Nature Bulletin No. 477   nJanuary 19, 1957
Forest Preserve District of Cook County
Daniel Ryan, President
Roberts Mann, Conservation Editor
David H. Thompson, Senior Naturalist

****:SAWDUST AND CHIPS

One of our greatest national assets, one of our most precious natural 
resources is wood.  It plays an important part in the daily life of every 
American.  Each year we are finding new uses for wood and wood 
products, such as paper, derived from it.  Trees grow slowly and there is 
danger that the demand for wood may exceed the supply.  Fortunately, 
scientists and ingenious manufacturers have discovered ways to utilize 
even the sawdust, chips, shavings, tree tops and other wood residues 
formerly wasted.

At the beginning of this century our forests and woodlands were 
disappearing rapidly because of destruction by fires, wasteful logging 
and the increasing demand for lumber and wood products.  We became 
alarmed and, since 1904, have been diligently preaching and teaching 
the vital need for protecting our timberlands and using them wisely.  
But, until recently, more than half of every tree cut was wasted.

Logging operations left the tops, branches and culls in a jackstraw 
jumble of "slash" which became a fire hazard.  Sawmills produced large 
piles of sawdust, slabs, edgings and shavings -- 15 percent of every log 
went into sawdust.  Some of those residues were used for fuel to 
produce power to operate the mills.  In large well-operated plants the 
rest was consumed in huge black incinerators that burned day and night.  
At small temporary mills the sawdust and "left-overs" were left to rot.

There used to be a few minor uses for sawdust.  Meat markets -- which 
were called "butcher shops" -- and many taverns -- known as "saloons" 
-- covered their floors with a fresh layer of sawdust every morning.  In 
Chicago, big sloping-sided wagons used to rumble around town, even in 
the Loop, delivering sawdust from the mills along the South Branch of 
the river, near Ashland Avenue  Sawdust was packed between the 
double walls of icehouses, as insulation, and between the cakes of ice 
stored in them.  On farms we strewed sawdust in muddy barnyards; and 
used small amounts, sprinkled with "coal oil", to start a fire in a stove.  
Otherwise, except for stuffing rag dolls, it was considered useless.

Times have changed.  Farmers and gardeners are being taught to use 
sawdust and chips -- chips are odds and ends of wood ground up in a 
machine -- as a source of humus for improving soils; as mulch in 
orchards, berry patches and gardens; as bedding for livestock; and as 
aggregated in concrete for floors and low walls.  They are being molded 
by tremendous pressure into "logs" for fireplaces -- sometimes with 
chemicals to produce variously colored flames.

Wood residues have become so valuable that most mills dispose of 
them for cash and buy coal or oil for fuel!  Tacoma, Washington, uses 
sawdust from mills around Puget Sound as fuel for its central heating 
plant.  Sawdust and chips are being combined with phenolic resins to 
form cheap plastics such as those used to make fountain pens and 
telephone receivers; they make the "wood flour" which is the filler in 
linoleum; they are used to make wallboard and hardwood panels -- such 
as Masonite -- of many types for many purposes.

Wood residues are now used extensively in the manufacture of 
industrial (ethyl) alcohol, adhesives, wood molasses used in cattle feed, 
synthetic yeast and -- believe it or not -- vanilla flavoring for ice cream.  
Portable machines are being used after logging operations -- and even 
in tracts cut years ago -- to convert the "slash" into chips for paper pulp.

Until some wizard like Luther Burbank produces a square tree, there 
will always be wood wastes but we are learning how to use them.