Coir fiber

Kokos, -baum, m. coco, coco palm, coconut tree, -butter,/, coconut butter (coconut oil), -faser, /. coco fiber, coir (fiber from the husk of the coconut), -fett, n. coconut oil. -gam,... 

Aside from SMC molded plastics, BMC molded natural fiber plastics with good mechanical properties can be produced. Owolabi et al. [59] made such plastics with coir fibers, their basic recipe is shown in Table II. 

In this examination, glass fibers were replaced by coir fibers. A proper treatment of the fibers improved adhesion and, therefore, tensile strength was increased (Fig. 18). 

Figure 7 SEM of (a) untreated and (b) alkali-treated coir fiber. (From Ref. 43.)...

The containers used for the semi-organic grow beds are standard hydroponic grow containers. The medium used is any basic hydroponic medium. You will not use the standard medium of perlite/vermiculite/potting soil that was used with the total organic grow process because the medium will leach into the water. Use only standard hydroponic materials such as lava rock, hydroponic rock, rockwool, perlite, coconut fiber, or coir fiber. Fill the container to the top (as opposed to only /a full as is done with the totally organic method) with any hydroponic medium you prefer. 

Gel-permeation chromatography" is used to compare the pore structure of jute, scoured jute and purified cotton cellulose. Both native and scoured jute have shown greater pore volumes than cotton. The effects of alkali and acid treatment on the mechanical properties of coir fibers are reported." Scanning electron micrographs of the fractured surfaces of the fibers have revealed extensive fibrillation. Tenacity and extension-at-break decrease with chemical treatment and ultraviolet radiation, whereas an increase in initial modulus and crystallinity is observed with alkali treatment. FTIR spectroscopy shows that the major structural changes that occur when coir fibers are heated isothermally in an air oven (at 100, 150 and 200 °C for 1 h) are attributable to oxidation, dehydration and depolymerization of the cellulose component. 

Coir fiber comes in two eategories white and brown. In a eoeonut, the fibrous husk eonstitutes the outer covering of the hard, nearly spherieal shell containing copra. The husk, itself covered by a stiff covering called exocarp, weighs about 0.25-0.43 kg, with the fiber... 

The brown coir fibers may receive several additional preparatory treatments, specific to the anticipated end-use, before they are graded, packaged, and shipped or exported. 

Owing to the tight packing, the middle lamella substance between the cells form a thin, mostly uniform, but unbroken film (layer or lamina) that surrounds each ultimate completely. Microscopic examinations of the morphological structure of the leaf (sisal, abaca, etc.) and multicellular seed (coir) fibers reveal very comparable structures. Thus, a comparable mechanism of formation of multicellular strands may also be postulated. 

Varma et al. [178] report elemental analysis of treated and untreated coir fiber as shown below the samples were dried for 18 h in vacuum at 60°C. 

IR spectra of treated and untreated bristle coir fibers have also been studied [178], No significant change was noted in the acetic acid-treated fibers in the alkali-treated fibers, a small absorption peak at 1740 cm (perhaps due to carbonyl group) disappeared. With the alkali treatment, the absorption band of 910-1200 cm of the untreated fibers changed to a strong absorption peak at 1020 cm The HCl-treated fiber exhibited a light shift in the absorption peak from 1600 cm to 1620 cm ... 

Chemical composition of coir fiber reported by Varma et al. [178] is given in Table 8.3. [124] had suggested the lignin content to be about 35%, most of it in the middle lamella and the primary wall as such, it is said to protect the cellulose from chemical and physical attack [139]. An estimated moisture content of 20% has also been reported [109]. Timell [172], based on extractive-free material, gives the carbohydrate content of hemp and jute products, as shown in Table 8.4. 

FIGURE 8.14 Coir fiber (a) cross section view of a bundle of ultimates (165x, approximately) (b) longitudinal view of ultimate (lOOx, approximately). (From TI Identification of Textile Materials, 7th ed. The Textile Institute, Manchester, U.K., 1975.)... 

In a somewhat similar vein, Kulkarni et al. [80] report a 50-58% decrease in the ultimate elongation and 20-45% increase in the tenacity of the coir fiber as it loses 9-10% of its moisture. While they attribute these changes to the increase of hydrogen bonds in the cellulosic part of the fiber, the changes could also more likely be attributed to the plasticizing effect of moisture on middle lamella substances (polyuronides and hemicellulose). 

The anisotropic character of textile fibers is well known. The load-deformation properties in the transverse direction are, therefore, generally different from those in the longitudinal direction. Chakravarty [36] estimated transverse moduli of jute, hemp, ramie, abaea, sisal, and coir fibers. The theoretical model on which the estimations are based is very simplistic the results cited in Table 8.20 and Table 8.21 should therefore be used with a great deal of caution. 

