Chapter 3
VARIETIES OF NATURAL FIBRES
As metallic reinforcements and synthetic fibres are costly and not suitable for
sustainable development, there is a need for substitution by natural fibres to the extent
possible solely with treatment or by blending. India abounds in vegetable fibre sources
such as, sisal, sunn-hemp, ramie, banana stem, pineapple and screwpine leaves. Grasses
such as moonj and sabai also yield fibre. Extraction of fibre from plants and grasses and
manufacture of utility articles are traditional occupation in India. Available vegetable
fibres are mostly long and staple with considerable softness. The stiffness in the fibre is
due to the presence of gums, resins and pectins. These fibres are obtained from
leaves- (e.g. sisal, pineapple etc;)
barks- (e.g. jute, hemp, ramie, banana etc;)
husks of fruits- (e.g. coir, cocoa, arecanut etc;)
Of the entire plants- grasses, reeds, bamboo, etc and flowers- cotton etc. some are
fit for spinning and weaving after proper treatment. Some can be used for the wefts, some
for warps and some for both. Some fibres are not at all suitable for spinning but can be
woven into baskets and plaits.
A large number of fibres, particularly those found in the leaves and barks contain
certain amount of impurities which come in the way of spinning in unprocessed state. In
many cases, these impurities are part of the fibres in the form of wax, acid and gums.
Some of them can be separated easily but some are so closely bonded up that special and
prolonged treatment becomes essential to release them. The length of the fibre, crimp,
twist, tensile strength, elasticity and lustre are the main factors that decide the spinning
suitability of the fibres. The maturity of fibres and extraction processes determine these
factors to a great extent.
3.1 Leaf fibres
Leaf fibres are obtained from leaves of monocotyledonous plants. The fibres
occur in bundles. The position of fibres in the leaf is not uniform. The more important
among them are listed as
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3.1.1 Agave
Agave is a native of Mexico. The plants were later taken to Europe, Africa and
the Far East by the Spanish and the Portuguese. It was introduced in India during the
fifteenth century by the Portuguese and is now found all over the country. There are
about 275 species of agave. In India, some varieties of agave viz., sisalana, cantala,
veracruz are available. In common use, the word 'sisal' is popular. They are found mostly
along the railway embankments and roadsides. They are also cultivated on the hedges of
private fields to protect them from cattle and to prevent soil erosion. Of late, the forest
departments of state governments have taken up the cultivation of sisal on an extensive
basis.
3.1.2 Pineapple (Ananas cosmos)
The pineapple is a small genus, native to Brazil in tropical America. It was
introduced in India by middle of the sixteenth century. It has been acclimatized in Assam,
Bengal and along the west coast. Of about 90 varieties and sub-varieties, the Qinu and the
Kew are popular in India. It thrives best in places having mild and humid tropical climate
with annual rainfall of about 1250 mm spread over the year and a mean annual
temperature of 18° to 32°C. It is a perennial herb with short stem bearing a rosette of
leaves 60 cm to I m long; propagation is by suckers, stips and crowns. The suckers come
into bearing in 15 to 20 months while stips and crowns take 2 to 2 'l'2 years. Fibre can be
extracted from the leaves after they become about two year old and the fruits are
harvested either by retting method or by mechanical process viz. raspador.
3.1.3 Screwpines (Pandarus)
Screwpines are trees with large narrow spirally arranged leaves. They are found
mostly in tropics. An origin of Mauritius, screwpines was introduced in India during the
sixteenth century. The plants are abundantly grown in the southern states.
It is difficult to classify some fibres listed below as leaf or bast fibres. For e.g.
bast fibres are generally soft.
3.1.4 Banana and plantain
Several varieties of banana are cultivated in the country. The plant grows up to a
height of 4 m. The plants are cut down as soon as fruits are harvested for extraction of
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fibre. Both stems and the ribs of the leaves contain a very good quality fibre of
considerable length. Millions of stems, which are now left, to rot can be converted into
fibre and then into high utility articles such as saree cloth, paper, cordage etc. It is
reported that firms in Alleppey have started manufacturing of banana fibre fabrics besides
coir for export.
3.2 Grasses
Th~ grasses contain fibres. The extraction of fibres from grasses is not common.
They are twisted into twines, strings and ropes in their dry or semi-wet conditions.
