Vol. 36(2), 2012

Flax Fibre Extraction: Problems and Prospects for Machine Development

R. K. Naik1 (LM-10471), D. K. Mohanty2 (LM-10462) and U. N. Borkar3 1,3 Central Research Institute for Jute and Allied Fibres (ICAR), Barrackpore, Kolkata, West Bengal – 700120, 2 Krishi Vigyan Kendra, Deogarh, Odisha, Email: ranjanagrieng@ rediffmail.com

ABSTRACT is a fibre of plant origin. Fibre is obtained from the plant called flax or linseed (Linum usitatissimum L.). Flax fibre is mostly utilized in due to its good qualities. Flax fibre production in India is negligible and domestic requirement of fibre is met by import. Valleys of the Himalayan ranges are the ideal geographical regions for cultivation of flax for fibre purposes. The crop is grown for oil purpose in some states like Maharashtra and Andhra Pradesh but the stalks after deseeding which contain fibre remain unutilized. One of the major reasons is non-availability of suitable machine for fibre extraction. Some efforts were made at CRIJAF, Barrackpore to develop machine for extraction of flax fibre. This paper discusses the process of extraction of flax fibre and development of machine. Key words: Extraction, Flax, Fibre, Scutching

INTRODUCTION making it most suitable for the manufacture of better Flax (Linum usitatissimum L.) is known for its fibre grade , canvas, hosepipes and various military and oil yield. When cultivated for fibre it is known articles (Gupta et al., 2006). Flax fibre is also utilized as flax, possessing tall (about 1 m), and flexible for making high quality paper used in currency notes straw with comparatively poor yield of seed. When and legal papers etc. grown as oil seed it is known as linseed, The demand for flax fibre for its urgent and essential characterized with short (about 0.5 m) stature plant domestic purposes in India is fulfilled mostly through with flower and fruit bearing lateral branches yielding import of raw flax fibre from the foreign countries higher quantity of seed with high oil content. The like Belgium, the Netherlands etc. India has to spend ideal geographical regions envisaged for successful considerable foreign currency for importing flax fibre flax cultivation in India are the valleys of the for its need of textile industries (Rao and Rao, 1989). Himalayan ranges where the winter simulates a Despite evolvement of good number of varieties and European summer. A cool humid climate with standardization of agronomical practices of flax crop 0 0 temperature ranging from 10 to 27 C and a diurnal by the research institutions in India, the flax fibre fluctuation of relative humidity between 30 and 95 production could not be augmented. Also, huge per cent, cloudy weather during the growing period quantity of linseed straw remains unutilized for fibre is preferred. In the hot and dry climate, flax plants extraction. The major constraint has been reported tend to branch and grow as linseed. In India, linseed in the post-harvest processing of the crop i.e. fibre is grown as oilseed mainly in Madhya Pradesh, Uttar extraction from the harvested straw. Lack of feasible Pradesh, Maharashtra, Bihar, Rajasthan, technology for fibre extraction and high cost Karnataka, Andhra Pradesh, and West Bengal. involvement in fibre extraction has been reported Flax fibre, next to and jute, is valued for its as a major limitation in flax fibre production in India outstanding strength, fineness and durability. (Borkar, 2000). This paper discusses the process Softness, lustre, flexibility and quick water absorbing of extraction of flax fibre and development of capacity are some of the special qualities of flax, machine.

