Search Results (33)

The large-scale release of natural enemies remains a major challenge in biological control. This study evaluated the viability of using biodegradable capsules produced from pineapple (Ananas comosus) leaf fibers for the release of the predator Euborellia annulipes. The objectives of the current research were: (I) to evaluate the viability of these capsules for predator release; (II) to validate the effectiveness of aerial release by drone (Agras T40); and (III) to evaluate the behavioral repertoire and performance of the predator after exiting the capsule in maize plants infested with susceptible and resistant Spodoptera frugiperda larvae. Predator-induced opening (in the absence of moisture) required a median time of 33 h (77.5% success, mortality ≤ 7.5%), whereas autonomous opening reached 100% in soil at field capacity. Aerial release achieved a 95.04% success rate. Under semi-field conditions, moisture facilitated rapid capsule opening (220 to 269 min); the predator exhibited active search behavior and achieved a higher predation rate on the resistant pest population (40%) than on the susceptible one (25%). The technology is therefore functional, compatible with the predator’s biology, and promising for sustainable integrated pest management strategies. Full article

Infrastructure expansion in Indonesia has increased demand for paving blocks, raising concerns over cement production costs and environmental impact. This study investigates the comparative effectiveness of pineapple leaf fiber (PALF, Ananas comosus) and sisal fiber (Agave sisalana) as reinforcements in paving blocks, evaluating water absorption and 28-day compressive strength at fiber contents of 0%, 1%, 3%, 5%, and 7% by cement volume. A full-factorial two-way ANOVA with post-hoc Tukey HSD was employed. A dosage of 3% for both fiber types resulted in compressive strengths of 14.5 MPa (PALF, +59% vs. control) and 15.2 MPa (sisal, +67% vs. control), both of which met the requirements of SNI 03-0691-1996 Class B. Sisal fiber demonstrated superior compressive performance, consistent with its higher stiffness and tensile strength as reported in the literature. Water absorption increased monotonically with fiber content for both types, with SNI Class D compliance (≤10%) maintained only at 0% for PALF and 0–1% for sisal, a known consequence of the inherently hydrophilic nature of plant-based natural fibers. A statistically significant interaction term (F = 3.697, p = 0.012) confirmed that the two fibers respond differently to dosage increases, providing nuanced practical guidance beyond what single-factor studies can offer. These findings demonstrate the promising compressive strength of agricultural waste fiber-reinforced paving blocks, warranting further investigation of abrasion resistance, flexural strength, and long-term durability before practical deployment. Such utilization supports circular economy principles in the construction industry. Full article

This study evaluated the ballistic performance and failure mechanisms of epoxy-based hybrid laminates reinforced with abaca/UHMWPE and pineapple leaf fiber (PALF)/UHMWPE fabrics fabricated by using vacuum-assisted hand lay-up. Ballistic tests utilized 9 mm full metal jacket (FMJ) rounds (~426 m/s impact velocity) under NIJ Standard Level IIIA conditions (44 mm maximum allowable BFS). This experimental test was complemented by finite element analysis (FEA) incorporating an energy-based bilinear fracture criterion to simulate matrix cracking and fiber pull-out. The results showed that abaca/UHMWPE composites exhibited lower backface signature (BFS) and depth of penetration (DOP) values (~23 mm vs. ~42 mm BFS; ~7 mm vs. ~9 mm DOP) than PALF/UHMWPE counterparts, reflecting superior interfacial adhesion and more ductile failure modes. Accelerated weathering produced matrix microcracking and delamination in both systems, reducing overall ballistic resistance. Scanning electron microscopy confirmed improved fiber–matrix bonding in abaca composites and interfacial voids in PALF laminates. The FEA results reproduced major failure modes, such as delamination, fiber–matrix debonding, and petaling, and identified stress concentration zones that agreed with experimental observations, though the extent of delamination was slightly underpredicted. Overall, the study demonstrated that abaca/UHMWPE hybridcomposites offer enhanced ballistic performance and durability compared with PALF/UHMWPE laminates, supporting their potential as sustainable alternatives for lightweight protective applications. Full article

