Y. K. Sharma , Sushma Mahajan , P. P. Bhola

Abstract

The present investigation reveals that the Su-babul can be utilised for the production of alpha-cellulose. The chemical purity shows that the raw material is suitable for preparing cellophane and textile in high yield (39.8%).

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Nirankari Devi , P. P. Bhola , Man Mohan Singh , S. R. D. Guha

Abstract

Studies in this Paper have been carried out with a view to understand Ihe effect of pH on prehydrolysis of bamboo (Dendrocalamus strictus). The bamboo chips have been cooked with 1% H₂SO₄ H₂O and 10% NaOH for 90 minutes and 150 minutes The acidic, aqueous and soda Lignins have been analysed These results show that pulp yield decreases at higher pH and at more cooking time, and is also effected by the final pH of the prehydrolysates. The lignin yield from prebydrolysate decreases as the pH goes towards acidic side. The methoxyl content in isolated lignins decrease with the increase of lignin yield, while total-OH increases with the increase in lignin yield. The ratio of syringaldehyde to vanillin is less in lignins Obtained at higher prehydrolysis time. The acidic and aqueous lignins are less condensed than soda lignin.

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P. P. Bhola , Y. K. Sharma

Abstract

Laboratory Investigation reveals the potentiality of Leucaena leucocephala, a fast growing species commonly cultivated to have diverse uses such as, firwood, timber, nutritious forage, dye, gum and rich organic fertilizer, for pulp and paper making to supplement the existing raw material resource. Leucaena wood has bigh holocellulose, low ash and solubilities. Unbleacbed kraft pulp. With about 48-56% yield can be produced with low active alkali (12-16% at 170°C for 150-240 minutes. The pulp with 14% active alkali and 2430 H -factor can be bleached to 70% ISO brightness with 10% chlorine by C/E/H sequence and Is suitable for writing and printing papers. The black liquor has good colloidal stablity during evaporation and burning properties.

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S. R. D. Guha , Man Mohan Singh , Y. K. Sharma , Krishan Kumar , P. P. Bhola

Abstract

India is all agricultural cenutry and the main crop beSides the cereals is cotton. In the three cotton growing tracts, there is a frasibility of setting up a small board or wrapping or writing and printing paper mill of inferior quality. In this investigation, production of board by lime procesn wrapping papers by soda or sulphate process and printing papers by alkaline processes have been described, Fibre characteristics as weJl as proximate chemical analysis have also been detailed. Pulping studies on hOsiery waste as well as cotton ginoing waste are also described.

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Man Mohan Singh , P. P. Bhola

Abstract

The lignin content of different species of bamboo of Indian origin varies within narrow limits of 24±3%. The carbon and hydrogen content of these lignins are 59.7±3% and 6.3±0.5% respectively. The number of C₉ units varies from 12 to 21 with an average of 14 indicating that the structure of bamboo lignin skeleton is more akin to hardwoods than conifers. The I.R. Spectra of all these is similar and show that bamoo lignin is composed of polymer of mainly propyl guaiacyl, propyl syringyl, as well as p-hydroxy benzal. There is a correlation between the number of C₉ units of different bamboos and breaking length of the beaten pulps.

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S. R. D. Guha , Man Mohan Singh , P. P. Bhola

Abstract

Recently Nepa Paper Mills have installed cold soda plant with facilities far doing hot or semi hot pulping Tectona grandis and Anogeiseus spp. off Cuts as well as lops and tops will be available around Nepa Nagar for their expansion programme. With this end in view effect of concentration of chemicals, sulphidity, temperature and time. were investigated It was found that optimum conditions of pulping were 15% chemicals on o d basic Sulphidity and boiling for one hour. As the pulp of Anogeissus spp. was darker, it requ'red bleaching with 5% available chlorine. The pulps were mixed with 40% bleached Sulphate bamboo pillp have satisfactory strength properties for newsprint.

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Man Mohan Singh , S. K. Purkayastha , P. P. Bhola , A. K. Gupta

Abstract

A fresh study of the suitablity of Melia azedarach for pulp and paper has shown that it is a very promising raw material for wrapping, writing aDd printing paper provided the trees are grown not too fast. Very fast grown material is characterised by very low specific gravity and wide fibres with large lumen. These fibres collapse due to their thin walls during the course of sheet formation resulting in poor strength properties. The earlier reports on its unsuitability were apparently based on tests carried out on very fast grown material.

