The cork industry in Portugal
by J. L. CALHEIROS E
MENESES, President, Junta Nacional da Cortiça, Portugal
Portugal produces about half the world output
of commercial cork, and its exports over recent years have accounted for around
70 percent of world trade.
The cork oak (Quercus suber L.) finds its most suitable habitat in the western Mediterranean. An abundant and evenly distributed rainfall, short summer dry periods tempered by atmospheric humidity, very mild winters, clear skies and plenty of sunshine, very permeable, moist and deep siliceous soils -- these are the ideal conditions for the economic cultivation of the species. Such conditions are in fact found only in the Mediterranean zone, and, more particularly along the Atlantic shore.
Production
Portugal
is a major cork-grower; in fact, nearly one-third of the total cork oak area,
estimated at 2,150,000 hectares (5.3 million acres) is in Portugal, which
produces approximately half the cork harvested annually in the world (about
310,000 tons). Cork oak stands extend throughout the country although the
intensity of production and quality of the cork vary in the different producing
zones. The species, which covers approximately 8 percent of the total area of Portugal and
constitutes 28 percent of its forests, grows best in the central and
southern parts of the country where the largest stands supplying the greatest
percentage of high-grade cork are to be found.
The best quality cork is obtained from the province of Algarve and some parts of Alentejo that produced in the north of the country usually being inferior. As regards quantity, the central and southern zones rank foremost. Portuguese law prohibits stripping the trees more than once every nine years in order to protect the species.
Industry
Cork
is an extremely light, compressible, elastic and flexible material, practically
impervious to moisture, and to liquid and gaseous substances. It has a very
high coefficient of friction, is a poor conductor of electricity, sound and
heat, and has an exceptional shock-absorbing capacity; it is also proof against
most chemical substances and has virtually unlimited durability.
The combination of such qualities in one substance led naturally to its industrial utilization, which dates back to very remote times. It only became important however after the invention of glass bottles, which opened up immense prospects for the sale of beverages and raised the problem of large-scale production of suitable stoppers. The stopper industry, which began in the Iberian Peninsula, has continued to expand to the furthest corners of the globe. Later a new type of stopper was devised - the American stopper or crown-cork - requiring a much smaller quantity of raw material than the ordinary stopper. This stopper, which consists of a metal or bakelite cap with a thin cork disc inside, has proved eminently satisfactory. The crown-cork began to be utilized on a large scale for bottles containing beer, mineral waters, fruit juices, pharmaceutical preparations, preserved foods, etc.
Among
other non-producing countries, which have a fairly important cork, industry may
be mentioned Argentina, Australia, Belgium, Brazil, Canada, Chile,
Czechoslovakia, Denmark, Germany, Japan, Mexico, Netherlands, the Scandinavian
countries, the United Kingdom, Uruguay, and the U.S.S.R.
Obviously, the producing countries play an important part in the industrial utilization of cork, and of these, Portugal, rightly occupies the foremost position. It has 500 factories, which employ about 20,000 workers, equipped with the latest machinery and utilizing the latest technological advances, enabling the industry to meet the demand for any product. This industry produces stoppers, discs, different types of floats, shoe soles, printing paper, cigarette tips, bath mats, table mats, hat bands, fishing rod handles, different kinds of packing. Cork wool is produced for cushions and mattresses and granulated cork employed chiefly as insulating material in ship-building, as a protective packing for fruit and eggs, and as tubing for plastic substances.