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For a hygiene paper such as tissue and towel, strength, softness, and absorbency are known as attributes that a user is looking for. It is proposed here that purchasing decisions are likely to be influenced by in-use experiences, which may be quite different from the physical properties measured with current standardized tests. There have been continuous efforts on developing physical test methods to replace subjective in-use tests because the benefits of the former are too significant to be overlooked. This paper considered some in-use test methods for paper towel products that can be carried out by panel members quickly in the course of sensory panel testing. In addition, laboratory tests were developed in an attempt to quantify such input. The sensory panel testing showed that (wet) strength and absorbency were the key contributions to the performance of paper towels. Softness did not show any significant contribution to it. Wet strength showed a high correlation with absorbency. The (wet) ball burst strength had the highest correlation with the in-use strength. Although both the tensile strength and the ball burst strength had a high correlation with preference, the ball burst tester is preferred because more reproducible and simpler to operate. [ABSTRACT FROM AUTHOR]

Grease-proof paper is an energy-demanding paper product to manufacture, especially during refining and dewatering. Increases in energy efficiency in either stage could result in major savings. This article investigates the potential gains with addition of a stepwise progression vacuum suction box to the forming section during production. For both a lighter, 50 g/m², and a heavier paper grade, 100 g/m², with a pulpdrainability of 86 °SR, a stepwise progression vacuum suction box in four steps would result in increased dryness, simultaneously with decreased energy expenditure. The observed effects were higher for the lower basis weight paper (50 g/m²). Both basis weights experienced clogging of the forming fabric due to the high degree of refining. This adversely affected the dewatering rate, decreasing the amount of air pulled through the paper even when increasing the vacuum pressure. When a stepwise progression suction box in four steps was compared to a single vacuum suction box, there was a 14% increase in dryness for lighter paper, over an equal energy consumption, measured as amount of air pulled through the paper. For the 100 g/m² paper, the increase in dryness was 3% compared to the 50 g/m² paper run over a single vacuum suction box. The results show great promise for energy savings when utilizing stepwise progression suction box dewatering for grease-proof paper production. [ABSTRACT FROM AUTHOR]

Size presses on paper machines are used to apply a solution of a polymer - usually starch - to the surface of the sheet and thereby to increase the stiffness, surface strength, and printing quality of the product. This article reviews publications dealing with the size press equipment, the materials, and factors affecting both the operating efficiency and attributes of the resulting paper. The emergence of film-press equipment (e.g. blademetering size presses) in the 1980s has greatly decreased the frequency of web breaks and increased productivity. Starch technology at the size press, though relatively mature, continues to evolve. By adjustment of starch attributes, solids levels, and incorporating other additives, modern papermakers can tune size press outcomes to meet a range of paper product requirements, including strength, hydrophobicity, and the reduction of air permeability. By application of various synthetic polymers, mineral particles, and even nanocellulose in combination with starch or other base polymers, there is potential to extend the technology to meet a range of future needs for paper products. [ABSTRACT FROM AUTHOR]

Tetra Pak® paper and PE (polyethylene) wastes were evaluated to obtain a new composite material with awareness of environmental responsibility. Fillers and coupling agents were used for this joining process. Calcite (CaCO3), boric acid (H3BO3), SPT (Sodium Perborate Tetrahydrate / NaBO3.4H2O), titanate, MAPE (maleic anhydride grafted polyethylene, and vinyltriethoxysilane (C8H18O) composites were produced in 30 x 30 cm plates. A total of 30 samples were prepared as 5 mg flour for thermogravimetric analysis (TGA). Samples were observed in a thermal analyzer at 10, 15, or 20 °C/min heating rate in nitrogen atmosphere. Graphs were obtained as a result of TGA, and the activation energies were calculated using these graphs. The activation energy was calculated using the Flynn-Wall-Ozawa method. The determined activation energies of the composites were close to each other for each temperature group. In the samples using calcite and vinyltriethoxysilane, relatively higher activation energies were observed in comparison to the samples with boric acid and MAPE. [ABSTRACT FROM AUTHOR]