3.2.1 Moonj (Saccharum cillare)
A tall grass about 3m in height grows in many parts of Punjab, U.P, Rajasthan,
M.P., Bihar and A.P. The extraction is possible by moistening and mallening. It is
extensively used in the manufacture of ropes, strings, mats, baskets and paper. Mattings
made from moonj are found to be resistant against termites. The stem is used for covering
carts. It is also used for manufacture of chairs (locally known as murha), tables, baskets
and screens as also covering for roof and storing purposes.
3.2.2 Sabai grass (Eulaliopsis bineta)
It is a perennial tufted grass with 0.60 to 2m length with erect, slender culms. This
is found all over India, but is abundant on dry, bare slopes and forest banks of Sub
Himalayan track growing uncultivated. Sabai grass is second only to bamboo in
importance as a raw material for paper manufacture.
3.2.3 Paddy grass
The straw, which remains after the paddy is threshed out, is an important cattle
feed. Only in few places, it is used for thatching cottages. Of late, it is being used for
packing bottles. But in Japan, ropes, bags, floor mats, baskets etc. are manufactured with
this grass. Straw mats and bags of paddy grass are used as substitutes for making sacks
and gunny bags in Japan.
3.2.4 Kora grass
About 60 species of this genus are available in India and five are important from
the fibre extraction point of view, especially for mat making. COf)mbosus or kora grass is
the most important grass in the mat industry. Golamethi, Mudarkati Mutha, Godu,
25
Thunga and Kadu are the other Indian names. It is a glabrous, robust sedge with 0.60 to
1.5 m height arising from a creeping woody rhizome. It is cultivated mostly in Tamil
Nadu and West Bengal. It is propagated by suckers or strips with bulbs containing short
lengths of culms. The value of the product depends on the quality and length of the
culms. The finest strands are used for exceptionally fine mats. The grass is to be soaked
in water mixed with bentonite clay for an hour, prior to weaving.
3.2.5 Elephant grass
Kno.wn botanically as Pennisstum Purpurem, this is a tall erect stout perennial
plant, which looks like a miniature bamboo plant. It is abundant in areas with an annual
rainfall of not less than 1000 mm. It grows to about 2.5 m in height and has a diameter of
20 mm at its base. The colour of the stem is pale or dark purple. It is usually found as
bushes rather than as a single plant and mostly along the sandy banks of streams or water
courses. The fibres close to the periphery of the stem are strong and closely spaced. The
distance between nodes range between 80 and 200 mm and this places a restriction on the
length of the fibre.
The fibres can be extracted mechanically between grooved and knurled headed
rollers in a roller crusher specially designed for this purpose. It was found that the
extraction would be very efficient if the grass is of diameter I to 2 cm. Further the
separation of the inner soft 'sap' fibre becomes difficult, i.f the grass is rolled in green
condition. If the grass is very dry, less separation and greater crushing, resulting in short
length large diameter fibres were found to occur.
3.2.6 Water reed
This plant is very similar to elephant grass in growth and size. But the stem is
hollow in the interior and the crest is fibrous and has a thickness of about 5 mm. This
hollow stem distinguishes it from elephant grass. The fibre can be extracted from mature
dry stems by hand cobbing and separation.
3.2.7 Bamboo
It belongs to the order of grasses. There are about 136 species in India. They
thrive best in monsoon. They differ widely in stature and fonn; some are as tall as 40 m
and some are only shrubs. Most of them are erect. They are usually hollow, round and
smooth. A few are solid also. They are known as male bamboos. They consist of fibre
26
bundles. The fibres are woody and brittle. It is very difficult to separate individual fibres.
These cannot be spun. It is used as a substitute for timber. Numerous articles of daily use
are made out of it viz., yoke, axles, tools, handles, fans, umbrellas, baskets, boxes and
furniture. It is also a good raw material for paper making.
3.2.8 Palm fibres
Palm has been called the 'Princess' of botanical kingdom. Palms contain about
270 genera with about 1,500 species. All are available in tropical regions. The coconut
palm (coco's nucifera), palmyra or bassine (borassus flabellifera), date palm (phoneix
sylvestris), sago palm (caryota urens), talipot (corypha umbraculifera) and canes
(calamus) are a few varieties of palm, which are exploited for the purpose of fibre
extraction.
3.2.9 Talipot palm
This is an erect handsome palm with tall stout trunk growing up to 30 m high and
0.5 to I m in diameter. It bears crown of large fan shaped leaves with stout petioles about
1.5 to 3 m long. The leaves are of one-sided umbrella type having opening from 2 to 5 m.
