Thermal comfort behavior of hemp based knitted fabrics

Abstract

The hemp fibres production is characterized by sharp ups and downs, from the extensively growing to their decline in the past decades. Thanks to the unique hemp fibre properties, such as physiological, hygienic and ecological properties, hemp is nowadays reintroduced as a potential fibre source for health clothing textiles. However, hemp fibres have some limitations concerning the coarseness and lower elasticity. The aim of this study was to investigate the possibilities of producing hemp based comfort textile materials by involving soft and warm synthetic (acrylic) yarn. Since the transport of heat, moisture and air through a fabric are the major factors in thermal comfort, thermal properties, water vapor permeability and air permeability of the knitted fabrics were measured by standard testing devices (Permetest and TexTest). Yarn structure seems to be a significant factor influencing thermal comfort properties of knitted fabrics. In this investigation the differences in the yarn structure came from the differences in fibre geometry and properties, and manifested through the packing density into yarn. The hemp+acrylic knitted fabric exhibited transport properties at a comparable level to pure hemp knitted fabric, so the possibility of obtaining hemp+acrylic knitted fabrics with satisfactory thermal comfort properties was confirmed.

Cilj ovog rada bio je ispitivanje mogućnosti proizvodnje komfornih tekstilnih materijala na bazi konoplje uvođenjem meke i tople poliakrilonitrilne pređe. Operacijom dubliranja pređa homogenog sirovinskog sastava (poliakrilonitrilne i pređe od konoplje) omogućeno je dobijanje pletenina homogenog sirovinskog sastava (100% konoplja, 100% poliakrilonitril) i pletenine od mešavine konoplje i poliakrilonitrilnih vlakana (50% konoplja + 50% poliakrilonitril). Kako su prenos toplote, vlage i vazduha kroz materijal glavni faktori toplotnog komfora, merena su termička svojstva, propustljivost vodene pare i vazduha pletenina upotrebom standardnih uređaja (Permetest, TextTest). Pokazalo se da su ispitivana svojstva konoplja+poliakril pletenine uporediva sa svojstvima pletenine od konoplje. Pored toga, rezultati su ukazali na efekte koje struktura pređe ispoljava u pogledu toplotnog komfora pletenina. Upotrebljena vlakana su manifestovala svoj uticaj na termička svojstva pletenina i njihovu sposobnost da propuštaju vazduh i vodenu paru kroz različitu sposobnost pakovanja vlakana u pređe. Ovim istraživanjem je potvrđena mogućnost dobijanja pletenina na bazi mešavine konoplje i poliakrilonitrilnih vlakana sa zadovoljavajućim svojstvima toplotnog komfora.