WASTE RUBBER

Wairarapa Times-Age, 13 June 1942, Page 4

WASTE RUBBER

RECLAMATION IN BRITAIN GREAT POSSIBILITIES. POSITION OF SUBSTITUTES. With the Japanese invasion of rub-ber-producing areas in the Far East there has been much talk of the necessity of conserving supplies of raw rubber, but rubber manufacturers have long been concerned about the less obvious (to the layman) but extremely important question of scrap, writes a rubber chemist in the “Manchester Guardian.” The British public is not yet “scrap conscious” so far as waste rubber is concerned, and it should be one of the chief measures taken by the recently constituted Rubber Control Board to make it so . This body has already, made itself felt by restricting the manufacture of such luxury lines as crepe soles, and inevitably it must devote a considerable amount of its time to the question of waste or “spent” rubber articles. Three first-class independent reclaiming plants were in operation in this country before the war, and the question of adequate supplies of scrap is of high importance to them and to others who are already or who may be operating. By “independent” plants is meant plants independent of control by any rubber-manufacturing company, for‘surprisingly few users of reclaimed rubber have shown practical interest in reclaiming their own waste. In peace time these companies preferred to sell such waste to scrap merchants or to have it reclaimed and returned to them. Where waste was heavily loaded with “fillers,” as in soles and heels, it was simply ground, sifted, and the resultant “crumb” Used again in their compounds. Such reclaim as is made by a few rubber-manufacturing concerns is x not of the same high quality ‘as that of the established reclaimers, because high production of first quality reclaim involves a heavy expenditure on plant. For the average manufacturer this is not an economical proposition. A further explanation is that British manufacturer’s are less interested in reclaim than their fellows in the United States, where consistently higher proportions of reclaimed,rubber to new rubber are employed. Indeed, in certain branches of British manufacture, such as cablemaking, reclaimed rubber is barely tolerated. EXPANSION POSSIBILITIES.

It is inadvisable under war conditions to disclose the British output of reclaims, but it is capable of much wider expansion, and steps have already been taken in this direction. Reclaimed rubber, of course, has to be combined, with natural rubber, Jhe supplies of which set a limit on the expansion of the reclaiming industry. The process of reclaiming rubber is broadly the same in all countries where it is carried on. Naturally enough, it is a mass-prdductibn job. Were this not the case reclaimed rubber’ would hardly have survived the slump years of 1931 and 1932. Discarded tires, which easily form the bulk of the scrap used, are first sorted. They are then stripped of wire in a debeading machine and chopped by large knives into sections. ’‘Cracking,” or rough grinding’ on large mills, is carried but and metal (such as nails picked up during the Ufe of the tire) removed by powerful magnets. The scrap is then digested in rotating autoclaves, Usifig hot alkaline solution under pressure, the effect being to destroy and dissolve the tire fabric, free sulphur, and remove impurities. The rubber after this stage is true reclaim. It is washed, dried, passed through fine screens to remove further impurities, and still further “refined” on tight rollers, finally being tested and bagged. The same process is applied to. other types of waste rubber, with slight variations according to the nature of the scrap. NEED TO ORGANISE COLLECTION. The collection of waste rubber- in recent years has never been on a properly organised footing, as any responsible scrap merchant will admit. Too much of it has been left to perish in odd places from which it may seldom, if ever, be disinterred. Today the salvaging of all such waste is a national necessity, and as much importance should be attached to it as the salvaging of metal, paper, etc. By the most effective means of propaganda the public should be invited to collect waste tires and tubes from automobiles and cycles, old rubber shoes of all types, hose, old hotwater bottles, play balls, bathing caps, sheeting .air-beds, and so on. In fact, rubber articles of any type that appear to have some measure of “rubberiness” will be needed. Discarded rainprbofs are unlikely to be needed for although these can be, and have been, reclaimed the proportional yield of rubber, is small.

That we shall have to ; go without many more of those accustomed luxuries- in rubber is only to be expected now that control has reached this youngest of our heavy industries. This will be accepted with good grace, for even the hardest-bitten low-handicap golfer would prefer to go short of balls rather than deprive our fighting weapons of essential rubbers. This war can be lost as easily through lack of rubber as of oil or steel. In spite of uninformed articles which have appeared in the newspapers, there is as yet no satisfactory substitute for natural rubber. Synthetic rubbers are as yet chemically and physically deficient in certain essential characteristics, and even if they were not both we and the United. States are behind Germany and Russia in the production of these synthetics. - ... Although encouraging strides "have been made in the production and application of artificial rubber, all technologists agree that for the -present these various synthetics can only be regarded as supplements to, arid hot substitutes for, the natural plantation, product.