This palm flowers once in its lifetime in a span of 30 to 40 years. They grow wild. Fibres,
which can be extracted from the stalks, are found commercially useful. The trees are not
exploited for the purpose. The fibre is extracted by retting the stalks into 0.6 to 1 m long
pieces, soaking in water, pounding, them with a mallet and drying. The resulting thread
like tissues- fibres are used for making mats, wall hangings, purses, bags and other useful
articles in different colours and designs.
3.2.10 Kenaf
It is popularly known as Ambadi or Patsan. It is cultivated in India from pre
historic times as a supplementary crop. It occupies an important place in dry tracts of
Madhya Pradesh, Andhra Pradesh, and Bihar. In other areas, it is cultivated on a limited
scale. It thrives well in humid climate within a temperature range of 15° to 25° C. It
becomes ready for harvesting in 3 to 5 months. If harvested at the flowering stage, good
quality fibres can be obtained. The plants are cut close to ground or even pulled out, tied
into bundles of 30 to 40 stalks, let on the field for a few days to dry and then steeped in
water for retting. The period of retting varies from 6 to 10 days depending on the
maturity of stalks. The extraction of fibres can be done by using a mechanical
27
decorticator. It is used in the manufacture of fishing nets, tying rafters, coarse canvas,
sacks and floor mattings. It can also be used for paper making.
3.3.11 Hemp
Hemp fibre is obtained from plant - cananabinus sativa. In India it is grown for
the narcotics bhang, ganja and charas under a government licence. The plant is
considered to be a native of Western and Central Asia, but it is naturalised in northern
parts of India viz; Himachail Pradesh, Punjab, Haryana, Uttar Pradesh, Bihar and West
Bengal. The stalks after cutting are laid to dry for a week or so. Then they are steeped in
water for 15 days and beaten with mallets. It is possible to obtain superior quality fibre. It
should be dried in the sun thereafter and further beaten to obtain soft fibres. The fibre is
used for the manufacture of sackcloth, bags, ropes, etc.
3.2.12 Flax (Linseed)
These plants are grown for both fibre and seeds. The seeds yield linseed oil. The
varieties grown for fibres have straight, slender, pale green stalks. They are planted so
closely that they branch out only at the top. They grow to a height of 1 to 1.5 m, 4 to
12 mm in diameter. These plants are called fibre flax. The fibre flax when properly
processed is creamy white in colour varying with the skill and quality of retting. It is
highly lustrous. This is due to the wax it contains. The wax imparts better spinning
properties. The fibre is quite strong. It is absorbent. It resists the effects of mild-dew and
moisture. It takes all dyes readily. Flax is also called linen.
3.2.13 Sunn - hemp
It is a shrub, which grows to 3 m in height. The crop is annual. It is one of the
common cultivated crops for fibre or for green manure. It is also a good fodder crop. The
plant is indigenous to India. About 99 per cent of the world production of sunn - hemp is
in India and Bangladesh. It is cultivated throughout India. Uttar Pradesh accounts for 40
percent, Madhya Pradesh 10 percent and Andra pradesh, Tamil Nadu and Karnataka
share the remaining percentage of total acreage in the country. The plant grows to a
height of 3 m with 6 to 12 mm stalks in diameter. The plants are pulled out or cut close to
the ground tied into bundles and laid down to ground for 2-3 days for the leaves to drop
off. Retting is done similar to that in the case of jute. The duration of retting depends on
the temperature of water and the stage during which the plants are harvested.
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The yield of fibre is about 80 percent of the dry stem. The quality of fibre is
judged by length, fitness, colour, uniformity etc. The fibre is light in colour, possesses
greater tensile strength and is more durable under exposure than jute. Hence it is more
popular than jute and gets higher price in foreign markets. Sunn is resistant to sea water
and really a cordage fibre, is used for fishing nets, cot- stringing, mattings, coarse canvas
bags etc. It is well suited for the manufacture of wrapping paper.
3.2.14 Ramie
It is' a perennial shrub 1 to 2 m high with straight slender stalks of 6 to 12 nun
diameter. It grows best in a warm, moist climate, on an elevation of 12,00 to 15,00 m.
The propagation is usually by means of stem cuttings. Plants can also be raised either
from seeds or from roots (rhizomes). If properly cultivated, no replanting is necessary for
6 to 15 years. It takes about 10 months for the stems to mature after the first planting. For
better fibre, the stems are to be cut before they mature and begin to flower. Retting
method is employed for extraction of fibre. Fibres occur in the form of bundles with the
ends overlapping so as to produce continuous filament throughout the length of stalk.
