Influence of Cellulase to Filtration and Fiber Morphology of Bleached Softwood Pulp

2012 ◽  
Vol 550-553 ◽  
pp. 1182-1185
Author(s):  
Min Du ◽  
Xin Ping Li ◽  
Meng Luo
Keyword(s):  
Mode Of Action ◽  
Fiber Length ◽  
Fiber Surface ◽  
Cellulose Hydrolysis ◽  
Enzymatic Treatment ◽  
Polymerization Degree ◽  
Fiber Morphology ◽  
Softwood Pulp ◽  
Before And After ◽  
Enzyme Dosage

Cellulase named as Celluclast 1.5L was used to deal with bleached softwood pulp. By analyzing the changes of fiber polymerization, fiber length and pulp freeness before and after enzymatic treatment, studied the influence of cellulase to filtration and fiber morphology of bleached softwood pulp, and discussed the mode of action of cellulase to bleached softwood pulp. The results show that while the enzyme dosage increasing, the degree of cellulose hydrolysis increases; the pulp polymerization degree decreases; fiber length decreases and the content of fines increase. Pulp filtration first increases and then decreases, but fiber surface does not appear the phenomenon of fibrillating. It indicates that the action of cellulase to fiber is from the inside to outside.

Modification of Bleached Softwood Pulp with Xylanase

2011 ◽  
Vol 393-395 ◽  
pp. 855-858
Author(s):  
Min Du ◽  
Xin Ping Li ◽  
Wu Guang Li
Keyword(s):  
Zeta Potential ◽  
Fiber Length ◽  
Fiber Surface ◽  
Enzymatic Treatment ◽  
Surface Wettability ◽  
Refining Efficiency ◽  
Tensile Index ◽  
Tear Index ◽  
Softwood Pulp ◽  
Enzyme Dosage

Xylanse named as Pulpzyme HC was used to modify bleached softwood pulp before refining. The efficiency of modification by different enzyme dosage was invested in this paper. The result showed that enzymatic treatment decreased the dissolved charge and absolute Zeta potential of the slurry and increased the fiber surface wettability. Appropriate Pulpzyme HC (0.4u/g) could improve the refining efficiency by 9.5°SR. The brightness and bulk of hand sheets increased with the increasing of the enzyme. Tensile index and tear index of hand sheets reached the maximum at the enzyme dosage of 0.2u/g. In this dosage, fiber length, knot index and curl index of fiber increased. But excessive enzyme decreased the tear index and had no effect on the tensile index.

Influence of Cellulase to Aggregation Structure of Bleached Softwood Pulp

2012 ◽  
Vol 549 ◽  
pp. 255-259
Author(s):  
Min Du ◽  
Xin Ping Li ◽  
Zhi Min Yao
Keyword(s):  
Water Retention ◽  
Enzymatic Treatment ◽  
Crystalline Region ◽  
Water Retention Value ◽  
Softwood Pulp ◽  
Aggregation Structure ◽  
Enzyme Dosage

Cellulase named as Celluclast 1.5L was used to deal with bleached softwood pulp. By analyzing the changes of water retention value and crystallinity of fiber after enzymatic treatment, studied the influence of cellulase to aggregation structure of bleached softwood pulp. The results show that with the increasing of the enzyme dosage, the proportion of long-fiber decreases and the content of fines increases. Water retention value of pulp first decreases and then increases. The fiber crystal does not change with the enzymatic treatment, but with the increasing of the enzyme dosage, the crystallinity of fiber first increases and then decreases. It indicates that the cellulase would act on the crystalline region of fiber in the higher enzyme dosage.

Carbon Fiber Reinforced Cement and Mortar

1990 ◽  
Vol 211 ◽  
Author(s):  
J. R. Linton ◽  
P. L. Berneburg ◽  
E. M. Gartner ◽  
A. Bentur
Keyword(s):  
Carbon Fibers ◽  
Fiber Length ◽  
Length Distribution ◽  
Fiber Breakage ◽  
Image Analysis Technique ◽  
Analysis Technique ◽  
Reinforcing Fibers ◽  
Before And After ◽  
Reinforced Cement ◽  
Critical Fiber Length

AbstractAlthough carbon fibers have high tensile strengths and are chemically inert, their application in cementitious composites is limited due to their brittleness. An image analysis technique employed to determine the length distribution of the reinforcing fibers before and after mixing in cement paste and mortar matrices indicates that substantial fiber breakage occurs during mixing. In paste mixtures, the average fiber length after mixing remains above the critical fiber length, but in mortar mixes the average fiber length falls below the critical fiber length resulting in no significant enhancement of composite flexural properties.

