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Paper from Thysanolaena maxima
Bioresource Technology 40 (1992) 245-248
Paper from Thysanolaena maxima D. C. Saikia, T. Goswami & B. E Chaliha Regional Research Laboratory, Council of Scientific & Industrial Research, Jorhat 785 006, Assam, India (Received 20 January 1990; revised version received 13 May 1991; accepted 17 May 1991 )
Abstract Thysanolaena maxima (Roxb) (tiger or broom grass), is a tall reed-like perennial grass, grown on shady slopes in forests in India and the Nicobar Islands. Culms are solid, smooth and rounded and up to a height of 4 m. The leaves and the tips are used as fodder; the bushy, fox-tail-like panicles (30-90 cm) are used for making brooms. When the panicles are cut, the stem portion (3-4 m) is left out in the field and is burnt. Fibres, of average 1"25 m m in length at 45% yield (unbleached), could be obtained from this grass. The laboratory handmade paper sheets exhibited good properties, with a burst factor of 30, a breaking length of 3555 m and a tear factor of 106. Hence, it can be suggested that T. maxima may become a potential source of raw material for pulp- and paper-making either alone or in combination with the conventional pulp- and paper-making raw materials. This material could help to meet the future demand for pulp- and paper-making raw material, if properly exploited.
Key words: Grass, kraft, anthraquinone, yield, brightness, potential.
INTRODUCTION
Thysanolaena maxima (Roxb), popularly known as 'tiger' or 'broom' grass, possesses certain properties which are attractive from the papermaking point of view. T. maxima is an annually renewable source of fibre which could become a useful supplemental material, like some of the annual-source paper-making raw materials (Cunningham et al., 1978), for pulp and paper in view of the shortage of common fibrous raw materials like bamboo and wood. The grass grows wild and is available in large quantities during June to
December. The leaves of the grass are used as cattle feed. The culms of T. maxima are solid, smooth, rounded, and up to 25 mm in diameter and 3-4 m in height, somewhat resembling those of bamboo but tapering to a fine point. The panicles are terminal, bushy, fox-tail-like and are used for making brooms (Wealth of India, 1976). The stem portion, which is usually a waste, but also used as fuel, was selected for a study on the paper-making characteristics. Attempts have been made to utilise various cellulosic wastes (Goswami et al., 1982; Shaikh, 1990) and aquatic weeds (Ghosh et al., 1981 ) in the manufacture of pulp, paper and allied products. METHODS
Proximate analysis The proximate analysis of T. maxima was carried out by standard procedures of the Technical Association of Pulp and Paper Industry, USA (TAPPI, 1980). Stalks were washed and dried in an oven. The dried material was powdered in a Wiley mill and sieved. The fraction passed through 60 BSS mesh and retained on 80 BSS mesh was used for proximate analysis. The length and the diameter of fibres of digested, bleached and washed material were measured under a microscope and the average, maximum and minimum results were recorded. Pulping Dried stalks of T. maxima received from the District Agricultural Office, Doomdooma, Assam, India, were used for pulping. All the chemicals used were of analytical reagent grade. Methods of analysis were from TAPPI (1980). The processes adopted for pulping were kraft and soda-anthraquinone.
245 Bioresource Technology 0960-8524/92/S05.00 © 1992 Elsevier Science Publishers Ltd, England. Printed in Great Britain
246
D. C Saikia, T. Goswami, B. P. Chaliha
Kraft pulp
Sheet making and testing
Kraft pulp was prepared by digesting 500 g of oven-dry stalk chips of about 2-2.5 cm length with 19% kraft liquor (20% sulphidity) as Na20 on dry weight of the raw material in an electrically heated, stainless steel, rotary digester at a material to liquor ratio of 1:4 and 165 + 2°C for 3 h (plus 1 h for raising the temperature). The black liquor was collected for analysis and the cooked material was washed thoroughly to remove the unreacted chemicals. Some batches of the material were digested by varying the liquor percentage from 15 to 20 and the temperature from 150 to 175°C. This gave the optimum conditions of 18% liquor and 165°C used above.
