The effect of fiber dimensions on fiber network activation and tensile strength

Holzforschung ◽  
2012 ◽  
Vol 66 (1) ◽  
Author(s):  
Iiro Pulkkinen ◽  
Ville Alopaeus
Keyword(s):  
Tensile Strength ◽  
Wall Thickness ◽  
Fiber Length ◽  
Fiber Quality ◽  
Pulp Fibers ◽  
Fiber Network ◽  
Network Activation ◽  
Fiber Wall ◽  
Technical Properties ◽  
Comparison Of The Results

Abstract The objective of this work was to check the fiber network activation parameter developed earlier by the authors for eucalypt pulp fibers to predict technical properties of paper. The fiber size analyses were performed with an optical fiber analyzer that applies 2D image analysis techniques on single fibers. The effects of fiber length, fiber width, fiber wall thickness, and fiber curl distributions on the quality potential of eucalypt fibers were evaluated. Fiber curl and fiber wall thickness based parameters were found to have a high potential for evaluation of eucalypt fiber quality. The variations in technical properties of paper were explained with differences in fiber wall thickness and fiber curl distributions. When the model was tested against industrial long fiber pulps, a further modification for fiber length was needed. The Page tensile strength model and the shear-lag theory were applied for comparison of the results obtained by the network activation model. With the approach presented in this article, the strength characteristics of hardwood and softwood pulps can be easily evaluated based on fiber geometry and water retention value.

New model for predicting tensile strength and density of eucalyptus handsheets based on an activation parameter calculated from fiber distribution characteristics

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Iiro Pulkkinen ◽  
Juha Fiskari ◽  
Ville Alopaeus
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Wall Thickness ◽  
Water Retention ◽  
Activation Parameter ◽  
Water Retention Value ◽  
Data Set ◽  
Network Activation ◽  
Fiber Wall ◽  
Fiber Segment

Abstract The activation parameter developed is based on the fiber wall thickness distribution, fiber curl distribution, and water retention value of the unrefined fibers. The mechanical properties of paper that contain chemical pulp depend, among other things, on the free fiber segment activation between fiber-fiber crossings that is created during drying. Experimental data revealed that the degree of fiber swelling is responsible together with the fiber shape factor (curl) and fiber wall thickness for the extent of fiber network activation. The amount of bonding between fibers also affects fiber segment activation. Based on the experimental data, it was deduced that interfiber bonding ability of fibers, characterized as the water retention value, was mainly responsible for the development of handsheet density. Tensile index development was more affected by the morphology of fibers, which was the main determinant for high activation potential of fibers. Factor analysis was used to identify the main causes of variation for a refining data set of 20 Eucalyptus grandis samples. Three independent descriptors were found to be responsible for the majority of the variation: the bonding and activation factor, the factor of microcompressions, and the factor of fiber wall thickness and fiber curl. The activation parameter developed in this study can be used to determine the effect of fiber segment activation and inter-fiber bonding on the inplane mechanical properties of paper.

scholarly journals Tensile Strength and Dispersibility of Pulp/Danufil Wet-Laid Hydroentangled Nonwovens

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3931
Author(s):  
Chao Deng ◽  
R. Hugh Gong ◽  
Chen Huang ◽  
Xing Zhang ◽  
Xiang-Yu Jin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fiber Length ◽  
Water Jet ◽  
Pulp Fibers ◽  
Wet Strength ◽  
Blend Ratio ◽  
Sewage Systems

Wet-laid hydroentangled nonwovens are widely used for disposable products, but these products generally do not have good dispersibility and can block sewage systems after being discarded into toilets. In this study, both pulp fibers and Danufil fibers are selected as we hypothesize that the high wet strength and striated surface of Danufil fibers would allow us to produce nonwovens with better dispersibility while having enough mechanical properties. The wet strength and dispersibility of nonwovens are systematically studied by investigating the influence of the fiber blend ratio, fiber length, and water jet pressure. The results indicate that the percent dispersion could be as high as 81.3% when the wet strength is higher than 4.8 N, which has been improved greatly comparing the percent dispersion of 67.6% reported before.

scholarly journals Wood and bark fiber characteristics of Acacia melanoxylon and comparison to Eucalyptus globules

CERNE ◽  
2011 ◽  
Vol 17 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Fatima Tavares ◽  
Teresa Quilhó ◽  
Helena Pereira
Keyword(s):  
Cell Wall ◽  
Wall Thickness ◽  
Eucalyptus Globulus ◽  
Fiber Length ◽  
Tree Height ◽  
Specific Pattern ◽  
Cell Wall Thickness ◽  
Wood Fibers ◽  
Acacia Melanoxylon ◽  
Fiber Wall

