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

Development of Hemp Fibers: The Key Components of Hemp Plastic Composites

“…The antibody RU2 against rhamnogalacturonan I backbone [44] does not recognize any epitopes within S1 layer, but binds to the thick inner cell wall layers of hemp fibers, both primary and secondary, same as to the primary cell wall/middle lamellae region [38] (Figure 6). Cytochemical staining for pectin is also positive in the inner layers of hemp fibers [6]. Presence of acidic component indicates that inner layer of hemp fibers is similar to G-layers of tension wood and flax fibers [45,46].…”

“…As usual for secondary cell wall layers, S1 gets lignified, especially at an advanced stage of hemp fiber development (Figures 5C and 6). Lignification occurs only in the outer cell wall layers of hemp fibers (middle lamellae, primary cell wall and S1): autofluorescence that is characteristic of lignin under UV light ( Figure 5C), and staining for lignin by specific dyes like phloroglucinol are not observed in the thick inner layers, though they are obvious for S1 [6,15]. The rest of cell wall remains nonlignified even in the fully formed fibers, which is especially obvious for primary fibers.…”

“…The rest of cell wall remains nonlignified even in the fully formed fibers, which is especially obvious for primary fibers. Since the proportion of S1 layer in total cell wall is higher in secondary fibers than in primary ones, the degree of their lignification is higher [6,15,38]. This makes secondary fibers more coarse and rigid, and is often considered as the major reason for their lower quality [9].…”

“…Hemp fibers, same as fibers of flax, ramie, nettle, and some other fiber crops, are distinguished by high-cellulose content [1][2][3]. The quality of such fibers varies depending on both the processing and the properties developed in planta [4][5][6]. We will consider the biological determinants of hemp fiber quality, comparing primary and secondary hemp fibers.…”

Characterization of Flax Water Retting of Different Durations in Laboratory Condition and Evaluation of Its Fiber Properties

“…Di Candilo et al (2010) conducted a research on well-water retting hemp straws at 35 °C for 6 different durations (from 1 to 6 days), which showed that the amount of reducing sugar in retting liquor for 2-day retting accounted for around 70% of that for 6-day retting and may thus prove the finding in terms of degumming rate in this study. In another study investigated by Liu et al (2015), it was also found that the pectin in late-harvested hemp straws was degraded rapidly during 7 days of field retting, but the degradation slowed down at later stages.…”