Cork insulation; a complete illustrated textbook on cork insulation ...

EXTENT OF CORK INDUSTRY 41
Africa much is being done by France and Spain to open up
that enormous area of virgin cork forests as a very appreciable
future source of supply,
29.—Changing Demands,—The growth of "prohibition"
throughout the world and the increasing substitution of
"Crown" caps and screw closures for cork stoppers has effected
a material decrease in the total quantity of corkwood
required for use in connection with bottles containing liquids.
The use of granulated cork for the packing of glass and
fruit is decreasing in favor of certain very soft woods. The
world's demand for corkwood for miscellaneous purposes,
such as life preservers, floats, buoys, etc., probably has not
changed a great deal in many years and probably will not
change much in the years to come. The demand for cork
waste, however, for cork <strong>insulation</strong> has increased irregularly
but slowly and certainl}^ ever since pure corkboard <strong>insulation</strong>
was first made some thirty-four years ago, the industry get-
ting its first important impetus when the basic pure cork
<strong>insulation</strong> patents expired, and its second important impetus
in 1925 when corkboard began to be used in large quantities
as a recognized essential <strong>insulation</strong> for electric household
refrigerators and standard <strong>insulation</strong> for industrial roof slabs.
At one time the breweries utilized about two-thirds of all
cork <strong>insulation</strong> that was produced. Then ice, ice cream and
cold storage plants replaced the breweries as the large consumers
of cork <strong>insulation</strong>. The mechanically-cooled corkinsulated
ice cream cabinet is replacing the ice plant as an
adjunct to the ice cream factory, the cork-insulated mechanically-cooled
commercial and household refrigerators are making
inroads on the use of ice, and thus it will be observed
that as new applications are made others are slightly reduced,
so that the world's urgent need for cork <strong>insulation</strong>, that is,
for use with cold storage temperatures where cork <strong>insulation</strong>
is now essential, has a habit of slowly increasing with the
growth of population and with the increasing per capita use
of refrigeration in the preservation of food. A great propor-
tion of all foodstuffs is today preserved by cooling, one place
or another, by ice or mechanical refrigeration, and cork in-
sulation is an essential item of all cold storage equipment.