Okra Fiber Research Articles

Some studies on Abelmoschus esculentus (Indian Okra) fiber characteristics

AbstractOkra fiber is the bast fiber, extracted from the stem of the Abelmoschus esculentus plant which belongs to the Malvaceae family. In the whole world, India is the largest producer of okra for the cultivation of “okra fruit”, which is one of the main vegetables in the Indian Diet. After collecting vegetables, a huge amount of okra plant stem is discarded on the field annually as agricultural waste. Okra stem is an abundant source of okra fiber which can be used for various textile applications. This study aims understand the basic morphological, thermal and structural characteristics of okra fibre and compare it with other bast fibres generally used for textile application to prove the suitability of okra fibre for textile application.

Comparative studies on tensile strength of okra fiber polyester based on with and without corn husk biocomposites

Comparative studies on tensile strength of okra fiber polyester based on with and without corn husk biocomposites

The impact of chemical treatment and gamma-ray irradiation on the okra hessian cloth reinforced high-density polyethylene composites

Okra hessian cloth-reinforced high-density polyethylene (HDPE) thermoplastic composites were prepared and characterized with both raw and alkali-treated fibers. The fiber contents were optimized for both the raw Okra thermoplastic composites and the alkali-treated Okra thermoplastic composites, and the optimum value of fiber content was 55 wt%. Samples that were alkali-treated and had 55 wt% fibers were subsequently exposed to gamma radiation at doses of 2.5, 5, and 7.5 kGy. Only the sample subjected to 5 kGy showed improved performance. Treated composites exhibited higher crystallinities than the untreated samples as observed by X-Ray diffraction analysis. The rupture surface micrographs of the composites exposed to 5 kGy gamma radiation revealed more compact than others. By using Fourier transform infrared spectroscopy analysis of composites, it was found that 5 kGy dose sample showed enhanced cross-linking between Okra fibers and HDPE matrix. The irradiated composite showed less water intake than the alkali-treated samples. Composites subjected to 5 kGy gamma rays showed improved tensile strength and Young’s modulus of values 66 MPa and 1925 MPa, respectively. Compared to raw and treated composites, the irradiated composites with a radiation dose of 5 kGy showed improved structural, mechanical, and thermal properties.

Egyptian okra Fibers, Extraction, and Investigation

Egyptian okra Fibers, Extraction, and Investigation

Extraction and processing of Indian Okra fibre for Industrial bio-packaging

Extraction and processing of Indian Okra fibre for Industrial bio-packaging

Novel okra woven fabric reinforced polylactic acid composites: Mechanical, morphological, and thermal properties

AbstractContemporary researchers are directing attention towards enhancing the structural integrity of biodegradable matrices, such as polylactic acid (PLA), through the incorporation of plant fibers. The utilization of novel fibers is becoming more prevalent to achieve the specific demands of composite applications, particularly in the automotive and packaging fields. Woven fabrics are commonly favored for reinforcing composites due to their elevated specific strength and dimensional stability. In pursuit of this context, we have developed a unique woven fabric using 100% okra fiber and utilized it in the production of PLA biocomposites. This approach was made due to the unexplored potential of okra woven fabric in the field of composite manufacturing. To optimize the performance of the composites, three distinct weight proportions of okra woven fabric (OWF) were chosen, including 20%, 30%, and 40%. The obtained composites were mechanically, morphologically, and thermally characterized. The manufactured composite's maximum tensile and thermal property was attained by adding 20% OWF to the PLA. Scanning electron microscopy analysis revealed that 20% OWF composite possessed superior fiber‐matrix adhesion, improving all properties' efficacy. The overall findings reveal that the OWF/PLA composites are promising as a green material for applications in the automotive and packaging industries.Highlights A novel class of composite has been created using 100% okra woven fabric. The composite with 20% fabric content showed the best mechanical properties. Thermal properties of composites are also optimized using 20% fabric content. SEM confirms the strong fiber‐matrix bonding of 20% OWF/PLA composites. The composites are suitable for automotive and packaging applications.