Pineapple leaf fibers (PALFs), obtained from abundant yet underutilized pineapple leaf residues, represent a promising feedstock for producing fibrillated cellulose. In this work, cellulosic fibers were isolated and characterized by Fiber Quality Analysis (FQA), showing lengths between 0.33 and 0.47 mm and widths of 12.2 µm after organosolv pulping using ethanol and acetic acid as a catalyst, followed by hydrogen peroxide bleaching with diethylenetriaminepentaacetic acid as a chelating agent. The cellulosic fibers were then subjected to TEMPO-mediated oxidation and subsequently disintegrated by microfluidization to produce micro-/nanofibrillated cellulose (MNFC) with a carboxylate content of 0.85 and 1.00 mmol COO⁻/g, zeta potential of −41 and −53 mV, and average widths of 15 and 12 nm for unbleached and bleached nanofibrils, respectively. The nanofibrillation yields were 73% and 68% for the bleached and unbleached MNFC samples, indicating the presence of some non-fibrillated or partially fibrillated fractions. X-ray diffraction analysis confirmed preservation of cellulose type I crystalline structure, with increased crystallinity, reaching 85% in the bleached MNFC. These findings demonstrate the feasibility of a sequential process, combining organosolv pulping, hydrogen peroxide bleaching, TEMPO-mediated oxidation, and microfluidization, for preparing MNFC from pineapple leaf fibers. Overall, this study highlights pineapple leaf residues as a sustainable source of MNFC, supporting strategies to transform agricultural waste into valuable bio-based materials. Full article

Focusing on the challenges of low utilization of pineapple leaves and the poor stability of phenolic compounds (PCs) in pineapple leaf fiber using traditional solvent extraction methods, the effects of different extraction media (including distilled water, neutral methanol, acidic methanol, alkaline methanol, neutral ethanol, and alkaline ethanol) was systematically investigated on the extraction efficiency of PCs from pineapple leaf fiber. Through response surface methodology (RSM), the optimal extraction conditions were determined. Additionally, the impacts of illumination and pH on the stability of PCs in pineapple leaf fiber were thoroughly examined. The results demonstrated that acidic ethanol outperformed other extraction media, with the optimized extraction conditions as follows: ethanol concentration = 80%, material-to-liquid ratio = 1:40, extraction temperature = 70 °C, and extraction time = 40 min. Under these conditions, the extraction yield of PCs reached 11.55 mg/g. Furthermore, the stability of PCs was significantly enhanced by minimizing light exposure and maintaining a pH range of 3–6. The potential application of PCs extracted from pineapple leaf fiber was also explored, particularly in mango preservation, revealing promising results. This study not only provides an efficient and sustainable approach for the extraction and stabilization of PCs from pineapple leaf fiber but also opens new avenues for the utilization of polyphenols in functional applications, contributing to the valorization of agricultural by-products. Full article

The use of plant fibers as reinforcement in cement composites has gained significant interest due to their favorable mechanical properties and inherent sustainability, particularly when sourced from agro-industrial waste. In this study, six types of pineapple leaf fibers from commercial and hybrid varieties were characterized in terms of morphology, crystallinity index, water absorption, dimensional stability, and mechanical properties to evaluate their potential as reinforcement in cement-based composites. An anatomical analysis of the leaves was conducted to identify fiber distribution and structural function. Cement-based composites reinforced with 1.5% (by volume) of long and aligned pineapple leaf fibers were produced and tested in bending. The results indicate that the tensile strength of pineapple fibers, ranging from 180 to 753 MPa, surpasses that of fibers already successfully used in composite reinforcement. Water absorption values ranged from 150% to 187%, while fiber diameter varied between 45% and 79% as fiber moisture changed from the dry state to the saturated state. The flexural behavior of the composites modified with pineapple leaf fibers exhibited multiple cracking and deflection hardening, with increases in flexural strength ranging from 6.25 MPa to 11 MPa. The cracking pattern under bending indicated a strong fiber–matrix bond, with values between 0.41 MPa and 0.93 MPa. All composites demonstrated high flexural toughness and great potential for the development of construction elements. Full article

