Effect Of Degumming Research Articles

Simulation Analysis of Sealing Performance of Rubber Core of Rotary Blowout Preventer

The performance of rotary control head or rotary blowout preventer will directly affect the success or failure of the underbalanced construction of oil and gas well. Once the failure occurs in the construction process, there may be blowout and other big drilling accidents. Based on the Yeoh constitutive equation, the dynamic sealing model of rubber core is established in this paper, and the sealing process of rubber core during tripping and tripping is calculated and analyzed. Then, the effect of the bubble defect in the core on the sealing performance of the core under different drilling fluid pressure was analyzed. Finally, the effect of metal degumming on the sealing performance of the core was analyzed. The results showed that the larger the initial sealing pressure and contact stress value of the Mises core was, the better the sealing effect of the Mises core was, while the larger the Mises stress value was, the more likely the Mises core was to suffer fatigue failure. The drilling fluid pressure significantly affects the maximum equivalent stress of the core, and the maximum equivalent stress appears in the bubble position inside the core at different times and under different drilling fluid pressure. The degumming position is placed in the contact position between metal and rubber core. When the tensile stress exceeds the limit of rubber core material, radial and circumferential cracks will occur on the upper surface of rubber core. With the increase of drilling times, rubber is prone to fatigue cracks, which eventually lead to mutual tearing.

Deep eutectic solvent degumming of hemp fiber: Key factors influencing fiber property and its mechanism

In order to remove non-cellulosic materials from the surface of hemp fiber for potential application in textile industry, a DES (choline chloride: urea, 1:2)- alkali H2O2 (DES- alkali H2O2, DAHD) hemp fiber degumming method was established. The changing regularity of DES treatment on the degumming effect of hemp fiber under different operational conditions (temperature, time and bath ratio) were fully investigated. The properties of purified fibers and the mechanism of degumming were systematically analyzed using several test methods. Chemical composition showed that treated fibers have higher cellulose content than alkaline treated ones, whereas removal rate of non-cellulose components reached 53%. The tenacity, length and degree of polymerization (DP) of the treated fiber was increased by 25%, 30% and 20%, respectively compared with traditional alkali degumming. Analysis by Py-GC/MS indicated the major pyrolysis product (LG) of cellulose was increased by 27.77% after DAHD treatment, and the major ester and ketones content was decreased by 1.07% and 11.13% due the removal of hemicellulose, respectively. Results from 2D NMR revealed that cleavage of β-O-4′ linkages significantly occurred and β-5′ linkages were all removed. The G-type lignin was further degraded than the S-type in DES-alkali H2O2 degumming system. Besides, DES still has enough degumming effect after repeated utilization. This study provides an potential practical method for hemp fiber extraction, which is characterized by high fiber quality, low energy consumption, eco-friendly and high efficiency.

A green process for flax fiber extraction by white rot fungus (Laccase mediators system) in a less-water environment

Degumming is required for all bast fibers before further processing. In this study, white rot fungi(WRF) were combined with solid state fermentation progressive bio-degumming(SPB) by introducing the electron mediator syringaldehyde(SA) to explore the feasibility of WRF bio-degumming in a less-water environment. The results indicated that the electron mediator (SA) could effectively enhance the oxidation effect of WRF and enhance the diffusion of WRF on the flax surface to improve its action range, thus enhancing the degumming effect. After degumming by this method, the fibers had a high degree of dispersion and a smooth surface. The removal of non-cellulose components was similar to that of the chemical method and meets the requirements for degumming. In addition, the fibers treated by this method had low molecular weight loss and high tensile strength. Thus, the SPB-L method offers a new strategy for the sustainable processing of bast fibers.

A promising degumming method to prepare kenaf fibers by using recyclable deep eutectic solvents

