SISAL FIBRES BY NCFA TEAM 

1. Historical and Botanical Information

Sisal, botanical name Agave sisalana, is a species of Agave native to southern Mexico but widely cultivated and naturalised in many other countries. Agave sisalana is a native of the Yucatan area of  Mexico where the fibre has been used by the native Mexican people for centuries. Later, around  1836, sisal was introduced in Florida. Other than Mexico, wide cultivation of sisal was started in  Tanzania, where it was introduced by Dr. Richard Hindorf, an Agronomist from Germany. Currently, major sisal-producing countries are Brazil, Kenya, Tanzania, Madagascar, China, Mexico, and Haiti.  China is the largest sisal fibre importing country, followed by Spain and Mexico, whereas Brazil and  Kenya are the main sisal fibre exporting countries. Sisal is a xerophytic, monocarp, semi-perennial leaf fibre-producing plant. It yields a stiff fibre used in making various products. The plant has a short stem, bears a rosette of sessile leaves, and linear-lanceolate attains a length of 1-1.5 m or more.  Leaves are thick, fleshy, and often covered with a waxy layer. Sisal fibre is extracted from the leaves of the plant Agave sisalana. 

In India, four main varieties of sisal plants are found—Sisalana, Vergross, Istle, and Natale. Different varieties of plants have different yields of fibres. Leaves from the first two varieties yield more fibres than those from the other two. The fibre content also varies with the age and source of the plant. The chemical composition of the leaf is moisture (87.25%), fibre (4%), cuticle (0.75%), and other dry matter (8%). The length of the fibre varies from 80 to 120 cm. The ends of the fibre are broad and blunt. Cells which are angular in shape are normally 500–6000 µm long and 5–40 µm wide, giving a maximum aspect ratio (length/diameter of fibre) of 150. Calcium oxalate crystals are present in parenchyma circular and are often found packed with tiny globules. The sisal leaf contains mechanical, ribbon, and xylem fibres. The lifespan of a sisal plant is about 10-12 years, during which it produces 200-250 usable leaves. Each leaf has about a thousand fibres that can be used to make ropes, paper, and cloth. Recently, it has been used to make a highly absorbent material as well. Sisal productivity is highest in China (4,000 kg/ha). The average yield of sisal fibre in India is poor and does not exceed 600 kg/ha. But with proper care and attention and by using improved cultivation techniques, the fibre yield could be achieved to 1500 kg /ha. 

2. Agronomic Conditions and Production of Sisal Fibres

Sisal grows best in subtropical climates. The plant grows well in hot climates with temperatures between 10°C to 32°C. The plants are not frost tolerant and produce the best in areas with an annual rainfall of 500 mm and higher. Sisal can grow in areas with less or erratic rainfall. In high-rainfall areas, production may become problematic due to weed infestation and the occurrence of diseases.  Waterlogging causes stunted growth. As the flowers of sisal begin to wither, buds growing in the upper angle between the stem and flower stalk, develop into small plants, or bulbils, that fall to the ground and take root. Sisal plants grow best in well-drained loamy soil. Sisal can be cultivated in most soil types except clay and has a low tolerance to very moist and saline soil conditions. Soil pH between 

SISAL FIBRES  BY NCFA TEAM 

4.0 pH and 6.0 pH are important for cultivation. Transplanting the sisal from its secondary buds is usually done before the beginning of the rainy season when the land is still dry because this will limit disease infection and weevil attacks. Sisal is an environment-friendly fibre plant and almost no fertilisers are used in its cultivation. 

The global sisal fibre production is around 4.5 million tons every year. In the present time, Brazil is the largest producer of sisal in the world (86060 tons/year). Sisal is also produced and cultivated in other countries such as Tanzania (34,875 tons/year), Kenya (28,000 tons/year), Madagascar (18,950  tons/year), China (16,500 tons/year), Mexico (12,000 tons/year), Haiti (9,000 tons/year), etc. In East  African regions, most of the sisal that is grown is in large plantations and exported, but in Brazil, it is mainly grown by smallholders and used within the country. The sisal fibre produced in Brazil is graded as lower quality than the ones produced in East African regions. The main reason behind this is the usage of less efficient decortication machinery. The weather quality and the drought situation also impact the quality of sisal fibre.  