15 Agricultural Engineering Today

Fibre Extraction Process The straw consists of five sections, namely, the Flax plants are harvested by manually pulling epidermis, the part containing the fibre, and a instead of being cut because the flax tends to section of soluble matter connected to the woody deteriorate at the point of cut. Moreover cut plant is core which adjoins the pith tube. The purpose of shorter than pulled one and there is a consequent retting (rotting) is to separate the various layers, loss of fibre especially in short crop. Plants are preferably by first dissolving the less resistant semi- harvested at the crop age between 60 to 100 days, ligneous layer that connects the woody core to the preferably at the yellow ripe stage of stem bast which has the fibre strands. Retting on the other (Anonymous, 1986; Guleria and Singh 1983; Gupta hand, is a bacteriological action accomplished by et al. 2010) (Fig. 1). After crop harvest the following fermentation or decomposition induced by germ operations are carried out in sequence to obtain activity. If the flax straw are placed in water that the marketable raw flax fibre. allows the rapid propagation of bacteria, fermentation is bound to set in, which dissolves the i) Drying. gummy matter, but does not affect the cellulose fibre. In practice this action is accomplished by ii) Rippling or deseeding. letting the straw rot naturally. Retting is the most iii) Sorting and bundling. important operation in production of flax and has to be carried out with much care in order to obtain the iv) Transport of straw bundles to retting pool. best yield and quality of fibre. If retting is not carried v) Steeping of straw bundles in water for retting. out properly the fibre may be ruined, or may lose quality. Retting cannot improve the fibre which is in vi) Drying of retted straw. the straw, but proper retting can ensure that the vii) Scutching of retted straw to extract fibre. original properties of the fibre are maintained and not lost. Good judgement and considerable viii) Hackling to clean fibre. experience on the part of the retter are required, if Harvested plants/straw are left on the ground to dry the best results are to be obtained. for one or two days and then stooped to complete Flax straw bundles are steeped in water for retting, the drying, which may take about 15 days. After which is done in between 3 to 7 days according to drying, seed pods are detached by beating and the prevailing conditions. Poor qualities of flax are separating the straw. When the seeds have been retted only once. Sometimes, the better quality flax removed, the dried straw is sorted by hand, and is retted twice if the best results are to be obtained. bundles are made of straw of similar length and The second ret will normally last for about 1 to 2 quality. These straw bundles are carried to the water days only. The straw is considered retted when it pool or tank for retting. readily breaks without bending and the fibre loosens easily from the central woody core. After the straw has been retted, it is dried in the open by standing up the sheaves in the field so that they resemble a cone, with the lower part spread out in order to let the air circulate thoroughly. After about two day this is turned inside out, so that the inside can be dried. Drying may take three to four days, or longer, according to the weather conditions at the time. Sometimes, drying is done by spreading the straw on the ground and turning it frequently. Completely dried straw are ready for scutching operation. The aim of the scutching operation is to separate the flax fibre from the straw and to clean them and Fig. 1: Full grown plant. open them up. This is done by simply beating or

16 Vol. 36(2), 2012 scutching the straw to break the internal pith (or fibre yield. Mechanization in scutching operation is boon), and to free it from the fibres with as little highly required in order to reduce the human power damage to them as possible. In scutching, care involvement and achieve speedy operation. To must be taken that the fibres are not injured when mechanize the fibre extraction process some efforts the boon is broken; the more the boon is broken, were made by developing machines, manually the higher will be the yield of fibre and the better its operated as well as power operated for scutching quality. Scutching is done manually or with the help operation are described below. of machine followed by shaking and finally hackling to obtain marketable fibre. Hackling is an operation Flax scutching machine to lay the fibres parallel and to comb out the Manually operated scutching machine designed and and short ends. The scutched fibre strands are developed at CRIJAF in the year 1974 could drawn manually through a bed of metal teeth or increase the scutching capacity about 3 kg long fibre spikes (hackle) in a action. per day (0.5 kg/h, in 6 working hours) (Fig. 2). About 207 working days per hectare is required for About 3 t/ha yield of retted and dried straw is scutching 3.0 t straw. The machine requires two available for scutching operation, which is obtained men for its working, one to run machine and the from about 10 t harvested green bio-mass. After other for feeding straw and collecting scutched fibre. drying, the harvested green straw reduces to about The machine consists three sets of fluted iron rollers 4.5 t which contain seed about 500 kg. Retting and and one set of wooden roller in pairs (one above drying of deseeded straw further reduces its weight the other) in series through which straw passes for by about one-fourth. Scutching and hackling scutching action. Scutching efficiency with this operation yields about 600 kg long fibre, 500 kg machine is slightly more than the manual scutching short tow fibre and 1.8 t shives. However, the yield and results in production of more yield (620 kg/ha) of long fibre could be increased with the efficient of long fibre by reducing the tow fibre. Labour scutching operation that reduces the tow fibre. Fibre requirement for the scutching and hackling recovery from the straw could be obtained up to operation amounts to about 414 man-days/ha. 26% on dry weight basis under the perfect retting Capacity of the machine is not enough to reduce and scutching conditions. In case of linseed crop the cost requirement of fibre extraction and also the retted and dried straw obtained for fibre make it feasible to use in field condition due to higher extraction ranges in between 1.0 and 1.5 t/ha. time requirement. Manual scutching is done by beating the retted and dried straw with a wooden mallet to break up the boon or internal pith followed by shaking and hackling. A person could deal in a day about 5 kg straw and extracts about 1 kg long fibre. With this capacity about 600 man-days are required to extract fibre from the straw of a hectare area, in addition to the labour requirement for the preparation of straw at various stages i.e. drying, deseeding, retting and then again drying of straw for scutching, which consumes about 65 man-days. It shows high cost requirement as well as long period in scutching fibre with the manual method. Thus the manual scutching method is uneconomical as well as not feasible.