The unbleached and bleached pulps were separately disintegrated and subsequently beaten in a stainless steel, lined, laboratory valley beater to get a pulp of desired freeness. Standard sheets of 60 + 1 g/m: were prepared from unbleached and bleached pulps on a British Standard laboratory sheet-making machine. The sheets were dried in air and conditioned at 65% relative humidity at 27°C for 2 h and then tested for various strength properties.
Soda-anthraquinone pulping Another batch of pulp was prepared by the soda-anthraquinone process. Oven-dry chips (500 g), of about 2-2.5 cm length, with 15% active alkali as Na20 and 0.3% anthraquinone on the weight of the dry material, were put in a stainless steel, electrically heated, rotary digester maintaining a material to liquor ratio of 1:4 at a temperature of 160 + 2°C for 3 h (plus 1 h to raise the temperature). Digestion experiments were also carried out with active alkali concentrations of 14-18% and anthraquinone of 0"1-0-4%, keeping temperature and time at 160 + 2°C for 3 h. This gave the optimum alkali used above. The cooked material was washed thoroughly to remove any unreacted chemicals.
RESULTS AND DISCUSSION Tables 1 and 2 show some properties of the T. m a x i m a stems. The properties of the pulps are given in Table 3. The yield of unbleached kraft pulp was slightly lower than that of the unbleached soda-anthraquinone pulp. In both the processes the pulp was well-cooked and recorded nil rejects. Both the pulps could be bleached easily by the two-step hypochlorite process, with an intermediate alkali extraction, and employing identical conditions (Table 4). The chlorine demand for both the pulps was 6%. The brightness of the bleached pulp is given in Table 4. The properties of unbleached and bleached paper sheets are given in Tables 5 and 6. The
Table 1. Proximate analysis of Thysanolaena maxima stems
Bleaching of pulp The unbleached pulp was bleached in a two-stage hypochlorite bleaching sequence with an intermediate alkali extraction. In the first stage, hypochlorite at 60% of total chlorine requirement was added according to the demand, at a pulp consistency of 10% for about 120 min at 30°C with occasional slow agitation. The pulp was washed thoroughly with fresh water and then extracted with 1% sodium hydroxide at a pulp consistency of 10% for 60 min at 60°C. This was washed thoroughly before the second-stage hypochlorite treatment. In the second stage of bleaching, hypochlorite at 40% of total chlorine demand was added to the pulp at a pulp consistency of about 10% and the pulp kept at 30°C for 120 min with occasional agitation. The pulp was then washed thoroughly. The yield of bleached pulp was determined and the properties of bleached pulp sheets recorded.
Oven-dry basis except moisture
Tests
('x,)
Cold-water solubility Hot-water solubility 1% NaOH solubility Alcohol-benzene ( 1 : 2) solubility Lignin Pentosan Cellulose Ash content Moisture content
12.5 14-1 38.5 13-6 23-3 24-0 58"3 2.5 9.6
Table 2. Fibre dimensions of Thysanolaena maxima
Minimum Maximum Average
Fibre length
Fibre diameter
(ram)
(pm)
0-73 2-07 1.25
0.005 0.020 0.010
Paperfrorn Thysanolaena maxima
247
Table 3. Properties of pulps
Property
Kraftp u l p
Initial freeness (CSF) Final freeness (CSF) Beating time (min) Screened yield (%) Rejects (%) on oven-dry chips Residual liquor pH
700 350 30 45 Nil 11.0
Soda-anthraquinone pulp 700 350 30 47.5 Nil 10-4
Table 4. Details of bleaching conditions
Particular
Kraftp u l p
Soda-anthraquinone pulp
Step 1 Consistency (%) Hypochlorite as available chlorine added in pulp (%) Temperature (°C) Time (min) pH (initial) pH (final) Brightness (%)
10 3.6
10 3"18
30 120 10.0 9.2 42
30 120 10.0 9-4 42
Step 2 Consistency (%) Alkali solution added (%) Temperature (°C) Time (min)
10 1 60 60
10 1 60 60
10 2.4
10 2"12
30 120 10 8-7 39.5 70
30 120 10 8"8 40.8 70
Step 3 Consistency (%) Hypochlorite as available chlorine added in pulp (%) Temperature (°C) Time (min) pH (initial) pH (final) Bleached pulp yield (%) Brightness (%)
Table 5. Properties of unbleached paper sheets
Property Basis weight (g/m 2) Bulk density (cm3/g) Breaking length (m) Burst factor Tear factor Number of double folds
Kraftp u l p 60 + 1 1-35 3840 38 102 12
Soda-anthraquinone pulp 60 + 1 1"34 3710 40 98 10
Table 6. Properties of bleached paper sheets
Property Basis weight (g/m2) Bulk density (cm3/g) Breaking length (m) Burst factor Tear factor Number of double folds
Kraft p u l p 60 + 1 1.29 3555 30 106 16
Soda-anthraquinone pulp 60 + 1 1-27 3450 28.6 108 15
248
D. C Saikia, T. Goswami, B. P. Chafiha
properties of the handmade sheets showed that good-quality writing and printing paper could be obtained from this raw material. The grass, if systematically cultivated, can become a potential supplemental raw material for the pulp and paper industry in India.
