by J. L. CALHEIROS E MENESESPresident, Junta Nacional da Cortiça, Portugal
A note on the first meeting of the FAO Permanent Working Party On Cork, held at Lisbon in May 1951, appeared in UNASYLVA, Vol. V, No. 2. In view of the interest aroused by this meeting, the President of the Junta Nacional da Cortiça was asked to summarize in an article the part that cork played in the economy of his country. 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 v inters, 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.
The cork oak and cork production are therefore characteristic of a very small number of countries whose relative importance is noted on Chart I, drafted from figures taken from a monograph published in 1947 by the FAO Regional Office in Europe entitled Cork Production and International Cork Trade.
This chart shows the importance of Portugal in the cork-growing world; 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 as can be seen from Table 1, which gives the average production per district on a 9-year-cycle basis. Portuguese law prohibits stripping the trees more than once every nine years in order to protect the species.
As can be seen, the districts of Santarém, Évora. Setúbal, Portalegre and Beja are the most important, since their cork groves supply about 90 percent of the total Portuguese cork production.
Obviously Portugal could not fail to profit from a tree with which it has been so generously endowed by nature. Consequently every government has followed the traditional practice of protecting the cultivation, exploitation, propagation and improvement of the cork oak through appropriate measures. Finally, there has come the establishment of a special research institute - "Estação de Experimentação Florestal do Sobreiro" (The Cork Oak Forests Experiment Station) - which has made an important contribution to the study of problems concerning the anatomy, physiology, cytology, genetics and the phytosociology of the species, with a view to devising more rational cultivation techniques, improving the quality of the cork and also increasing yield. These efforts are justified by the preference shown by buyers for Portuguese cork, as is evident from the high overseas demand.
TABLE 1 - ANNUAL AVERAGE PRODUCTION OF PORTUGUESE CORK (1941-1949)
|
District |
Tons |
% |
|
Aveiro |
302 |
0.2 |
|
Beja |
14804 |
10.1 |
|
Braga |
314 |
0.2 |
|
Braganza |
1929 |
1.3 |
|
Castello Branco |
3901 |
2.6 |
|
Coimbra |
557 |
0.4 |
|
Évora |
31596 |
21.5 |
|
Faro |
3690 |
2.5 |
|
Guarda |
245 |
0.2 |
|
Leiria |
889 |
0.6 |
|
Lisbon |
821 |
0.6 |
|
Portalegre |
25624 |
17.4 |
|
Oporto |
164 |
0.1 |
|
Santarém |
31912 |
21.7 |
|
Setúbal |
29194 |
19.9 |
|
Vianna do Castello |
58 |
0.0 |
|
Villa Real |
563 |
0.4 |
|
Vizeu |
384 |
0.3 |
|
Total |
146947 |
100.0 |
Formed of myriads of minute cells with very fine highly resistant, cutin membranes enclosing a gaseous mixture similar to air, the tissue which covers the cork oak, because of its structure, has special properties; making it ideal for the many current and expanding needs of 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.
Two utilization problems, however, arose: that of the high percentage of waste accruing from making stoppers, discs and other products manufactured from natural cork, in order to reduce costs; and that of low-grade cork which is not suitable for such articles. The production, towards the end of the last century, of agglomerates made of cork wastes solved these problems and opened new avenues for the cork industry. From this moment, thanks to successive technological improvements, it has been possible to evolve cork agglomerates to meet the most important and the widest range of needs.
Today, the cork industry is a vital force. As a result of increasing research on cork products, it has spread from one zone far beyond the cultivation limits of cork oak and has attained considerable size in many countries, some of which have tried to adapt the tree to their soils, an attempt which so far does not seem to have met with great success.
Among the present non-producing centers where cork products are manufactured on a large scale, the United States ranks first. The potential of the American cork industry is very great, as can be surmised from the fact that it employs 6,000 to 7,000 men and comprises several score factories where almost half the world's cork crop is processed, with an output worth over 40 million dollars.
Among the products manufactured in the United States, the agglomerates predominate, as is fully justified by their use in cold storage and air-conditioning plants, in the automobile industry, textile machinery, electrical appliances, etc. The production of natural cork commodities is much smaller and represents only about 6 to 8 percent of the total output. Cork, which is in high demand in peace time, is considered by the United States as an essential raw material in time of war and is even listed as one of the most important strategic materials; it is used in the manufacture of various items of military equipment, insulating material, attachments or fittings for aircraft, 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.
