5 - Forensic identification of bast fibres

Abstract

By definition, bast fibres are the structural components of the stems of plants. They are of interest in the context of composite materials as they have lower density, but may possess similar specific modulus and specific strength to glass fibres. They are also generally perceived as more ‘sustainable’ than synthetic fibres. Bast fibres are ligno-cellulosic systems which have many similarities imposed by their common role in the plant. In the context of industrial supply chain quality, forensic techniques could be employed to confirm that each batch of fibres is from the specific plant species required for the composite application before the materials/structures go into production. In forensic fibre examinations, there is a requirement for analysis to be robust and reliable, such that it can be presented in a court of law, whilst also being cost effective. This chapter reviews the technologies that have been utilized in both the textile industry and in forensic analysis, which would enable the discrimination of the respective fibres. It is assumed that reinforcement fibres are used in their native form or after treatments which change the fibre surface. The review does not consider regenerated cellulose or apparel fabrics where there is a requirement for dyes, pigments, delustrants, and other inclusions. In addition to their use for the confirmation of unadulterated materials supplied to the composites industry, the forensic techniques do find applications in archaeological or criminal investigations (especially for apparel and furniture textiles).