ACKNOWLEDGEMENT The authors wish to express their sincere gratitude to Dr J. N. Baruah, Director, Regional Research Laboratory, Jorhat, Assam, India, for permission to publish this paper.
REFERENCES Anon. (1976). Thysanolaena maxima. In Wealth of lndia, vol. X. Publications & Information Directorate, CSIR, New Delhi, India, pp. 237-8. Cunningham, R. L., Clark, T. F. & Bagby, M. O. (1978). Crotalaria juncea -- annual source of paper making fibre. TAPPI, 61 (2), 37-9. Ghosh, S. R., Saikia, D. C., Gohain, E & Chaliha, B. P. (1981 ). Water hyacinth (Eiehhornia crassipes) for paper and boards. Indian Pulp Paper Tech. Assoc., 18 (4), 1-9. Goswami, T., Ghosh, S. R., Hazarika, J. N. & Chaliha, B. P. (1982). Paper and paperboards from Sikkimensis grass
( Cymbopogon flexuous ). Indian Pulp Paper Tech. Assoc., 19 (4), 12-18. Shaikh, A. J. (1990). Blending of cotton stalk pulp with bagasse pulp for paper making. Bio. Wastes, 31, 37-43. TAPPI (1980). Standard and Suggested Methods. Technical Association of the Pulp and Paper Industry, New York, pp. T-200-65.
Paper from Thysanolaena maxima D. C. Saikia, T. Goswami & B. E Chaliha Regional Research Laboratory, Council of Scientific & Industrial Research, Jorhat 785 006, Assam, India (Received 20 January 1990; revised version received 13 May 1991; accepted 17 May 1991 )
Abstract Thysanolaena maxima (Roxb) (tiger or broom grass), is a tall reed-like perennial grass, grown on shady slopes in forests in India and the Nicobar Islands. Culms are solid, smooth and rounded and up to a height of 4 m. The leaves and the tips are used as fodder; the bushy, fox-tail-like panicles (30-90 cm) are used for making brooms. When the panicles are cut, the stem portion (3-4 m) is left out in the field and is burnt. Fibres, of average 1"25 m m in length at 45% yield (unbleached), could be obtained from this grass. The laboratory handmade paper sheets exhibited good properties, with a burst factor of 30, a breaking length of 3555 m and a tear factor of 106. Hence, it can be suggested that T. maxima may become a potential source of raw material for pulp- and paper-making either alone or in combination with the conventional pulp- and paper-making raw materials. This material could help to meet the future demand for pulp- and paper-making raw material, if properly exploited.
Key words: Grass, kraft, anthraquinone, yield, brightness, potential.
