Optical and Scanning Electron Microscopic Study of the Effects of Charring on Indian Hemp (Apocynum cannabinumL.) Fibres

Abstract

Indian hemp (Apocynum cannabinum L.) fibres were subjected to carbonization or charring by heating, varying the temperature (250° and 350°C), the ambient atmosphere (air and vacuum atmosphere) and the initial condition of the fibres (more and less exposed). Fibre diameter measurements showed that all carbonizing treatments resulted in a reduced fibre diameter. Observation using scanning electron microscopy indicated that higher carbonization temperatures and the presence of oxygen had a more severe effect on fibres and associated tissue. The initial condition of the fibre also had an effect on the consequences of carbonization, with more exposed fibres and fibres present as individuals being more severely carbonized than fibres protected by cambium and present in bundles.