Natural fiber-reinforced composites have become an important field of research due to their environment-friendly nature, low cost, lightweight, and excellent mechanical properties. In the current study, natural composites were fabricated by the hand layup technique to investigate the influence of pineapple leaf fiber (PALF) orientation on the mechanical properties and water absorption behaviors of epoxy composites. Pineapple leaf fibers, known for their natural fiber reinforcement capabilities, were incorporated into polymer matrices at various orientations (45°, 60°, 75°, and 90°) to evaluate their impact on the composite’s performance. Mechanical properties (tensile strength, flexural strength, impact energy, and micro-hardness) were assessed to understand how fiber alignment influences the overall structural integrity of the composite. Additionally, the water absorption characteristics of the fabricated composites were assessed by immersing specimens in water and measuring water uptake over time. Results revealed that fiber orientation plays a crucial role in enhancing mechanical strength and tribological properties, with composites reinforced with fibers aligned at 90° demonstrating efficient load transfer and reduced water absorption. Conversely, composites with fibers oriented at 45° showed relatively lower mechanical strength, higher water absorption, and lower tribological performance. These findings suggest that the optimization of fiber orientation in polymer composites can lead to enhanced performance and durability, making them suitable for an extensive range of eco-friendly and sustainable applications. Full article

This study examines the impact of Pineapple Leaf Fiber (PALF) loading on the properties of High-Density Polyethylene (HDPE)/PALF composites successfully produced through a melt extrusion process. The melt-extruded HDPE/PALF composites were characterized by their thermal and mechanical properties and their morphologies. Subsequently, adding 5% maleic anhydride (MA) to the HDPE/PALF composite formulation led to significant improvements in the mechanical strength properties. Moreover, adding 10 wt.% PALF and 5% MA to the composites improves the crystallinity (10.38%) and Young’s modulus (17.30%) properties and affects the thermal stability. The optimal formulation is achieved with 10 wt.% PALF filler incorporated into the HDPE composite. This study highlights the promising potential of HDPE/PALF composites for plastic product applications. Full article

Plant fibers’ wide availability and accessibility are the main causes of the growing interest in sustainable technologies. The two primary factors to consider while concentrating on composite materials are their low weight and highly specific features, as well as their environmental friendliness. Pineapple leaf fiber (PALF) stands out among natural fibers due to its rich cellulose content, cost-effectiveness, eco-friendliness, and good fiber strength. This review provides an intensive assessment of the surface treatment, extraction, characterization, modifications and progress, mechanical properties, and potential applications of PALF-based polymer composites. Classification of natural fibers, synthetic fibers, chemical composition, micro cellulose, nanocellulose, and cellulose-based polymer composite applications have been extensively reviewed and reported. Besides, the reviewed PALF can be extracted into natural fiber cellulose and lignin can be used as reinforcement for the development of polymer biocomposites with desirable properties. Furthermore, this review article is keen to study the biodegradation of natural fibers, lignocellulosic biopolymers, and biocomposites in soil and ocean environments. Through an evaluation of the existing literature, this review provides a detailed summary of PALF-based polymer composite material as suitable for various industrial applications, including energy generation, storage, conversion, and mulching films. Full article

Fiber-reinforced composites are among the recognized competing materials in various engineering applications. Ramie and pineapple leaf fibers are fascinating natural fibers due to their remarkable material properties. This research study aims to unveil the viability of hybridizing two kinds of lignocellulosic plant fiber fabrics in polymer composites. In this work, the hybrid composites were prepared with the aid of the hot compression technique. The mechanical, water-absorbing, and thickness swelling properties of ramie and pineapple leaf fiber fabric-reinforced polypropylene hybrid composites were identified. A comparison was made between non-hybrid and hybrid composites to demonstrate the hybridization effect. According to the findings, hybrid composites, particularly those containing ramie fiber as a skin layer, showed a prominent increase in mechanical strength. In comparison with non-hybrid pineapple leaf fabric-reinforced composites, the tensile, flexural, and Charpy impact strengths were enhanced by 52.10%, 18.78%, and 166.60%, respectively, when the outermost pineapple leaf fiber layers were superseded with ramie fabric. However, increasing the pineapple leaf fiber content reduced the water absorption and thickness swelling of the hybrid composites. Undeniably, these findings highlight the potential of hybrid composites to reach a balance in mechanical properties and water absorption while possessing eco-friendly characteristics. Full article