Wood and bark fibers of Acacia melanoxylon were characterized and compared to Eucalyptus globulus which is a major quality source of pulp fibers. In 20 trees from four sites, fiber length and wall thickness were measured at 5, 35 and 65% of total tree height and at 10, 30, 50, 70 and 90% of the distance from pith. Maceration were prepared in a 1:1 glacial acetic acid:hydrogen peroxide solution. Wood and bark fiber length varied between 0.90 - 0.96 mm and 1.33 - 1.59 mm respectively. The cell wall thickness varied between 3.45 - 3.89 µm in wood and 5.01 - 5.40 µm in bark. Wood and bark fiber length decreased from the bottom to the top of the tree and cell wall thickness had no specific pattern for axial variation. Fiber length and wall thickness increased from the pith to the bark, but the wall thickness increased slightly with some fluctuations. In Acacia melanoxylon significant site differences were found in relation to bark fiber length and to wood wall thickness. The fibers of Acacia melanoxylon were similar to those of Eucalyptus globulus but the wood fibers were thinner and the bark fibers thicker. The radial variation was similar in both species. In wood of Eucalyptus globulus, fiber wall thickness increases from the base to the middle of tree height and decreases to the top; in the bark decreases from the base to the top. In Eucalyptus globulus fibers bark are higher in the top.

scholarly journals Effect of fertilization on cell size in wood of Eucalyptus grandis Hill ex Maiden

CERNE ◽  
2010 ◽  
Vol 16 (4) ◽  
pp. 465-472 ◽  
Author(s):  
Israel Luiz de Lima ◽  
Eduardo Luiz Longui ◽  
Luiz Santini Junior ◽  
José Nivaldo Garcia ◽  
Sandra Monteiro Borges Florsheim
Keyword(s):  
Cell Size ◽  
Wall Thickness ◽  
Fiber Length ◽  
Fiber Diameter ◽  
Eucalyptus Grandis ◽  
Vessel Diameter ◽  
Radial Position ◽  
Vessel Element ◽  
Fiber Wall ◽  
Vessel Element Length

The use of fertilization in forest stands results in yield gains, yet little attention has been directed to its potential effects on the quality of wood produced. Information is scarce about the effect of fertilization on anatomical structures of older Eucalyptus wood. This work aims to study the effect of fertilization on tissue cell size of wood from a Eucalyptus grandis stand at age 21 years, the management system of which is based on selective thinning and fertilizer application at the start of the thinning season. Factors to consider include: presence or absence of fertilizers, two log positions and five radial (pith to bark) positions. Results led to the conclusion that fertilization significantly influenced only vessel frequency. Vessel element length was influenced by tree height. Fiber length, fiber diameter, fiber wall thickness, vessel element length, vessel diameter and vessel frequency were influenced by the radial position of the sample in relation to the log. A positive correlation was observed between fiber length, fiber diameter, fiber wall thickness, vessel element length, vessel diameter, ray width and radial position, while a negative correlation was observed between ray frequency and radial position.

scholarly journals Biocomposite of Cassava Starch Reinforced with Cellulose Pulp Fibers Modified with Deposition of Silica (SiO2) Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Joabel Raabe ◽  
Alessandra de Souza Fonseca ◽  
Lina Bufalino ◽  
Caue Ribeiro ◽  
Maria Alice Martins ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Sol Gel ◽  
Fiber Surface ◽  
Sio2 Nanoparticles ◽  
Thermoplastic Starch ◽  
Cassava Starch ◽  
Sem Analysis ◽  
Pulp Fibers ◽  
Moisture Adsorption ◽  
Cellulose Pulp

Eucalyptuspulp cellulose fibers were modified by the sol-gel process for SiO2superficial deposition and used as reinforcement of thermoplastic starch (TPS). Cassava starch, glycerol, and water were added at the proportion of 60/26/14, respectively. For composites, 5% and 10% (by weight) of modified and unmodified pulp fibers were added before extrusion. The matrix and composites were submitted to thermal stability, tensile strength, moisture adsorption, and SEM analysis. Micrographs of the modified fibers revealed the presence of SiO2nanoparticles on fiber surface. The addition of modified fibers improved tensile strength in 183% in relation to matrix, while moisture adsorption decreased 8.3%. Such improvements were even more effective with unmodified fibers addition. This result was mainly attributed to poor interaction between modified fibers and TPS matrix detected by SEM analysis.

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.

