Physical parameters of dew retted and water retted hemp (Cannabis sativa L.) fibres

Abstract

Even small additions of hemp fibres to fabrics result in sig nificantly higher surface resistance and increased heat sorption. The two major retting methods (dew retting and water retting) are used to extract fibbers for industrial uses. Both methods produce fibres of different quality. The results of research, carried out at the Lithuanian Institute of Agriculture, Upytė Experimental Station in 2006-2007, showed that dew retted and water retted hemp fibres differed in appearance. Hemp variety as a factor showed higher impact on physical fibre parameters: fibre content in dew retted and water retted hemp straw, dew retted hemp straw output from hemp stalks, the strength of fibre obtained from dew retted and water retted hemp. Seed rate as a factor did not show any significant influence on physical fibre parameters, and only some trends of higher parameters at higher seed rates could be observed. Statistical evaluation indicated that the year as a factor affected the majority of physical parameters tested. Statistical data processing also showed that the fibre extraction method as a factor had a significant influence on the fibre content in hemp straw in 2006, on the straw output from hemp stalks in 2007, on the fibre content in hemp stalks and hemp fibre flexibility in both years of investigation, on the hemp fibre strength in 2006.

Chemical composition and physical properties of dew- and water-retted hemp fibers

“…The obtained air-dried fiber was weighed and fiber content in the straw was calculated, along with the fiber content in the stems (Jankauskienė and Gruzdevienė, 2013).…”

Effect of harvest time and field retting duration on the chemical composition, morphology and mechanical properties of hemp fibers

“…When hemp stems start to degrade, fungal colonies appear as dark flecks on the surface of the bark and continue to develop until the surface turns to a steel-grey color (Jankauskienė and Gruzdevienė, 2013). At the initial stage of attack, growth of microorganisms is vigorous but as retting proceeds, the growth rate decreases (Donaghy et al, 1990).…”

Enable Environmental Policies for Eco-Industrial Growth: A Voluntary Government Tool for Local Productive Areas in Tuscany (Italy)

“…) were lower than annual C 11.54 652 671 ns not statistically significant, significance of differences evaluated from mean * significant at P < 0.05 ** significant at P < 0.01 accumulated per ha for aspen stands; however exceeded those for jack pine stands. Our results also showed that C production per above-ground biomass and stems of hemp (5866 and 5149 kg C ha − 1 yr − 1 on average) noticeably exceeded that of mature forests.…”

“…Growing well in Central Europe, both hemp and stinging nettle are promising candidates for nonfood market production: textile, paper, building industries as well as bioenergy [6][7][8][9][10][11]. Hemp is an annual monoecious or dioecious plant and it is considered as being a crop that requires no pesticides, since it outcompetes weeds, uses little fertiliser or irrigation in temperate areas and potentially causes little land use change since it can be grown on marginal land (though it will require more inputs if not grown on cropland) [12].…”