New composites made of natural fiber polymers such as wasted date palm surface fiber (DPSF) and pineapple leaf fibers (PALFs) are developed in an attempt to lower the environmental impact worldwide and, at the same time, produce eco-friendly insulation materials. Composite samples of different compositions are obtained using wood adhesive as a binder. Seven samples are prepared: two for the loose natural polymers of PALF and DPSF, two for the composites bound by single materials of PALF and DPSF using wood adhesive as a binder, and three composites of both materials and the binder with different compositions. Sound absorption coefficients (SACs) are obtained for bound and hybrid composite samples for a wide range of frequencies. Flexural moment tests are determined for these composites. A thermogravimetric analysis test (TGA) and the moisture content are obtained for the natural polymers and composites. The results show that the average range of thermal conductivity coefficient is 0.042–0.06 W/(m K), 0.052–0.075 W/(m K), and 0.054–0.07 W/(m K) for the loose fiber polymers, bound composites, and hybrid composites, respectively. The bound composites of DPSF have a very good sound absorption coefficient (>0.5) for almost all frequencies greater than 300 Hz, followed by the hybrid composite ones for frequencies greater than 1000 Hz (SAC > 0.5). The loose fiber polymers of PALF are thermally stable up to 218 °C. Most bound and hybrid composites have a good flexure modulus (6.47–64.16 MPa) and flexure stress (0.43–1.67 Mpa). The loose fiber polymers and bound and hybrid composites have a low moisture content below 4%. These characteristics of the newly developed sustainable and biodegradable fiber polymers and their composites are considered promising thermal insulation and sound absorption materials in replacing synthetic and petrochemical insulation materials in buildings and other engineering applications. Full article

In the pursuit of sustainability and reduced dependence on new plastic materials, this study explores the upcycling potential of high-density polyethylene (HDPE) milk bottles into high-stiffness, high-heat-distortion-temperature (HDT) composites. Recycled high-density polyethylene (rHDPE) sourced from used milk bottles serves as the composite matrix, while reinforcing fillers are derived from dried pineapple leaves, comprising fibers (PALF) and non-fibrous materials (NFM). A two-roll mixer is employed to prepare rHDPE/NFM and rHDPE/PALF mixtures, facilitating filler alignment in the resulting prepreg. The prepreg is subsequently stacked and pressed into composite sheets. The introduction of PALF as a reinforcing filler significantly enhances the flexural strength and modulus of the rHDPE composite. A 20 wt.% PALF content yields a remarkable 162% increase in flexural strength and a 204% increase in modulus compared to neat rHDPE. The rHDPE/NFM composite also shows improved mechanical properties, albeit to a lesser degree than fiber reinforcement. Both composites exhibit a slight reduction in impact resistance. Notably, the addition of NFM or PALF substantially elevates HDT, raising the HDT values of the composites to approximately 84 °C and 108 °C, respectively, in contrast to the 71 °C HDT of neat rHDPE. Furthermore, the overall properties of both the composites are further enhanced by improving their compatibility through maleic anhydride-modified polyethylene (MAPE) use. Impact fracture surfaces of both composites reveal higher compatibility and clear alignment of NFM and PALF fillers, underscoring the enhanced performance and environmental friendliness of composites produced from recycled plastics reinforced with pineapple leaf waste fillers. Full article