In India, sisal is mainly found in Orissa, Maharashtra, and southern states. Types of sisal available in  India are Agave sisalana, Agave cantala, Agave vera-cruz, Agave amaniensis, Agave angustifolia and  Agave fourcryodes. Among these types, A. sisalana is the commercial type and is used for fibre production. 

3. Optimum Agro Climatic Conditions and Cultural Practices 

3.1 Agave, in general, is well adapted to arid environments as the species is xerophytic. It can withstand a maximum temperature of nearly 50oC and grows well with evenly distributed rainfall of 600-1250 mm. Excessive rains (causing water stagnation) and very low temperatures cause frost to tend to damage the plantation. 

3.2 Characteristics of the Soil  

Sisal thrives best on dry, permeable, sandy-loam soils with a good quantity of liming materials (Ca and  Mg) but can also grow on various other types of soils. In India, it is grown in light calcareous and gravelly soils with good drainage. Heavy soils having the possibility of water logging are not suitable as the condition causes pale and stunted growth of sisal. Adequate calcium in the soil promotes the development of the root system. It has been tested that red earth and coral limestone give a higher fibre yield of sisal. Acidic soils with poor calcium content are not suitable for sisal plantations. Moderate wastelands can also be utilised for sisal with economic benefits provided adequate care is taken by fertilising the crop and adopting suitable agricultural practices including soil ameliorants. 

3.3 Planting in the Main Field  

Grading of sisal planting materials has proved beneficial, but it is not in practice in India due to several factors including a shortage of planting materials. The planting materials should not be kept in heaps. It may be kept for 30-45 days on soil under shade in a single layer without any adverse effects on growth and fibre yield.  

3.4 Land preparation and plantation of sisal saplings. 

Being a xerophytic and hardy crop, lands available for sisal cultivation are often sloppy, and eroded and most of them are without any vegetation cover. So, it is not advisable to plough-open the whole area encouraging further erosion. Pit planting is recommended for such land situations.

SISAL FIBRES BY NCFA TEAM 

Fig 2. A sisal plantation in Morogoro, Tanzania 

3.4a Size of Pits  

A pit size of 1 ftX3ft is preferred for getting fast and uniform growth of sisal plants. Pits are dug during summer months and filled up with soil-organic matter mixture. Soil ameliorants may be used in the pits to rectify the pH of the spoil. 

3.4b Planting Method  

Two methods of planting are followed. The single-row planting method is conventionally practised and is less profitable. Whereas the double row planting method has several merits including checking soil erosion, accommodating more plants/ha and giving higher yield. Rows are made across the soil slopes. 

3.4c Spacing

Plant density depends on the nature and fertility status of the soil, type of farming, investment, and management capacity of the grower. The following spacings are suggested to be suitable for plantation. 

✓ 4 m + 1 m × 1 m (4000 plants/ha) 

✓ 4 m + 1 m × 0.8 m (5000 plants/ha) 

✓ 3 m + 1 m × 1 m (5000 plants/ha) 

✓ 3 m + 1 m × 0.8 m (6250 plants/ha) 

✓ 2 m + 1 m × 1 m (6666 Plants/ha). 

3.4d Time of Planting

Planting should be taken up with the onset of monsoon so that plants get sufficient time to establish well during the favourable rainy season. 

3.4e Gap filling

Even after careful planting, non-surviving gaps are common; so, gap filling is necessary in the next rainy season if irrigation facilities are not available. 

3.4f Mulching

Sisal waste can be used as good mulching material to conserve soil moisture. It can also improve soil conditions and add nutrients to the soil. Mulching can also be practised by using locally available grasses and other weeds before flower or seed formation.  

3.4g Intercropping

During the initial three-year growth period of sisal, harvesting of leaves is not recommended and during this phase, inter-row space may be utilised by practising intercropping in a double-row planting system. Crops like horse gram, black gram, finger millet and other small millets can be intercropped successfully.