Action Mechanism of the Improvement of Printability for Eucalypt Bleached Kraft Pulp Pretreated by Cellulase

2013 ◽  
Vol 779-780 ◽  
pp. 294-301
Author(s):  
Wan You Tang ◽  
Li Chen ◽  
Zheng Jian Zhang
Keyword(s):  
Tensile Strength ◽  
Fiber Length ◽  
Kraft Pulp ◽  
Pulp Fiber ◽  
Fiber Morphology ◽  
Strength Index ◽  
Bleached Kraft Pulp ◽  
Tear Index ◽  
Pulp Sample ◽  
The Mean

Enzymatic refining of eucalypt bleached kraft pulp with the cellulase NOV476 was studied. The effects of this cellulase on the physical properties of pulp, fiber morphology and fiber appearance of the eucalypt bleached kraft pulp in different application conditions were discussed. The results show that, with the increase in the amount of enzyme, tensile strength index, burst index and TEA index of paper are increased and then decreased; elongation and tear index of paper have been declining, Zeeil tensile strength index has been an upward trend. Without beating the pulp sample, gradually increases as the amount of enzyme, the average fiber length and the average fiber width are gradually reduced, while mean kink index substantially constant. Number of vessels in fiber overall reduced tendency reaches a minimum in the amount of enzyme 0.5μ/g, the phenomenon is most obvious. In the same conditions of beating time, gradually increases as the amount of enzyme, the average fiber length is gradually reduced, an average fiber width is gradually increased, the mean kink index reaches a maximum in the amount of enzyme is 0.5μ/g. Number of vessels in fiber overall reduced trend.

Enhancement of AOCC Pulp by Laccase Treatment

2011 ◽  
Vol 236-238 ◽  
pp. 1336-1341
Author(s):  
Bing Sun ◽  
Yu Xin Liu ◽  
Shu Lan Shi
Keyword(s):  
Molecular Weight ◽  
Ferulic Acid ◽  
Model Compound ◽  
Fiber Surface ◽  
Gel Permeation Chromatography ◽  
Fiber Morphology ◽  
Wet Strength ◽  
Gel Permeation ◽  
Heating Treatment ◽  
Scanning Electron

The Americal Old Corrugated Containers (AOCC) was treated with laccase. Fiber morphology, molecular weight and distribution of lignin were analyzed by scanning electron microscope (SEM) and gel permeation chromatography (GPC). Through the model compound of lignin (ferulic acid) was treated by laccase, the correlative mechanism for improvement of the wet-strength of pulp by laccase was discussed. The results showed that the molecular weight of lignin decreased and the lignin adhered on the fiber surface after the pulp was treated by laccase. While the laccase treated pulp with heating treatment, the condensation degree of lignin and adhesion area on fiber increased. In addition, when the ferulic acid was treated by laccase, the results were similar to AOCC pulp.

Relation of Cotton Fiber Properties to Sliver Cohesion

1977 ◽  
Vol 47 (11) ◽  
pp. 755-760 ◽  
Author(s):  
Reba Lawson ◽  
Smith Worley ◽  
H. H. Ramey
Keyword(s):  
Fiber Length ◽  
Stepwise Regression ◽  
Statistical Evaluation ◽  
Fiber Surface ◽  
Cohesive Force ◽  
Independent Variables ◽  
Fiber Properties ◽  
Positive Correlations ◽  
Relationship Of ◽  
The Relationship

A statistical evaluation was made of the relationship of certain fiber properties to cohesive force and coefficient of variation of cohesive force. Significant positive correlations were found between the cohesive force and fiber length, tenacity, and fiber yellowness (+b); negative correlations were found with fiber perimeter and reflectance (Rd). When length, colorimeter values, and Micronaire readings were used as independent variables in a stepwise regression program, 53% of the variation in the cohesive force could be explained by upper half mean length and Rd. The addition of other fiber properties whose measurement was influenced by fiber surface properties increased the explainable variation in the cohesive force to 71%.

scholarly journals Presence of 19 Mycotoxins in Human Plasma in a Region of Northern Spain

Toxins ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 750
Author(s):  
Beatriz Arce-López ◽  
Elena Lizarraga ◽  
Ángel Irigoyen ◽  
Elena González-Peñas
Keyword(s):  
Enzymatic Hydrolysis ◽  
Human Exposure ◽  
Human Biomonitoring ◽  
Enzymatic Treatment ◽  
Plasma Samples ◽  
Human Metabolism ◽  
Northern Spain ◽  
High Incidence ◽  
Before And After ◽  
Phase Ii Metabolites

