A high-efficiency and eco-friendly degumming process for ramie fibers

2020 ◽  
Vol 276 ◽  
pp. 124217 ◽  
Author(s):  
Tong Shu ◽  
Yun Bai ◽  
Ya-wei Wang ◽  
Hui-hui Wang ◽  
Pan-deng Li ◽  
...  
Keyword(s):  
High Efficiency ◽  
Ramie Fibers ◽  
Degumming Process

scholarly journals Effect of Na2CO3 degumming concentration on LiBr-formic acid-silk fibroin solution properties

2016 ◽  
Vol 20 (3) ◽  
pp. 985-991
Author(s):  
Zhi Liu ◽  
Yuqin Wan ◽  
Hao Dou ◽  
Ji-Huan He
Keyword(s):  
Formic Acid ◽  
Silk Fibroin ◽  
Sodium Carbonate ◽  
High Efficiency ◽  
Lithium Bromide ◽  
Solution Properties ◽  
Acid System ◽  
Acid Dissolution ◽  
Carbonate Concentration ◽  
Degumming Process

Salt-acid system has been proved to be of high efficiency for silk fibroin dissolution. Using salt-acid system to dissolve silk, native silk fibrils can be preserved in the regenerated solution. Increasing experiments indicate that acquirement of silk fibrils in solution is strongly associated with the degumming process. In this study, the effect of sodium carbonate degumming concentration on solution properties based on lithium bromide-formic acid dissolution system was systematically investigated. Results showed that the morphology transformation of silk fibroin in solution from nanospheres to nanofibrils is determined by sodium carbonate concentration during the degumming process. Solutions containing different silk fibroin structure exhibited different rheological behaviors and different electrospinnability, leading to different electrospun nanofibre properties. The results have guiding significance for preparation and application of silk fibroin solutions.

scholarly journals Green degumming process of ramie fiber thermal effect and optimization

2019 ◽  
Vol 23 (4) ◽  
pp. 2447-2451 ◽  
Author(s):  
Guoliang Liu ◽  
Dan Tian ◽  
Bangze Zhou ◽  
Yumeng Zhang ◽  
Tao Xu ◽  
...  
Keyword(s):  
Natural Fibers ◽  
Weight Ratio ◽  
Raw Material ◽  
Effect Of Temperature ◽  
Ramie Fiber ◽  
Traditional Treatment ◽  
Sodium Percarbonate ◽  
Ramie Fibers ◽  
Degumming Process ◽  
Environmentally Friendly Process

Ramie is a kind of natural fibers, it requires degumming process before it can be used as a raw material for various applications. The traditional treatment uses alkali, which is not an environmentally friendly process. In this paper, ramie fibers are degummed using sodium percarbonate, which causes no any negative environmental problems, and its decomposition, hydrogen peroxide, is a clear liquid, it can be used as an oxidizer, bleaching agent and antiseptics for surface treatment of ramie fibers. Effect of temperature and concentration of sodium percarbonate on the degumming process are studied theoretically and verified experimentally. Finally an optimal degumming process is suggested for maximal weight ratio of degummed ramie fiber to raw bast.

The Study on Eri-Silk Degumming Process Optimization and its Properties

2013 ◽  
Vol 446-447 ◽  
pp. 384-389
Author(s):  
Wen Zhong Wang ◽  
Lei Zhao ◽  
Li Shan Fan
Keyword(s):  
Alkaline Protease ◽  
Ph Value ◽  
Breaking Strength ◽  
Natural Fibers ◽  
Performance Comparison ◽  
Initial Modulus ◽  
Ramie Fibers ◽  
Friction Performance ◽  
Degumming Process ◽  
Eri Silk

Study the influence of eri-silk degumming process for degumming results of 2709 alkaline protease; combined with the orthogonal experimental analysis of high degumming rate and breaking strength of the best eri-silk degumming process, and then compare the optimized extracted eri-silk with mulberry silk, virgin silk, cotton, wool and ramie fibers for their fineness, mechanical properties, and friction performance comparison. The results show that the 2709 alkaline protease can effectively remove silkgum, and that the amount of enzyme is the main factor affecting degumming rate; pH value is the main factors for the breaking strength. Comparing with other fibers, eri-silks average fineness is smaller, breaking strength and initial modulus tend to be larger, but their coefficient of variation also tend to be larger. Besides, eri-silkis breaking elongation is not as good as wool and silk, but better than other fibers. Natural silks dynamic and static coefficient of tangential impedance is lower in comparison with other natural fibers. Ramie has the largest tangential resistance factor. Among the natural silks, the eri-silks tangential impedance coefficient is greater than tussah and smaller than mulberry silk.