SISAL FIBRES BY NCFA TEAM 

3.4h Key Factors for Sisal Growing 

• Needs constantly hot temperatures above 20°C to grow well. 
• Grows well at an altitude of about 900–1500m above sea level. 
• Requires an annual rainfall of about 650mm during the planting season and can also tolerate drought. 
• A long dry season for harvesting the crop. 
• Requires moderately fertile sandy-loamy soils for growing the crop. 
• A large labour force is needed especially during the planting and harvesting season. • Extensive and flat landscape because the crop can’t be grown alongside other crops and needs a lot of spacing. 
• Availability of ready market both local and international to sell the crop. 

4. Features of Sisal Fibres

 4a. The leaf of the sisal plant will be dark green. Sisal fibre is derived from an agave (Agave sisalana). It is valued for cordage because of its strength, durability, ability to stretch, affinity for certain dyestuffs, and, like coir, it is resistant to deterioration in saltwater. The higher-grade fibre is converted into yarns for the carpet industry. Sisal fibre has higher strength and modulus, easy accessibility, low price, high durability, and recyclability with lower maintenance, wear, and tear. It has high water absorption power. 

4b. Sisal fibre, being extracted from the ever-enduring Agave plant, offers an impressive array of benefits and features. Apart from being constructed from a sustainable, renewable, and natural resource, sisal fibre is moth & rot-resistant, anti-static, anti-bacterial, dust & mite resistant, is a great heat and sound insulator, regulates environmental moisture and is biodegradable. 

4c. Most importantly, sisal is durable and has a stunning natural & textured aesthetic and will easily work in living spaces for very many years to come. 

4d. Sisal fibres are highly absorbent, and when the rug gets wet, it can soak up water like a sponge. 

4e. Sisal fibre is exceptionally durable with low maintenance with minimal wear and tear. 4f. It is biodegradable and recyclable. 

4g. Sisal fibre being anti-static, does not attract or trap dust particles and does not absorb moisture or water easily. 

4h. The fine texture of sisal fibre takes in dyes easily and offers the largest range of dyed colours of all-natural fibres. 

4i. It exhibits good sound and impact-absorbing properties. 

4j. Some of the major properties are as follows: 

• Length: The average length of strands of sisal fibres varies from 80-120 cm in length. 
• Cross-section: The cross-section of sisal fibre is not uniform throughout its length. Depending on the location and rainfall, it is either circular or sometimes elliptical. 
• The longitudinal shape of the sisal fibre is cylindrical. 
• Diameter: The sisal fibre has a diameter of 0.2 – 0.4 mm. in diameter. 
• Appearance: Sisal fibres are smooth, straight, and yellow. The surface of sisal fibre is coarse and inflexible, but they are lustrous in appearance. 
• Density: Sisal fibre has a real density of 1.45 g/cm3 and an apparent density of 1.20 g/cm3. 
• Tensile strength: The tensile strength of sisal fibre is around 400-700 MPa. 
• Durability: Sisal fibre is exceptionally durable and has low maintenance with minimal wear and tear. 
• Anti-static property: Sisal fibres are anti-static, and do not attract or trap dust particles. 
• Moisture Regain: Moisture regain of sisal fibre is 11(%) at 65 % relative humidity (RH) and 32(%) at  100 % RH. The Moisture absorbency of sisal fibres is very bad as they do not absorb moisture or water easily. 
• Dyeability: The fine texture of sisal fibres takes dyes easily and hence can be dyed in a large range of colours.

SISAL FIBRES  BY NCFA TEAM 

• The Chemical components of sisal fibre (% by weight) is as follows: 

Sl. No	Details	%
1	Cellulose	55-65
2	Hemi-cellulose	10-15
3	Pectin	2.0 -4.0
4	Lignin	10-20
5	Water soluble materials	1-4
6	Fat and wax	0.15-0.3
7	Ash	0.7-1.5

5. Harvesting of Sisal 

Harvesting is carried out by hand. All lower leaves, standing at an angle of more than 45 degrees to the vertical, are cut away from the bole of the plant with a sharp flexible knife. First cutting, in general, starts at 3 ½ years of crop age. However, in an intensive cultivation programme with appropriate care, the first harvest can start at 2 ½ years of age. At first, cutting 16 leaves and in each subsequent cutting 12 leaves are left on the plant. Harvesting from November to February is advised considering several factors like comparatively lower temperature, minimum rain hindrance,  restricted active growth and economy in harvesting and extraction operation. After cutting, the leaves are bundled (say 50 numbers) and the bundles are transported to the extraction unit.  Extraction of fibre is done on the same day or preferably next day as early as possible. 

