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The use of mineral-based fillers tends to reduce the mechanical properties of paper, which can limit their application. The filler surface modification is a significant treatment to overcome this limitation. This research aims to offer a novel modified mineral-based filler to provide its industrial application. The surface of precipitated calcium carbonate (PCC) was modified with xylan (XS), which is a type of hemicellulose, a polysaccharide consisting mainly of xylose residues. It is used as a filler at different filler dosage levels in paper pulp. Modified PCC(MPCC) was characterized with Fourier transform infrared spectroscopy, Thermogravimetric analysis, X-ray photoelectron spectroscopy, X-ray diffraction and Field-emission scanning electron microscopy analyses. The analysis demonstrated that the MPCC filler surface was coated with XS successfully. The effect of PCC and MPCC-filled hand-sheet paper physical, chemical and optical properties were studied. The experimental results showed that the mechanical (tensile, burst, tear strength) and optical (brightness, opacity) of hand-sheet paper filled with MPCC were significantly improved compared with unmodified PCC-filled paper at the same ash content. The filler retention of PCC and MPCC fillers in paper was investigated, and the MPCC filler showed better filler retention properties in paper stock than the PCC filler. [ABSTRACT FROM AUTHOR]

The main aim of the present research is to examine the effect of progressive deinking and reprinting on the paper properties of inkjet-printed paper. A typical office copy paper was selected as the base paper and printed using an inkjet printer having at least 50 % ink coverage. Thereafter, it was deinked and reprinted thrice, and its paper properties were measured. The paper properties that were measured were roughness, porosity, opacity, brightness, specular gloss, whiteness, bursting strength, tearing resistance, tensile strength, contact angle, deinkability efficiency, visible dirt area, ink elimination factors, and color differences. The results showed that in comparison to the base paper, the progressively deinked and reprinted paper samples showed an increase in roughness, porosity, opacity, tearing resistance, dirt area, and color difference. On the other hand, there was a decrease in brightness, gloss, whiteness, burst strength, tensile strength, contact angle, deinkability efficiency, and ink elimination factors. The experiment shows that the progressively deinked and reprinted papers can be compared to the base paper in the major paper properties. [ABSTRACT FROM AUTHOR]

A novel paper multifunctional protective solution was prepared by mixing berberine modified trimethoprimed carboxymethyl cellulose (TMP-DCMC-BBR), KH-791 modified nano-SiO2 (KH791-SiO2) and hydroxypropyl starch phosphate (HPDSP), and the mechanical properties, optical properties, antibacterial properties, aging resistance, acid and alkali resistance of the paper coated with the protective solution were investigated. It is shown that the paper coated with the multifunctional protective liquid showed good mechanical properties, and has little influence on optical properties of the paper. At the same time, it had good antibacterial properties, aging resistance and acid and alkali corrosion resistance, and there is no obvious change in paper appearance, no decolorization and ink diffusion, which is in line with the principle of "repairing the old as the old and keeping the original appearance". Moreover, the compound solution has certain reversibility and can absorb a certain degree of ultraviolet rays, so as to weaken the damage of ultraviolet rays to the paper. It is an ideal multifunctional protective liquid for paper and has broad application prospects in paper protection. [ABSTRACT FROM AUTHOR]

The pulp and paper industry is increasingly seeking a sustainable and conscientious development, minimizing the environmental impacts caused by it. Therefore, reducing efficiently the number of stages used in the bleaching process can mean less consumption of water and chemical reagents, contributing to the reduction of harmful waste to the environment. Thus, this study sought to evaluate the pulp quality and some physical-mechanical properties (smoothness, tear and tensile indexes) of two new bleaching sequences A*DP and A*E*DP and compare them with the reference D0(E+P)D1P. To do so, industrial eucalyptus Kraft pulp pre-delignified with oxygen was used. The bleached pulp was refined to 1200, 1800 and 2400, in PFI mill and tested according to TAPPI standards to determine smoothness, tear and tensile indexes. Based on the results obtained, it was verified that the sequences studied are viable for using in bleaching plants, which allowed a reduction in the chlorine dioxide consumption and presented satisfactory smoothness, tear and tensile indexes for paper. [ABSTRACT FROM AUTHOR]