TABLE 2 - PORTUGUESE CORK EXPORTS
|
Consumer Countries |
1937-39 (average) |
1948-50 (average) |
||||||||
|
Raw Cork |
Manufactured Cork |
Total |
Raw Cork |
Manufactured Cork |
Total |
|||||
|
Tons |
% |
Tons |
% |
Tons |
% |
Tons |
% |
|||
|
United States |
54128 |
99.8 |
130 |
0.2 |
54258 |
74939 |
96.3 |
2890 |
3.7 |
77829 |
|
United Kingdom |
25284 |
75.0 |
8425 |
25.0 |
33709 |
22753 |
61.2 |
14395 |
38.8 |
37148 |
|
Germany |
20810 |
94.1 |
1314 |
5.9 |
22124 |
6721 |
95.8 |
291 |
4.2 |
7012 |
|
Other Countries |
37267 |
83.2 |
7532 |
16.8 |
44799 |
34792 |
68.0 |
16399 |
32.0 |
51191 |
|
TOTAL |
137489 |
88.8 |
17401 |
11.2 |
154890 |
139205 |
80.4 |
33975 |
19.6 |
173180 |
The demand for Portuguese agglomerates has increased rapidly. Pure agglomerates, so called because agglutination is produced solely by means of the natural cork resins, are extensively employed as insulating material in buildings, acoustic insulators and correctors in theatres, lecture halls, etc., for absorption of vibrations produced by heavy industrial machinery and for wall and floor coverings. Composite agglomerates, made with auxiliary substances, are used for discs, soles, packing for machinery, sleeves and other casings for the textile industry, sports gear, electric appliances, etc., as well as household articles and numerous other goods for widely differing purposes.
An industry has recently been started for the chemical disintegration of cork for the purpose of producing a wax With a very high melting point and capacity for absorbing solvents, excellent as a substitute for Carnauba1 and Candelilla2 wax, and also to obtain suberolin, a non-fusible, insoluble substance. Very promising prospects are undoubtedly open to these new products which will be utilized in making carbon paper, polishes and polishing waxes, varnishes for metallic containers for food preserves, and for impregnating fishing nets etc.
1 A product of the Brazilian wax-palm (Copernicia cerifera).2 Obtained from Euphorbia cerifera Alc., a shrubby plant native of the drier parts of Mexico.
The cork trade today has become very important and forms an immense network covering practically the entire world. The annual world expenditure on cork products may be estimated at 100 million dollars, a figure which gives some indication of its importance.
Cork is the most important of Portuguese exports and alone represents about 16 percent of the total foreign income derived from trade. Cork exports are steadily increasing, as can be seen in Chart II which shows from the beginning of this century, by 5-year periods, the increase in cork tonnage exported.
The only years which show no increase are 1915 and 194a, abnormal years because they fall within war periods, and 1930, a year of world economic depression.
Portuguese cork exports are directed to three main consumer markets - the United States of America, the
United Kingdom and Germany which absorb approximately 70 percent of the total. Among the other consumer centers scattered over the world the most important are: Australia, Belgium-Luxembourg, Brazil. Canada, Czechoslovakia, Denmark, the Netherlands, Japan, Mexico, Norway, Russia, Sweden. Switzerland and the Union of South Africa.
Table 2 shoves the average tonnage of Portuguese exports of raw and manufactured cork during the three-year periods 1937-39 and 1948-50; figures are given for the three principal consumer markets. This table shows the expansion of Portuguese cork, due mainly to the marked increase in demand for manufactured cork, both in quantity and percentage, an increase which raised exports to double the total before World War II.
This increase is the result of research and marketing efforts, and the quality and reasonable prices of cork manufactured in Portugal are becoming universally recognized. Even the United States, despite its own important manufacturing industry, has raised its imports of Portuguese finished products by approximately one-fifth during this period.
Amongst the other important consumer countries. Germany had its economy completely disrupted by the war and is only now gradually recovering; the United Kingdom, however, traditionally the largest buyer of Portuguese manufactured products, has nearly doubled its pre-war purchases during the 1948-50 period.
CHART II: Increase in tonnage of cork exports, 1900-1950
Portugal has an organization for co-ordinating cork activities - the "Junta Nacional da Cortiça" - whose task is to supervise and guide the cork industry and trade. Its main objectives are to expand the country's export trade; to guarantee the quality of the products exported and protect their trade reputation. The "Junta" has a Cork Research and Experiment Laboratory qualified to test manufactured articles, to compare cork products with possible substitutes and to discover new properties as well as new uses for cork.
Portugal has given every care to production in order to increase its cork-oak stands and to improve the quality of the cork, and possesses industrial plants capable of meeting all demands for manufactured products and of maintaining a well-established trade of high repute with assured economic prospects. A traditional industry, this branch of production will undoubtedly be able to adapt itself, as a result of the experience acquired over many years, to future directives and trends.