Traditional degumming methods of bast fibers are largely limited due to long procedures, high energy consumption, serious environmental pollution, or low efficiency. In this study, deep eutectic solvents (DESs) synthesized with hydrogen bond acceptor (HBA) and three representative hydrogen bond donors (HBDs) were applied to kenaf bast degumming. The morphologies, chemical compositions, crystallinities, polymerization degrees and physical properties of the kenaf fibers were determined. The effects and mechanisms of different DESs on dispersing kenaf bast were discussed. The results showed that alkalinity amide DES (ChCl-urea, CU) showed the best degumming effect. The optimal processing temperature is 160 °C and the processing time is 2 h. Due to competition from chloride ions, DES first weakens the hydrogen bond interaction in kenaf fibers. Then, the alkalinity amide DES removed lignin by deprotonation of phenolic hydroxyl groups and breakage of β-O-4 bonds for different lignin units. Finally, the solvent can be reused at least 3 times. The results showed that CU degumming treatment could effectively remove the gummy components in kenaf bast and had the potential to prepare refined dry kenaf fibers. This study provided a simple and green degumming method for kenaf bast. Scheme. The flowchart of DES degumming experiments. • A facile and greener DES degumming method for preparation of kenaf fibers. • Recycable and reusable DES degumming waste. • The mechanisms of kenaf bast degumming by three kind of DESs.

Influence of refining on the properties of buriti oil (Mauritia flexuosa L.f.)

Vegetables oils are renewables sources of ready availability with vast commercial employability. The application of these oils, generally, requires refining procedures for the removal of substances that make it unfeasible, such as phosphatides, proteins and free fatty acids. The objective of this study was to evaluate the effect of acid and aqueous degumming on the physical-chemical properties of crude oil of Mauritia flexuosa L.f. (buriti), palm tree of the family Arecaceae, very commercially exploited and well adapted to the Cerrado biome. Physical and chemical analysis were performed as acidity index, peroxide index, refraction, viscosity, density, gas chromatography coupled to the mass spectrometer and infrared spectroscopy before and after the refining process. The acidity, density and refraction indices didn´t change significantly during the treatments; however, significant differences were observed for the peroxide and viscosity parameters after the acid degumming process. Chromatographic and infrared spectroscopy results didn´t reveal changes in the constitution of constituent esters. The acid degumming was more efficient for the removal of undesirable substances, with significant variation (p < 0.05) for the peroxide index after this process. However, M. flexuosa oil presented good stability, keeping indexes acceptable in view of the current resolutions for its use.

Oxidative stability of Moringa oleifera seed oil: Effect of degumming and deodorization on tocopherol retention

Oxidative stability of <i>Moringa oleifera</i> seed oil: Effect of degumming and deodorization on tocopherol retention

Convenient method for the simultaneous production of high-quality fragrant rapeseed oil and recovery of phospholipids via electrolyte degumming

A degumming protocol, which utilized sodium chloride solution (SCS), was developed to remove phospholipids (PLs) and retain the flavor of fragrant rapeseed oil (FRO). The composition of PLs, physicochemical characteristics, and flavor profile of FRO were determined to assess the degumming effect of SCS. The PL removal rate of the finally optimized degumming procedure (SCS concentration of 3%, w/w) was 90.7%, which was superior to that of water degumming (86.3%). Moisture, total phenolic, and phytosterol contents indicated the high quality of the oils subjected to 3% SCS degumming. Additionally, FRO produced via the developed method had a bright color, and its flavor was well retained. Moreover, the PLs obtained via 3% SCS degumming exhibited better emulsifying capability than commercial lecithin, suggesting that the recovered PLs could be reclaimed. Therefore, the proposed technology is economical and effective. It has a promising prospect in industrial FRO degumming.

Green Degumming Technology of Hemp and a Comparison between Chemical and Biological Degumming.

This paper provides an efficient and environmentally friendly biochemical degumming method for hemp fiber, which can address the problems of high temperature, high pressure, and extreme pollution of the traditional chemical method and the harsh reaction conditions of biological degumming, such as a long reaction time and pH. In the biochemical method, dilute solutions of alkali pectinase lyase and chemical additives were used to process the hemp fiber and then the fiber composition and structure were investigated. A comparison of the chemical, biological, and biochemical degumming methods shows that the biochemical method can replace the chemical one causing a similar degumming effect, both being better than the biological method. The best proportion of the biochemical solution was found to be 1.5% alkali pectinase lyase, and for chemical auxiliaries the total amount of alkali was ≤0.4% and the total amount of salt was ≤0.8%. The best conditions of the biochemical degumming process were determined to be a bath ratio of 1:10, reaction temperature of 60 °C, and the time of 60 min. After degumming, the composition of the fiber was as follows: lignin 3.69%, pectin 4.09%, hemicellulose 13.34%, and cellulose 78.87%. The fiber quality index of fibers dealt by the biochemical method shows that the linear density was 4.66 dtex, length was 35.6 mm, and fracture strength was 64.5 cN/dtex, which were higher than those treated by the chemical method. This shows that the biological degumming method can be a green degumming method with higher efficiency, lower consumption, and pollution, as well as has a broad application scope.