Okra Micro-Cellulose Crystal (MCC) and Micro-Clay Composites for the Remediation of Copper, Nickel, and Dye (Basic Yellow II) from Wastewater

Water pollution by contaminants such as toxic metals and dyes is now a major concern due to their high toxicity and persistence in the environment. Advances in nanotechnology have enabled the use of micro/nanomaterials to treat and purify water in various industries. In this study, Bijoypur clay was modified with ethyldiamine and incorporated into an okra fiber (Abelmoschus esculentus) micro-cellulose crystal (MCC) to produce a composite that could absorb copper (Cu), nickel (Ni), and dyes like basic yellow (II) from industrial wastewater. Composites were prepared using different percentages of MCC and clay. Atomic absorption spectroscopy (AAS) was used to determine the concentrations of Cu and Ni whereas a UV–Visible spectrophotometer measured the absorbance of basic yellow (II). The synthesized composites were extensively characterized using a range of techniques including thermogravimetry (TG) and differential thermogravimetry (DTG), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Results show that both the MCC and clay could absorb Cu, Ni, and basic yellow (II) from the contaminated wastewater. The MCC and clay composite showed the maximum efficiency of metals removal, which was up to 95% (24 mg/g) for Cu at pH 6, 20 min contact time, 2 g/L adsorbent dose, and 100% (31 mg/g) for Ni at pH 8, 60 min contact time, and 2 g/L adsorbent dose, respectively, at the initial concentration of 50 mg/L. The maximum dye uptake capacity of 85% (19 mg/g) was observed by the MCC and clay composite under optimized conditions at the initial concentration of 50 mg/L, pH 8, 30 min contact time, and 1 g/L adsorbent dose compared to the pure clay, which had an efficiency up to 26% for Cu and 24% for dye removal. All of the results indicate that incorporating clay into MCC increases the absorption capacity of contaminants from wastewater, which could be more effective for environmental applications compared to untreated cellulose.

Characteristics ofAbelmoschus esculentus(Indian okra) fiber varieties

Okra fiber is the natural cellulosic bast fiber extracted from the bark of the Abelmoschus esculentus plant stem. India is the largest producer of okra for the cultivation of ‘okra fruit’. After the okra plant is harvested in the field, the okra fruit is collected as a vegetable, and the okra plant is thrown out as agricultural waste. In India, an estimated 4.5 Mt of green okra plants is discarded annually as agricultural waste. The okra plant has the potential to produce 150–160 kg of okra fibers per hectare and about 13.4 million kg of okra fibers annually. The okra plant is cultivated in two seasons: summer and winter. The summer variety and winter variety of okra fibers are extracted from okra plants cultivated in the summer and winter seasons, respectively. In this study, the characteristics of the summer and winter varieties of okra fibers (morphological, thermal and structural) were investigated by optical and electron microscopy (scanning electron microscopy), thermogravimetric analysis (differential thermogravimetry, differential scanning calorimetry), X-ray diffraction analysis and Fourier transform infrared spectrometry. This study analyzed the characteristics of both varieties of okra fibers, compared them and proved their potential for commercial applications, similar to those of banana, jute, flax, hemp and kenaf bast fibers.

Nontraditional Natural Filler-Based Biocomposites for Sustainable Structures

In recent years, there has been a growing awareness and demand for global sustainability, as well as a mandate for the use of renewable and environmentally sustainable materials and processes. Due to which, massive efforts are being made to develop and nurture the next generation of composite materials that are energy efficient, environmentally friendly, and biodegradable. Light weight, lower coefficient of thermal expansion, and comparable tensile strength exhibited by natural fibers render them the choice for use in several industrial products and applications over the last decade. Natural fibers as the reinforcing entity are pitted against their synthetic variants primarily because of the superior aspects like biodegradability and excellent strength-to-weight ratio. This article presents the review on various nonconventional natural fibers such as tamarind seed and shell, Luffa cylindrica, groundnut shell, coconut coir, papaya bast, okra, and Ashoka tree seed. The flow of the chapter includes the introduction, extraction methodologies, and fabrication, and investigations of mechanical properties, applications, and sustainability are dealt in detail for nontraditional natural fibers. The okra fibers possess greater tensile strength of up to 262.8 MPa in comparison with other fibers, while the Ashoka tree seed fibers are known to possess a maximum flexural strength of up to 125 MPa. Further, these fibers are used as reinforcements in potential applications in interiors and automobile and aircraft panels and wood-based particle board composites owing to the increase in tensile and flexural strengths of composites.