The ash condensation ability of the cigarette paper is an important factor affecting the cigarette grades. In this study, we put forward an effective method of improving this ability. Xanthan gum was successfully synthesized, applied as an ash integrator in the dip-coating process of cigarette paper production, and showed good performance. Cationic guar gum, cellulose phosphate and Hydroxyapatite (HAP) have been added in the pulp and showed better performance of the ash condensation property. The ash become much whiter and the scatter of the ash have been suppressed. Moreover, the further addition of HAP would result in a worse combustion efficiency, leading to the burning out of the cigarette in early time. [ABSTRACT FROM AUTHOR]

A novel macro-RAFT emulsifier was synthesized with S, S'-bis(α, α'-dimethyl-α"-acetic acid)-trithiocarbonate (BDATT), M13-10 (self-made emulsifier) and acrylate monomer, which was further used to prepare surface sizing agent. On the other hand, M13-10 was synthesized with iso-tridecanol polyoxyethylene ether, sodium methoxide and sulfamic acid as the starting materials. The hydrophilicity of macro-RAFT emulsifier and the performance of surface sizing agent were affected by BDATT used as the chain transfer agent and M13-10 as the hydrophilic monomer. So, the CMC and HLB of the emulsifier prepared with different M13-10 content and BDATT content, were compared, as well as the particle size of the prepared surface sizing agent, and the cobb, bursting resistance, tensile resistance, folding endurance and roughness of paper sized. The results reveal that surface sizing agent with macro-RAFT emulsifier of which the amount of M13-10 is 7 w% and the amount of BDATT is 2.5 w% demonstrates the best sizing effect on paper with the contact angle of 119°, the surface water absorption (cobb) of 48.8 g/m2, the bursting strength of 285 kPa, the folding endurance of 19 and the tensile strength of 59.6 kN/m. [ABSTRACT FROM AUTHOR]

This work has been conducted to investigate the effect of accelerated ageing on the filler-free (control) handsheets and the ones having Precipitated Calcium Carbonate (PCC) and Zeolite (Clinoptilolite) fillers. The diagnosis approach of this work has been based on the use of the techniques of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction (XRD). The FT-IR technique has allowed identifying the changes in cellulose components of handsheets. Likewise, the XRD technique has provided to diagnose the changes in crystallinity of the handsheets and fillers. The results found out that PCC and Zeolite fillers could be easily added to the structure of the paper network by changing various experimental variables. The loss of C−O functional groups and the formation of carbonyl groups in handsheets has been analysed by accelerated ageing. The spectroscopy results confirmed that usage of zeolite filler has a retarding and structurally improving effect on the glycosidic linkages. Recent findings have been provided new insights into the role of the synergistic effect of the combination of PCC and zeolite fillers in the decelerating of certain ageing mechanism. [ABSTRACT FROM AUTHOR]

The dimensional stability of paper products is a well-known problem, affecting multiple engineering applications. The macroscopic response of paper to moisture variations is governed by complex mechanisms originating in the material at all length-scales down to the fiber-level. Therefore, a recently-developed method, based on Global Digital Height Correlation of surface topographies is here exploited to measure the full-field hygro-expansion of single fibers, i. e. a surface strain tensor map over the full field of view is obtained as function of time. From the strain field, the longitudinal and transverse hygro-expansion and principle strains can be calculated. Long- and intermediate-duration dynamic tests are conducted on softwood and hardwood fibers. A large spread in the softwood fiber's transverse and longitudinal hygro-expansion coefficient ratio was found, while hardwood fibers behave more consistently. Computing the principle strain ratios reduces this spread, as it takes into account the variations of the deformation direction, which is directly affected by the micro-fibril angle (MFA). Furthermore, long-duration tests allow identification of the half-times at which the fibers equilibrate. Finally, the determined major strain angles for all fibers are consistent with the MFA ranges reported in the literature. [ABSTRACT FROM AUTHOR]