Comparison of acid degumming methods and their influence on the formation of 3-MCPD-esters and glycidyl esters in sunflower oil deodorization

Degumming is the first stage in processing of vegetable oils, and it is aimed at removing phospholipids. The article compares the results of degumming by phosphoric and citric acids, their effects on the extraction of calcium and magnesium ions from oils, these ions being the main components of nonhydratable phospholipids. We showed the appropriateness of combining citric and succinic acids (the final content of phospholipids in oil was 0.034%, whereas it was equal to 0.048% when citric acid was used) and citric and ascorbic acids (the final content of phospholipids in oil was 0.040%). We studied the effect of acid degumming on the formation of 3-MCPD-esters and glycidyl esters. The content of glycidyl esters after degumming with citric acid and phosphoric acid was 310 g kg–1 and 200 g kg–1, respectively. After degumming with citric acid and phosphoric acid, the content of 3-MCPD-esters in the deodorized oil was 680 g kg–1 and 470 g kg–1, respectively. On the contrary, aqueous degumming does not increase the content of these esters in the deodorized sunflower oil (the content is less than 100 g kg–1) and its implementation can be recommended as one of the ways to prevent the formation of these toxic substances during deodorization.

Isolation and characterization of lignocellulosic fiber from jute bast by the organic solvent degumming system: an alkali-free method

Degumming is the dominant method for insolating lignocellulosic fibers in textile applications. Traditional alkaline degumming (TAL), as a common method, requires a high-concentration alkali and has been a severe challenge to the environment. In the research reported here, the possibility of innovative jute degumming by organic solvents 1-2 propylene glycol and a combination of additive green oxygen (GO-OS) was studied. The results revealed that fibers could be extracted by this system (under condition of 0.9% GO-OS, 180°C, 120 min), and obtained fibers with higher breaking tenacity (7.1 cN/dtex), yield (65.7%), breaking elongation (2.87%) and residual gum (11.7%), which all meet the requirement of the relevant Chinese Textile National Standards. Notably, the required reaction time (120 min) of the GO-OS system was 180 min shorter than that of the TAL method. Furthermore, the modifications introduced by the degumming effect on physicochemical aspects were characterized and confirmed by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. This study provides a promising degumming method for separating jute lignocellulose without acid and alkali consumption.

Novel scouring method of hemp fibers based on electrochemical techniques

Hemp fiber has excellent performance as a renewable fiber material. It is of great significance to study more efficient, energy-saving and environmentally friendly pre-treatment methods of hemp textiles. A novel hemp fiber scouring method based on electrochemical techniques was presented in the research. A type of water solution with high and stable oxidative potential due to in-situ- generated oxidative components was produced by the proposed electrical method, and was applied to scouring treatment of raw hemp fibers by just soaking the fibers in it. Hemp fibers with different treatments were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction, and residual gum rate, lignin content and whiteness of the samples were tested. Experiment results show that electrochemical scouring has a similar degumming effect of hemp fibers compared with traditional chemical scouring, with a better lignin removal and whiteness, implying an effective and short process method of hemp textiles pre-treatment with low impact on the environment.

Study on cocoonase, sericin, and degumming of silk cocoon: computational and experimental

