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

USES OF CORKWOOD AND CORK WASTE 19
yards and sheds of cork plants, covering much area and in-
volving considerable capital, for a shortage in raw material
would not only throw men out of work and put the plant into
disuse but would cause the loss of much business through in-
ability to supply the trade with first-grade cork materials, the
other grades always being compelled to await a favorable
market.
For whatever purpose it is to be used, all corkwood upon
reaching the factory is again sorted by highly skilled men
and the original twenty or twenty-five grades are re-classed
into perhaps one hundred and twenty-five or one hundred and
fifty grades, according to quality and thickness. Success in
the "cork business" hinges on the care and skill displayed in
the various sorting operations that are meticulously followed
at every step from the stripping of the bark to the packing
of the finished product for delivery to consumers. So slight
is the difference between many of the grades that the inexperi-
enced eye would detect none whatever, yet the speed with
which this sorting work is skillfully done is often astounding.
The importance of the initial sorting operations is increas-
ing as the uses of cork increase; because various grades can
now be used for so many different things, without longer being
thought of as a by-product. In order that the full value be
obtained from all corkwood, the sorter must have a thorough
understanding of the uses to which the many grades of the
material may be put, and for that reason he is now thought
of as an expert and a valuable member of the manufacturing
organization.
13,—<strong>Cork</strong> Stoppers.—No account of the uses of corkwood
and the utilization of cork waste can be given without at least
a short description of the modern processes followed in manu-
facturing cork stoppers, for the waste from the production of
these stoppers has long been an appreciable percentage of the
total cork waste annually made available for utilization,
although this percentage is now decreasing.
The sorted slabs of corkwood are first placed in a steam
box, which process increases its flexibility greatly, its bulk
slightly, and otherwise prepares it for the mechanical opera-
tions that rapidly follow. First, the steamed corkwood is
;