carried by fine woollen 

 felts. 



Evaporating the Water, 



Most of the water is removed by 

 evaporation, the paper passing over 

 steam-heated drums called "dryers." 

 This, of course, is expensive, so as 

 much water as possible is removed l:iy 

 mechanical means, although the best 

 that can be accomplished is to deliver 

 a sheet about 3; ])er cent, dry to the 

 dryers. As the finished paper will 

 contain from seven to ten per cent, of 

 moisture, nearly two tons of water 

 must be evaporated. 



Smoothing the Surface. 



The finishing, or smoothing of the 

 surface, is done by the part of the 

 machine called the calender, a stack 

 of nine to thirteen special steel rolls. 

 The friction and weight of the rolls 

 on the paper as it winds down 

 through the stack really "irons" out 

 the roughness, presses down the friz- 

 zy fibres and gives a surface flat 

 enough to take the ink properly from 

 type and cuts in the press room. The 

 endless sheet is then wound on reels 

 nnd from these, in turn, is passed 

 through a set of rotary shears that 

 divide it into strips of the proper 

 widtli, and these strips are wound on 



cojes in rolls of the correct width and 

 diameter, for the newspaper presses. 

 Any breaks are carefully joined and 

 a "flag" or signal is placed in the roll 

 at that point to warn the pressman 

 of some defect in the roll. Wrapping 

 the roll is comparatively simple, yet 

 this and the loading into the cars 

 must be conscientiously and carefully 

 done if the paper is to arrive in good 

 condition. 



Some r.ewspapers require paper in 

 sheets. To accommodate them the 

 mill must have another department, 

 where the paper from the rolls is 

 passed through a cu*"ter, whose re- 

 volving knife cuts the strip into pieces 

 the desired length. The sheets are 

 then counted by reams and pack d in 

 l^undles. 



For special effects an extra high 

 finish is sometimes required. To get 

 this, the strips are passed through 

 the super-calender, a calender stack 

 made up of alternate rolls of steel and 

 compressed paper or cotton. A very 

 high luster can thus be obtained, the 

 paper often going through sew ral 

 times. The product is called "super 

 news" and is largely used for pic- 

 torial sections of the paper. 



When it is necessary to produce a 

 special color or some other effect re- 

 quiring a fundamental treatment of 

 the stock, the necessary materials, 

 color, sizing, clay, etc.. are added in 

 the mixer or the beater. 



For other grades of paper, the op- 

 eration of the paper machine is prac- 

 tically the same as described, but 

 such papers usually require special 

 additional processes for the prepara- 

 tion of the raw material and the fin- 

 ishing of the paper. The selection of 

 stock is of greatest importance, and 

 more care is required at most points 

 in the process. 



? Forest fires drive out population, j 

 T There are no jobs in dead | 

 I forests. t 



• 



I Canada has not one acre of tim- * 

 I ber to throw away. i 



