M. C. Tewari , S. S. Rajput

Abstract

Supply of conventional raw material for wood based industries is shrinking day by day. The solution lies in the use of alternate raw materials. Plantations of several fast growing species have been done on a large scale in different parts of the country. While parts of these plantations are basically meant to reduce the pressure on already over exploited forests to meet the demand of fuel wood, remaining may be diverted to raw material starved wood based industries like paper, panel products and for solid wood utilisation like construction, joinery and furniture and other specialised uses. Studies have been undertaken recently at the Forest Research Institute to find the suitability of these plantation woods for different industrial uses and to modify the processing techniques and production processes to make them suitable for different industrial uses. The results of these researches have been reviewed in this paper.

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S. S. Rajput , M. C. Tewari

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Eucalyptus terelieorni popularly known as Eucalyptus hybrid or Mysore gum has been plated extensively throughout India under the plantation programmes in the successive five year plans. Although most of the plantations have been raised for pulp and paper for which the species provides an excellent raw material, the question are often posed about its suitability for other purposes. In order to determine its suitability for varied purposes, investigations have been recently undertaken and several are underway at Forest Research Institute, Dehra Dun. The results of these studies have been reviewed in the present paper. On the basis of physical and mechanical properties, E. tereticornis has been found to be 10% heavier, 15% harder and 15% higher in shock resisting ability in comparison to teak. However, it has heen found to be 25% weaker than teak in strength. Under machining operations, it has been found that this species can be very well machine planed, turned, bored or mortised. The working quality index of E. tereticornis has been found to be 94 with teak as 100. The studies on seasoning, durability and treatability behaviour are in progress. However, the results obtained so far indicate that it can be seasoned well with suitable modification in sawing techniques as well as with preseasoning chemical treatment The species belongs to non-durable and non-treatable class with proper care E. tereticornis can be used for making simple as well as bentwood furniture, tool handles, pallets and many other items. By proper selection the species can he used for overhead power and telecommunication line poles, it is already well known that, the eucalypts yield excellent raw material for pulp and paper. Some trees of E. teretlcornls yield Cineole rich medicinal oil. The bark of E. tereticornis can be used for producing oxalic acid and can also be used for making hardboard. Plywood has also been developed from the species but the results are not very encouraging. Many studies are underway to find still more and more uses of Eucalyptus tereticornis and the results will be available In the near future.

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J. C. Jain , M. C. Tewari

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S. Padmanabhan , S. Ananthanarayana , J. C. Jain , M. C. Tewari

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M. C. Tewari , J. N . Pande , A. Purushothau

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The wood preservative copper-chrome-boric acid composition which is a modification of the copper-chrome-arsenic composition ( ASCU ) replacing arsenic pentoxide by boric acid, was tested in the laboratory and in the field. These tests indicated that :-(I) thin veneer specimens treated with this preservative were all sound in the test yard after about 2 years. While the untreated ones were all destroyed within 5-10 months; (2) the preservative gets satisfactorily fixed in wood. The following conclusions were, therefore, arrived at :-(I) this preservative cannot be considered as a substitute for ASCU, but can be used in place of Celcure; (2) for treatment of timber for use in dwelling houses and packing cases, it may be preferred to ASCU which is likely to give poisonous arsenic fumes under a fire accident; (3) an absorption of 0.75 to 1.0 lt. per cubic foot for house-building timbers, and 0.5 lt. per cubic foot for packing case timbers, can be expected to give satisfactory protection against attack by fungi and insects including termites and (4) for treatment of poles, piles, etc., it is best to wait till sufficient service data are obtained.

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M. C. Tewari

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M. C. Tewari , J. N. Pande

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A. Purushotham , M. C. Tewari

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M. C. Tewari , P. S. Rao

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M. C. Tewari , P. S. Rao

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M. C. Tewari , T. ChandraShekar

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M. C. Tewari , S. N. Mitra , M. Nagaraja Sharma

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In the present paper, results of experiments on the preservative treatment of fenceposts by the sap-displacement method are presented. In this method freshly-cut, debarked posts are treated with water-borne preservatives by placing the butt ends into solutions of the preservatives. The preservative rises through and replaces the sap of the posts by 'wick' action. This method works out satisfactorily with all water-borne preservatives. The present method appears to be simpler and easier than other sap displacement methods.

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J. C. Jain , B. S. Kamala , M. C. Tewari

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It is found that treatment of timbers with Ascu and a mixture of creosote and furnace oil (1:1) generally does not affect their natural nail-holding power, though treatment with creosote alone may sometimes bring about a slight increase in the strength property. Results of experiments with 12 species of timbers of Southern India have been given.

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K. S. Shukla , P. S. Kukreja , M. C. Tewari , Man Mohan Singh , S. R. D. Guha

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Results of all investigation on treatment of paper by deeping in different fire retardant formulations are reported. Best results were obtained using Borax which imparted fire resistance.

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