Calendering Effects on Coating Pore Structure and Ink Setting Behavior

TAPPI Journal ◽  
2010 ◽  
Vol 9 (1) ◽  
pp. 27-35 ◽  
Author(s):  
PETER RESCH ◽  
WOLFGANG BAUER ◽  
ULRICH HIRN
Keyword(s):  
Pore Structure ◽  
Mercury Porosimetry ◽  
Total Pore Volume ◽  
Theoretical Models ◽  
Surface Appearance ◽  
Coated Papers ◽  
Structure Changes ◽  
Ink Setting ◽  
Paper Gloss ◽  
Reduced Surface

Coating layer pore structure significantly affects surface appearance, optical properties, and print-ability performance of multiply coated papers. Generally, fast ink setting can be realized by use of fine pigments, or pigments with steep particle size distribution. Ink-paper interaction of coated papers also changes significantly in calendering. The objective of this study was to better understand the influence of calendering on the pore structure of multilayered coated papers and to highlight the effect of this pore structure change on ink setting behavior. Laboratory calendering trials demonstrated that the pore structure of calendered paper is reduced with increased calendering temperatures. Mercury porosimetry and image analysis of scanning electron microscope images of calendered papers highlighted the gradual reduction of total pore volume, which, in combination with the reduced surface porosity, resulted in slower ink setting. If ink setting speed is to be preserved, calendering at low surface temperatures and a higher number of nip passes is preferred to reach a desired paper gloss level. Results also were compared to common theoretical models for liquid penetration into porous structures. These models can also be used to describe the influence of calendering-induced pore structure changes on ink setting. This work demonstrates optimization of calendering parameters to reach a balance for paper gloss and ink setting. The optimum depends on the machine equipment available and has to be checked separately for each concept of multiply coated paper and calender conditions.

Pore Structure Of Hydrated Cement Determined By Mercury Porosimetry And Nitrogen Sorption Techniques.

1988 ◽  
Vol 137 ◽  
Author(s):  
Yahia Abdel-Jawad ◽  
Will Hansen
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Pore Volume ◽  
Mercury Porosimetry ◽  
Total Pore Volume ◽  
Curing Temperature ◽  
Vycor Glass ◽  
Degree Of Hydration

AbstractThe pore structure (i.e. total pore volume, surface area and pore-size distribution curves) was measured using mercury porosimetry and nitrogen sorption. Hydrated portland cement (type I) of water-cement (w/c) ratios 0.3, 0.4 and 0.6 by weight was analyzed at three degrees of hydration (i.e., 30%, 50% and 80%; 70% for the 0.3 w/c system) corresponding to low, intermediate and high levels of hydration. The effect of curing temperature (3°, 23°, and 43°C) on pore structure was also studied. The two techniques were evaluated as well on porous Vycor glass, which has a narrow pore size distribution in the size range accessible to both. Results obtained by both techniques on porous Vycor glass agreed well. However neither technique can be used alone to study the entire pore structure in well-hydrated cement due to the wide range in pore sizes and the presence of micropores. Due to the unstable pore structure in cement a specimen treatment procedure such as methanol replacement, combined with volume-thickness (V-t) analysis, is necessary in order to measure the micropores. At low hydration values the pore structure can be estimated by mercury intrusion porosimetry (MIP). At higher hydration values, however, this technique underestimates total pore volume and surface area due to the presence of micropores which MIP cannot determine. In the pore size range of overlap, higher pore volumes were obtained with MIP. Nitrogen V-t analysis shows that micropores are more pronounced with lower w/c ratios. This finding is consistent with pore size distribution curves obtained by MIP. For a given w/c ratio and degree of hydration the total pore volume measured by MIP was found to be independent of curing temperature in the temperature range studied. At any w/c ratio, capillary porosity is controlled by degree of hydration alone.

scholarly journals Study on the Relationship between Pore Structure and Uniaxial Compressive Strength of Cemented Paste Backfill by Using Air-Entraining Agent

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Fengwen Zhao ◽  
Jianhua Hu ◽  
Dongjie Yang ◽  
Ye Kuang ◽  
Hongxing Xiao ◽  
...  
Keyword(s):  
Pore Structure ◽  
Fractal Theory ◽  
Total Pore Volume ◽  
Linear Increase ◽  
Theory Analysis ◽  
Structure Changes ◽  
Small Pore ◽  
Paste Backfill ◽  
Air Entraining Agents ◽  
The Relationship

To control pores in the backfill, the air-entraining agents (AEAs) are used as an admixture to realize the pore structure changes under artificial action and explore the effect of pore structure on strength. Two AEAs at different dosages were added to the backfill. The relationship was then analyzed between them from the macro- and mesoscopic aspects. The results indicate that AEA can regulate pore structure changes of AEACPB. With the increase in AEA content, the total pore volume of different pore sizes in AEACPB increases, in which the proportion of big and medium pore gradually increases while the proportion of small pore gradually decreases. The AEACPB’s UCS is linearly negatively correlated with the porosity and pore percentage, which is the primary factor affecting the AEACPB of the pore structure. When the total pores’ volume in the AEACPB is constant, the influence of different pore structures differs. A higher proportion of small pores leads to a linear increase in strength; a higher proportion of medium pores leads to a linear decrease in strength; and a higher proportion of big pores leads to an exponential decrease in strength. And the fractal dimension has a linear negative correlation with the UCS by fractal theory analysis.