6. Extraction of sisal fibres

After harvesting, the leaves are transported to a central factory and decorticated to extract the cortex of ribbon fibres that run along the length of the leaves. Fibre is extracted from the harvested leaves by using decorticators. Two types of decorticators are used. Raspador-type decorticators redesigned at Central Research Institute for Jute and Allied Fibres (ICAR), Barrackpore, West Bengal are now widely used in India. These are one drummed and single feeder decorticators which are run by 5 HP diesel engines. AC-operated motors can also be used in place of diesel engines. Leaves are fed into the machine’s mouth by one person. A 6 distinctive feature of this type of raspador is that the leaves enter the machine endwise to make a rasping action gradually. On entering, the knives/blades progressively smash and tear off the leaf tissues at closely and regularly spaced blades. The fibre portion of the leaf remains in the hand of the operator. The average output of these decorticators is  100 kg wet fibre/day. The said small decorticators are easy to work and cost only Rs 12,000. With some modifications, these decorticators have been converted to two men-fed decorticators (double-fed). The fibre output is nearly double as compared to the one-man-fed decorticators. Automatic fibre decorticators consist of two covered drums placed at opposite sides of a central line along which the leaves are conveyed, and the fibre is delivered after decortications. In this process, the leaves enter crosswise instead of endwise and decortications take place in one full swoop. All the leaf tissues are crushed and scraped off the fibres almost simultaneously because the feeding of leaves can be done at a much faster rate. Such a decorticator can extract 25,000 leaves or 10 tones leaves by weight/hour. These decorticators are not manufactured in India.

Extracted fibres are extensively washed during decortication, sun-dried, brushed to separate, and align the individual strands of fibre, graded, and packed into bales. The sisal fibre obtained after crushing is cleaned with water to remove the dust and the extra water. Then, the fibre is placed for drying.

SISAL FIBRES BY NCFA TEAM   

Fig 3. Sisal fibre drying machine in Java. Fig 4. Sisal fibre   

7. Processing of Sisal Fibres

7a: Bleaching of Sisal Fibres 

After decortications, the fibres are washed in water and then spread in thin layers on ropes or iron wires till it is adequately dry. Drying machines can be used to dry the fibres faster. Thereafter the fibre is beaten with round wooden poles to remove foreign cells/materials which remain attached to the fibre during the extraction process. Usually, the dried fibres show slight greenness in colour. To make fibres white, the greenish fibre is spread under direct sunlight on the cement or grass floor the next day. The green-coloured fibres bleached quickly to whiteness in the presence of moisture; hence,  water is sprinkled over the fibres to accelerate the bleaching process. On completion of drying, fibres are collected in small bundles and then baled for transportation and marketing. Some degree of occupational hazards is involved in sisal fibre processing. Processing of sisal fibres has a high prevalence of acute respiratory symptoms. Brushing workers are more affected than the decortication workers. A mask is recommended to be used to overcome dust allergy/ pollution. 

7b. Spinning Process 

After cleaning and drying, the sisal fibre bale is sent to the sisal yarn manufacturing factory. Before use, the fibres are sprayed with certain moisture and sesame oil to make sure the process goes smoothly. Then to comb fibre, a sisal combing machine is used. This makes the sisal sliver to be of average size and straight. After the combing process, the sisal fibre is sent to the drawing machine for drawing processing. There the sisal sliver is passed through a series of rollers, resulting in straightening the individual fibres and making them more parallel. And finally, for making yarns, the fibres are then sent to the spinning machine.

SISAL FIBRES  BY NCFA TEAM 

8. Typical Uses of Sisal Fibres

8.1 The sisal fibre is traditionally used for rope and twine and has many other uses, including paper,  cloth, footwear, hats, bags, carpets, geotextiles, and dartboards. It is also used as fibre reinforcement for composite fibreglass, rubber, and concrete products. It can also be fermented and distilled to make mezcal. 

8.2 Sisal pulp and paper – As sisal biomass contains a high proportion of cellulose, its pulp is a substitute for wood fibres and adds bulk to paper and cardboard as well as being absorbent and having high fold endurance characteristics making it a high-quality input for paper products. Given its porosity, it can be used in cigarette paper filters and things like tea bags. 