Cellulose nanofibers isolated from unbleached pulp are characterized by different surface properties due to presence of lignin at their surface, in addition to lower cost than isolated from bleached pulp. In the current work, the effect of cellulose nanofibers isolated from unbleached neutral sulfite and bleached soda rice straw pulps (so called UBCNF and BCNF) on improving paper sheet properties of unbleached and bleached rice straw pulp (so called UBP and BP) was studied. The effect on mechanical properties (tensile strength, burst strength, and tearing resistance) and physical properties (porosity and water vapor permeability) was studied. Scanning electron microscopy (SEM) was used to assist in explaining the obtained results. The result showed that using BCNF and BP resulted in better improvement in mechanical properties and also more effective in reducing porosity of paper sheets than in case of using UBCNF and UBP. These results indicated stronger bonding between nanofibers and pulps' fibers in case of using BCNF and BP (surfaces rich in cellulose hydroxyl groups) than in case of UBCNF and UBP (surfaces rich in lignin). Water vapor permeability of paper sheets made from unbleached or bleached pulps did not significantly affect by the addition the nanofibers. [ABSTRACT FROM AUTHOR]

Paper has been the most significant carrier of written information for many centuries. To prolong the life expectancy of papers, the polyurethane based on nanosilica was used to strengthen the paper fibers in this work. The relation between the mass concentration of polyurethane based on nanosilica and the specific properties of papers (e. g., folding endurance, tensile strength, tearing strength, whiteness and glossiness) were investigated. In addition, the effect of polyurethane based on nanosilica on the acid/alkali resistance and ageing resistance were studied. The results showed that polyurethane based on nanosilica could significantly improve the mechanical properties and ageing resistance of papers. [ABSTRACT FROM AUTHOR]

This study examined the use of Plantago psyllium seed husk flour as paper additive with the aim of improving the properties of cellulose sheet. The husk flour was added in 5 wt%, 10 wt%, 20 wt% and 30 wt% to the cellulose suspensions and its effect on the handsheet properties was studied. The results showed that the direct addition of husk flour highly improves the mechanical properties of the handsheets like tensile index (with up to 400 %), burst index (with up to 600 %) and tear index (with up to 1200 %). Cobb and contact angle tests with distilled water showed that the handsheets containing husk flour are more hydrophobic compared to the unmodified handsheets. The Cobb-Unger and contact angle tests with oil revealed that the additive reduces the oil absorbency of the handsheets as well, at the highest by 86 %. Additionally, the water vapor and especially the air barrier properties were improved. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant capacity test showed that the modified handsheets had free radical scavenging properties. The direct addition of Plantago psyllium seed husk flour can be a promising, easy and green method to improve the mechanical and barrier properties, oil and water resistance of cellulose sheets. [ABSTRACT FROM AUTHOR]

Coatings are generally applied for opacity, smoothness and gloss on the paper surface. Pigments such as CaCO3, Kaolin-Clay and Zeolite are used, and natural or synthetic binders are used. In this study, coatings using the CaCO3, Kaolin-Clay and Zeolite pigments on 80 gr/m2 high grade papers were made. PVOH was used as binder. Following coating, papers were processed through supercalendaring and printed with inkjet printer. Using INGEDE method 11p. recycling process printed papers were deinked. The optical properties of the recycled papers obtained after the deinking treatment, were compared with the unprinted papers. At the end of the study, the effect of coating on paper surface and the recycling performances of the inkjet printed papers were revealed. It was determined that the papers in which zeolite was used as a pigment were better, in terms of both surface properties and recycling performance when surface properties and recycling performance of coated papers were examined. When all the results were compared, it was found that the performances of coatings for which zeolite was used were much better than coatings such as CaCO3 and Kaolin-Clay, both in terms of surface coating properties such as opacity, roughness and gloss and recycling results such as brightness. [ABSTRACT FROM AUTHOR]

