## 1 Introduction  
Hemp fibers are abundantly available, sustainable, renewable and biodegradable. Hemp fibers have some outstanding mechanical properties (mainly tensile strength at break and tensile modulus) when compared with other naturally available plant fibers, such as date palm, jute, flax, to mention but a few [1; 2; 3; 4]. These fibers have a good environmental impact, especially when compared with conventional fibers, such as glass [5]. These attractive attributes have resulted into an increased use of these fibers as reinforcements in composite materials. These best fibers such as hemp and flax provide good acoustic insulating properties due to their hollow structure. During their processing stages, lesser energy is required when compared to the synthetic (carbon and glass) fiber-reinforcedpolymer (FRP) composites. However, natural (hemp) fibers attract few drawbacks. These include the lack of confidence in the use and performance of natural plant fiber and their composites and low degradation temperature, which is about 230 \({}^{\circ}\)C [6]. Poly(\(\varepsilon\)-caprolactone) (PCL) is a biodegradable matrix, semi-crystalline, non-crytotoxic polyester. Reported works on natural fibers as reinforcement in composites have revealed that the shortcomings such as less compatible with hydrophobic matrices, natural variability, low processing temperatures and comparatively lower mechanical properties in comparison to conventional glass and carbon fibre reinforcements have been minimised by modifying fiber surfaces using various treatments. These different modification methods have helped achieving improvements in physical, mechanical and thermal properties of various natural fibres by making fibers compatible with different polymer matrices [7,8]. In addition to these techniques, fiber aspect ratio (AR), which is determined as length divided by diameter of the fiber (\(\ll\)/4), is one of the significant factors that determines the mechanical properties of the polymer matrix composites (PMCs) [9]. Therefore, effects of variable hemp fiber ARs on some important properties are investigated in this present paper. Few experimental studies have been reported on mechanical properties of biocomposites. [PERSON] et al. [10] investigated into the effects of low-velocity impact from falling on jute/methacrylated soybean oil bio-composites. Four different types of samples, different fiber geometry and various thicknesses were impacted and they reported that the biocomposites displayed satisfactory impact resistance behavior. Furthermore, another reported works on composites based on biodegradable PCL matrices and reinforced with lignocellulosic reinforcements have suggested that the biocomposites displayed comparable mechanical properties to that of conventional-based matrices. The influence of the extrusion parameters on the fiber length evolution along the screw profile on hemp fiber-reinforced poly (\(\varepsilon\)-caprolactone)-based biocomposites was investigated [11]. They suggested that fiber length was rapidly decreased after introduction of the fiber and during the flow through the kneading blocks. A recent comprehensive work on amorphized cellulose as filler in biocomposites based on PCL has been reported [12]. The properties of fiber-reinforced composites depend on many factors. These factors include, but are not limited to, types of matrices and reinforcement used, fiber volume fraction, fiber AR, fiber dimensions and interfacial adhesion between reinforcement and the matrix. At low AR, the addition of reinforcement into the composite can create the phase of discontinuity leading to structural heterogeneity and can result in poor mechanical performance. At higher AR up to its threshold, the mechanical properties are expected to increase as a result of good interfacial interaction between the matrix and the reinforcement [13].