8.3 Traditional – Twine, ropes, string, yarn which can also be woven into carpets, mats, and various handicrafts. 

Fig 5: Sisal fibre products (a-f) (Image courtesy: sagepub.com) 

8.4 Textile – A major use of the fibre is in buffing cloth because sisal is strong enough to polish steel and soft enough not to scratch it. The use of sisal in non-woven textiles is also of prime significance,  as sisal is an environmentally friendly strengthening agent to replace asbestos and fibreglass in composite materials. This has led to increased employment of sisal fibre in the automobile industry. 

8.5 The use of sisal fibre depends on its grade. The main use of sisal fibre is for the manufacturing of ropes and twines and other forms of cordage; although, a considerable quantity of fibres are also utilised for padding and upholstery and formats as well as for bags and sacking. 

8.6 Other uses include sausage casings, reinforced plastics and building boards, carpets, crafts and speciality papers, different types of nets and brushes, straps of different uses, and ladies’ fancy purses and belts. 

SISAL FIBRES BY NCFA TEAM 

8.6 Microcrystalline cellulose (MCC) derived from sisal are as good as other industrial MCCs used in the medicine industry. 

8.7 Sisal plants with leaf spines can be used as Live Fences for controlling grazing by stray cattle/animals.  

8.8 Sisal Plant Parts Contain 0.05-0.14% Hecogenin, a glycoside of commercial importance.  Hecogenin is one of the important precursors for the synthesis of steroid hormones (cortisone,  cortisol, progesterone, stanozolol etc). Rough agave flower (Agave scabra) has the potential to  partially replace alfalfa in diets for growing goats [Rangeland Ecol Manage, 

8.9 Shipping Industry: Sisal is used commonly in the shipping industry for making products like mooring small craft, lashing, and handling cargo. 

8.10 Industrial Purpose: Sisal fibre is also used as the fibre core of the steel wire cables of elevators,  because of its lubrication and flexibility purposes. 

8.11 Automobile Industry: Sisal fibre is used in the automobile industry with fibreglass in composite materials. 

8.12 Building Materials: Sisal fibre can be used in making construction materials such as cement composites. Due to lower costs, sisal fibre-reinforced cement is used to make products such as tiles,  bricks, water tanks, and roofing sheets. 

8.13 Fashion Accessories: Sisal fibre is used to manufacture various fashion accessories such as footwear, hats, bags, etc. 

8.14 Upholstery: Sisal is also used in manufacturing carpets or in blends with wool and acrylic for a softer hand. The higher-grade sisal fibres are converted into yarns which are used to manufacture carpets. 

8.15 Paper Industry: The lower grade of sisal fibre has a high content of cellulose and hemicelluloses because of which it is used by the paper industry to manufacture paper. 

8.16 Cordage Industry: The medium grade of sisal fibre is used for making ropes, balers, and binder twine. These products are used in various other industries such as marine, agricultural, and general industries. 

8.17 Other types of products developed from sisal fibre include spa products, cat scratching posts,  lumbar support belts, rugs, slippers, cloths, and disc buffers. 

9. Bibliography
10. chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/.
11. https://krishi.icar.gov.in/jspui/bitstream/123456789/38805/1/Paper_19.pdf 3. https://nedia.com/sisal-fibre/
12. https://www.textilesphere.com/2020/03/sisal-fibre-properties-applications.html 5. https://www.yarnsandfibers.com/textile-resources/natural-fibers/plant-cellulosic-fibers natural-fibers/sisal-fiber/about-sisal-fiber/what-is-sisal-fiber/

SISAL FIBRES  BY NCFA TEAM 

6. “Agro Textiles and its Applications”, Grace Annapoorani; Woodhead Publishing India Pvt Ltd;  2018 
7. “Handbook of Properties of Textile and Technical Fibres”, A volume in The Textile Institute Book Series. Book (Second Edition), Edited by: Anthony R. (Pub.)2018. 
8. “Fibres to Fabrics” Bev Ashford, Author House UK, 2016, (ISBN 9781496984685) 9. “Bast and Other Plant Fibres” Elsevier,2005, Edited by Robert R Franck (ISBN: 9781845690618)