scholarly journals Nanometer Pore Structure Characterization of Taiyuan Formation Shale in the Lin-Xing Area Based on Nitrogen Adsorption Experiments

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 298
Author(s):  
Chenlong Ding ◽  
Jinxian He ◽  
Hongchen Wu ◽  
Xiaoli Zhang
Keyword(s):  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Shale Gas ◽  
Pore Volume ◽  
Ordos Basin ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Taiyuan Formation

Ordos Basin is an important continental shale gas exploration site in China. The micropore structure of the shale reservoir is of great importance for shale gas evaluation. The Taiyuan Formation of the lower Permian is the main exploration interval for this area. To examine the nanometer pore structures in the Taiyuan Formation shale reservoirs in the Lin-Xing area, Northern Shaanxi, the microscopic pore structure characteristics were analyzed via nitrogen adsorption experiments. The pore structure parameters, such as specific surface area, pore volume, and aperture distribution, of shale were calculated; the significance of the pore structure for shale gas storage was analyzed; and the main controlling factors of pore development were assessed. The results indicated the surface area and hole volume of the shale sample to be 0.141–2.188 m2/g and 0.001398–0.008718 cm3/g, respectively. According to the IUPAC (International Union of Pure and Applied Chemistry) classification, mesopores and macropores were dominant in the pore structure, with the presence of a certain number of micropores. The adsorption curves were similar to the standard IV (a)-type isotherm line, and the hysteresis loop type was mainly similar to H3 and H4 types, indicating that most pores are dominated by open type pores, such as parallel plate-shaped pores and wedge-shaped slit pores. The micropores and mesopores provide the vast majority of the specific surface area, functioning as the main area for the adsorption of gas in the shale. The mesopores and macropores provide the vast majority of the pore volume, functioning as the main storage areas for the gas in the shale. Total organic carbon had no notable linear correlation with the total pore volume and the specific surface area. Vitrinite reflectance (Ro) had no notable correlation with the specific surface area, but did have a low “U” curve correlation with the total pore volume. There was no relationship between the quartz content and specific surface area and total pore volume. In addition, there was no notable correlation between the clay mineral content and total specific surface area and total pore volume.

scholarly journals Physicochemical factors affecting the wettability of copper mine blasting dust

2021 ◽  
Author(s):  
Longzhe Jin ◽  
Jianguo Liu ◽  
Jingzhong Guo ◽  
Jiaying Wang ◽  
Tianyang Wang
Keyword(s):  
Particle Size ◽  
Physicochemical Properties ◽  
Pore Structure ◽  
Total Pore Volume ◽  
Open Pit ◽  
X Rays ◽  
Factors Affecting ◽  
Copper Mine ◽  
Mineral Components ◽  
Hydrophobic Component

AbstractTo investigate the factors affecting the wettability of copper mine blasting dust, the primary blasting dust was collected from an open-pit copper mine and separated into hydrophilic blasting dust (HLBD) and hydrophobic blasting dust (HBBD) using water flotation method. The physicochemical properties of HLBD and HBBD were measured and compared with each other. The properties included particle size distributions (PSDs), micromorphologies, pore structures, mineral components and surface organic carbon functional groups. The results show that particle size and pore structure of the blasting dust are the main factors affecting its wettability. Specifically, particle size of HBBD is smaller than that of HLBD, and their respiratory dust (less than 10 µm) accounts for 61.74 vol% and 53.00 vol%, respectively. The pore structure of HBBD is more developed, and the total pore volume of HBBD is 1.66 times larger than that of HLBD. The identical mineral compositions were detected in HLBD and HBBD by X-rays diffraction (XRD); however, the surface organic hydrophobic component of HBBD is slightly larger than that of HLBD, this may be the reason for the poor wettability of HBBD. This study is significant to understand the effects of physicochemical properties of copper mine blasting dust on its wettability.

Tomographic analysis of reactive flow induced pore structure changes in column experiments

2009 ◽  
Vol 32 (9) ◽  
pp. 1396-1403 ◽  
Author(s):  
Rong Cai ◽  
W. Brent Lindquist ◽  
Wooyong Um ◽  
Keith W. Jones
Keyword(s):  
Pore Structure ◽  
Reactive Flow ◽  
Column Experiments ◽  
Structure Changes ◽  
Tomographic Analysis

scholarly journals Nitrogen-Doped Hierarchically Porous Carbons Derived from Polybenzoxazine for Enhanced Supercapacitor Performance

