Barking Wood by Machinery 



The logs of wood are made to rub against each 

 other and scrape the bark off automatically 



WOOD barking today is not what it 

 used to be — a hand process carried 

 out with long sharp knives. One 

 or two hollow steel drums are all that 

 are now seen in the modern barking mill, — 

 drums that remove the bark from many 

 tree trunks at one time. 



Perhaps a dozen huge trees are cut up 

 into a thousand pieces. These are fed into 

 one end of the horizontal, rotating drums. 

 The angle irons, which make up the steel 

 framework, grip the edges of the logs, 

 tumbling them about so that they rub 

 against one another. The bottom of the 

 drum is immersed in a tank of water, so 

 that the bark is soaked and easily peeled 

 off. Fresh logs fed into the drum on con- 

 veyors push the barked logs on to dis- 

 charge-conveyors at the opposite end of 

 the drum. 



The con- 

 struction of 

 this barking 

 drum is as in- 

 genious as is 

 its principle. 

 Since j t 

 would not do 

 to immerse 

 the bearings 

 of the drum 

 in the water, 

 the drum is 

 suspended on 

 endless 

 chains which 

 run over pul- 

 leys mounted 

 1 1 { . , The revolving drum which 



high and i ogs peel off ^^ own bark 



dry" on the top of the barking machine 

 structure. 



There is little about the operation that 

 requires attention. In fact, one operator 

 now takes the place of nine skilled whittlers. 

 Altogether, the result in a fair-sized mill 

 which turns out six or seven hundred cords 

 of barked wood in a day, is a saving over 

 the hand method of about three hundred 

 thousand dollars a year. 



Strangely enough, though theory would 

 seem to indicate that sharp points mounted 

 radially in the inside of the drum would 

 be more efficient than blunt angle irons, 

 such points are not the choice of experience. 

 While these points would peel off the bark 

 in considerably less time than the irons do, 

 they would also dig into the "flesh" of 

 the wood. The resulting saving in time 



would be 

 more than 

 offset by the 

 decrease in 

 the commer- 

 cial value of 

 the wood. 

 For this rea- 

 son, it has 

 been found 

 best not even 

 to grind 

 down the 

 edges of the 

 angle irons. 

 As a result 

 the wood 

 comes out 



makes a thousand or more - . 



It is operated by one man bruise. 



BarK 

 scrapers 



'conveyor 



1 Barbed conveyor 

 to boiler room 



Perforated plate 



Diagram show- 

 ing the principle 

 and operation of 

 the wood-bark- 

 ing machine. A 

 dozen huge trees 

 cut up into a 

 thousand or 

 more pieces may- 

 be fed into the 

 drum at one 

 time, tumbled 

 about and 

 soaked in water 

 and finally dis- 

 charged clean 



885 