Effects of Silane-Treated High-Content Cellulose Okra Fibre and Tamarind Kernel Powder on Mechanical, Thermal Stability and Water Absorption Behaviour of Epoxy Composites

Effects of Silane-Treated High-Content Cellulose Okra Fibre and Tamarind Kernel Powder on Mechanical, Thermal Stability and Water Absorption Behaviour of Epoxy Composites

Impact of wet-drying Treatment of Raffia and Okra Fibres on Their Morphological, Physicochemical and Mechanical Properties

ABSTRACT Hornification is an irreversible effect that occurs on lignocellulosic fibers when they are subjected to drying and re-wetting cycles. This study aimed to evaluate okra and raffia fibers morphological, physico-chemical, and mechanical properties. The fibers were subjected to four and six wet-dry treatment cycles to assess the effect of the number of cycles on the performance of each fiber. The results show that four wet-dry cycles show an increase in density from 1.40 g/cm3 to 1.78 g/cm3 and from 1.34 g/cm3 to 1.58 g/cm3 for okra and raffia fibers, respectively. Furthermore, a decrease in fiber lumen is observed, resulting in a reduction in water absorption capacity of up to 18.3% for raffia fiber and 56.3% for okra after four hornification cycles. Statistical analysis reveals a significant improvement in the elastic modulus of raffia fiber up to 37% after treatment, while no significant improvement is observed in the elastic modulus and tensile strength of okra fiber. This is attributed to the strengthening of intracellulosic bonds, which resulted in the creation of more available -OH sites on the fibers. The physico-chemical and mechanical changes in fiber properties resulting from wet-dry processing have demonstrated their suitability to replace synthetic fibers in composites.

Sustainable production and evaluation of the properties of polyester-okra blended knitted fabric

The demand for fashionable knit fabric is increasing. Besides that, blended knit fabric, prepared from the blended yarn as well as using different types of yarn is also very popular to the modern customer. That's why, finding of new resource of raw material for fashionable knit fabric preparation is promising in the recent decade. Okra fiber is a biodegradable long staple bast fiber that can be obtained from abundant natural fiber sources after being extracted from lady's finger plants. It has high cellulosic content, worthy strength and modulus, and better thermal properties, making it a potential candidate as a raw material for the creation of stylish knit fabrics. Because of its rigidity and lack of flexibility, okra fiber cannot be spun into yarn on its own. In the current study, 1 × 1 rib fabric prepared from 30 Tex polyester/okra (PO) blended yarn of 80/20 and 85/15 blend ratio. For better comparison corresponding polyester/flax traditionally known as polyester/linen (PL) blended 1 × 1 rib fabric was also prepared. Current study found that, fabric characteristics, such as fabric weight, fabric dimension, air permeability, and bursting strength of PO blended fabric was compatible with PL blended fabric, with the exception of the fabric's hand feel characteristics. The overall findings revealed that the knit fabric qualities of PO mixed fabric were satisfactory. Due to the affordability and accessibility of okra fiber, the PO blended fabrics are very promising, sustainable and may be a viable choice to address the actual need for blended fabrics in the textile knitting industries.

Fatigue, fracture toughness and DMA of biosilica toughened epoxy with stacked okra fiber and Al 2024‐T3 fiber metal laminate composite

AbstractIn this present study, a natural fiber‐based fiber metal laminate (FML) was fabricated for various engineering applications. The primary aim of this present investigation was to study the effect of adding natural fiber along with metal and the effect of the surface‐treatment process on the reinforcements on load‐bearing and thermo‐mechanical properties. Okra fiber woven mat, aluminum 2024‐T3 foil and rice husk‐derived biosilica were used as reinforcements. For surface treatment, the metal foil was sandblasted whereas the okra fiber and biosilica were silane‐treated. The FML was fabricated using the vacuum bag method utilizing as‐received and silane‐treated reinforcements as two separate models. According to the results, the addition of Al foil and okra fiber improved the storage modulus and loss factor of about 4.2 GPa and 0.39 for surface‐treated reinforcements. Similarly, maximum fracture toughness and energy release of 39.42 MPa √m and 0.76 MJ/m2 for surface‐treated EOA2 composite designation. Moreover, the addition of okra fiber and Al foil increased the fatigue life counts up to 54,266, 48,116, and 26,263 for surface‐treated EOA2 composite at 30%, 60%, and 90% of ultimate tensile stress (UTS). Such thermo‐mechanical and load‐bearing properties improved FMLs could be used in automotive, aircraft, drone and other industrial applications requiring high structural rigidity and load absorbing capability.