scholarly journals An alkali-free method to manufacture ramie fiber

2018 ◽  
Vol 89 (17) ◽  
pp. 3653-3659 ◽  
Author(s):  
Yan Song ◽  
Wei Jiang ◽  
Kai Nie ◽  
Yuanming Zhang ◽  
Haoxi Ben ◽  
...  
Keyword(s):  
Deep Eutectic Solvent ◽  
National Standards ◽  
Ramie Fiber ◽  
The Novel ◽  
X Ray Diffraction ◽  
Ramie Fibers ◽  
Novel Method ◽  
Gum Content ◽  
Traditional Manufacturing ◽  
Degumming Process

Ramie is one of the most important fiber resources and it needs the degumming process to produce fibers. The traditional manufacturing process of ramie fibers requires a large amount of alkali, which causes serious environmental issues. This paper provides a novel path to manufacture ramie fibers without alkali. In this study, ramie bast was pretreated by steam explosion and then treated with deep eutectic solvent. The properties of ramie fibers prepared by the novel alkali-free method, including physical properties, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD), were compared with that produced by the traditional alkali process. Results showed that the fiber qualities, including residual gum content (4.68%), average fiber fineness (1419.99 Nm) and breaking tenacity (5.98 cN/dtex), were comparable with the traditional alkali process, which all meet the requirement of the relevant Chinese National Standards. The FTIR, SEM and XRD results all confirmed the degumming ability of the novel method to manufacture ramie fibers. Moreover, the novel method was proved to be eco-friendly. Taken together, these data indicate that the novel alkali-free method is green and effective in manufacturing ramie fibers.

scholarly journals Ramie-degumming methodologies: A short review

2020 ◽  
Vol 15 ◽  
pp. 155892502094010
Author(s):  
Lifeng Cheng ◽  
Shengwen Duan ◽  
Xiangyuan Feng ◽  
Ke Zheng ◽  
Qi Yang ◽  
...  
Keyword(s):  
Raw Materials ◽  
Natural Fibers ◽  
Short Review ◽  
Fiber Spinning ◽  
Raw Material ◽  
Perennial Herb ◽  
Fiber Properties ◽  
Ramie Fibers ◽  
Fiber Plant ◽  
Degumming Process

Ramie ( Boehmeria nivea L.), a perennial herb, is an important bast fiber plant. Its fiber with the advantages of attractive luster, high tenacity, enhanced strength, and good microbial resistivity is well known as the queen of natural fibers. The abundant cellulose fibers in ramie raw materials are stuck tightly by gums consisting of pectic substances, hemicelluloses, and little lignin. The gum should remove from the ramie raw material through degumming process to separate fibers, unveil unique fiber properties, and improve fiber-spinning ability to fulfill textile requirements. Low degumming efficiency and high environmental pollution are the major problems hindering the utilization of ramie fibers. Ramie degumming involves the degradation of pectin and hemicelluloses, which requires chemical, physical, biological treatment, or a combination of several treatments. No stereotyped parameters of the given degumming method have been yet established for the extraction of textile-grade ramie fibers. This review evaluated integrated methodology involving chemical, physical, biological and biochemical methods to degum raw ramie and obtain textile-grade refined fibers.

The chemical degumming process and effect on the composition, structure and properties of Apocynum venetum

2019 ◽  
Vol 90 (1) ◽  
pp. 3-9
Author(s):  
Jianting Lou ◽  
Lan Yao ◽  
Yiping Qiu ◽  
Huoyue Lin ◽  
Ye Kuang ◽  
...  
Keyword(s):  
Average Length ◽  
Wild Plant ◽  
X Ray Diffraction ◽  
Bast Fibers ◽  
Ramie Fibers ◽  
Apocynum Venetum ◽  
Color Data ◽  
Composition Structure ◽  
The Fourier Transform ◽  
Degumming Process

