Advantages and drawbacks of using non-wood fibre for papermaking

Some non-wood fibres used as raw materials for papermaking have high annual yields per hectare. The average annual yield per hectare of kenaf, a non-wood fibre, is about twice that of fast-growing softwoods (see table below) (Pierce, 1991). Non-woods have lower lignin content than woods and generally it is easier to delignify non-woods, as they have lower activation energies (Bobalek and Chaturvedi, 1989). 

Producing paper from non-wood fibres would help in reducing the need to procure pulpwood from natural forests, and for large-scale plantations. Under certain climatic conditions, non-wood fibre production may be a reasonable alternative to tree plantations. 

Average annual yields of different papermaking raw materials

Plant	Fibre yield	Pulp yield
	(tonnes/year/ha)	(tonnes/year/ha)
Scandinavian softwood	1.5	0.7
Fast-growing softwood	8.6	4
Temperate softwood	3.4	1.7
Fast-growing hardwood	15	7.4
Wheat straw	4	1.9
Rice straw	3	1.2
Bagasse	9	4.2
Bamboo	4	1.6
Kenaf	15	6.5
Hemp	15	6.7
Elephant grass	12	5.7
Canary grass	8	4.0

Leading sources of non-wood fibres

At the present time, the most commonly utilized non-wood fibre is straw, which accounts for 46 percent of total production (see table below). This is followed by bagasse (14 percent) and bamboo (6 percent) (Atchison, 1995). Other non-wood fibres such as cotton, hemp, sisal and kenaf are also becoming more important in the manufacture of pulp and paper.

Leading non-wood fibres

Raw materials	Non-wood papermaking pulp capacities
	1985	1988	1993	1998 (estimate)
	('000 tonnes)
Straw	6166	5260	9566	10187
Bagasse	2339	2267	2984	3682
Bamboo	1545	1674	1316	1850
Miscellaneous: cotton, reeds, sisal, jute, hemp, abaca, kenaf, flax	3302	6366	6870	7742
Total	13352	15567	20736	23471

                                

The current situation

On a global scale, non-wood fibres are a minor part of raw material supply to paper and paperboard manufacture. In many countries, however, they are still widely used and are of significant importance in terms of overall volume and as a percentage of total pulp supply. The following table gives an idea of current use of non-wood fibres in papermaking in the 18 countries that account for nearly 98 percent of world supply:

Leading users of non-wood fibres in papermaking

Country	1993		1998 (estimate)
	Non-wood pulping capacity	Percentage of total pulping capacity	Non-wood pulping capacity	Percentage of total pulping capacity
	('000 tonnes)		('000 tonnes)
China	15246	86.9	16830	84.3
India	1307	55.5	2001	61.3
Pakistan	415	100	415	100
Mexico	321	29.2	324	29.3
Peru	298	95.2	296	95.2
Indonesia	267	22.1	267	10.1
Colombia	218	45.1	218	37.2
Thailand	209	100	509	100
Brazil	196	3.1	238	3.3
Venezuela	185	75.2	187	75.4
United States	179	0.3	204	0.3
Greece	150	85.7	160	84.2
Spain	140	7.9	141	7.7
Argentina	140	14.6	140	12.8
Egypt	127	100	127	100
Italy	120	13.3	120	13.3
Cuba	108	100	108	100
Turkey	103	16.5	103	16.5

Source: Oye et al., 1991.

Non-wood fibres in papermaking: A brief history

Currently, wood is by far the major raw material for the global pulp and paper industry. It is, however, a relatively new raw material in papermaking. Historically, paper was made exclusively from non-wood plant fibres. The first true production of paper is credited to T. S'ai Lun in AD 5 in China. This first paper was apparently made from textile wastes, old rags and used fishnets, which consisted of the fibres of true hemp and China grass (ramie) (Atchison and McGovern, 1993).

While non-woods were originally used for papermaking, in the late seventeenth century wood became the predominant fibre source in Europe. The seemingly inexhaustible supply and versatility of wood were the major causes of this shift. Today, most modern pulp and paper enterprises rely on wood (Smook, 1992). 

Background

Formed from wood pulp or plant fiber, paper is chiefly used for written communication. The earliest paper was papyrus, made from reeds by the ancient Egyptians. Paper was made by the Chinese in the second century, probably by a Chinese court official named Cai Lun. His paper was made from such things as tree bark and old fish netting. Recognized almost immediately as a valuable secret, it was 500 years before the Japanese acquired knowledge of the method. Papermaking was known in the Islamic world from the end of the eighth century A.D.

Knowledge of papermaking eventually moved westward, and the first European paper mill was built at Jativa, in the province of Valencia, Spain, in about 1150. By the end of the 15th century, paper mills existed in Italy, France, Germany, and England, and by the end of the 16th century, paper was being made throughout Europe.

Paper, whether produced in the modern factory or by the most careful, delicate hand methods, is made up of connected fibers. The fibers can come from a number of sources including cloth rags, cellulose fibers from plants, and, most notably, trees. The use of cloth in the process has always produced high-quality paper. Today, a large proportion of cotton and linen fibers in the mix and create many excellent papers for special uses, from wedding invitation paper stock to special paper for pen and ink drawings.

The method of making paper is essentially a simple one—mix up vegetable fibers, and cook them in hot water until the fibers are soft but not dissolved. The hot water also contains a base chemical such as lye, which softens the fibers as they are cooking. Then, pass a screen-like material through the mixture, let the water drip off and/or evaporate, and then squeeze or blot out additional water. A layer of paper is left behind. Essential to the process are the fibers, which are never totally destroyed, and, when mixed and softened, form an interlaced pattern within the paper itself. Modern papermaking methods, although significantly more complicated than the older ways, are developmental improvements rather than entirely.