Transplanting improves the allometry and fiber quality of Bt cotton in cotton–wheat cropping system

2019 ◽  
Vol 56 (1) ◽  
pp. 26-36
Author(s):  
Muhammad Asghar Shah ◽  
Mubshar Hussain ◽  
Muhammad Shahzad ◽  
Khawar Jabran ◽  
Sami Ul-Allah ◽  
...  
Keyword(s):  
Fiber Length ◽  
Fiber Strength ◽  
Management Practice ◽  
Cropping Systems ◽  
Fiber Quality ◽  
Cropping System ◽  
Bt Cotton ◽  
Area Index ◽  
Fiber Fineness

AbstractIn cotton–wheat cropping system of Pakistan, wheat (Triticum aestivum L.) is harvested in late April; however, the optimum sowing time of Bt cotton is mid-March. This indicates a time difference of 4–6 weeks between the harvest of wheat and cotton sowing. It is hypothesized that this overlapping period may be managed by transplanting cotton seedlings (30–45 days old) in late April, after the harvest of wheat due to better performance of already established seedlings. To this end, this study was conducted to evaluate the allometric traits and fiber quality of transplanted Bt cotton after harvesting wheat in the cotton–wheat cropping system. The Bt cotton–wheat cropping systems were flat sown wheat (FSW)–conventionally tilled cotton, FSW–zero tilled cotton, ridge sown wheat–ridge transplanted cotton using 30- and 45-days-old seedlings, and bed sown wheat (BSW)–bed transplanted cotton (BTC) also using 30- and 45-days-old seedlings. The study was conducted at Vehari and Multan in Punjab, Pakistan. Bt cotton in BSW–BTC with 45-days-old seedlings showed better performance for allometric (leaf area index; (LAI), net assimilation rate; (NAR), and crop growth rate; (CGR)), seed cotton yield, and fiber traits (fiber uniformity, fiber length, fiber strength, and fiber fineness) in comparison to other treatments. Most of the fiber quality traits were positively correlated with allometric traits and biological yield (dry matter yield at maturity) at both locations, except correlations of CGR and LAI with fiber fineness and fiber length and NAR with fiber length. As plant growth and fiber quality of transplanted cotton was significantly higher than conventionally grown cotton, our data indicate transplanting is an interesting management practice for improving productivity in wheat–cotton cropping systems.

scholarly journals New technology for developing a lightweight refiner plate for hardwood kraft pulp fibers

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9128-9142
Author(s):  
Byeong-Geol Min ◽  
Ji-Young Lee ◽  
Chul-Hwan Kim ◽  
See-Han Park ◽  
Min-Seok Lee ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Fiber Length ◽  
Kraft Pulp ◽  
New Technology ◽  
Strength Properties ◽  
Pulp Fibers ◽  
Low Intensity ◽  
Novel Technology ◽  
Draft Angle ◽  
Reducing Energy

Sand casting makes it difficult to manufacture a fine bar plate for low intensity refining. This study introduced a novel technology for manufacturing lightweight fine bar plates and compared the effects to traditional bar plates. The lightweight fine bar plate base was manufactured using a lightweight aluminum alloy and stainless-steel. Because the bars were inserted into the plate vertically without the draft angle, the stock throughput was improved by approximately 27% compared to the sand-casted bar plates. Additionally, the lightweight fine bar plate maximized internal and external fibrillation while minimizing fiber length loss. In conclusion, the lightweight fine bar plate was shown to be more effective in improving the strength properties of paper and reducing energy consumption.

scholarly journals A comparative fiber morphological analysis of major agricultural residues (used or investigated) as feedstock in the pulp and paper industry

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7935-7952
Author(s):  
Dimitrios Tsalagkas ◽  
Zoltán Börcsök ◽  
Zoltán Pásztory ◽  
Vladimir Gryc ◽  
Levente Csóka ◽  
...  
Keyword(s):  
Cell Wall ◽  
Rice Straw ◽  
Sugarcane Bagasse ◽  
Wall Thickness ◽  
Fiber Length ◽  
Slenderness Ratio ◽  
Agricultural Residues ◽  
Lumen Diameter ◽  
Coconut Husk ◽  
Flexibility Coefficient

The suitabilities of major agricultural residues were assessed as papermaking feedstocks. All the examined agricultural residues were assumed as potential candidates for substituting hardwood fibers in mixed pulp blends from a fiber morphological perspective. Wheat, barley, rice, rapeseed, maize, sunflower, sugarcane bagasse, coconut husk, and two genotypes of miscanthus grass underwent identical maceration. The fiber length, fiber width, cell wall thickness, and lumen diameter were measured to calculate the slenderness ratio, flexibility coefficient, and Runkel ratio. The average fiber length ranged from 0.50 mm ± 0.32 mm (MG-S-02-V) to 1.15 mm mm ± 0.58 mm (sugarcane bagasse). The fiber width ranged from 10.77 μm ± 3.28 μm (rice straw) to 22.99 mm ± 5.20 mm (sunflower stalk). The lumen diameter ranged from 4.52 μm ± 2.52 μm (rice straw) to 13.23 μm ± 4.87 μm (sunflower stalk). The cell wall thickness ranged from 3.02 μm ± 0.95 μm (rice straw) to 4.80 μm ± 1.48 μm (sunflower stalk). The slenderness ratio, flexibility coefficient, and Runkel ratio values ranged between 28.08 to 58.11, 37.97 to 60.8, and 0.62 to 1.68, respectively. Wheat, maize, rapeseed, sugarcane bagasse, and coconut husk were found to be appropriate residue sources for papermaking feedstocks.

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