INTRODUCTION
Thysanolaena maxima (Roxb), popularly known as 'tiger' or 'broom' grass, possesses certain properties which are attractive from the papermaking point of view. T. maxima is an annually renewable source of fibre which could become a useful supplemental material, like some of the annual-source paper-making raw materials (Cunningham et al., 1978), for pulp and paper in view of the shortage of common fibrous raw materials like bamboo and wood. The grass grows wild and is available in large quantities during June to
December. The leaves of the grass are used as cattle feed. The culms of T. maxima are solid, smooth, rounded, and up to 25 mm in diameter and 3-4 m in height, somewhat resembling those of bamboo but tapering to a fine point. The panicles are terminal, bushy, fox-tail-like and are used for making brooms (Wealth of India, 1976). The stem portion, which is usually a waste, but also used as fuel, was selected for a study on the paper-making characteristics. Attempts have been made to utilise various cellulosic wastes (Goswami et al., 1982; Shaikh, 1990) and aquatic weeds (Ghosh et al., 1981 ) in the manufacture of pulp, paper and allied products. METHODS
Proximate analysis The proximate analysis of T. maxima was carried out by standard procedures of the Technical Association of Pulp and Paper Industry, USA (TAPPI, 1980). Stalks were washed and dried in an oven. The dried material was powdered in a Wiley mill and sieved. The fraction passed through 60 BSS mesh and retained on 80 BSS mesh was used for proximate analysis. The length and the diameter of fibres of digested, bleached and washed material were measured under a microscope and the average, maximum and minimum results were recorded. Pulping Dried stalks of T. maxima received from the District Agricultural Office, Doomdooma, Assam, India, were used for pulping. All the chemicals used were of analytical reagent grade. Methods of analysis were from TAPPI (1980). The processes adopted for pulping were kraft and soda-anthraquinone.
245 Bioresource Technology 0960-8524/92/S05.00 © 1992 Elsevier Science Publishers Ltd, England. Printed in Great Britain
246
D. C Saikia, T. Goswami, B. P. Chaliha
Kraft pulp
Sheet making and testing
Kraft pulp was prepared by digesting 500 g of oven-dry stalk chips of about 2-2.5 cm length with 19% kraft liquor (20% sulphidity) as Na20 on dry weight of the raw material in an electrically heated, stainless steel, rotary digester at a material to liquor ratio of 1:4 and 165 + 2°C for 3 h (plus 1 h for raising the temperature). The black liquor was collected for analysis and the cooked material was washed thoroughly to remove the unreacted chemicals. Some batches of the material were digested by varying the liquor percentage from 15 to 20 and the temperature from 150 to 175°C. This gave the optimum conditions of 18% liquor and 165°C used above.
The unbleached and bleached pulps were separately disintegrated and subsequently beaten in a stainless steel, lined, laboratory valley beater to get a pulp of desired freeness. Standard sheets of 60 + 1 g/m: were prepared from unbleached and bleached pulps on a British Standard laboratory sheet-making machine. The sheets were dried in air and conditioned at 65% relative humidity at 27°C for 2 h and then tested for various strength properties.
Soda-anthraquinone pulping Another batch of pulp was prepared by the soda-anthraquinone process. Oven-dry chips (500 g), of about 2-2.5 cm length, with 15% active alkali as Na20 and 0.3% anthraquinone on the weight of the dry material, were put in a stainless steel, electrically heated, rotary digester maintaining a material to liquor ratio of 1:4 at a temperature of 160 + 2°C for 3 h (plus 1 h to raise the temperature). Digestion experiments were also carried out with active alkali concentrations of 14-18% and anthraquinone of 0"1-0-4%, keeping temperature and time at 160 + 2°C for 3 h. This gave the optimum alkali used above. The cooked material was washed thoroughly to remove any unreacted chemicals.
RESULTS AND DISCUSSION Tables 1 and 2 show some properties of the T. m a x i m a stems. The properties of the pulps are given in Table 3. The yield of unbleached kraft pulp was slightly lower than that of the unbleached soda-anthraquinone pulp. In both the processes the pulp was well-cooked and recorded nil rejects. Both the pulps could be bleached easily by the two-step hypochlorite process, with an intermediate alkali extraction, and employing identical conditions (Table 4). The chlorine demand for both the pulps was 6%. The brightness of the bleached pulp is given in Table 4. The properties of unbleached and bleached paper sheets are given in Tables 5 and 6. The
Table 1. Proximate analysis of Thysanolaena maxima stems
Bleaching of pulp The unbleached pulp was bleached in a two-stage hypochlorite bleaching sequence with an intermediate alkali extraction. In the first stage, hypochlorite at 60% of total chlorine requirement was added according to the demand, at a pulp consistency of 10% for about 120 min at 30°C with occasional slow agitation. The pulp was washed thoroughly with fresh water and then extracted with 1% sodium hydroxide at a pulp consistency of 10% for 60 min at 60°C. This was washed thoroughly before the second-stage hypochlorite treatment. In the second stage of bleaching, hypochlorite at 40% of total chlorine demand was added to the pulp at a pulp consistency of about 10% and the pulp kept at 30°C for 120 min with occasional agitation. The pulp was then washed thoroughly. The yield of bleached pulp was determined and the properties of bleached pulp sheets recorded.