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 131 ◽  
Author(s):  
Yanhui Wang ◽  
Liyan Dong ◽  
Guiping Lai ◽  
Meng Wei ◽  
Xingbi Jiang ◽  
...  
Keyword(s):  
Pore Structure ◽  
Rate Capability ◽  
Total Pore Volume ◽  
High Specific Capacitance ◽  
High Specific Surface Area ◽  
Koh Activation ◽  
Porous Carbons ◽  
Activation Temperature ◽  
Hierarchically Porous ◽  
Nitrogen Doped

Nitrogen-doped hierarchically porous carbons (HPCs), which are synthesized from benzoxazine resins, were successfully prepared following the processes of polymerization, carbonization, and potassium hydroxide (KOH) activation. As the key factor, the KOH activation temperature influences the pore structure and surface functionality, which are crucial for the excellent performance. The HPC-800 material, with the highest activation temperature (800 °C), displays a hierarchical pore structure, a high specific surface area (1812.4 m2·g−1), large total pore volume (0.98 cm3·g−1), high nitrogen content (1.27%), and remarkable electrical conductivity. It has also presented an excellent electrochemical performance of high specific capacitance of 402.4 F·g−1 at 0.1 A·g−1, excellent rate capability of 248.6 F·g−1 at 10 A·g−1, and long-term cycling stability with >99.0% capacitance retention after 500 cycles at 1 A·g−1 in 6 M KOH aqueous solution.

scholarly journals Pore Structure Characterization and the Controlling Factors of the Bakken Formation

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2879 ◽  
Author(s):  
Yuming Liu ◽  
Bo Shen ◽  
Zhiqiang Yang ◽  
Peiqiang Zhao
Keyword(s):  
Pore Structure ◽  
Oil And Gas ◽  
Vitrinite Reflectance ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Controlling Factors ◽  
Structure Characterization ◽  
Bakken Formation ◽  
Main Controlling Factors ◽  
Bakken Shale

The Bakken Formation is a typical tight oil reservoir and oil production formation in the world. Pore structure is one of the key factors that determine the accumulation and production of the hydrocarbon. In order to study the pore structures and main controlling factors of the Bakken Formation, 12 samples were selected from the Bakken Formation and conducted on a set of experiments including X-ray diffraction mineral analysis (XRD), total organic carbon (TOC), vitrinite reflectance (Ro), and low-temperature nitrogen adsorption experiments. Results showed that the average TOC and Ro of Upper and Lower Bakken shale is 10.72 wt% and 0.86%, respectively. The Bakken Formation develops micropores, mesopores, and macropores. However, the Upper and Lower Bakken shale are dominated by micropores, while the Middle Bakken tight reservoir is dominated by mesopores. The total pore volume and specific surface area of the Middle Bakken are significantly higher than those of the Upper and Lower Bakken, indicating that Middle Bakken is more conducive to the storage of oil and gas. Through analysis, the main controlling factors for the pore structure of the Upper and Lower Bakken shale are TOC and maturity, while those for Middle Bakken are clay and quartz contents.

Characterisation of pore structure by combining mercury porosimetry and micrography

2001 ◽  
Vol 34 (2) ◽  
pp. 76-82 ◽  
Author(s):  
S. Roels ◽  
J. Elsen ◽  
J. Carmeliet ◽  
H. Hens
Keyword(s):  
Pore Structure ◽  
Mercury Porosimetry

scholarly journals Laboratory Study on Changes in the Pore Structures and Gas Desorption Properties of Intact and Tectonic Coals after Supercritical CO2 Treatment: Implications for Coalbed Methane Recovery

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3419 ◽  
Author(s):  
Erlei Su ◽  
Yunpei Liang ◽  
Lei Li ◽  
Quanle Zou ◽  
Fanfan Niu
Keyword(s):  
Pore Structure ◽  
Coalbed Methane ◽  
Supercritical Co2 ◽  
Total Pore Volume ◽  
Experimental Results ◽  
Methane Recovery ◽  
Enhanced Coalbed Methane Recovery ◽  
Gas Desorption ◽  
Pore Structures ◽  
Tectonic Coal

Tectonic coals in coal seams may affect the process of enhanced coalbed methane recovery with CO2 sequestration (CO2-ECBM). The main objective of this study was to investigate the differences between supercritical CO2 (ScCO2) and intact and tectonic coals to determine how the ScCO2 changes the coal’s properties. More specifically, the changes in the tectonic coal’s pore structures and its gas desorption behavior were of particular interest. In this work, mercury intrusion porosimetry, N2 (77 K) adsorption, and methane desorption experiments were used to identify the difference in pore structures and gas desorption properties between and intact and tectonic coals after ScCO2 treatment. The experimental results indicate that the total pore volume, specific surface area, and pore connectivity of tectonic coal increased more than intact coal after ScCO2 treatment, indicating that ScCO2 had the greatest influence on the pore structure of the tectonic coal. Additionally, ScCO2 treatment enhanced the diffusivity of tectonic coal more than that of intact coal. This verified the pore structure experimental results. A simplified illustration of the methane migration before and after ScCO2 treatment was proposed to analyze the influence of ScCO2 on the tectonic coal reservoir’s CBM. Hence, the results of this study may provide new insights into CO2-ECBM in tectonic coal reservoirs.

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