For about two millennia, paper has served as a main medium for preservation of people’s ideas, stories, contracts, and art. This article reviews what is known about the various components that make up paper from the perspective of their long-term stability under typical storage conditions. Literature evidence is considered relative to the susceptibility of different paper components to embrittlement, acid hydrolysis, microbiological attack, and discoloration, among others. The cellulose that makes up a majority of most paper items is demonstrably stable enough to persist for many hundreds of years on the shelves of archival collections, though it is susceptible to acid-catalyzed hydrolysis, which can be accelerated by byproducts of decomposition. Though less attention has been paid to the archival performance of various minor components of modern paper products, evidence suggests that at least some of them are subject to likely breakdown, embrittlement, or decay in the course of prolonged storage. Based on these considerations, one can envision different categories of paper that can be expected to meet different levels of storage stability: ancient recipes for handmade papermaking, e.g. washi and hanji, archival-grade paper products, ordinary modern alkaline paper products, and paper manufactured without concerns for its longevity. [ABSTRACT FROM AUTHOR]

A surface profilometry technique was used to characterize the surfaces of paper products. A stylus-contact type profilometer capable of simultaneously generating both surface roughness- and friction-profiles was used. As a stylus for the profilometer, a conical shape whose tip was rounded to have a 0.5 mm curvature radius was designed and successfully employed in both printing & writing (P&W) papers and hygiene papers such as bathroom tissues and kitchen towel. From the profiles, the mean absolute deviation (MAD) from the averages, i.e., R-MAD from the roughness average and F-MAD from the average coefficient of friction, were suggested as the new surface characterization parameters. To elucidate the surface roughness profiles by fractal dimension analysis, the variogram method was applied to get the fractal dimensions of the paper products. Generally, the value of the fractal dimension increased as the surface roughness increased. The surface profilometry technique with the fractal dimension analysis with the variogram method looks promising to gain additional insight on the surface characteristics of paper products. [ABSTRACT FROM AUTHOR]

Tissue paper is deep-rooted in our daily life because of its different types of products that allow various applications. Tissue paper is a low grammage paper that is mainly characterized by softness, tensile strength, liquid absorption, and elasticity. These characteristics are essential when producing products such as toilet paper, kitchen rolls, hand towels, napkins, and facials. The tissue paper production involves two stages: formation of the tissue paper sheet itself and its converting into different finished products. Converting is characterized by several operations, namely: unwinding, winding, embossing, lamination, perforation, cutting, packaging, and palletizing. The most impacting operation is the embossing, which consists of marking a pattern on the paper sheet by applying pressure, with the intent to produce papers more aesthetically pleasing to the final consumer and/or a way to identify a particular brand. Also, it affects final properties, increasing the liquid absorption capacity and bulk but reducing softness and tensile strength. Converting is complex and has a huge impact on the finished products properties. In this review, the authors explored the different steps of converting and how they impact the different properties of finished tissue products. [ABSTRACT FROM AUTHOR]

Chemical crosslinking is an established method for improving the wet performance of paper. In the chemical crosslinking process, covalent bonds are formed between cellulosic surfaces. The formed intra- and interfiber bonds increase the paper's wet strength and reduce its water absorptivity. The majority of published studies concern crosslinking treatments with glyoxal, citric acid (CA), or with 1,2,3,4-butanetetracarboxylic acid (BTCA). The most severe disadvantage of the crosslinking treatments with glyoxal, CA, and BTCA is that the formed crosslinks make the fibers and the paper more brittle. This downside effect has largely impeded the utilization of crosslinking in paper and paperboard making. In the present study, handsheets made from Nordic bleached softwood kraft pulp (NBSK) were crosslinked with methylated 1,3-dimethylol-4,5-dihydroxyethylene urea (mDMDHEU), which is commonly used in cotton fabric finishing. Similar to using glyoxal and citric acid, crosslinking with mDMDHEU notably increased the handsheet wet strength and decreased the water absorption. Compared to the use of glyoxal or CA, the crosslinking with mDMDHEU did not make the handsheets that brittle. These results suggest that mDMDHEU could be a more viable crosslinking agent for improving the wet performance of paper products. [ABSTRACT FROM AUTHOR]