They are held to each other by gums, waxes and pectins. After retting or decorticating the
stems, degumming process is necessary to make the fibres free from gums, waxes and
pectins. It resists the effects of bacteria and fungi. It is resistant to moisture and does not
change its colour when exposed to sun. The fibre is used to. make fishing nets, industrial
sewing thread, packing canvas, fire hose, filter cloth and upholstery fabric. The gas
mantles are also made out of it. It is a good substitute for cotton and sunn-hemp and a
raw material for papermaking. It therefore deserves consideration for cultivation and
exploitation on scientific lines.
3.2.15 Bagasse
Bagasse, the residue from sugar cane was originally tried for boards, but not
found to be very successful as reinforcement in cement sheets due to the poor alkaline
resistance. But bagasse reinforced phenolic composite sheets function satisfactorily. The
cost of these are however prohibitive.
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3.3 Jute
Among the natural fibres used for industry, jute and coir are the most important
fibres grown extensively in India and has many applications in civil engineering. Jute is
called the "Golden Fibre". This lustrous and tough fibre has now been brought into the
limelight in the form of new generation products. The first jute mill was established in
1855 in Bengal. It is a bast fibre obtained from the stacks of plants of the genus of
corchorus of tiliaceal family. The stacks range in height from 2 to 3 m and of diameter 12
to 18 mm. The plants can be harvested in about 120 days. Originally used for jute cloths,
geojute has now come to be used as a soil saver for erosion control and moisture
retention. The Indian Jute Industries Research Association founded in 1966 is
contributing to the development of the use of jute. The ability of jute to absorb water is a
unique property, which contributes to erosion control and moisture retention. It is very
light and highly drapable over the contours of land. Bituminised jute has been used
successfully as early as 1920 for road strengthening. Some of the major applications are,
river bank protection on Padma at Hasanpur, and Hooghly River at Barrackpur both in
West Bengal.
Jute is used both as woven and nonwoven products particularly for short term
applications of consolidation of subsoil. Jute drains are preferred for this (Chattopadhyay
and Chatterjee, 1996).
3.4 Processing of fibres
Natural fibres have to be processed to enable them to be made into geotextile for
civil engineering applications. These processes are different from those for geosynthetics
and also vary from one natural fibre to another. The following section describes the
sequence of operations mainly for jute and coir, the most common fibres, which hold
promise for geotextile applications.
3.4.1 Jute fibres
Sequence of processing:
Prior to 1960, rove spinning system was in practice and the sequence of jute
processing was as follows:
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softener/spreader breaker card finisher card first drawing (push bar) second
drawing (push bar) roving spInning
Etwisting
warp winding
weft winding
beaming weaving J. - s ewiing (Khatua and Neogi, 1998)
weavmg
From 60s, sliver spinning system was introduced discarding the roving operation
and the system of drawing with screw gill came into operation in place of the old method
of drawing with push bar. The modified sequence of processing therefore, became
softener/spreader breaker card finisher card first drawing (screw gill) second
drawing (screw gill) third drawing (screw gill) spInning
Etwisting
warp winding
weft winding
beaming weaVing] .- sewIng
weaving
One of the outlets for jute which is gaining importance is its blending with cotton.
3.4.2 Selection of appropriate processing sequence for jute/cotton blends
Jute has its own spinning system, which differs, substantially from cotton system
in its technological details. Cotton spinning system would be appropriate only if jute
fibres have a fairly uniform length, generally not exceeding 65 mm. So for processing
jute fibres on cotton system, jute fibres are cut to appropriate length.
Work carried out to produced jute/cotton blended yams on rotor spinning showed
that there was preferential falling of jute in large quantities during processing especially
at licker-in zone (Figure 3.1) during carding and at opening roller region during rotor
spinning. However, the causes and hence the remedial measures have not been reported
in the published literature. So it became a major research to avoid PF of jute during
processing not only to maintain desired blend composition but also to reduce loss of good
jute fibres and avoid reprocessing of these fibres.
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WN
Lickerin cover
40/60 Jute/Cotton lapFeed plate
SF Short fibresLT Lighter trashlIT Heavier trashJF Jute fibres
Figure 3.1: Jute falling at licker-in zone during carding
Back plate
The observations showed that the two places i.e. licker-in zone of carding and
)pening roller region at rotor spinning had two common features. Other types of
nachines need not have similar features:
(i) saw tooth type of beater (ii) sharp leading edge
To confirm whether these two features are the major reasons for PF of jute, the
material was processed on shirley type beater in blow-room and shirley trash analyzer,
which also have the above two features. Falling of substantial quantity of jute, confirmed
that, these' two features along with the coarseness and stiffness of jute fibres, are
responsible for preferential falling of jute. Further studies showed that (i) the lower the
jute content, the better the spinning performance and (ii) the coarser the count, the less
the end-breakage rate at rotor spinning. It was also found that (i) with the given blend
composition, the larger the rotor diameter, the better the spinning performance and (ii)
higher the jute content in the blend, the larger the diameter required for satisfactory
spinning performance.
