Analysis of the properties of hemp fiber

Abstract

Hemp fiber (Cannabis sativa)- one of the oldest cultural plants (Fig. 1). In Lithuania hemp was used from the ancient times, residues of seeds and cords made of hemp fiber were found in the middle Neolithic and Narva culture sett-lement Šventoji. First hemp fiber was started to cultivate 5000 years ago in Chi-na, from where it spread over the world. Currently hemp is cultivated in China, Europe (most of it being grown in Spain, Russia and Romania), North America (Canada) [1]. The cultivation of Hemp in Lithuania was legalized in 2014. Hemp is a cellulose fiber, the fiber contains 62-67% alpha cellulose, 8-15% hemicellulose, 4% lignin, the stem is composed of cortex, collenchymas, 35 primary and secondary bast rings and wood located in the central part of the stem. Namely from pectin glued bundles of bast the hemp fiber is extracted [3]. The process of extracting fiber from the hemp plant is similar to that of flax, although for hemp fiber, the process is known to be easier. For processing hemp fiber, commonly aplied methods are water or dew retting, during which, the pectins that bind the fibre bundles and the surrounding tissues of the plants stem together loosened. On completion of the water or dew retting, the plants stems classed as straw [4]. In straws, the bonds between the fibre and surroun-ding tissue are loosened and therefore, make further extracting operations easier. During the following, treading and scutching operations, the woody part of the straws is crushed into smaller particles – shives. While scutching, the shives are loosened and removed, leaving only the valuable plant fiber (Fig. 2). Hemp fiber can be applied in many fields: clothing is sewn, hemp fiber can be mixed with silk and cotton on purpose to obtain soft and gentle materials, the fiber is used in home textiles: tablecloths, tapestries, towels are made [...]