Apocynum venetum (AV) is a kind of rare wild plant with a strong capability for survival in the world and is named the “the king of wild fiber.” As AV bast fibers have defects due to natural and operational interventions, it is difficult to degum them thoroughly. In this study, chemical degumming was applied to obtain degummed fibers for further treatment. The details of degumming were provided and the necessary characterizations of the degummed fibers were tested and analyzed. The average length of AV fiber was 29.68 mm, concentrated in the range of 10–50 mm, which was suitable for blending with cotton, wool, etc. In addition, the fineness of AV fibers was 4673.25 Nm. From the results of color data, AV fibers were reddish yellow. Scanning electron microscopy results showed that the degummed single AV fiber had a certain number of nodes distributing randomly on the surface. The Fourier transform infrared spectrum showed that the peaks associating with the pectin, hemicellulose and lignin decreased significantly, indicating the effectiveness of the chemical degumming. In addition, the AV bast fibers and AV fibers had strong abilities in absorbing water moisture with regains of 11.56% and 8.7%, respectively. For the mechanical properties, the degummed AV fibers had a similar modulus of 401.56 cN/dtex to that of ramie fibers. The X-ray diffraction results indicated that after degumming, the crystalline structure was more obvious. These results provided the necessary basis for studying the structures of AV bast and degummed fibers and provided preparation for further fiber mat reinforced composites.

Study on the processing of stretch-broken ramie yarns in a cotton spinning system

2016 ◽  
Vol 87 (16) ◽  
pp. 2018-2027 ◽  
Author(s):  
Saipeng Guan ◽  
Hai Zhong ◽  
Jianping Yang ◽  
Chongwen Yu
Keyword(s):  
Fiber Length ◽  
High Efficiency ◽  
Ramie Fiber ◽  
Short Fibers ◽  
Yarn Quality ◽  
Comprehensive Performance ◽  
Ramie Fibers ◽  
High Length

In this study, conventional long ramie fiber was stretch-broken into short fibers with lengths of 30 mm, 35 mm, 40 mm, 45 mm, and 50 mm. Then, these stretch-broken fibers were processed in a cotton spinning system. The results show that, compared to long ramie fibers processed in a conventional ramie spinning system, the stretch-broken fibers, with reasonable fiber length and high length uniformity, can be processed in a cotton spinning system with high efficiency and generally have better resultant yarn quality. For all of the stretch-broken yarns, the yarn processed from fiber with 40 mm length shows the best comprehensive performance.

Microcalorimeters for X-Ray Spectroscopy

1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  
Keyword(s):  
High Resolution ◽  
High Efficiency ◽  
Thermal Response ◽  
Low Noise ◽  
High Resolution Spectroscopy ◽  
Superconducting Transition ◽  
Sapphire Substrates ◽  
Laboratory Plasmas ◽  
Adiabatic Demagnetization ◽  
Theoretical Predictions

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.

Imaging and diffraction modes in Scanning Transmission Electron Microscopy

1986 ◽  
Vol 44 ◽  
pp. 684-687
Author(s):  
J. M. Cowley ◽  
R. Glaisher ◽  
J. A. Lin ◽  
H.-J. Ou
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
High Efficiency ◽  
Fiber Optic ◽  
Image Intensifier ◽  
Detector System ◽  
Detector Plane ◽  
Secondary Electrons ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Special Detector

Some of the most important applications of STEM depend on the variety of imaging and diffraction made possible by the versatility of the detector system and the serial nature, of the image acquisition. A special detector system, previously described, has been added to our STEM instrument to allow us to take full advantage of this versatility. In this, the diffraction pattern in the detector plane may be formed on either of two phosphor screens, one with P47 (very fast) phosphor and the other with P20 (high efficiency) phosphor. The light from the phosphor is conveyed through a fiber-optic rod to an image intensifier and TV system and may be photographed, recorded on videotape, or stored digitally on a frame store. The P47 screen has a hole through it to allow electrons to enter a Gatan EELS spectrometer. Recently a modified SEM detector has been added so that high resolution (10Å) imaging with secondary electrons may be used in conjunction with other modes.

Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

1985 ◽  
Vol 43 ◽  
pp. 364-365
Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
Growth Conditions ◽  
Nonradiative Recombination ◽  
Device Structure ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

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