A Study in Physical and Mechanical Properties of Hemp Fibres

Asim Shahzad

doi:10.1155/2013/325085

Abstract

This paper presents the results of the experiments undertaken to evaluate various physical and mechanical properties of hemp fibres. The study of these properties is vital for comparison with similar properties of synthetic fibres and for assessing hemp fibres’ suitability for use as reinforcement in composite materials. The properties of hemp fibres were found to be good enough to be used as reinforcement in composite materials. However, the issues of relatively high moisture content of fibres, variability in fibre properties, and relatively poor fibre/matrix interfacial strength were identified as factors that can reduce the efficiency with which these fibres can be utilised.

Highlights

Hemp fibres are finding increasing use as reinforcements in composite materials, often replacing glass fibres
The weight loss behaviour of hemp fibres in a desiccator was observed by keeping a sample of hemp fibres, cut out from hemp fibre mat conditioned at 23∘C and 50% relative humidity (RH), in the desiccator containing the desiccant copper sulphate and recording weight changes with the passage of time
At 140∘C, the fibres have lost almost all (9%) of their initial moisture which is consistent with the previous results. These results showed that the hemp fibres had equilibrium moisture content of about 10% when kept at standard conditions of 23∘C and 50% RH

Summary

Introduction

Hemp fibres are finding increasing use as reinforcements in composite materials, often replacing glass fibres. Found in the bast of hemp plant, these fibres have specific strength and stiffness that are comparable to those of glass fibres. The physical and mechanical properties of these fibres are still being explored One of these properties is the thermal degradation at elevated temperatures. Natural fibres are heterogeneous mixtures of organic materials and heat treatment at elevated temperatures can result in a variety of physical and chemical changes. The physical changes are related to enthalpy, weight, colour, strength, crystallinity, and orientation of microfibril angle [1]. Thermogravimetric analysis (TGA) of jute fibres shows that they start degrading at 240∘C [2]. For flax fibres, it has been shown [3] that degradation starts at just above 160∘C

Methods

Results

Conclusion