Effect of Okra Plant Lifespan upon Tensile Properties of Okra Fibers

ABSTRACT This study has been carried out to identify the effect of the okra plant lifespan upon the tensile properties, that is, fiber bundle strength and elongation of the yielded fibers. 90 ± 10 days, 120 ± 10 days, and 160 ± 10 days matured crop waste were subjected to different retting conditions (retting duration and retting medium flow rate). Water was used as retting medium with two different flow rates (0 and 6.5 m/min). Five retting durations were taken for this study between 11 and 35 days. The bundle tenacity (gf/tex) and elongation at break (%) were measured by Instron automatic bundle strength tester for the extracted okra fibers. The study revealed that okra fiber extracted through the running water showed better tensile strength (at least 14% higher, range 14–80%) than fiber extracted through stagnant water retting conditions at every retting duration (11–35 days) for the different lifespans of okra plants. Okra fiber bundle tenacity continuously reduced with the retting period ranging from 11 to 35 days irrespective of okra plant lifespan and retting conditions. Improvement in tenacity was found from 90 ± 10 days to 120 ± 10 days okra plant lifespan, but no significant improvement was found after 120 ± 10 days okra plant lifespan. No significant effect of elongation at break (%) was found for the okra plant lifespan and retting conditions.

Investigation of the performance of okra fiber in woven fabric

There has been an increase interest in natural plant fibers over the last decades with the intension to identify the ecologically acceptable alternatives to reduce the dependency on synthetic fibers. Naturally extracted okra fiber (Abelmoschus esculentus) was used in this study. Since okra is a stiff fiber, yarns with 100% Okra fiber was not possible to produce and tried to blend with polyester. The maximal ratio of okra was 20% with polyester to spin yarns in traditional ring spinning system. This study explores, for the first time, the possibility of manufacturing woven fabric with polyester-okra (80/20) yarns at weft direction with 100% cotton yarn at warp direction in order to prominent blend effect at weft direction. The properties of produced fabrics were compared with the same produced widely-used polyester-linen (PL) (80/20) counterpart. The both PO and PL woven fabrics were characterized in terms of fabric weight, thickness, abrasion, pilling, fuzzing, air permeability, tensile strength and tear strength. In addition, the morphological aspects of the fiber alignment in the woven fabric structure were observed using optical microscopic images. The performance of PO woven fabric was in acceptable ranges and can be considered as a sustainable blended woven fabric to meet the actual demand in the textile weaving industries.

Effect of Okra Plant Lifespan upon Optical Properties of Okra Fibers

ABSTRACT The present research study has been made to identify the effect of the okra plant lifespan upon the optical appearance of the yielded fibers. 90 ± 10 days, 120 ± 10 days, and 160 ± 10 days matured crop waste were subjected to two different retting conditions. For this study, stagnant water retting conditions and running water retting conditions were approached. Optical properties such as whiteness index, yellowness index, and brightness index of yielded okra fibers were measured by spectrophotometer. The study revealed that for both the retting conditions, the whiteness and the brightness index increased with the retting period up to a certain level, i.e., approximately 5–15% improvement for the whiteness index while approximately 10–40% improvement for the brightness index. While the yellowness index mostly showed a reverse effect with the retting period. The reduction in the yellowness index was approximately 2–7%. However, the effect of the retting period got saturated after a certain retting period, i.e., in between 17 and 25 days. Okra fiber yielded from both 90 ± 10 days and 120 ± 10 days matured okra plants showed similar optical properties, but better whiteness index than fiber yielded from 160 ± 10 days matured okra plants. In this research study, similar optical properties were observed for the fibers yielded from both the retting conditions.

Production of Reinforced Polyester Composite from Okra Fibre and Sawdust

This research presents properties of okra and sawdust reinforced polyester composite. The compatibility of the simple woven okra and sawdust with polyester was enhanced with stearic acid treatment. FTIR analysis confirmed decrease in hydrophilicity of the fibre and dust. Six composite samples; pure polyester, sawdust reinforced polyester composite, okra reinforced polyester composite, 10% sawdust in okra fibre reinforced composite, 20% sawdust in okra fibre reinforced composite and 30% sawdust in okra fibre reinforced composites were fabricated and characterized. The morphological analysis showed that the homogeneity of polyester in the samples reduces with increase in sawdust filler (10-30 wt%). Water absorption was highest (1.6%) in 30% sawdust in okra. The densities of all the composites were between 3.5 – 4.5 kg/m3. The sawdust reinforced composite recorded low impact energy of 0.25 J while the woven okra fibre reinforced polyester recorded the highest impact energy of 9.9 J. Hardness property reduced as the biomass content increased. Unreinforced polyester recorded the highest average elongation of 25% (1400 µm) and reduced elongation as filler increased. The storage modulus was highest for unreinforced composite at 40oC but as the temperature reached 81oC the storage modulus of unreinforced polyester dropped lower than the sawdust composite. The damping factor (1.41) was highest for 20 wt% sawdust/okra polyester composite. This research concludes that sawdust and okra are suitable for lightweight and energy damping materials in automobile applications.