Friction profilometry is a powerful technique that is suitable for the surface characterization of paper products. In this technique, a stylus-type contact method that resembles papermaking processes is used for evaluating the quality attributes of products. The surface characterization requires both surface roughness and friction measurements. At present, however, few reports have been available regarding characterization of the friction by the surface profilometric method. The objective of this study was to provide guiding principles of a stylus-type contact surface profilometry for determining the friction properties of paper. Another objective was to introduce the concept of the mean absolute deviation (MAD) from the average coefficient of friction as a new friction parameter. [ABSTRACT FROM AUTHOR]

The overall usefulness of the bursting energy absorption (BEA) was studied for a better analysis of paper strength properties. Additionally, the changes of the BEA during more complex deformations of paper products, e.g., preliminary or simultaneous tensile and burst, were determined. For the purpose of the research, an experimental setup was designed. The results showed that the correlation between BEA and bursting strength was linear, but the proportionality strongly depended on paper grade. Thus, a more accurate method to characterize the bursting resistance (BR) of paper was proposed. The BR parameter is described by the three following parameters: average bursting strength, average bursting energy absorption, and the slope of the fitted linear regression curve (relationship between the bursting energy absorption and the bursting strength). This method revealed new mechanical behaviors of papers related to their preloading. [ABSTRACT FROM AUTHOR]

Surface properties include both surface roughness and friction. With a stylus-type contact method, it is necessary to obtain either a surface roughness profile or a friction profile that is affected by stylus shape and size, its contact force on the sample, the scan speed, and the data acquisition rate. As a new surface parameter, the mean absolute deviation (MAD) from an average property has been introduced. It represents the deviation from either the roughness average (Ra) and the average coefficient of friction (COF), respectively. While Ra or average COF depends on the instrument and its operating conditions, the MAD should not depend on them because it represents the variations within the sample. [ABSTRACT FROM AUTHOR]

As a global environmental problem, plastic pollution has attracted worldwide attention. Plastic wastes not only disrupt ecosystems and biodiversity, but they also threaten human life and health. Countries around the world have enacted regulations in recent years to limit the use of plastics. Paper products have been proposed as promising substitutes for plastics, which undoubtedly brings unprecedented opportunities to the pulp and paper industry. However, paper products have some deficiencies in replacing certain plastic products. Research and development to improve paper properties and reduce production costs is needed to meet such challenges. [ABSTRACT FROM AUTHOR]

A xylan-based antimicrobial additive agent was prepared and studied for use in paper products against Escherichia coli bacteria. The derived cationic-xylan-grafted-guanidine polymer (CX-g-PHGH) was successfully synthesized by graft copolymerization of cationic-xylan with polyhexamethylene guanidine hydrochloride (PHGH) using ceric ammonium nitrate as an initiator. The obtained CX-g-PHGH had a maximum PHGH grafting ratio of 18.4% and efficiency of 58.4% and showed good viscosity and thermal stability. Furthermore, the paper samples prepared in this work were reinforced noticeably with the addition of CX-g-PHGH, after which exhibited improved mechanical properties. Compared to the reference paper without any of the xylan derivatives, the index of tensile, tear, burst, and folding endurance of the paper were increased by up to 20.1%, 25.3%, 30.2%, and 77.8%, respectively. Moreover, the prepared CX-g-PHGH paper exhibited efficient antimicrobial barrier properties against E. coli bacteria, by which many applications based on the new xylan derived additive agent obtained in this work could be found, especially in field of antimicrobial paper products against E. coli bacteria from contaminated food. [ABSTRACT FROM AUTHOR]

Based on publications related to the use of micro- and nanofibrillated cellulose (MNFC) in papermaking applications, three sets of parameters (intrinsic and extrinsic variables, furnish composition, and degree of dispersion) were proposed. This holistic approach intends to facilitate understanding and manipulation of the main factors describing the colloidal behavior in systems comprising of MNFC, pulp fibers, and additives, which directly impact paper product performance. A preliminary techno-economic assessment showed that cost reductions driven by the addition of MNFC in paper furnishes could be as high as USD 149 per ton of fiber (up to 20% fiber reduction without adverse effects on paper's strength) depending on the cost of papermaking fibers. It was also determined that better performance in terms of strength development associated with a higher degree of MNFC fibrillation offset its high manufacturing cost. However, there is a limit from which additional fibrillation does not seem to contribute to further strength gains that can justify the increasing production cost. Further research is needed regarding raw materials, degree of fibrillation, and combination with polyelectrolytes to further explore the potential of MNFC for the reduction of weight of paper products. [ABSTRACT FROM AUTHOR]

