“BUNA” HAS ITS USES

Evening Star, Issue 23352, 23 August 1939, Page 6

“BUNA” HAS ITS USES

SYNTHETIC RUIBER IN AUSTRALIA In use to-day in Sydney in a variety of forms is a new raw material, synthetic rubber—not merely a substitute for natural rubber, but a material having all the valuable characteristics of rubber as well as properties not found in the natural article (says a writer in the ‘ Sydney Morning Herald ’). Nearly every hose attached to new petrol pumps in Sydney is made wholly or in part from synthetic rubber. Pipes and cables, and packing which comes in contact with oils, are increasingly being manufactured from synthetic, in preference to natural, rubber, because of the former’s resistance to oil and fats. Natural rubber swells and perishes very quickly when used to convey those substances. The development of synthetic rubber is one of progress. It is the more dramatic because the product is still so completely now that industry has not yet had time to realise its full possibilities.

Virtually blockaded during the World War, Germany practised self-sufficiency to survive. Out of her struggle to do so came the first commercial production of synthetic rubber. Though the methyl rubber her chemists produced during the war years did not long survive the coming of peace, the base had been laid for future work in European laboratories. THE GREAT SLUMP. British and Dutch interests dominated the world rubber market during the early ’twenties, gaining control of nairly 95 per cent, of the world supply. Under the Stevenson Plan, they were able to fix prices and dole out rubber to the rest of the world. In the United States the motor industry was leaping ahead, but could not get enough rubber from the monopoly. Neither could Germany, another great industrial nation, get as much of the raw rubber as she would have liked.

Chemists took up the work again. This time they were not alone. In the United States the powerful Pont de Nemours Company, and in England the chemists of Imperial Chemical Industries, were engaged on the same task of finding an economic substitute for natural rubber. In the midst of their search disaster struck the rubber industry. Prices, which had stood at 4s 6d in 1925, crashed to less than 6d in five years, as the Stevenson Plan was abandoned and all rubber stocks were thrown on the market. Planters in the East Indies, Malaya, and New Guinea were ruined as the bottom fell out of the rubber world.

Under Adolf Hitler, with no foreign currency to purchase raw materials, Germany grasped eagerly at the announcement of her chemists .that “ the problem of synthetic rubber may be considered finally solved.” Simultaneously—actually the announcement to the world came earlier—the chemists of the du Pont Company developed a synthetic rubber of similar composition. In announced that for 10 years they had been perfecting Neoprene, the British equivalent of the German Buna and the American Duprene. All had been made from the same elements—coal,'limestone, and salt. The chemists found > a Substance akin to [the basic substance of the natural rubber molecule, which they had obtained from acetylene, out ofi coal and lime. From this they constinoted (or polymerised) the molecule of the artificial product. In the German synthetic rubber this substance was known as Butadien. The British chemists called theirs Chloroprene. Several Australian rubber firms are now experimenting synthetic rubbers, and one company is now impoiting British Neoprene in quite considerable quantities, American synthetic rubber is also being used here, but as yet only small experimental lots of the German Buna have been placed on the Australian market. It was reported recently that a shipment of this substance is now on the way to Sydney. While both Germany and America have found extensive use for synthetic rubber in industry, its cost landed in this country prevents general use where rubber can be obtained. Paw rubber can be landed for less ih.iu la a lb, but both British and American synthetic rubbers cost at least 3s landed at Sydney, while the German product is slightly higher. Superior qualities cost as much as 7s a lb. Germany claims that tests of motor car tyres made from Buna have shown that the synthetic rubber is 30 per cent, more resistant to abrasion than natural rubber. It has been announced that during 1939 all German cars produced will be equipped with Buna tyres. The total production of Buna this year is expected to cover about one-third of the German rubber consumption. Except for certain special brands, such as Perbunan, which is being exported for the manufacture of packings, belting, protective clothing, and such uses, German Buna is required by the home market.

HOW IT IS USED. Marketed in the United States at about 23 cents a lb, Duprene and' other British and American synthetic materials are being used extensively for rubber rollers and blankets in printing establishments, wheels for trucks using oily floors, mountings on machines which spread oil when hot, clothing for flremen, and pipes carrying oils or hot water. Another interesting use is the making of seams for petrol tanks in aeroplanes. In the event of a crash, the tank is less likely to be damaged and to explode. Synthetic rubber has been applied to some of these uses in Sydney already. An American brand of synthetic latex, or liquid rubber, is being used experimentally to spray fabric gloves used by railway and tramway employees whose woi'k brings them in contact with acids and oils. Of Australian interest is the use of synthetic rubber in the manufacture of dairying machinery. Rubber, used extensively in some of these, perishes in contact with the lactic acid contained in milk. Synthetc rubber is not affected, but at the moment its pronounced odour makes it unsuitable for use in contact with foodstuffs. Chemists overseas are now eliminating the smell from the synthetic rubbers, and when these materials reach Australia they will probably revolutionise dairying machinery, particularly as regards durability. The examples of rayon and synthetic dyes have shown that a process, however costly it may be at first, may be so improved .that the artificial product will eventually cost only a fraction of the price of the natural one, while being of equal or superior quality. Within six years synthetic rubber has been adapted to diverse uses in an extraordinary variety of industries. As its cost falls with improved manufacture, this new raw material should find increasing scope in Australian industry.