Pineapple leaf fiber (PALF), striped sunflower seed fiber (SFSF), and watermelon seed (WMS) are considered natural waste polymer materials, which are biodegradable and sustainable. This study presents new novel thermal insulation and sound absorption materials using such waste as raw materials. PALF, SFSF, and WMS were used as loose, bound, and hybrid samples with different compositions to develop promising thermal insulation and sound-absorbing materials. Eleven sample boards were prepared: three were loose, three were bound, and five were hybrid between PALF with either SFSF or WMS. Wood adhesive was used as a binder for both the bound and hybrid sample boards. Laboratory scale sample boards of size 30 cm × 30 cm with variable thicknesses were prepared. The results show that the average thermal conductivity coefficient for the loose samples at the temperature range 20–80 °C is 0.04694 W/(m.K), 0.05611 W/(m.K), and 0.05976 W/m.K for PALF, SFSF, and WMS, respectively. Those for bound sample boards are 0.06344 W/(m.K), 0.07113 W/(m.K), and 0.08344 W/m.K for PALF, SFSF, and WMS, respectively. The hybrid ones between PALF and SFSF have 0.05921 W/m.K and 0.06845 W/(m.K) for two different compositions. The other hybrid between PALF and WMS has 0.06577 W/(m.K) and 0.07007 for two different compassions. The sound absorption coefficient for most of the bound and hybrid boards is above 0.5 and reaches higher values at some different frequencies. The thermogravimetric analysis for both SFSF and WMS shows that they are thermally stable up to 261 °C and 270 °C, respectively. The three-point bending moment test was also performed to test the mechanical properties of the bound and hybrid sample boards. It should be mentioned that using such waste materials as new sources of thermal insulation and sound absorption materials in buildings and other applications would lead the world to utilize the waste until zero agrowaste is reached, which will lower the environmental impact. Full article

In the present research, a plant-based leather substitute material or leather alternative was developed from natural rubber (NR) and pineapple leaf fiber (PALF) using a simple process. Pineapple leaf fiber was extracted from waste pineapple leaves using a mechanical method. Untreated PALF (UPALF) and sodium hydroxide-treated PALF (TPALF) were then formed into non-woven sheets using a paper making process. PALF non-woven sheets were then coated with compounded natural rubber latex at three different NR/PALF ratios, i.e., 60/40, 50/50, and 40/60. Epoxidized natural rubber with an epoxidation level of 10% (ENR) was used as an adhesion promoter, and its content was varied at 5, 10, and 15% by weight of the total rubber. The obtained leathers were characterized in terms of tensile properties, tear strength, and hardness. The internal structure of the leathers was observed with a scanning electron microscope. Comparison of these properties was made against those reported in the literature. It was found that the leather with NR/PALF equal to 50/50 was the most satisfactory; that prepared from TPALF was softer and had greater extension at break. With the addition of ENR at 5%, the stress-strain curve of each respective leather increased significantly, and as the amount of ENR was increased to 10 and 15%, the stresses at corresponding strains dropped to lower values but remained higher than that without ENR. PALF leather prepared in this study has comparable or better properties than other alternative leathers reported in the literature and is much stronger than that made from mushrooms. Thus, this type of leather alternative offers unique characteristics of being bio-based and having a lower carbon footprint. Full article

In this study, we compare the reinforcing efficiency of pineapple leaf fiber (PALF) and cultivated flax fiber in unidirectional poly(butylene succinate) composites. Flax, known for robust mechanical properties, is contrasted with PALF, a less studied but potentially sustainable alternative. Short fibers (6 mm) were incorporated at 10 and 20% wt. levels. After two-roll mill mixing, uniaxially aligned prepreg sheets were compression molded into composites. At 10 wt.%, PALF and flax exhibited virtually the same stress–strain curve. Interestingly, PALF excelled at 20 wt.%, defying its inherently lower tensile properties compared to flax. PALF/PBS reached 70.7 MPa flexural strength, 2.0 GPa flexural modulus, and 107.3 °C heat distortion temperature. Comparable values for flax/PBS were 57.8 MPa, 1.7 GPa, and 103.7 °C. X-ray pole figures indicated similar matrix orientations in both composites. An analysis of extracted fibers revealed differences in breakage behavior. This study highlights the potential of PALF as a sustainable reinforcement option. Encouraging the use of PALF in high-performance bio-composites aligns with environmental goals. Full article