Failure Studies on Adhesive Bonded and Bolted Joints of Natural Fiber Composites

Composites with natural fibers as reinforcements are playing a vital role in recent developments. The present work deals with the fabrication of okra and empty fruit bunch banana fiber polyester matrix composites with varying reinforcement content (5%, 10%, and 15%). Composites were fabricated by using the hand layup technique. After the fabrication process, composites were then adhesively bonded and also joined with bolts. The main objective of this work is to analyse the failure studies on adhesive bonded and bolted joints of okra and empty fruit bunch banana composite specimens. The specimens were tested under tensile load, flexural creep studies, and SEM analysis. It has been observed that empty fruit bunch banana fiber composites exhibited better joint strength properties under tensile loading when compared to the okra fiber composites. To estimate the flexural creep behaviour, all the samples were tested at a constant load of 2.5kg and 5kg. The deflections obtained during regular time intervals (four months) were noted. The presence of internal defects and void content was observed by using the scanning electron microscope. The results showed that adhesive-bonded composites were exhibited less deflection compared to the bolted joints. The empty fruit banana fiber composites exhibited higher creep than okra fiber composites. Decreased creep with the increased fiber has been observed in both cases. SEM Adhesively bonded joints possessing better sustainability as compared to the bolted joints in both the fiber-reinforced composites.

Chemo-mechanical synthesis, characterization of nanocellulose from okra fibre and their epoxy composites

ABSTRACT Nanocellulose synthesised from the diversified natural fibres sources has several times higher strength and modulus than macro, long fibres. This work attempts to engage the chemical synthesis route majorly and marginally through mechanical techniques to produce nanocellulose from okra fibre by following systematic procedural steps. The nanocelulose has a mean diameter of 540.7 nm. SEM measured the minimum agglomerated mass of carbon nanofiber (CNF), and its value was 0.41 μm. Cotton fabric (CF) was considered in this work for better settlement of nanocellulose (NC). Sonication was done with the intermittent variation of amplitude and pulse/cycle at each weight fraction of reinforcement in the hardener. Huntsman grade aerospace epoxy resin was used to fabricate the composite laminae with the various reinforcements. The highest tensile strength, modulus of 28.52 MPa, 0.254 GPa was achieved at a weight fraction of 0.04% CNF, 0.39% NC, respectively. Hybrid composites (CF+NC+CNF) flexural strength, the modulus was 116.48 MPa, 4.21 GPa. At 0.11 Wf % of NC-epoxy composites showed the highest impact strength of 2.19 kJ/m2 and is more than hybrid composites experimented within this work. Heat flow, thermal degradation characteristics of reinforcements, matrix, and composites are characterised using Differential Scanning Calorimetry, Thermogravimetric Analysis.

A comprehensive study on Physico-Mechanical characteristics of Okra fibre (Abelmoschus esculentus) for textile applications

Objectives: The objectives of this research is to investigate the physicomechanical characteristics of okra bast fibres (OBF) as well as to go through all the process to make this okra fibre as one of the commercial cellulosic fibres which can be used in different textile applications such as reinforcements in polymer matrix composites, carpets, materials used for absorbing oils and liquids, packaging industries, basic textiles products, coarse decorative textile products, Geo-textiles etc. all over the world. Methodology: In this work, OBFs are characterized by using Fourier transform infrared spectroscopy (FTIR), Breaking strength and breaking extension test, linear density analysis, Microscopic view and Scanning electron microscopy (SEM) analysis, and the crystallinity is measured by X-Ray Diffraction (XRD) data. Findings: XRD data indicates that the amorphous region is far greater than the crystalline region in OBFs, SEM analysis displays the technical fibres are overlapped and cemented by non-cellulosic compounds. These test results show a great similarity to other bast fibres properties mainly physical, mechanical, microstructural (crosssectional and longitudinal view) properties. Keywords: Okra bast fibre (OBF); SEM; FTIR; XRD; Breaking strength and breaking extension; Linear density