The use of mineral fillers in the paper industry has attracted much attention due to its low cost and ability to improve optical properties and printability. Besides the filler characteristics, paper properties, such as bulk, tensile, and opacity, are greatly affected by filler distribution in the z-direction. Therefore, optimization of filler distribution is an effective way to maximize the value of fillers. In this work, a filler distribution factor (Fc) was proposed to quantitatively describe the concentrated degree of filler distribution in the z-direction. The reduction in Fc resulted in an increase in paper bulk, porosity, and opacity, due to the generation of more interfaces between fibers and fillers. When filler particles were concentrated in one layer (Fc = 1), the tensile strength of the filled paper increased between 26 to 40% in comparison to the paper with various Fc values. For a given Fc, better tensile and opacity properties were achieved by increasing filler concentration on the surface layer of paper. [ABSTRACT FROM AUTHOR]

Increasing global paper consumption has fostered the search for new alternative non-wood fiber sources. The aquatic weeds Cyperus digitatus, Cyperus iria, and Scirpus grossus were analysed for their fiber characteristics and chemical composition, and the processed fibers were transformed into handmade paper. The selected species yielded mediumlength fibers (0.92 mm to 1.03 mm), which were thin-walled with a lumen diameter (3.37 μm to 5.26 μm) wider than cell wall thickness (2.73 μm to 2.97 μm). In terms of fiber derived values, the selected species possessed a slenderness ratio of 86.5 to 113.1 (favourable, > 30) and flexibility coefficient of 35.2 to 47.6 (favourable, within the range 50 to 70), which was classified as rigid fiber. The species also contained high cellulose, 42.1% to 44.8% (favourable, > 40%) and hemicellulose content, 42.8% to 45.6% (favourable, within the range of 30% to 50%), and low lignin content, 10.6% to 11.8% (favourable, < 12%). Handmade paper of Cyperus digitatus possessed relatively high tensile strength (2.61 ± 0.15 kN/m) and breaking length (1.20 ± 0.07 km) among studied species. Comparison with other non-wood fibers indicated that the studied plants fibers can be used for production of paper plates, paperboard, and decorative paper. [ABSTRACT FROM AUTHOR]

Elongation is an important property of many packaging board and paper grades. Paper with high extensibility could provide an alternative for oilbased packaging materials. Micro- (CMF) and nanofibrillated (CNF) cellulose are known to increase the strength of a paper, but their effect on the drying shrinkage and elongation is not well-studied. In this work, paper was reinforced with fibrillated material. Added fibrillated material increased the drying shrinkage, which was generally proportional to the increase of paper elongation before breakage. Results differed depending on the fibrillated material and how it was added to paper (wet-end addition or spray application). The papers were dried unrestrained in order to achieve the highest elongation potential for the paper. Spray application of CMF increased elongation by 13%, while wet-end additions increased elongation by 20% and also strength by 10%, but only with high dosages. Spray application of oxidized-CNF improved elongation by 33%, while wetend applications increased only strength by 20%. Thus, boosting the drying shrinkage with fibrillated cellulose is one potential way to increase elongation and 3D formability of paper. [ABSTRACT FROM AUTHOR]

This study aimed to identify the performance properties that drive the shelf price of kitchen paper towels and evaluate whether sustainability is an important driver for pricing. Nineteen products were compared according to their performance (softness, absorbency, and strength), technology, and fiber morphology. Metrics to rank the products in different grades (economy, premium, and ultra) according to their performance were provided. A multiple linear regression showed that absorbency and softness are the most significant properties used to predict the price. Market data indicates that there is a segment of consumers willing to pay a premium price for products marketed as "sustainable", even though their performance is comparatively inferior to the majority of the samples. Sustainable products are up to 85% more expensive than regular products. The metrics obtained in this work can contribute to improvement in market transparency, and aid companies in deciding strategies for product development and new investments. [ABSTRACT FROM AUTHOR]

