Revitalization of Industrial Hemp Cannabis sativa L. var. sativa in Slovenia: a Study of Green Hemp Fibres

Abstract

The importance of industrial hemp as a source of highly valuable textile fi bres is briefl y presented through its use for textiles and composites and its increasing cultivated areas in the 21 st century. On the territory of present Slovenia, about 160 ha of agricultural area was cultivated with hemp before WWII, then it quickly began to decline and at the end of the 1970s, it was no longer cultivated. Revitalization of industrial hemp in Slovenia with fi eld experiments started already in the years 2000/2001 for producing seeds, whereas hemp fi bres were used only as an insulation for buildings. The textile technological properties of hemp fi bres from diff erent varieties grown in Slovenia have not been examined till now. They are important for using hemp fi bres in highly valuable textile products. The properties of green hemp fi bres extracted mechanically from non-retted hemp stems of Cannabis sativa L. var. sativa (varieties: Novosadska, Juso-11, Bialobrzeskie, Unico-B and Beniko) were determined. All the analysed varieties except Beniko had stem height over 200 cm. The highest yield of green fi bres was 33.1% (Novosadska). The analysed green fi bres' content was 1.24-3.26% of ash, 7.77-8.50% of moisture regain, 10.69-13.92% of water-soluble substances and 8.45-10.83% of pectin. Through a biodegradation process of retting green hemp fi bres in tap water at temperature 35°C, 9.01-18.89% of dry mass was removed after ten days. Average linear density of green hemp fi bres was very high, around 200 tex. Tenacity of fi bres' bundles was in the range of 167-272 MPa, but tenacity of elementary fibres was 548-672 MPa. From the curves of specifi c stress-strain, it is seen that green hemp fi bres from all fi ve varieties had similar superstructure. All analysed green hemp fi bres had high linear density and low mechanical properties. For textile application, they should be further processed into fi ner fi bres in order to increase their tensile stress and become also more fl exible and soft.

Industrial Hemp (Cannabis sativa L.) Agronomy and Utilization: A Review

“…Hemp fibers have many uses in the textile industry, and hemp fabrics have a wide range of uses, including clothing, jeans, sportswear, bags, hats, pillowcases, blankets, shoes, and socks. It is also used to make hemp jewelry, and other ornaments [85][86][87]. Another study [88] has noted that there are no differences between hemp and cotton materials in terms of color fastness to breaking, oil stain discharge, ignitability, rip power, breaking power, and lengthening.…”

Hemp-Based Sustainable Slippery Surfaces: Icephobic and Antithrombotic Properties

“…9,10 However, domestic hemp's dominance in the United States took a significant downturn in 1937, when the United States federal government began to criminalize all cannabis. 11,12 Relatively recently, the passage of the 2018 Farm Bill removed hemp from the Controlled Substances Act altogether and made it legal for United States farmers to grow, process, and sell hemp commercially. 13 Over 40 states have now passed legislation allowing hemp cultivation, and the hemp market in the United States has increased tremendously.…”

“…The demand for sustainable materials is evolving speedily, and their prevalence is increasing in recent times. − Sustainable materials are safe, non-toxic, and biodegradable or recyclable, thereby limiting waste. , Hemp (Cannabis sativa) is one such sustainable material that is considered as a strong alternative for numerous plant products. − The cultivation of hemp initiated around 2700 BC, when its properties as a medicinal plant were discovered for the first time. , However, domestic hemp’s dominance in the United States took a significant downturn in 1937, when the United States federal government began to criminalize all cannabis. , Relatively recently, the passage of the 2018 Farm Bill removed hemp from the Controlled Substances Act altogether and made it legal for United States farmers to grow, process, and sell hemp commercially . Over 40 states have now passed legislation allowing hemp cultivation, and the hemp market in the United States has increased tremendously. , Hemp-based materials have many applications in the global market, , and production of hemp is experiencing a renaissance. , …”

Hempseed Oil Quality Parameters: Optimization of Sustainable Methods by Miniaturization

“…Industrial hemp, Cannabis sativa L., is a herbaceous annual and its cultivation takes place in central Asia [1]. Hemp is probably one of the first plants to be cultivated and exploited by humans for centuries; its cultivation has been spread across all countries, including Italy [2].…”