BackgroundCocoonase is a proteolytic enzyme that helps in dissolving the silk cocoon shell and exit of silk moth. Chemicals like anhydrous Na2CO3, Marseille soap, soda, ethylene diamine and tartaric acid-based degumming of silk cocoon shell have been in practice. During this process, solubility of sericin protein increased resulting in the release of sericin from the fibroin protein of the silk. However, this process diminishes natural color and softness of the silk. Cocoonase enzyme digests the sericin protein of silk at the anterior portion of the cocoon without disturbing the silk fibroin. However, no thorough characterization of cocoonase and sericin protein as well as imaging analysis of chemical- and enzyme-treated silk sheets has been carried out so far. Therefore, present study aimed for detailed characterization of cocoonase and sericin proteins, phylogenetic analysis, secondary and tertiary structure prediction, and computational validation as well as their interaction with other proteins. Further, identification of tasar silkworm (Antheraea mylitta) pupa stage for cocoonase collection, its purification and effect on silk sheet degumming, scanning electron microscope (SEM)-based comparison of chemical- and enzyme-treated cocoon sheets, and its optical coherence tomography (OCT)-based imaging analysis have been investigated. Various computational tools like Molecular Evolutionary Genetics Analysis (MEGA) X and Figtree, Iterative Threading Assembly Refinement (I-TASSER), self-optimized predicted method with alignment (SOPMA), PROCHECK, University of California, San Francisco (UCSF) Chimera, and Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) were used for characterization of cocoonase and sericin proteins. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), protein purification using Sephadex G 25-column, degumming of cocoon sheet using cocoonase enzyme and chemical Na2CO3, and SEM and OCT analysis of degummed cocoon sheet were performed. ResultsPredicted normalized B-factors of cocoonase and sericin with respect to α and β regions showed that these regions are structurally more stable in cocoonase while less stable in sericin. Conserved domain analysis revealed that B. mori cocoonase contains a trypsin-like serine protease with active site range 45 to 180 query sequences while substrate binding site from 175 to 200 query sequences. SDS-PAGE analysis of cocoonase indicated its molecular weight of 25–26 kDa. Na2CO3 treatment showed more degumming effect (i.e., cocoon sheet weight loss) as compared to degumming with cocoonase. However, cocoonase-treated silk cocoon sheet holds the natural color of tasar silk, smoothness, and luster compared with the cocoon sheet treated with Na2CO3. SEM-based analysis showed the noticeable variation on the surface of silk fiber treated with cocoonase and Na2CO3. OCT analysis also exemplified the variations in the cross-sectional view of the cocoonase and Na2CO3-treated silk sheets. ConclusionsPresent study enlightens on the detailed characteristics of cocoonase and sericin proteins, comparative degumming activity, and image analysis of cocoonase enzyme and Na2CO3 chemical-treated silk sheets. Obtained findings illustrated about use of cocoonase enzyme in the degumming of silk cocoon at larger scale that will be a boon to the silk industry.

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

Degumming is the most critical step in the preparation of ramie fibers for textile application. However, the traditional chemical degumming process, which uses large amounts of alkali at high temperature, has been a severe challenge to the environment. In this study, a bacterial strain Pectobacterium carotovorum HG-49, was isolated and successfully applied to the degumming of ramie fibers at an industrial scale. The gum removal ratio can reach 82.16% within 16 h of degumming, which is more efficient than most reported methods. Analyses of changes in bacterial populations and community structures over the degumming process showed that strain HG-49 is the dominant bacteria at all time points with a maximum concentration of 2.17 × 109 CFU/mL at 12 h. The maximum activities of pectinase, mannanase, and xylanase reached 110.89, 39.89, and 32.17 U/mL at 10–12 h, respectively. The residual gum content of refined ramie fibers decreased to 1.85% after degumming, and their bundle breaking tenacity and whiteness reached 5.03 cN/dtex and 52, respectively. These values exceed the first-class standards of China textile criteria. Scanning Electron Microscopy (SEM) and Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR FT-IR) analysis further confirmed the excellent degumming effects of the proposed method. The whole genome sequencing of strain HG-49 was completed, and 28 degumming enzyme genes were found, which explains its high-efficiency degumming abilities. Moreover, because the method abandons the use of acid and greatly reduces alkali consumption, it is eco-friendly. This study provides a promising cleaner degumming method for the ramie textile industry.

Silicon dioxide as an efficient adsorbent in the degumming of rapeseed oil

Traditional degumming techniques used in the edible oil industry require high temperatures and consume more energy. As a result, green refining techniques are required to be developed. Rapeseed oil is one of the preferred edible oils used in southwest China because of its unique flavor. However, the dark color of the oil is an element of concern. It is important to find a refining method that can improve the color of the oil while retaining its flavor. The main purpose of this study was to evaluate a low-energy consumption degumming method that used different dosages (0.5%, 1.5%, 2.5%, and 3.5% w/w) of silicon dioxide when applied to rapeseed oil. The concentration of phospholipids, total phenolic content including that of canolol, and the color, flavor profile, acid value, chlorophyll content, and oxidative stability of the rapeseed oil were analyzed to evaluate the degumming effect of silicon dioxide. It was observed that the adsorption by silicon dioxide eliminated up to 85% of phospholipids from crude rapeseed oil, retained up to 96% of the total phenolic content, and had little effect on the amount of canolol, which is the dominant phenolic compound in rapeseed oil. In addition, the method improved the color of rapeseed oil by increasing the L∗/neutral value and decreasing the a∗/red values, and had little effect on the flavor according to E-nose. Using silicon dioxide as the adsorbent reduced the acid value and chlorophyll content of the oil, apart from largely shortening its induction period. When the recommended silicon dioxide dosage of 1.5% (w/w) was used, phospholipids, total phenolic content, a∗, and red values decreased by 81%, 5%, 38.2%, and 12.7%, while the L∗ and neutral values increased by 9.8% and 28.6%. This technology is economical and environmentally friendly due to its mild reaction conditions and zero wastewater production. It provided a new strategy and showed a great potential in the degumming of rapeseed oil.

