R. N. Madan , R. Tandon

Abstract

Wood pulp or any other hlghly purified form of cellulose manufactured for commercial conversation into derivative is known as dissolvling pulp. The paper gives data on the proximate chemical analysis, bleaching and analysis of dissolving pulp produced from eucalyptus speceis, Pinus speceis, Sebania speceis, Moringa speceis, Prosopis juliflora, leucena leucocephaia and grevillea robusta. The dissolving pulps have been classified and characterised according to their and use. The general process of manufacturing of viscose rayon fibre from rayan grade pulps ha been described and the relsultsof commercial visoce rayon fibre are also gives for comparisons. The position of rayon grade pulp units in the country is given respect of raw material process and production.

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Rajeev Kumar , R. N. Madan , Y. K. Sharma

Abstract

Cold soda pulps were prepared from Sesbania aculeata and Sesbania aegyptiaca (with bark) under identical conditions. The chips Were soaked in a solution of caustic soda of different concentrations (11.25 gpl.-22.5 gpl.) for a period of 4 hours keeping the chips to liquor ratio 1 : 4. The softened chips were refined twice in Sprout Waldron refiner at about 10% consistency and keeping tbe clearance between plates 250 and 125 microns respectively. Temperature during refining was kept about 50°C. The pulps were screened on vibratory screen having 0.25 mm slots. The unbleached yield of screened pulps was determined in the range of 70.62-78.9% in case of Sesbania aculea, a and 70.50-76.29% in case of Sesbania aegypliaca. The pulps were beaten in lampen mill varying the beating time, to obtain different freeness. The pulps were classified. using Bauer Mc.-Nett classifier. The fines passing tbrougb 200 mesb wne 15.01-31.63% and 14.41-34.8% in Sesbania aculeala and Sesbania argyptiaca respectively. This is comparable with the hardwood chemi-mechanical pulps. Tbe opacity and brightness of unbleached pulps were 96.9% and 54.5% in case of S. aculeata and 97.1% and 565% in case of Sesbania aegyptiaca respectively. The cold soda pulps obtained from the above two species, can be admixed with long fibre chemical pulps to produce newsprint. The pulps are also suitable when admixed long fibre pulp for the production of several industrial papers.

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Man Mohan Singh , R. N. Madan , Rita Dhawan , K. K. Karira , B. G. Karira

Abstract

Laboratory scale experiments were carried out on the production of wrapping, writing, printing and newsprint grade pulps from seven species by different pulping processes like sulphate, neutral sulphite, semi-chemical (N.S.S.C) and cold soda Unbleached pulps suitable for wrapping papers were obtained in satisfactory yield, and having satisfactory strength properties by using sulphate and (N.S.S.C.) process. For writing printing,paper the pulps were bleached by CEH sequence. Bleached pulps in satisfactory yield and good strength properties were obtained. Pulps in high yield could be obtained by cold soda process. Which when admixed with 28 bamboo sulphate pulp were considered to be suitable for newprint. Comparative suitability indice of wood, for wrapping and writing printing papers were calculated. From the results it Can be conciuded that all the seven species are suitable for wrapping, writing, printing and newsprint grade pulps.

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S. R. D. Guha , R. N. Madan

Abstract

Eucalyptus hybrid (mainly E.tereticornis) was cooked by NSSC Process for the production of corrugated medium. The concentration of Na₂ SO₃ was varied from 8-15 per cent and the concentration of Na₂CO₃ was kept constant at 3 percent. The cooking temperatqre was varied from 162-170°C. Pu1p could be prepared in satisfactory yie1d and with adequate property for corrugating medium.

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S. R. D. Guha , R. N. Madan

Abstract

Laboratory experiments on production of chemical pulps from Morus alba for writing and printing papers by sulphate process are described. The average fibre length of the pulp was 1.02 mm. and the average fibre diameter was 0.011 mm. Easy bleaching pulps in good yield with satisfactory strength properties could be prepared. The investigation reported in this paper has shown that Morus alba is a promising fibrous raw material for the manufacture of white writing Bnd printing papers.

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S. R. D. Guha , V. N. Mukherjea , R. N. Madan

Abstract

Laboratory experiments on the production of mechanical pulp from Eucalypltus tereticornis are described. Standard pulp sheets were made from a mixture of 60 per cent mechanical pulp from this species and 40 per cent imported bleached sulphate wood pulp. Strength properties of standard sheets prepared from mechanical pulp produced under suitable conditions are satisfactory for the production of newsprint but the colour is poor and cannot be easily bleached.

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S. R. D. Guha , R. N. Madan

Abstract

Laboratory experiments on production of chemical pulps from Casuarina equisetifolia for writing and printing papers by sulphate process are described. The average fibre length of the pulp was 1.08 mm and the average fibre diameter was 0.011 mm. Easy bleaching pulps in good yield with satisfactory strength properties could be prepared. The investigation reported in this paper has shown that C. equisetifolia is a promising fibrous raw material for the manufacture of white writing and printing papers.

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S. R. D. Guha , R. N. Madan

Abstract

Laboratory experiments on the production of mechanical pulp from Eucalyptus (M.H.) are described. Standard pulp sheets were made from this species and 40 per cent imported bleached sulphate wood pulp. Strength properties of standard sheets prepared from mechanical pulp produced under suitable conditions are satisfactory for the production of newsprint, but the colour is poor. Pulp of satisfactory colour for newsprint, can be obtained by bleaching with 10 per cent available chlorine.

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S. R. D. Guha , R. N. Madan

Abstract

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S. R. D. Guha , G. M. Mathur , R. N. Madan , Krishan Kumar , G. C. Agarwal , Rajesu Pant , S. Rajendra Prasad , A. H. Shah , D. K. Tiwari , K. M. Mehta

Abstract

Laboratory experiments on production of chemical pulps from individual six species of Andhra Pradesh hardwoods for wrapping papers by sulphate process are deacribed. Mixed pulping of these six species was also carried out. To confirm the laboratory reaults pilot plant trial was also undertaken. The investigation reported in this paper has shown that pulps in good yield and satisfactory strength properties could be prepared from these hardwood species.

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