The yam spun from tail fibre shows higher yam tenacity, better regularity and
improved performance. Ability of jute to absorb water is a unique property, which
contributes to its erosion control capability. Its high degree of drapability, i.e., ability to
maintain intimate contact with soil, makes it highly flexible compared to other alternative
fibres. Further, comparatively very low cost and easy availability of geojute along with
its eco-friendliness, make it an ideal material for use in case of filtration, separation,
drainage and erosion (Chattopadhyay et aI., 1998). A large number of geotextiles has
been developed by the Indian Jute Industry Research Association for different
engineering purposes (Datta et. aI., 1997). Geojutes have been applied very successfully
in many bank protection works on rivers and canals and safeguard banks from erosion
due to flowing water and wave actions.
3.4.3 Coir
There are four methods of extraction of coir fibres from the husk.
Retting
Crushing
Scraping
Hackling or combing
Of these, retting is the age old practice adopted in Kerala as it is cheap, but has an
33
adverse environmental impact.
Water retting:
Water retting consists of soaking or immersing the vegetable matter in the tanks,
pits, ponds, streams of slow moving water or in stagnant water. Bacterial action begins
within 24 hours of the immersion. It hydrolyses the gummy and resinous matter. The
micro- organism responsible for the action can act only in the water. The fibres in the
tender vegetable stage ret more easily than in an advanced stage. A higher temperature of
the water a9celerates the pace. In stagnant water, retting proceeds briskly for the simple
reason that as the hydrolysis proceeds, the temperature of the water rises. The water in
which retting has been done once, speeds up the retting of a fresh stock since the bacteria
once released is available for immediate action. This is not so in the case of the flowing
waters. The hydrolyzed matter is washed away by the new water replacing the old one.
Hence retting takes a longer time. But retting in the flowing water is of great advantage
as the fibres get a great lustre with white colour, called white fibre and hence fetch higher
price in the market. Those retted in stagnant water become coloured and dull in
appearance.
Over- retting destroys the strength of the fibres. It is therefore, necessary to be
very careful about retting operation and the fibres should be removed as soon as retting is
complete. Otherwise, the bacteria attack the fibres. Under- retting too has its own
disadvantages. It makes the fibres .coarse and harsh. The main objective of the retting is
to remove unwanted foreign and unuseful material. In some parts of the European
countries, the retting in natural ponds takes place. Natural ponds are replaced by
artificially constructed tanks of cement and concrete having covers. The temperature of
the water is maintained at 35° C. An outlet releases the acid water gently into another
tank. This water contains some bacteria, which become available for a fresh stock. The
process is costly but has the advantage in that the retting can be controlled.
Dew retting:
In dew retting, the fibres are evenly spread over grassy land. Due to the climatic
condition, the bacteria and moulds release the enzymes, which convert the gummy
substance into soluble material that may be washed away by dew or rain. This method
produces brownish or greenish fibres. Dew retting is practiced mostly in the case of flax.
In hot climate, putrification starts early and hence if possible, water and dew retting
34
should be avoided, particularly when the fibre is weak (viz, pineapple). But when the
retting is perfect, the product becomes soft, lustrous and fit for spinning.
Crushing:
A common or proper mode of cleaning certain varieties of vegetable matter from
the fibres is to crush the fibres between the rollers moving in opposite directions. To
begin with, the material is simply fed into rollers. When a degree of sap is removed from
them, they are twisted and subjected to the pressure of the rollers. It is further scraped by
blunt knife·for removal of the pulp etc. The fibres thus obtained are soaked in the water
for an hour or two, cleaned and then hung up to dry in shade. Drying under the sun
discolours the fibres. This process is followed in the case of sisal, agave and aloe fibres
also. This is called brown fibre.
Scraping or decortication:
This operation involves the scraping of the bark, rim or outer coat of the plant.
For this purpose, decorticators or raspadors are employed. This process is adopted for the
recovery of coir, sisal and other leaf fibres, viz. pineapple, as they do not contain woody
parts or bark. Gums and resins do remain in certain quantities after decortication.
