Effects of hydrophobic sizing on paper dry and wet-strength properties: A comparative study between AKD sizing of NBSK handsheets and rosin sizing of CTMP handsheets

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5350-5360
Author(s):  
Antti Korpela ◽  
Aayush Kumar Jaiswal ◽  
Jaakko Asikainen
Keyword(s):  
Hydrogen Bonding ◽  
Comparative Study ◽  
Liquid Water ◽  
Strength Properties ◽  
Thermomechanical Pulp ◽  
Alkyl Ketene Dimer ◽  
Wet Strength ◽  
Softwood Pulp ◽  
Practical Experiences ◽  
Sizing Agents

Alkyl ketene dimer (AKD) and rosin sizing are used in papermaking to decrease paper’s tendency to absorb liquid water. Earlier information regarding the effects of internal sizing on paper dry strength is not consistent. In the present laboratory study, AKD sizing of handsheets made from Nordic bleached softwood pulp (NBSK), and rosin sizing of handsheets made from Nordic hardwood chemi-thermomechanical pulp (CTMP) were done via an internal sizing method, and by immersing handsheets in aqueous sizing agent dispersion. In the study, AKD sizing had no significant effect on the dry strength of NBSK handsheets. The result corresponds to practical experiences of papermakers. However, both AKD sizing methods resulted in a substantial and long-lasting increase of handsheet wet-strength. Unlike internal AKD sizing of NBSK handsheets, rosin internal sizing of CTMP handsheets resulted in decreased handsheet dry strength. The decrease indicates that, under the conditions present during the experiment, rosin sizing agents interfered with interfiber hydrogen bonding of CTMP fibers. Given that, in practice, no such undesired effects have been commonly linked to rosin sizing, the observed effect may be specific to sheet-making conditions. However, the effect of rosin sizing on strength properties and their variation cannot be ruled out completely.

scholarly journals Surface Energy Compatibilites of Cellulose and Polypropylene

1992 ◽  
Vol 266 ◽  
Author(s):  
Daniel T. Quillin ◽  
Daniel F. Caulfield ◽  
James A. Koutsky
Keyword(s):  
Hydrogen Bonding ◽  
Surface Energy ◽  
Adhesive Bonding ◽  
Alkyl Ketene Dimer ◽  
Recycled Paper ◽  
Adhesion Properties ◽  
Polypropylene Composites ◽  
Surface Energies ◽  
Lignocellulosic Fiber ◽  
Sizing Agents

AbstractIn addition to its use in recycled paper products, recovered lignocellulosic fiber can be used as a reinforcement filler in composites with polyolefins. However, problems in both processing and product performance are often caused by the incompatibilities of surface energies between hydrophilic cellulose and non-polar polyolefin. This poor match in surface polarities is detrimental to strong adhesive bonding between olefin and cellulose. This work examines the effect of surface energy on the adhesion properties of polypropylene and cellulose. In particular, three materials accepted as paper-sizing agents were used to change the cellulosic fiber's surface energy to make it more compatible withthe surface energy of polypropylene.Cellulose fibers were treated by various methods with (1) alkyl ketene dimer, (2) alkenyl succinic anhydride, and (3) stearic acid and were characterized by their surface energies as determined by single fiber wettability measurements using the Wilhelmy technique. These measurements are discussed in detail. Results from these measurments can be related to differences in adhesion between treated cellulose and polypropylene, which can be measured by internal bond tests on hot-pressed composite sheets.Results indicate that the use of sizing agents reduces the acid/base (hydrogen bonding) character of the cellulose surface. Interactions involving hydrogen bonding are important in cellulose/modified-polypropylene composites. Reduction of these interactions appears to lead to a corresponding reduction in adhesion between cellulose and polypropylene.

scholarly journals High strength paper from high yield pulps by means of hot-pressing

2020 ◽  
Vol 35 (2) ◽  
pp. 195-204
Author(s):  
Tove Joelsson ◽  
Gunilla Pettersson ◽  
Sven Norgren ◽  
Anna Svedberg ◽  
Hans Höglund ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Hot Pressing ◽  
Kraft Pulp ◽  
High Strength ◽  
Strength Properties ◽  
High Yield ◽  
Thermomechanical Pulp ◽  
Wet Strength ◽  
Chemical Pulp ◽  
Bleached Kraft Pulp

AbstractThe hypothesis is that it should be possible to modify papermaking conditions in line with the softening properties of high yield pulp fibres and achieve similar strength properties to conventional chemical pulp based paper. We therefore investigated the rheological and physical properties of high yield pulp based papers during hot-pressing. Our results confirm that increased temperature combined with sufficient pressure enables permanent densification by softening of lignin, producing very high tensile strength. This treatment also significantly improved the wet tensile strength in comparison to bleached kraft pulp without using wet strength agents. The high yield pulps used here were spruce based thermomechanical pulp, chemi-thermomechanical pulp, and high temperature chemi-thermomechanical pulp, and birch-aspen based neutral sulphite semi chemical pulp, with spruce-pine based bleached kraft pulp as reference. Rapid Köhten sheets of 150\hspace{0.1667em}\text{g}/{\text{m}^{2}} and 50 % dryness were hot-pressed in a cylinder-press at 20–200 °C, 7 MPa, and 1 m/min. The mechanical properties showed great improvements in these high yield pulp papers, with tensile index increased to 75 kNm/kg and compression strength index to 45 kNm/kg; levels close to and better than bleached kraft. Wet strength increased to 16 Nm/g compared to 5 Nm/g for bleached kraft.