The application of the wrinkle measuring method described in Müller et al. (2017) and the subsequent evaluation algorithm of a range of deepdrawn samples were used to determine the influences and interdependencies of blankholder force, tool temperatures, and drawing height on the formation of wrinkles in paperboard. The main influences were identified and quantitatively evaluated. For the given experimental space, a regression function was derived and validated in further experiments. It was shown that a quadratic regression was superior to the previously used linear regression. The findings were discussed and compared with the results of similar experiments from past publications. Special attention was given to the wrinkles formed and the resulting quality of the formed paperboard cups. The restrictions of the data acquisition from the measuring method that was used and limitations of the model were presented to demonstrate the reliability of the results. [ABSTRACT FROM AUTHOR]

China is the largest waste paper importing market in the world. Due to more and more demands and awareness of environment/ safety issues, in recent years the Chinese government has implemented a number of new regulations on waste paper importing, for example, prohibiting importing of unsorted waste paper and lowering the foreign (non-paper) content in the imported waste paper from 1.5% to 0.5%. Small-scale (less than 50,000 tons per year capacity) paper mills are not eligible for importing waste paper. These new regulations have had profound impacts on the global waste paper recycling practice and the papermaking industry in China. At the same time, these new regulations bring up new challenges to the global waste paper recycling practices, such as increased labor costs and decreased recycling efficiency. [ABSTRACT FROM AUTHOR]

Increasing filler content in paper while maintaining paper strength is a continuous need in the paper industry. The bonds between cellulosic fibers and fillers are essential to increase filler level in paper. Besides tensile strength, which traditionally has been used to investigate different fillers on fiber bonding, a new factor, i.e. a filler bondability factor, can be applied in evaluating the mitigation effect of filler addition on fiber bonding. This factor shows its effectiveness in optimizing the key parameters for filler modification and the choice of filler, and it helps to maximize the use of filler in the paper industry. [ABSTRACT FROM AUTHOR]

Two kinds of macromolecules applied in papermaking were modified with β -cyclodextrin (β -CD) and loaded with ciprofloxacin hydrochloride (CipHCl) in an attempt to compare their potential applications in antimicrobial paper. β -CD grafted cellulose (β -CD-Cel) and β -CD grafted cationic starch (β -CD-CS) were prepared by grafting β -CD onto cellulose fiber and cationic starch using citric acid (CA) and epichlorohydrin (ECH) as crosslinking agents, respectively. β -CD-Cel and β -CD-CS were both loaded with an antimicrobial agent (CipHCl) to form inclusion complexes, namely β -CD-Cel-CipHCl and β -CD-CS-CipHCl. Furthermore, the inclusion complexes were added to the pulp to prepare antibacterial paper. The antimicrobial activity and physical properties of the paper were investigated. The results showed that the paper with both inclusion complexes exhibited excellent antibacterial activity, and the antibacterial activity with β -CD-CS-CipHCl was higher than that with β -CD-Cel- CipHCl. Moreover, the addition of both β -CD-Cel-CipHCl and β -CD-CSCipHCl affected the tensile and tear strengths of the paper. The paper with β -CD-CS-CipHCl had better physical properties than that with β -CDCel- CipHCl because the CS acts as a reinforcing agent in papermaking. These prepared antibacterial paper sheets may be useful for preventing wound and nosocomial infections in the medical and packaging fields. [ABSTRACT FROM AUTHOR]

Paper production requires large amounts of cellulosic fiber, whereas the world's forested lands and croplands have a finite capacity to supply such resources. To deal with likely future pressure on forest resources, as well as to hold down costs of materials, publications examined in the preparation of this review suggest that the paper industry will need to implement several concurrent strategies. In particular, the industry can be expected to view recycling as a central part of its activities. Basis weights of various paper-based products can be expected to decrease over the coming decades, and more of the fiber content will be replaced with fillers such as calcium carbonate. Such trends will place intense demands upon chemical-based strategies to enhance the bonding within paper and paperboard. Based on the literature, further progress in reducing the amount of new forest resources used to meet a given set of paper product requirements will require a combined approach, taking into account various fiber attributes, nanostructures, novel concepts in bond formation, and advances in the unit operations of papermaking. [ABSTRACT FROM AUTHOR]