Prasad et al. [138] report on alkali treatment of coir fibers. Soaked in 5% NaOH at 28 + 1°C for 72-76 h, the tenacity of the fibers increased by 15% soaking beyond 76 h caused the tenacity to decrease gradually. The decrease was more pronounced if the alkah was replenished every 24 h. SEM observations revealed removal of cuticle and tyloses from the surface of the fiber by the alkali treatment, resulting in a rough surface with regularly spaced pits tyloses are globular particles, 10 pm in diameter, embedded in pits in the cell walls. 

Varma et al. [178] report change in color of the coir fiber from pale yellowish brown to dark brown, on treatment with 10% NaOH. The fibers develop crimp and their diameter decreases the latter effect is more pronounced in fibers that are initially coarser. The size of the central lacuna of the fiber and the lumen of the cell also decreased the solution turned dark brown. A weight loss of about 9.3% was reported [178]. 

Treatment of coir fiber with 10% acetic acid caused a slight brownish tinge and a weight... 

The chemical composition of the fibers influences their susceptibility to microorganism growth. Lignin content offers some protection, as evidenced by the high resistance of coir fibers, which contain 35% lignin. The lignin-hemicellulose ratio, the crystalline content of cellulose fraction, and the presence of micronutrients are other factors that determine the extent of microorganism activity on the fibers. 

Geethamma, V.G. Pothen, Laly A. Rhao, Bhaskar Neelakantan, N.R. Thomas, Sabu. Tensile stress relaxation of short-coir- fiber -reinforced natural rubber composites. Journal of Applied Polymer Science, 94(1), 96-104 (2004). 

Rajan, A., Abraham, T.E., Coir fiber process and opportunities. The Journal of Natural Fibers, To be published. 

M.M. Haque, M. Hasan, M.S. Islam, M.E. Ali, Physico-mechanical properties of chemieally treated palm and coir fiber reinforced polypropylene composites. Bioresour. Technol. 100(20), 4903 906 (2009)... 

Nor, M.J.M. Jamaluddin, M Tamiri, F.M. (2004). A Preliminary Study of Soimd Absorption Using Multi-layer Coconut Coir Fibers. Electronic Journal "Technical Acoustics", Vol.3, (March 2004), p>p. 1-8, ISSN 1819-2408, Retrieved from http //ejta.org/ en/ tamiril... 

Fibers are collected from the fruit of the plant, e.g. coconut (coir) fiber. Fibers are actually the stalks of the plant. For example, straws of wheat, rice, barley, and other crops including bamboo and grass. Tree wood is also such a fiber... 

V. G. Geethamma and S. Thomas, Diffusion of Water and Artificial Seawater Through Coir Fiber Reinforced Natural Rubber Composites, Polymer Composites, 2005, 136. 

Fig. 8.3 Fractographs of some lignocelMosic fibers (a) Coir (b) Coir fiber showing the helical spiral structure (c) Pineapple (d) Curaua (e) Sisal (f) American agave leaf Aechmea magdalenae) fiber [a-e Adopted from [1,26,29]]...

Kulkami et al. [15] found that both the strength and elongation of these fibers were found to increase in the range of fiber diameters from 100 to 200 pm and then remain constant up to 450 pm. The fracture strength values of coir fiber showed large scatter (Fig. 8.4a), suggesting that more samples have to be tested to get meaningful result. On the other hand, when 20 samples were tested, the plot showed very low scatter (Fig. 8.4b). 

Fig. 8.4 Plot of fracture strength versus diameter for coir fiber (Reproduced with the kind permission of publishers of [15])...

Fig. 8.6 Calculated the CV and plots of % of CV versus fracture strength for coir fibers (Reproduced from [15] with kind permission of the Publishers)...

In the first instance, when the results were analyzed by simple mean and standard deviation analysis, Amico et al. [16-18] got large relative standard deviatiOTi, indicating limitatimi of this method for the proper characterizatiOTi of the diameter. Then, they used Weibull probability density and cumulative distribution functions [20,56,58] to estimate two parameters, the characteristic life and a dimensionless positive pure number, which were supposed to determine the shape and scale of the distribution curve. For this, they adopted two methods, the maximum likelihood technique, which requires the solution of two nonlinear equations, and the analytical method using the probability plot as mentioned earlier for coir fibers. 

In the second case, the analysis showed that all the fibers followed a unimodal distribution as illustrated by the plots of tensile strength versus diameter on logarithmic scale. Typical plots for coir fibers are shown in Fig. 8.9. Also, both methods showed an inverse relation between the diameter and the tensile strength for each fiber represented by a hyperbolic equation. These equations are shown in Table 8.3. 

Kulkami AG, Satyanarayana KG, Rohatgi PK (1983) Weibull analysis of strength of coir fibers. Eibre Sci Technol 19 59-76... 

Kulkami AG, Satyanarayana KG, Sukumaran K, Rohatgi PK (1981) Mechanical behavior of coir fibers under tensile load. J Mater Sci 16 905-914... 

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