Natural fiber-reinforced polymer composites are gaining in popularity due to recyclability and availability. This research investigates how oil palm shell (OPS) filler materials impact the interlaminar shear and the dynamic properties of flax fiber-reinforced hybrid composites under cryogenic circumstances. Filler materials in two different proportions (0, 2, 4, and 6 wt.% OPS) and 40 wt.% flax fibers were used to make composites. The OPS filler-filled polymeric materials were invented through typical hand lay-up. The hybrid materials were imperiled to liquid nitrogen for varying amounts of time after production (15 and 30 min). According to the findings, OPS nanoparticles can be used as natural rather than artificial fillers. Furthermore, loading 4 wt.% OPS nanoparticles into organic fabric-strengthened epoxy polymeric materials during 15 min of cryogenic settings resulted in the best interlaminar shear and dynamic performances. The storage and loss modulus of the flax/epoxy composites were improved by adding a 4% OPS nanofiller. The improvement can be ascribed to the hardness and stiffness of the additional OPS nanofillers. The 4% nano-OPS/flax/epoxy hybrid nanocomposite’s damping factor was substantially reduced compared to the flax/epoxy composites. The OPS nanofiller limits the epoxy molecular chain’s free segmental mobility, resulting in a lower damping factor and enhancing the adherence among flax fibers and the epoxy resin. The shattered specimen of the hybrid materials was investigated using a scanning electron microscope.

At present, composites are being utilized on account of simplicity in manufacturing and their characteristics are low weight, non-abrasive, non-flammable and non-harmful. This article attempts to achieve good mechanical properties of the wood and woven jute based natural fiber-reinforced plastics. The required composite materials were fabricated by using a hand layup method. The fabricated laminates were immersed in liquid nitrogen at 77 K for cryogenic treatments. The following parameters are (i) wood density, (ii) wood weight ratio, (iii) woven jute type, (iv) number of jute layers, (v) cryogenic treatment durations and (vi) alkaline treatment durations, each at three different levels were picked for composite development by utilizing the Gray-Taguchi method. Mechanical testing of fabricated laminates was done as per ASTM standards to estimate compressive, double shear and hardness properties. Based on the L₂₇ (3⁶) orthogonal array of the Grey Taguchi technique, 27 investigational trials were conducted. According to the Gray relation analysis, 300 kg m⁻³ of wood density with a weight ratio of 12%, three layers of 350 gsm woven jute, 60 min of cryogenic treatment and 4 h of alkaline treatments resulted in good mechanical strength of the composites. Based on the Analysis of Variance, wood density was identified as the most influencing parameter that contribute up to 35.65% to the improvement of the mechanical strength of hybrid composites. The morphological expositions of NaOH treated hybrid composites and degree of fibers’ dispersion into the matrix were discussed based on Optical and SEM images.

The characteristics of natural fiber reinforced composites such as light weight, non-abrasive, nonflammable, nontoxic, low cost and biodegradable have grabbed the attention of current researchers in the area of composites. The objective of this study is to examine the interlaminar shear strength of the polyester based wood and woven jute hybrid composite. To accomplish this objective, the following parameters such as (i) wood density, (ii) wood weight ratio, (iii) woven jute type, (iv) number of jute layers, (v) cryogenic treatment duration and (vi) alkaline treatment duration, each at three different levels were picked and optimized using the Taguchi method. The fibers were pretreated with 5% of NaOH solution for different length of time to reduce the moisture absorption. The L₂₇ orthogonal array was selected for the chosen parameters and the required composite materials were fabricated using hand lay-up techniques. The fabricated composites were then subjected to cryogenic treatment by immersing in liquid nitrogen at 77 K for different period of time. The interlaminar shear strength of the fabricated hybrid composites was done according to ASTM standard. The morphological features and degree of dispersions of fibers into the matrix of the fabricated hybrid composites were further studied and discussed.

The present study is aimed at investigating the effect of hybridisation on Kevlar/E-Glass based epoxy composite laminate structures. Composites with 3 mm thickness and 16 layers of fibre (14 layers of E-glass centred and 2 outer layers of Kevlar) were fabricated using compression moulding technique. The fibre orientation of the Kevlar layers had 3 variations (0, 45 and 60°), whereas the E-glass fibre layers were maintained at 0° orientation. Tensile, flexural, impact (Charpy and Izod), interlaminar shear strength and ballistic impact tests were conducted. The ballistic test was performed using a gas gun with spherical hard body projectiles at the projectile velocity of 170 m/s. The pre- and post-impact velocities of the projectiles were measured using a high-speed camera. The energy absorbed by the composite laminates was further reported during the ballistic test, and a computerised tomographic scan was used to analyse the impact damage. The composites with 45° fibre orientation of Kevlar fibres showed better tensile strength, flexural strength, Charpy impact strength, and energy absorption. The energy absorbed by the composites with 45° fibre orientation was 58.68 J, which was 14% and 22% higher than the 0° and 60° oriented composites.

Natural fibre-based composites are replacing traditional materials in a wide range of structural applications that are used in different environments. Natural fibres suffer from thermal shocks, which affects the use of these composites in cold environment. Considering these, a goal was set in the present research to investigate the impact of cryogenic conditions on natural fibre composites. Composites were developed using polyester as matrix and jute-fibre and waste Teak saw-dust as reinforcement and filler, respectively. The effects of six parameters, viz., density of saw-dust, weight ratio of saw-dust, grade of woven-jute, number of jute layers, duration of cryogenic treatment of composite and duration of alkaline treatment of fibres on the mechanical properties of the composite was evaluated with an objective to maximise hardness, tensile, impact and flexural strengths. Taguchi method was used to design the experiments and response-surface methodology was used to model, predict and plot interactive surface plots. Results indicated that the duration of cryogenic treatment had a significant effect on mechanical properties, which was better only up to 60 min. The models were found to be statistically significant. The study concluded that saw-dust of density 300 kg/m³ used as a filler with a weight ratio of 13 wt.% and a reinforcement of a single layer of woven-jute-fibre mat of grade 250 gsm subjected to alkaline treatment for 4 h in a composite that has undergone 45 min of cryogenic treatment presented an improvement of 64% in impact strength, ca. 21% in flexural strength, ca. 158% in tensile strength and ca. 28% in hardness.