The efficiency of optical brightening agents (OBAs), also known as fluorescent whitening agents (FWAs), has long been of interest in the production of uncoated fine paper, particularly in uncoated fine paper grades containing high-yield pulp (HYP). The increasing levels of whiteness and also the increasing HYP substitution in fine papers has made OBA efficiency an important issue. This paper summarizes recent research findings in understanding and enhancing OBA efficiency in fine papers containing HYP, with focus on the main factors affecting OBA efficiency in both wet end and size press application. These factors include the base sheet brightness and whiteness of the pulp, UV competitors, OBA retention, quenching effects, and OBA migration at the size press. Some new technologies to improve OBA efficiency are discussed. [ABSTRACT FROM AUTHOR]

Cellobiose-pendant polymers were synthesized by radical polymerization and their affinity for a cellulose matrix was investigated by quartz crystal microbalance (QCM). A 2-(methacryloyloxy)ethylureido cellobiose (MOU-Cel) macromer was synthesized by coupling cellobiosylamine with 2-(methacryloyloxy)ethyl isocyanate followed by polymerization in an aqueous radical reaction system. The interaction of the resulting poly(MOU-Cel) with a pure cellulose matrix in water was evaluated by QCM analysis. Poly(MOU-Cel) was strongly adsorbed to the cellulose substrate, whereas neither cellobiose nor MOU-Cel macromer exhibited an attractive interaction with cellulose. This specific interaction was not inhibited by the presence of ionic contaminants, suggesting that multiple cellobiopyranose moieties in each polymer molecule might cooperatively enhance its affinity for cellulose. Moderate insertion of acrylamide units into the polymer backbone improved the affinity for cellulose, possibly due to an increased mobility of sugar side chains. Polymers such as these, with a high affinity for cellulose, have potential applications for the surface functionalization of cellulose-based materials, including paper products. [ABSTRACT FROM AUTHOR]

The response to refining of wheat straw and eucalyptus pulps as well as the relationships between refining, fiber properties, and paper properties are described in this paper. Pulps were bleached applying different bleaching sequences and thereafter refined to varying degrees. Pulp and fiber properties were investigated and set into relation to the final sheet properties. The results show that wheat straw pulps respond to refining more easily than eucalyptus pulps and that the differences are due mainly to morphological and ultrastructural differences as well as fines content and xylan content. The development of strength properties of the different pulps was found to be strongly correlated to the number of dislocations, i.e. weak points in the fiber wall, as well as to the morphological appearance of the pulp fibers after refining. A higher initial number and a faster development of dislocations together with the creation of large amounts of fines explain the slower and lower development of strength properties of wheat straw pulps than of eucalyptus pulps. Removal of fines from wheat straw pulps improved not only the drainability of the pulp suspension but also the mechanical and optical sheet properties. This indicates that the fines in the wheat straw pulps act mainly as filler with low bonding properties. The fact that fractionated D(EOP)D wheat straw pulps can deliver good mechanical sheet properties at very good drainability with no or only minor refining is very interesting when evaluating the potential of replacing or partially replacing eucalyptus with domestic Chinese raw materials in furnishes for production of different paper products. [ABSTRACT FROM AUTHOR]

Functional fillers can facilitate the development of novel composite paper products for specific end uses. But using functional components as fillers by direct addition to the fiber suspension may fall short of the desired goals. The functional filler may fail to be efficiently retained. Gels can serve as carriers of functional paper fillers by coupling with them during in-situ synthesis and the gelation process. This strategy is favorable for the effective utilization of functional paper fillers, without hampering the intrinsic properties of paper. Additional merits of this strategy include versatility and compatibility with existing paper-making processes. [ABSTRACT FROM AUTHOR]

As expressed by the chorus lyrics of a song by Dan Einbender, "it really isn't garbage 'til you mix it all together. It really isn't garbage 'til you throw it away. Separate your paper, plastic, compost, glass and metal. Then you get to use it all another day." It's worth paying attention to these lyrics once again in the face of yet another type of product that is starting to show up in stores. Extruded sheets of polyethylene (no. 2 plastic) with as much as 80% ground calcium carbonate content are being sold as "paper". Calcium carbonate is widely used as a component of real paper. However, it rubs me the wrong way when the word "paper" is being used to refer to something that has no fibers in it and is not formed on a screen and dried. My more serious concern is that such materials, if they become widely used, have the potential to contaminate paper recycling operations. [ABSTRACT FROM AUTHOR]