An eco-friendly degumming process of flax roving without acid pickling and NaClO2-bleaching

Flax fiber is an important textile material with excellent antibacterial activity and moisture wicking. Degumming of flax roving is essential in determining flax-fiber quality. Traditional degumming requires a large amount of chemicals to process flax roving. This study aimed to reduce the chemical usage and achieve cleaner production during this process by applying microbial treatment to degum flax roving. Microbial degumming instead of acid pickling and NaClO2-bleaching steps can no longer use H2SO4 and NaClO2, and the amount of alkali can be reduced by 50%. By analyzing the compositional changes of the main steps in traditional degumming processes and microbial-treatment sample, the application of Bacillus subtilis HR5 can achieve a good degumming effect. Results of environmental scanning electron microscopy, Fourier-transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffractometry analyses showed that the gum was remarkably reduced, which can be confirmed by the gum components. Overall, the breaking tenacity and antibacterial activity of fibers degummed by microbial treatment were better than those treated by traditional degumming. These findings demonstrated the feasibility of microbial treatment as a solution for flax roving degumming.

Influence of refining processes on the bioactive composition, in vitro antioxidant capacity, and their correlation of perilla seed oil

The effect of chemical refining process on the bioactive composition, in vitro antioxidant capacity, and their correlation of perilla seed oil (PSO) were investigated. In this paper, seven samples corresponding to each step of the refining process (degumming, neutralization, bleaching, deodorization, winterization, crude, and refined oils) were studied. The results showed that phenolic compounds and tocopherols were removed from PSO to a degree of 19.4% and 5.4%, respectively. In addition, the carotenoid content of PSO decreased during the refining process. The main carotenoid of PSO was found to be lutein, and the compound was lost completely during the bleaching step of the refining process. In this paper, we analyzed the variation of carotenoid content in PSO during the refining process for the first time. Neutralization affected the contents of phytosterols the most, followed by the effects of degumming and bleaching. The demonstrated results of Pearson product-moment correlation indicated that total tocopherols were significantly correlated with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorption capacity (ORAC) values, whereas carotenoids were significantly correlated with the DPPH value. However, phenolic compounds and phytosterols have no significant difference with DPPH, 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, ORAC, and ferric reducing antioxidant power values. The collected information can be applied to seeking out optimum factors needed to suffice the fundamental requirements for PSO production and minimize micronutrient losses to enhance its market value. PRACTICAL APPLICATION: The present study aimed to determine influence of chemical refining in the bioactive composition of perilla seed oil (PSO) as well as its antioxidant capacity in vitro. Moreover, we also intend to find the correlation between them. Results indicated that this study supplies a good reference for the industrial parameters of the refining process to minimize micronutrient losses and further obtain high-quality PSO products for consumers.

Study on biochemical degumming process of mulberry fiber,part 1:single factor analysis

ABSTRACT Mulberry fiber is a new natural fiber. More and more attentions are paid to mulberry because of its good properties. The traditional chemical degumming method is liable to cause environmental pollution. This subject adopts the method of biochemical degumming technology to obtain mulberry fibers with certain spinnable properties. The degumming process of mulberry bark is studied on the basis of knowing the chemical composition and percentage content of the material composition of the raw material of mulberry bark, and the influence of different process conditions and parameters on the degumming effect is analyzed. Through single factor experiment and analysis of results, the optimized process parameters of biochemical combined degumming are as follows: the temperature and concentration of pickling acid pretreatment are 60°C and 2.5 g/L, respectively. The concentration, duration of action, and bath ratio of alkaline pectinase are 47 g/L, 8 h, and 1:20, respectively. The concentration and action time of sodium hydroxide in alkali boiling are: 10 g/L, 3 h. The concentration, duration of action, and bath ratio of xylanase are 10 g/L, 4 h, 1:20, respectively. The optimization process parameters obtained above lay the foundation for further orthogonal experiments to obtain the optimal degumming process.