This study was conducted to investigate human exposure to 19 compounds (mycotoxins and their metabolites) in plasma samples from healthy adults (n = 438, aged 19–68 years) from Navarra, a region of northern Spain. Samples were analyzed by LC-MS/MS, before and after enzymatic hydrolysis for the detection of possible glucuronides and/or sulfates (Phase II metabolites). The most prevalent mycotoxin was ochratoxin A (OTA), with an incidence of 97.3%. Positive samples were in the concentration range of 0.4 ng/mL to 45.7 ng/mL. After enzymatic treatment, OTA levels increased in a percentage of individuals, which may indicate the presence of OTA-conjugates. Regarding ochratoxin B, it has also been detected (10% of the samples), and its presence may be related to human metabolism of OTA. Sterigmatocystin was detected with a high incidence (85.8%), but only after enzymatic hydrolysis, supporting glucuronidation as a pathway of its metabolism in humans. None of the other studied mycotoxins (aflatoxins B1, B2, G1, G2 and M1; T-2 and HT-2 toxins; deoxynivalenol, deepoxy-deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol; zearalenone; nivalenol; fusarenon-X; neosolaniol; and diacetoxyscirpenol) were detected in any of the samples, neither before nor after enzymatic treatment. To the best of our knowledge, this is the first report carried out in Spain to determine the exposure of the population to mycotoxins and some of their metabolites using plasma, and the obtained results justify the need for human biomonitoring and metabolism studies on mycotoxins.

Metaplexis japonicaseed hair fiber: a member of natural hollow fibers and its characterization

2019 ◽  
Vol 89 (21-22) ◽  
pp. 4363-4372 ◽  
Author(s):  
Zongqian Wang ◽  
Dengfeng Wang ◽  
Mingrong Wang ◽  
Wei Li ◽  
Qing Sui
Keyword(s):  
Length Distribution ◽  
Hollow Structure ◽  
Fiber Surface ◽  
Surface Characteristics ◽  
Extensive Study ◽  
Research Literature ◽  
Retention Performance ◽  
Fiber Morphology ◽  
Surface Absorption ◽  
Fiber Wall

Metaplexis japonica seed hair fibers (Mj-fiber), harvested from the seed pods of Metaplexis japonica (Apocynaceae: Asclepiadoideae) originating in China, Japan and Korea, have features ensuring its potential application in the textile and other industrial fields. In spite of the extensive study on the medicinal properties of Metaplexis japonica, research literature about Mj-fiber is quite limited. We obtained Mj-fibers by artificial peeling and seed removing; then the fiber morphology, chemical composition, structures, fiber surface absorption characteristics, and tensile and thermal properties were studied in detail. From the results, Mj-fiber has a hollow structure with a thin fiber wall and large lumen, in which the hollowness is over 92%. Uniquely, Mj-fiber is a natural profiled fiber with a cross-section of a "cross flower" morphology. At the same time, the density of it is very low, accounting for only one-fifth of the cotton fibers, and the fiber length distribution is relatively concentrated. The main component is cellulose, with a content of 53.9 ± 3.20% and structure of cellulose I. In particular, Mj-fiber has excellent hydrophobic and oil affinity surface characteristics. Moreover, the fibers bulkiness and warmth retention performance are comparable to that of duck down. Therefore, the results provide an experimental basis for the application of Mj-fibers in the textile and other industrial fields.

Modification of Rabbit Yarn by Milk Protein Grafting and Cross-Linking

2015 ◽  
Vol 10 (4) ◽  
pp. 155892501501000
Author(s):  
Li Jiali ◽  
Zhang Tonghua ◽  
Cheng Lan ◽  
Guo Min
Keyword(s):  
Milk Protein ◽  
Breaking Strength ◽  
Fiber Surface ◽  
Cross Linking ◽  
Knitted Fabric ◽  
Grafting Ratio ◽  
Locus Method ◽  
Graft Modification ◽  
Before And After ◽  
Friction Performance

Rabbit yarn was treated by milk protein grafting and cross-linking to improve its abrasion resistance performance and breaking strength. Grafting ratio and washing fastness of the rabbit yarn after graft modification were tested. The surface morphology of the rabbit yarn before and after graft modification was observed by a scanning electron microscope(SEM). The mechanical properties and friction performances of the treated and untreated rabbit yarns were also tested. The treated yarns were utilized to design and weave rabbit hair-knitted fabric. The anti-pilling resistance of the rabbit hair-knitted fabric was tested by circular locus method; the pills were then counted and weighed. The stiffness of the fabric was observed. Results showed that milk protein could obviously be grafted on the fiber surface, resulting in a rougher surface of the treated fabric than that of the untreated ones. The average grafting ratio is 3.701%. The protein retention ratio of the rabbit yarn treated by milk protein grafting and cross-linking is 99.312%. The breaking strength of the rabbit yarn was enhanced and friction performance improved significantly after treatment. The pilling grade of the fabric significantly improved and the stiffness of the fabric was reduced.

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