DEVELOPMENT OF MACHINES After retting, scutching operation carry utmost importance in extraction of quality fibre as well as Fig. 2: Flax scutching machine

17 Agricultural Engineering Today

CRIJAF Flax Extractor CONCLUSIONS CRIJAF has developed a power operated machine It is concluded from the above that using CRIJAF ‘CRIJAF Flax Extractor’ in the year 2007, to scutch Flax Extractor, the fibre yield increases to about 4% fibre about 3 kg/h (Fig. 3). The portable machine is along with reduction of man-days to about 83% per powered by 0.5 hp motor. Two men are needed for hectare. Hence flax fibre extraction with this fibre extraction, one for feeding straw and other for machine is economical in terms of labour cost. material handling. The machine delivers scutched Further, harvesting of flax crop at the optimum stage fibre at the straw feeding side below the feeding and proper retting are two critical steps, which hopper and the shives or waste collected at the other contributes to quality fibre. Hence, farmers need to side of the machine. About 84 kg straw is processed be sensitized and encouraged to take interest on in a day (6 working hours) and extracts about 18 kg adoption of appropriate production technology and flax fibre. To extract fibre of a hectare area the scutching machine for better fibre production. machine needs about 36 working days and 72 man- days for its operation. Scutching efficiency of this REFERENCES machine is slightly more than the manual scutching Anonymous. 1986. Salient research Findings on flax machine and yields fibre about 643 kg/ha. Flax fibre in Himachal Pradesh. Information Bulletin, extraction with this machine was found economical Himachal Pradesh Krishi Vishva Vidyalaya, than the earlier developed flax scutching machine. Palampur, Himachal Pradesh. pp-29. Borkar U N. 2000. Extraction of jute and allied fibres. In National Level Workshop on February, 22-26 at CRIJAF Barrackpore, W. B. pp-102-107. Guleria W S; Singh C M. 1983. Effects of cultural practices on growth, yield and economics of flax fibre production in the North Western Himalayas. Expl Agric.19: 87–90. Gupta D; Hazra S K; Saha A; Mahapatra A K. 2010. Prospects of flax cultivation in India. Jute and Allied Fibres- Production, Utilization and Marketing. pp- 136-140. Gupta D; Hazra S K; Saha A; Mahapatra A K. 2006. Flax – The fibre of linum. Information Bulletin No. 2, CRIJAF, Barrackpor, W. B. pp-34. Rao M V; Rao R. 1989. 40 years of agricultural research and education in India. Publ. and Inf. Fig. 3: CRIJAF Flax Extractor Div., ICAR. New Delhi. 96 - 97.

18