Pilot trials of hemicelluloses extraction prior to thermomechanical pulp production: Part 1

TAPPI Journal ◽  
2011 ◽  
Vol 10 (5) ◽  
pp. 21-28 ◽  
Author(s):  
CARL HOUTMAN ◽  
ERIC HORN
Keyword(s):  
Oxalic Acid ◽  
Energy Savings ◽  
Wood Chip ◽  
Strength Properties ◽  
Thermomechanical Pulp ◽  
Sugar Solution ◽  
Bisulfite Treatment ◽  
Pilot Trials ◽  
Pulp Production ◽  
Production Part

Pilot data indicate that wood chip pretreatment with oxalic acid reduced the specific energy required to make thermomechanical pulp. A combined oxalic acid/bisulfite treatment resulted in 21% refiner energy savings and 13% increase in brightness for aspen. A low level of oxalic acid treatment was effective for spruce. Energy savings of 30% was observed with no significant change in strength properties. Adding bisulfite did not significantly increase the brightness of the spruce pulp. For pine, the optimum treatment was a moderate level of oxalic acid, which resulted in 34% energy savings and an increase in strength properties. For all of these treatments 1–3 w/w % carbohydrates were recovered, which can be fermented to produce ethanol. The extract sugar solution contained significant quantities of arabinose.

Does kraft hardwood and softwood pulp viscosity correlate to paper properties?

TAPPI Journal ◽  
2016 ◽  
Vol 15 (10) ◽  
pp. 643-651 ◽  
Author(s):  
ROBERT J. OGLESBY ◽  
HUMPHREY J. MOYNIHAN ◽  
RICARDO B. SANTOS ◽  
ASHOK GHOSH ◽  
PETER W. HART
Keyword(s):  
Physical Properties ◽  
Strength Loss ◽  
Strength Properties ◽  
Clear Correlation ◽  
Paper Properties ◽  
Physical Strength ◽  
Pulp Viscosity ◽  
Softwood Pulp ◽  
The Impact ◽  
Related Paper

The impact of commercially prepared, fully bleached pulp viscosity variation on handsheet physical properties was evaluated at different levels of pulp refining. Hardwood pulps from the same brownstock species mix, cooking parameters, and kappa numbers were processed through two different commercial bleach plants: one with a D0(EP)D1D2 sequence and the second with an OD0(EOP)D1 sequence. Additionally, a commercial softwood (predominately Scotts pine) brownstock pulp bleached by an OD0(EP)D1D2 sequence was employed in this study. Pulps with viscosities ranging from 14 to 21 mPa∙s were refined in a Valley beater to two freeness levels, and the associated handsheet physical properties were measured in this study. Over the pulp viscosity range of 14 to 21 mPa∙s, no clear correlation was found to exist between pulp viscosity and related paper physical properties. Finally, a series of laboratory prepared bleached pulps were purposely prepared under non-ideal conditions to reduce their final viscosities to lower values. Handsheets made from these pulps were tested in their unbeaten condition for physical strength properties. Significant and rapid strength loss occurred when the measured pulp viscosity dropped below 12 mPa∙s; overall strength properties showed no correlation to viscosity above the critical 12 mPa∙s value.

Relationship between Hydrogen-Bonding Motifs and the 1b1 Splitting in the X-ray Emission Spectrum of Liquid Water

2021 ◽  
Vol 12 (16) ◽  
pp. 3996-4002
Author(s):  
Vinícius Wilian D. Cruzeiro ◽  
Andrew Wildman ◽  
Xiaosong Li ◽  
Francesco Paesani
Keyword(s):  
Hydrogen Bonding ◽  
Emission Spectrum ◽  
Liquid Water ◽  
X Ray

Computational analysis of the effect of [Tea][Ms] and [Tea][H2PO4] ionic liquids on the structure and stability of Aβ(17–42) amyloid fibrils

2021 ◽  
Vol 23 (11) ◽  
pp. 6695-6709
Author(s):  
D. Gobbo ◽  
A. Cavalli ◽  
P. Ballone ◽  
A. Benedetto
Keyword(s):  
Ionic Liquid ◽  
Hydrogen Bonding ◽  
Ionic Liquids ◽  
Liquid Water ◽  
Computational Analysis ◽  
Amyloid Fibrils ◽  
Aβ Peptides ◽  
Structure And Stability ◽  
Water Solutions ◽  
Kinetics Of

Tight coordination of peptides by organic anions driven by hydrogen bonding affects the fibrillation kinetics of Aβ peptides in ionic liquid/water solutions.

Comparative Study on Mechanical Strength Properties of Concrete by Using Demolished Concrete Waste

2019 ◽  
Vol 1 (6) ◽  
pp. 235-239
Author(s):  
Sabarinathan K ◽  
Ashwathi R
Keyword(s):  
Comparative Study ◽  
Mechanical Strength ◽  
Coarse Aggregate ◽  
Environmental Awareness ◽  
Strength Properties ◽  
Raw Material ◽  
Construction Waste ◽  
The World ◽  
Day By Day

The growing environmental awareness and Construction waste, is increasing day by day which in turn makes the world in seeking for examining the characteristics of Construction waste and obtaining a solution by using its reliable segments such that it can be used as a raw material and Conservation the natural recourses like Coarse aggregate

Enabled Cellulose Nanopaper with Outstanding Water Stability and Wet Strength via Activated Residual Lignin as a Reinforcement

2021 ◽  
Author(s):  
jinlong wang ◽  
Wei Chen ◽  
Tengteng Dong ◽  
Haiqi Wang ◽  
Shurun Si ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Plant Cell ◽  
Cell Walls ◽  
Water Stability ◽  
Plant Cell Walls ◽  
Residual Lignin ◽  
Wet Strength ◽  
Cellulose Nanopaper

Due to water-sensitive hydrogen bonding, uncontrolled deformation and mechanical decay of cellulose nanopaper (CNP) caused by water remain challenging. Inspired by plant cell walls and bonding strengthening, a strategy is...

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