The effect of chemical additives on the strength, stiffness and elongation potential of paper

Strand, Anders; Khakalo, Alexey; Kouko, Jarmo; Oksanen, Antti; Ketola, Annika; Salminen, Kristian; Rojas, Orlando J.; Retulainen, Elias; Sundberg, Anna

doi:10.3183/npprj-2017-32-03-p324-335

Cited by 37 publications

(25 citation statements)

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“…Examples of mechanical treatments include creping, which can result in elongation of 15-300%, compaction, which increases elongation by up to 10-15%, and patterning of the paperboard with a creaser (Vishtal and Retulainen 2012;Panthi 2016). Strand et al (2017) studied the effect of wet-end additives on paper elongation and found that certain combinations of carboxymethyl cellulose and cationic starch helped to maintain paper elongation after unrestrained drying, although the studied polysaccharides had only a very small effect on elongation if restrained drying was used. Recent findings suggest that MFC improves paper elongation.…”

Section: Introductionmentioning

confidence: 99%

Influence of pulp type on the three-dimensional thermomechanical convertibility of paperboard

et al. 2019

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This study examines the effect of pulp type on the formability and elongation of paperboard, which are of key importance when producing 3D packages. Material performance was studied with a press-forming machine using laboratory handsheets as substrates. The handsheets were prepared from bleached softwood and hardwood kraft pulps, chemithermomechanical pulp, recycled newsprint, and mixtures of birch kraft and other pulps. The effect of microfibrillated cellulose (MFC) on substrate properties and material formability was also investigated. The 3D elongation of MFC-free handsheets varied between 1.2 and 5.5%. Depending on the pulp type and sheet composition, three essential sheet properties were recognized. These properties were bulk, elastic modulus and bending stiffness, the first two of which

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Section: Introductionmentioning

confidence: 99%

Influence of pulp type on the three-dimensional thermomechanical convertibility of paperboard

et al. 2019

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“…One of the effective ways to increase the strength of cardboard and paper products from waste paper is the addition of chemical auxiliaries to a fibrous suspension. Starches, especially cationmodified, carboxymethyl cellulose, liquid glass and synthetic polymers, such as cationic polyacrylamides and high-molecular polyvinyl amine [8][9][10], are used for this purpose.…”

Section: Introductionmentioning

confidence: 99%

Reinforcing a testliner with supporting chemical materials

2019

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The simulation of the chemical interaction of amphoteric polymer resin with sucrose having hydroxyl groups that are similar to cellulose were carried out using 13 C NMR spectroscopy. The transformation of azetidine groups of amphoteric polymer resin proved to result in the formation of covalent chemical bonds between the resin molecules and the hydroxyl groups of sucrose. The mechanism of the interaction of amphoteric polymer resin with cellulose macromolecules was confirmed. The effect of the consumption of amphoteric polymer resin on the physical-mechanical properties of a testliner with different composition was investigated. It was determined that there is a significant increase in the cardboard indices of all studied compositions with an increase in the consumption of resin from 1 to 4 kg per ton. A further increase in the consumption of resin does not practically change the strength of the cardboard, and hence is economically unreasonable. It was found that a greater efficiency of the use of amphoteric polymer resin is achieved when the content of a short-fiber fraction cardboard in the composition grows. It was shown that the consumption of resin of 4 kg per ton and the use of 30% short-fiber waste paper in the composition ensure an increase in the burst resistance and the destructive force during the compression of the ring by 23% and 18%, respectively; these parameters being the main indicators of mechanical strength of the cardboard. This, in turn, will reduce the cost of a testliner. The samples of a testliner with different composition were examined by the SEM method, the samples were fabricated without and with the addition of amphoteric polymer resin. The formation of a dense structure of a cardboard in the case of the use of resin and short-fiber waste paper was shown, this led to an increase in the strength of cardboard.

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“…The amount of water moving with the polyelectrolyte can be quite substantial, if the polyelectrolyte forms extended loops, trains, or tails. It was previously shown that adsorbed layers of CMC and these cationic starches onto nanocellulose surfaces contained between 52 and 66% of coupled water by weight at adsorption equilibrium (Strand et al 2017). Cationic starches with high DS onto cellulose surfaces results in a significantly more rigid layer, compared to cationic starches with a low DS, because polyelectrolytes with high DS are more strongly attracted to surfaces of opposite charge.…”

Section: Particle Countmentioning

confidence: 99%

“…Adsorption studies using QCM-D and SPR techniques have revealed that polyelectrolytes adsorb differently depending on their chemical properties, such as molar mass and charge density, onto model cellulose or silica surfaces (Tammelin et al 2004;Kontturi et al 2008;Strand et al 2017). A polyelectrolyte with a high charge density will adsorb as a stiffer and more rigid layer, compared to a polyelectrolyte with a low charge density (Kontturi et al 2008).…”

Section: Introductionmentioning

confidence: 99%

“…Cationic starches are the most commonly used additive in papermaking (Fornue et al 2011). Studies have shown that CMC greatly increases both the strength and stiffness of paper, which makes it a very interesting papermaking additive (Beghello et al 1997;Strand et al 2017). An additional aim of this work was to determine the hydrophobicity of PECs, and to study the time dependent stability of different PEC mixtures, since contact times between polyelectrolytes in papermaking can vary between fractions of a second to several hours.…”

Section: Introductionmentioning

confidence: 99%

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In-situ analysis of polyelectrolyte complexes by flow cytometry

et al. 2018

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Polyelectrolyte complexes (PECs) from common papermaking additives were prepared at different cation/anion ratios, resulting in colloidal light scattering particles. The polycations were cationic starches and polyDADMACs, while the polyanions were different carboxymethyl celluloses. The PECs were studied by turbidity measurements, as well as by flow cytometry (FCM). Turbidity maxima were detected close to the theoretical neutralization point of the polycation and polyanion. The turbidity response of the PEC mixtures varied with polyelectrolyte charge density. The PECs were in most cases quite stable over 24 h, but certain combinations resulted in unstable particles over time. Flow cytometry of PECs revealed clear populations of hydrophilic particles. The light scattering properties of PECs in side direction (SSC) and forward direction (FSC) were recorded for the different PEC combinations. The determined FSC and SSC offered information about very different PEC properties, and a new term was suggested for better understanding the mechanisms behind PEC formation; FSC/SSC. It was suggested that the determined FSC/SSC values were connected to the structural density of different particles. The premise was tested by analyses of solid, dense particles as well as swollen, soft particles. In addition to this, the hydrophobicity of PECs was determined by FCM. It was seen that the PECs were quite hydrophilic overall and that the measured hydrophobicities were lowest around the theoretical point of neutralization. Finally, the behavior of a coagulating PEC mixture as a function of contact time was studied with FCM.

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The effect of chemical additives on the strength, stiffness and elongation potential of paper

Cited by 37 publications

References 38 publications

Influence of pulp type on the three-dimensional thermomechanical convertibility of paperboard

Influence of pulp type on the three-dimensional thermomechanical convertibility of paperboard

Reinforcing a testliner with supporting chemical materials

In-situ analysis of polyelectrolyte complexes by flow cytometry

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