Prospects for Existing Extractives-Based Industries

In terms of volume and value, the most significant wood-based extractives industries are natural rubber, resin and terpenes, carbohydrate gums, and tannins. The reasons for survival, growth, or decline in the future for each of these industries are quite different and are illustrative of the business principles described in the preceding section. 

Less than two decades ago, the natural rubber industry was faced with prices about equal to production costs and the prospect of intense competition from synthetic cw-polyisoprene. This was, of course, not the first threat to the future of natural rubber. 

Up to the advent of World War II, practically all of the rubber consumed was of the natural variety, mostly derived from Hevea brasiliensis plantations in the Far East. With the entrance of Japan into the war, both the United States and western Europe were cut off from the main source. At this point one of the most massive organic chemistry research and development efforts in history was launched, which ultimately resulted in the development of synthetic elastomers such as Buna N, Neoprene, Thiokol, and styrene-butadiene. While these were not equivalent to the natural product in some respects, product improvement continued so that by 1970 worldwide synthetic rubber production was 3.8 million metric tons compared to 2.7 million of the natural product. Styrene-butadiene rubber sold for about the same price as natural rubber. Although national defense interest dictated a policy of independence from foreign raw materials, conventional bias-belted tires still required 15% natural rubber for optimum performance. 

The latter uses an average of 2.34 kg of natural and 3.61 kg of synthetic rubber compared to 0.70 and 4.08 for bias tires (43). Radial truck tires, which are just now growing in importance, use an even larger ratio of natural to synthetic rubber. The net result is that natural rubber production and consumption have continued to grow more than 2% per year over the last decade. Production is now estimated to grow about 1.5% per year while consumption is expected to increase to 3%, leading to possible shortages. However, eastern European countries are currently 

Since it seems unlikely that synthetic c/5-polyisoprene will become economically attractive in the next 5 to 10 years, and excellent markets persist for natural rubber, there is every reason to expect that the natural rubber industry will remain viable into the next century. The substantial potential for increasing yields and lowering costs through chemical treatment and genetic studies should encourage continued research in this field. According to a recent estimate (10), Hevea produces 95 tons of dry matter per acre each year. Even under the best of conditions only about 5% of this is biochemically converted into rubber by the tree, but the 

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