Oven-dry basis except moisture
Tests
('x,)
Cold-water solubility Hot-water solubility 1% NaOH solubility Alcohol-benzene ( 1 : 2) solubility Lignin Pentosan Cellulose Ash content Moisture content
12.5 14-1 38.5 13-6 23-3 24-0 58"3 2.5 9.6
Table 2. Fibre dimensions of Thysanolaena maxima
Minimum Maximum Average
Fibre length
Fibre diameter
(ram)
(pm)
0-73 2-07 1.25
0.005 0.020 0.010
Paperfrorn Thysanolaena maxima
247
Table 3. Properties of pulps
Property
Kraftp u l p
Initial freeness (CSF) Final freeness (CSF) Beating time (min) Screened yield (%) Rejects (%) on oven-dry chips Residual liquor pH
700 350 30 45 Nil 11.0
Soda-anthraquinone pulp 700 350 30 47.5 Nil 10-4
Table 4. Details of bleaching conditions
Particular
Kraftp u l p
Soda-anthraquinone pulp
Step 1 Consistency (%) Hypochlorite as available chlorine added in pulp (%) Temperature (°C) Time (min) pH (initial) pH (final) Brightness (%)
10 3.6
10 3"18
30 120 10.0 9.2 42
30 120 10.0 9-4 42
Step 2 Consistency (%) Alkali solution added (%) Temperature (°C) Time (min)
10 1 60 60
10 1 60 60
10 2.4
10 2"12
30 120 10 8-7 39.5 70
30 120 10 8"8 40.8 70
Step 3 Consistency (%) Hypochlorite as available chlorine added in pulp (%) Temperature (°C) Time (min) pH (initial) pH (final) Bleached pulp yield (%) Brightness (%)
Table 5. Properties of unbleached paper sheets
Property Basis weight (g/m 2) Bulk density (cm3/g) Breaking length (m) Burst factor Tear factor Number of double folds
Kraftp u l p 60 + 1 1-35 3840 38 102 12
Soda-anthraquinone pulp 60 + 1 1"34 3710 40 98 10
Table 6. Properties of bleached paper sheets
Property Basis weight (g/m2) Bulk density (cm3/g) Breaking length (m) Burst factor Tear factor Number of double folds
Kraft p u l p 60 + 1 1.29 3555 30 106 16
Soda-anthraquinone pulp 60 + 1 1-27 3450 28.6 108 15
248
D. C Saikia, T. Goswami, B. P. Chafiha
properties of the handmade sheets showed that good-quality writing and printing paper could be obtained from this raw material. The grass, if systematically cultivated, can become a potential supplemental raw material for the pulp and paper industry in India.
ACKNOWLEDGEMENT The authors wish to express their sincere gratitude to Dr J. N. Baruah, Director, Regional Research Laboratory, Jorhat, Assam, India, for permission to publish this paper.
REFERENCES Anon. (1976). Thysanolaena maxima. In Wealth of lndia, vol. X. Publications & Information Directorate, CSIR, New Delhi, India, pp. 237-8. Cunningham, R. L., Clark, T. F. & Bagby, M. O. (1978). Crotalaria juncea -- annual source of paper making fibre. TAPPI, 61 (2), 37-9. Ghosh, S. R., Saikia, D. C., Gohain, E & Chaliha, B. P. (1981 ). Water hyacinth (Eiehhornia crassipes) for paper and boards. Indian Pulp Paper Tech. Assoc., 18 (4), 1-9. Goswami, T., Ghosh, S. R., Hazarika, J. N. & Chaliha, B. P. (1982). Paper and paperboards from Sikkimensis grass
( Cymbopogon flexuous ). Indian Pulp Paper Tech. Assoc., 19 (4), 12-18. Shaikh, A. J. (1990). Blending of cotton stalk pulp with bagasse pulp for paper making. Bio. Wastes, 31, 37-43. TAPPI (1980). Standard and Suggested Methods. Technical Association of the Pulp and Paper Industry, New York, pp. T-200-65.