Sawdust and Chips
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
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.
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Update: June 2012