STUDIES ON NONWOVEN FABRICS PRODUCED FROM MESTA AND ITS BLEND
Introduction
Mesta is a bast fiber which grows extensively in India and also in some parts of Eastern Asia. It is used as a substitute for jute.
The fiber of Mesta is obtained from stem of Hibiscus sabdariffa var. altissima and Hibiscus Cannabinus, family Malvaceae. Hibiscus sabdariffa and Hibiscus Cannabinus denote varieties of the two species.
The area which favours for mesta fibre cultivation are within the jute belt, the yield of mesta is high in West Bengal, Bihar, Assam and Tripura. Outside the jute belt, the highest acreage is in Andhra Pradesh and the areas assuming importance are Dandakaranya, Orissa, eastern Madhya Pradesh, Maharashtra, Karnataka and Uttar Pradesh. Other states grow Hibiscus Cannabinus types over small areas, mostly for home consumption. Yield in the drier areas is a less than that in the humid ones.
The favourable climatic conditions are a warm and humid climate suits both Hibiscus sabdariffa and Hibiscus Cannabinus varieties. Both these varieties grow in drier rain fed areas, the latter being more drought-resistant.
In areas with 500-900 mm of rainfed, Hibiscus Cannabinus suits better by virtue of its shorter duration and faster growth. Neither varieties can withstand prolonged water-logging. Both the kharif crops and are sown in April-June with the first showers of the monsoon. Heavy, continuous rains and low temperature are harmful.
Both varieties of mesta grow on a variety of soils, including new and old alluvium soils. However, the rich loams give the highest yield, but acid soils are not suitable without amendment. With a high pH (above 7.0) of the soil, chlorosis appears in HS mesta. Both are unfit for low-lying areas, subject to inundation. The cultivators in India, in general, grow mesta in relatively poorer soils without much care as profits are marginal.
Soil for the mesta crop is prepared in much the same way as in the case of jute. Hibiscus Sabdariffa when sown broadcast, requires 12 to 17 kg of seed per hectare. Seedlings, when 10-12 cm tall, are manually thinned in two installments to a spacing of 15-18 cm between plants. When raised in rows, seed is drilled 30 cm apart, the seed requirement being 10-12.5 kg per hectare. Seedlings are manually thinned to 12-15 cm apart in the rows. A minor adjustment in spacing is permissible on the basis of the fertility of the soil, rainfall and the nature of the soil.
The fertilizers and nutrient management for the fibre cultivation depends on, Hibiscus Sabdariffa variety of mesta fibre crop responds well to the application of nitrogen from 25 to 60 kg per hectare, depending on the soil type, the method of application and the rainfall. In drier areas, a basal dose of 20 kg of Nitrogen has been found consistently giving 25 per cent higher yield. In areas having a better rainfall pattern, the quantity of nitrogen can be increased to 40 kg per hectare, and the application may be one-third of the basal dose and the remaining may be top-dressed in one or two installments between 45 and 70 days of sowing.
Although the application to soil ensures best results, nitrogen as urea can be fed through foliage at the rate of 15 kg of Nitrogen per hectare. Five kilograms of Nitrogen in 100 litres of water is sprayed with a low-volume power sprayer. A single spray is effective between 30 and 75 days from the time of germination. A high pH of soil leads to chlorosis in Hibiscus Sabdariffa varieties because of iron deficiency ; such soils are not to be used for growing mesta.
‘Hibiscus Sabdariffa 4288’ is harvested when 50 per cent of the plant population is in flower delayed harvesting give more fibre, but of coarser quality. ‘Hibiscus Cannabinus 583’ is harvested usually a month or more earlier. In Andhra Pradesh, plants are harvested by uprooting, which practice is not recommended in the jute belt, they are cut close to the ground, as in the case of jute. All Hibiscus Sabdariffa types are of longer duration (180-210), whereas Hibiscus Cannabinus flowers in about 150 days after sowing.
Retting is done in the same manner as in the case of jute, but the low temperature and the paucity of water or both pose a problem. The harvested stems of both Hibiscus Sabdariffa and Hibiscus Cannabinus can be stored under dry conditions for retting next season during the middle of the monsoon. The resulting Hibiscus Cannabinus fibre is better than that of Hibiscus Sabdariffa. Retting in the current season, if possible, is always preferable.
The quality of the mesta fibre is judged on the basis of almost the same criteria as in the case of jute and the grading is done on the same lines, although the I.S.I. specifications are now due.
Materials
The materials used for producing the pure Mesta nonwoven is the mesta fibre with 50mm staple length and the fineness of the fibre is about 249m.tex.
The materials used for producing the mesta blended nonwoven is the mesta fibre with 50mm staple length and the fineness of the fibre is about 249m.tex and the jute fibre with 50mm staple length.

Process Sequence
Results & Discussions
Areal Density (g/Sq. m)
From the result it is observed that the GSM of the 100 % Mesta fibre 70-30 and 50-50 blend is more or less equal. But while analyzing the individual GSM results 100 % pure Mesta fibre have wide range of GSM variation this is due to the high fibre stiffness.

Spray rating test
From the Below results the absorbency property for the blend proportions 50/50 and 100% mesta are lower when compared to other three blends so these three blends can be used for sweeping cloth, table mats for the purpose higher absorbency.

Air Permeability
From the below graph it is clearly understood that the air permeability of the 90% mesta with 10% jute nonwoven is high when compared to other samples so this material can be used as air filtration fabrics. And this can be used as back filling fabrics in A/C ductile instead of jute.

Surface Analysis through SEM
The Surface of the Mesta fibre is similar to that of jute. this helps to have a better mixing & fibre transportation while laying. Similar surfaces in the fibres will also help to maintain the inter fibre cohesive force hence there will not be any localized fibre slippage in the needled felts.

Tensile Properties
The Maximum load reduces with the increase in Mesta fibre proposition since the <esta fibres are stiffer than the jute fibres the needling process under the standard manufacturing will not transfer more Mesta fibres from top to the bottom thus the mechanical strength is lower. it also reflects in the elongations for the fabrics.

Tearing Strength & Flexural Rigidity
From the below result, it is clear that 90-10 blend has higher tearing strength value. Here the pure Mesta has lower tearing value when compared to 90-10 blend due to the internal GSM variation during the laying process.
The result shows that the 100% Mesta fibre sample has high flexural rigidity than the other samples due to the high stiffness of fibre. The flexural rigidity decreases as the amount of mesta fibre in the sample decreases.

Sound Absorbency
From the sound absorbency result for various samples the percentage of sound absorbed is more or less equal but the values slightly reduced as the reduction in the Mesta fibre content.

Conclusion
Based on the Study
Mesta fibre have high stiffness by proper enzymatic treatment we can reduce the stiffness.
100% pure mesta nonwoven have more unevenness due to the fibre stiffness.
The samples 90% mesta with 10% jute, 80% mesta with 20% jute and 70% mesta with 30% jute have very good absorbency.
Air permeability and tearing strength is high for 90% mesta 10% jute sample.
100% mesta sample have good tensile properties and flexural regidity.
Sound absorbency reduces as the reduction in composition of mesta fibre.
These nonwoven materials can be used as:
Scrubber
Floor mats
Carpets
Quilting for automobiles
Heat insulation materials in home textiles
Apparel accessories