Degumming is done by a chemical process, which is necessary before spinning. The
remaining gums, waxes and resins render the fibres brittle and cause entanglement of the
fibres with one another. Bacteria attack them easily. Hackling or combing operation is
not much in use because of many disadvantages.
Cleaning and spinning of fibres:
Various types of tools and equipment are used for different purposes. They are
simple hand tools and few power - operated machines.
The cleaning of retted fibres particularly from sisal, pineapple leaves and banana
stems is carried out by rapsador machine. The raspador machine consists of drum (35cm
diameter), the carbon steel angle blades fitted on the periphery of the drum and an
adjustable roller with scraping plate in front of the drum. The shaft carrying the drum is
fitted with ball bearings mounted on the framework. The drum rotates (700- 800 rpm)
with the help of an electric motor or an oil engine. The tip end of the leaf is inserted
between the adjustable rollers and the rotating drum to the extent of three fourth of the
leaf and then drawn back. The other end of the leaf is inserted into the machine by
holding the cleaned portion of leaf. Then the leaf is drawn back. This process produces
35
clean fibre. The roller and the drum is to be adjusted in such a way that the clean fibres
are obtained. The fibre is further cleaned in water and then allowed to dry. It requires
some skill for which practice is necessary.
Carding machine:
After extraction of fibre, the fibre strands are separated for further processing. For
this purpose the hand carders are used in the villages. A hand carder is a block of wood
on which the nails are set with pointed ends upwards. The fibres are brushed over these
nails. Fibre filaments are then separated and the pithy portion in fibres is removed.
Single ply machine:
Fibre filaments are twisted into plies by palms or by takli charkhas like batara
charkha or single ply machines known for their efficiency. The machine is used for
plying coarse as well as fine yam. It consists of a flyer and drying wheel, operated by
paddle as well as power. The flyer along with bobin is mounted on \vooden/metal
framework. Some length of yarn is wound on the bobin and one end is taken out through
a slide provided to the arm of the flyer. The combed carded fibre slightly moistened is fed
as soon as the flyer is set in motion. This operation gets the fibre filaments twisted into
yarn and wound on the bobin.
Ban making machine:
It is known as Japanese type 2- ply rope making machine. It consists of cast iron
case with twisters. Gear wheels and rope eyes are fitted on the wooden framework. 1\ext
to rope eye, a twisting wheel is fitted. A pair of drawing rotters is adjacent to the counter
twisters. The rear drum, fitted on the frame wheel is bolted to a flywheel. The flywheel is
connected to the main shaft to which the paddle is connected. Hard fibres and long staple
fibres like, moonj, bhabar, sisal, pineapple etc., are converted into two ply yarn. This can
be operated with paddle or power.
Coir spinning wheel:
The spinning wheel for banana, sisal and coir fibre consists of a stationary
spinning wheel having two to four spindles. The spindles are fitted on the arms of the
frame or on an arc made of iron. Each of these spindles is provided with a pulley at the
centre. A driving rope is passed round the pulley and over the flywheel mounted on the
shaft with handle. Another movable wheel carries one spindle. The workers feed fibre
36
walking backwards and a worker turns the handle of stationary wheel till the other worker
reaches the required distance. When the required length is reached, two of the plies are
put together into the notch of the movable wheel opposite the stationary one. These two
plies are guarded by a yarn guide and the movable wheel is turned. The rope is thus
ready.
Rope making machine:
This machine has five or more hooks fixed to pinion wheels, which are geared by
a gear wheel. The gear wheel is connected to a handle. For sturdiness, this assembly is
fitted on angle iron frames. There are two parts - a stationary machine and a hook or a
machine mounted on trolley. The fibre laps are converted directly into ropes. But for
strong cordage of ropes, it is desirable to use a number of twine yams already spun on
single ply machine. These yarns are further twisted into three or more equal parts. One
end of these yams is tied individually to the hooks of the stationary assembly (machine)
and the other ends of all strands to the opposite hook or to the trolley with hooks. Then
the rope guide is passed through the strands. The individual strands are given the required
twist by rotating the moving assembly. When sufficient twist is given to the strands, the
machine (hook) on the trolley is rotated in the opposite direction moving the rope guide
towards the stationary assembly till the rope guide reaches the assembly. The stationary
~ssembly is continued to be turned into its original di~ection. When the rope guide
reaches the stationary assembly, all the strands are removed from the stationary machine
(assembly) and a knot is given. Now the rope is ready which forms the basis for woven
37
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