Analysis of the Relationship Between Enzymatic Activity and Microbial Degumming Effect of Kenaf Bast

ABSTRACT Degumming is the most important step before kenaf bast fibers used in textile industry. Microbial degumming is an environmental protection and energy-saving technology to replace the conventional chemical degumming. Higher efficiency strains are the essential prerequisite to promote the application of microbial degumming technology. Generally, the screening and evaluation of strains for kenaf bast degumming were based on activity of functional enzymes produced by microorganism. In order to investigate the relationship between enzymatic activity and effect of kenaf bast degumming, strains DCE-01, 1101, B6, B7, and B8 were incubated in pure cultured, sterilized and non-sterilized degumming systems. After culturing for 16 h, functional enzymes for kenaf bast degumming (such as pectinase, neutral protease, xylanase, β-mannanase, laccase, lignin peroxidase and manganese peroxidase) were detected in the supernatant, and degumming effect of kenaf bast under sterilized and non-sterilized systems were evaluated respectively. Results revealed that strain DCE-01 was the best for kenaf bast degumming, though its enzymatic activity was not the highest among five strains. And the pretreatment of kenaf bast by high-pressure-steam sterilization could promote the degumming effect. This study suggested that there were limitations when screening or evaluating high-efficient strains for kenaf bast degumming with the guidance of enzymatic activity.

Effect of enzymatic treatment on wool fabric

Wool has been a precious raw material for people for a long time. Today we are able to select between a huge variety of fibres with varying properties, but the continuing use of wool – in spite of the competition with other natural fibres and new synthetic fibres can be attributed to the unique properties of wool such as good thermal regulation, high moisture absorption, low creasing tendency, low flammability and high wearing comfort. However a big disadvantage, which emerges during washing, is the felting tendency. Felting is an undesirable feature of woolen clothes which occurs as a result of the directionally dependent frictional coefficient of the wool fibers. To reduce felting, this directional dependency must be reduced. Nowadays, this is done by treating the wool in a chlorine-containing solution and due to its various advantages; the chlorination is the most frequently used process in the industry today. This process, though effective, results in the production of polluted wastewaters containing large quantities of chloro-organic compounds. Therefore, this procedure has to be replaced and develop clean technologies such as enzymatic finishing processes. Enzymes are natural protein molecules that act as highly efficient catalysts in biochemical reactions. Enzymes not only work efficiently and rapidly, but they are also biodegradable. The present study was undertaken to find the effect of Protease enzyme treatment on wool fabric and the effect of enzymatic degumming on dye ability of wool fabric. The control, scoured and enzyme treated samples were tested for various physical and colorfastness properties. Untreated wool fiber showed fair handle, no absorbency, rough and sharp scales on the surface of fiber, but after enzyme treatment wool fabric showed improvement in all the physical and colorfastness properties. With the single-step enzymatic treatment process, the scales of the wool were partially degraded and resulted in smoother surface structure which will facilitate the sliding of wool fibres in both directions and decrease felting tendency that way.

Circulating solution for the degumming and modification of hemp fiber by the laccase–2,2,6,6-tetramethylpiperidine-1-oxyl radical–hemicellulase system

Hemp fiber, as a kind of renewable textile fiber, has evoked much interest due to its excellent properties in various fields. It has been investigated in just one step to finish the process of chemo-enzymatic degumming and modification of hemp fiber, which is done in acetic acidsodium acetate buffer solution containing laccase (6.0 g), hemicellulase (0.3 g) and 2,2,6,6-tetramethylpiperidine-1-oxyl radical (0.3 g) under a mild condition (pH 5, 50C). The degumming effects of different batches of raw hemp fibers were also discussed. We found that the residual rate, fineness, length and tensile strength of degummed fiber were 15–27%, 9.00–24.00 dtex, 14.00–19.00 cm and 3.8–5.1 cN/dtex, respectively. Meanwhile, some of the oxidized functional groups were introduced into degummed fiber, which improved the moisture absorption and water retention value of the hemp fiber. The hemp fiber treated by this process could be further improved and then applied in the textile industry.