Using disposable screen-printed electrodes is a convenient way of monitoring environmental pollution, production process control etc. Usually, commercially available screen-printed electrodes are used, but more and more studies are being carried out in the field of printing electrodes on thinner, low-cost and versatile substrates, including paper. In the present research, the comparison of screen-printed electrodes printed on different paper-based materials is presented. Two unique and innovative invasive plant-based papers made from (1) Japanese knotweed, (2) Canadian and Giant goldenrod and (3) commercially available cardboard were used as a printing material for the electrodes. The selected paper substrates were characterized, and screen-printed electrodes were printed. The influence of substrates' properties and pre- or post-treatment of the screen-printed electrodes on the electrochemical behaviour is thoroughly analyzed. The results indicate that the printing substrate (roughness) had the most significant influence on the cyclic voltammetry response. Comparing pre- and post-treatment of screen-printed electrodes, it was shown that grinding influenced the electrochemical activity significantly, while corona discharge does not have as significant influence. Besides, it was shown that the invasive plant-based papers are viable alternatives to commercially available papers and can be used as low-cost and eco-friendly alternatives for disposable screen-printed electrodes. [ABSTRACT FROM AUTHOR]

A composite filler was developed by pre-flocculation of fiber fines and precipitated calcium carbonate (PCC) particles with flocculants such as cationic polyacrylamide (cPAM) and bentonite. The composite filler was compared with a conventional loading method in terms of physical properties of handsheet and filler retention. The handsheets using the composite filler showed higher strength properties than that using a conventional loading at a similar paper ash content level, implying that paper ash content can be increased maintaining same level of paper strength. Optical properties such as opacity and brightness of the paper with the composite were quite similar with the paper with the conventional loading. Filler retention of the composite filler was slightly higher than that of the conventional loading even though retention aids were not used for the composite filler. Paper formation of the composite filler was better than the case of the conventional loading. However, the sheet with the composite filler showed lower bulk than that with the conventional loading. Conclusively, the composite filler technology by pre-flocculation of fines and filler has a potential to be utilized to produce a high loaded paper. [ABSTRACT FROM AUTHOR]

In this study we have evaluated the suitability of laboratory testing methods to predict inkjet printing results. We have developed and used testing liquids that are spanning the operational window of industrial High Speed Inkjet (HSI) printers while still covering the maximum possible range of viscosity and surface tension. First we correlated liquid penetration measured with ultrasound (ULP) and direct absorption (ASA) to print through from HSI prints. The best correlation (R² É 0.7) was found for the sized paper. For papers with increasing liquid penetration speed we found a decreasing ability of both testing methods to predict print through, for the strong absorbing paper the correlation drops to R² É 0.2. Second we correlated contact angle and drop diameter to the dot area from HSI prints. Contact angle turned out to be a better predictor for printed dot area than drop diameter. Evaluating the change in contact angle over time we found the highest correlation to the dot area in the print when measuring the contact angle as soon as possible, in our case 1 ms after deposition of the drop on the paper. We also compared contact angle with microliter drops to picoliter drops, which are in the size scale of the actual inkjet droplet. To our great surprise correlations for microliter drops were equal or better than for picoliter drops, particularly for highly absorbing papers. Thus in order to predict dot spreading on paper our results suggest to measure the contact angle with microliter drops. Overall we found that, using laboratory testing methods, print through and dot spreading for HSI printing can be quite well predicted for slow absorbing papers but not very well for fast absorbing papers.

Surface characterization is important and has many applications in the paper industry. Surface characterization requires both surface roughness and surface friction. The relationship between the two has not been fully established for paper and paperboard. It has been a common practice that only the average property and the standard deviation with the coefficient of variation (COV) are reported for surface roughness and friction measurements. This practice, however, provides few information on surface structure and can lead to wrong judgments because two samples having the same average and the COV can have different physical properties. To avoid such mistake, a new surface characterization method has been developed. To this end, surface roughness- and frictionprofiles have been obtained using a latest version of Kawabata surface tester (Model: KES-SESRU, Kato Tech, Kyoto Japan). This new version uses the same stylus for both measuring surface roughness and friction under the same operating conditions. It was found that a correlation between the surface roughness and surface friction was very low. This indicates that they should be independent of each other. Therefore, both should be determined for surface characterization.