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S. R. D. Guha , Man Mohan Singh , P. P. Bhola

Abstract

High alpha cellulose pulps have been prepared from Albizia amara and Acacia planifrons and mixture of hardwoods compressing of Artocarpus sp., Dyera sp.,(Jilutong), Shorea sp. (red meranti) and Shorea sp. or Parashorea (meranti) by water-prehydrolysis sulphate process followed by multistage bleaching. These pulps could be considered for preparing various products like viscose rayon, tyre cord, nitrocellulose etc., provided these pulps pass further tests required.

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P. P. Bhola

Abstract

Proximate chemical analysis and fibre dimensions of Hill Jati Bamboo growing in Cachar Hills (Bambusa tulda) are given. Pulping and bleaching studies of this species are also recorded. It is observed that under the conditions studied, this species of bamboo is suitable for manufacture of wrapping, writing and printing papers.

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Man Mohan Singh , S. K. Purkayastha , P. P. Bhola , Krishna Lal , Swarna Singh

Abstract

Fibre morphology and pulp strength of twelve species of bamboos grown in the arboratum of the Forest Research Institute, Dehra Dun were studied in two sets of pulps. In all the species fibre dimensions and particularly lumen width were found to vary widely indicating highly heterogenous nature of the pulp. The fibre dimensions were also significantly different in the two sets. Parenchyma proportions were also found to be different in the two sets. No marked differences were found in the various species as regards chemical composition of either chips or pulps, as well as alkali consumed during pulping. But, wide differences were found in strength properties, in unbeaten and beaten pulps of the 12 species of bamboos studied. However, these differences were considerably reduced on beating. As the ranking of tbe species on the basis of strength in unbeaten and beaten conditions is different strength of beaten pulp cannot be predicted from the unbeaten one. Further, significant differences were observed between the two sets of pulps in both unbeaten and beaten hand sheets. No relationships could be found between the fibre characteristics and the pulp strength properties, It appears from this study that because of wide variations within a species, fibre characteristics cannot be used as a criterion for classifying the bamboos for paper and pulp production. On the basis of pulp yield, alka1i consumption and sheet properties of the 12 species, they have been graded and Dendrocalamus hamiltonii has been found to be the best.

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S. R. D. Guha , P. P. Bhola , G. M. Mathur , Y. K. Sharma

Abstract

no abstract

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S. R. D. Guha , Man Mohan Singh , P. P. Bhola , G. M. Mathur , Y. K. Sharma , G. C. Aggarwal

Abstract

Laboratory as well as pilot plant trials have been carried out on the production of newsprint grade paper from a mixture of mechanical pulp from Eucalyptus hybrid and soda semi-chemical pulp from bagasse. The results show that the newsprint produced in this manner compares very favourably with imported newsprint and Indian newsprint.

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S. R. D. Guha , Man Mohan Singh , P. P. Bhola , Boon Sueb Chittivanich , Lee Seng Gay

Abstract

With the increase of standard of living in the country it is essential to produce different grades of pulps and papers for domestic consumption. To meet the production target, it is essential to produce more of fibrous raw materials especially long-fibre material. Agathis robusta is a fast-growing exotic conifer from Australia. Wrapping papers, writing and printing papers and rayon grade pulps have heen produced on the laboratory scale with encouraging results. Proximate chemical analysis of wood as well as of fibre dimensions and their distribution in the pulp have also been recorded. It is seen that this material is suitable for producing the various grades of pulps and papers enumerated above.

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Man Mohan Singh , S. K. Purkayastha , P. P. Bhola , Laxmi Sharma

Abstract

By testing hand sheets made from 32 mixtures of different fractions of a pulp of Dendrocalamus striclus, beaten to 250 ml. (C.S.F.), the effect of variations in fibre dimensions on strength properties have been investigated. Fibre length, determined from unbeaten pulp, accounts for 77 to 90 per cent of the variation in strength properties viz. breaking length, burst factor and tear factor. Other fibre characteristics viz. ratio of lumen width to fibre diameter and percentage of fibres with obliterated lumen, which also exhibit similar relationship with the strength properties, are highly correlated with fibre length. Parenchyma proportion shows a high negative correlation with the sheet properties. Fibre length and parenchyma proportion together account for 94 per cent of the variation in strength properties.

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S. R. D. Guha , Man Mohan Singh , P. P. Bhola

Abstract

Laboratory experiments carried out on the production of newsprint from a furnish containing 30% chemical pulp from Eetta reed (Ochlandra travancorica) and 70% stone ground wood pulp, refiner mechanical pulp or cold soda pulp or hot sulphite pulp from stored and fresh Eucalyptus hybrid (Mysore gum) are described. The results show that newsprint of satisfactory strength properties could be prepared from fresh and stored wood. The power consumption in case of fresh wood is lower than the stored wood in all the cases. Fresh wood gives a brighter and easily bleachable pulp.

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