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The potential of paper and paperboard as fiber-based materials capable of replacing conventional polymer-based materials has been widely investigated and evaluated. Due to paper's limited extensibility and inherent heterogeneity, local structural variations lead to unpredictable local mechanical behavior and instability during processing, such as mechanical forming. To gain a deeper understanding of the impact of mechanical behavior and heterogeneity on the paper forming process, the Finite Element Method (FEM) coupled with continuum modeling is being explored as a potential approach to enhance comprehension. To achieve this goal, utilizing experimentally derived material parameters alongside stochastic finite element methods allows for more precise modeling of material behavior, considering the local material properties. This work first introduces the approach of modeling heterogeneity or local material structure within continuum models, such as the Stochastic Finite Element Method (SFEM). A fundamental challenge lies in accurately measuring these local material properties. Experimental investigations are being conducted to numerically simulate mechanical behavior. An overview is provided of experimental methods for material characterization, as found in literature, with a specific focus on measuring local mechanical material structure. By doing so, it enables the characterization of the global material structure and mechanical behavior of paper and paperboard. [ABSTRACT FROM AUTHOR]

The primary aim of this research was to explore the feasibility of producing environmentally friendly composite materials by employing diverse hybrid matrices consisting of dammar natural resin, supplemented with small proportions of two synthetic resins: one epoxy and the other acrylic. A blend of paper and chicken feathers served as the reinforcing elements. The fabrication of these composite materials utilized a hand layup technique. Targeted for applications in the furniture industry or interior design, their mechanical properties were assessed through various tests. Specimens were obtained from the manufactured samples and subjected to evaluations for tensile strength, compression, flexure, vibrations, Shore hardness, and water absorption. Results indicated that irrespective of the testing method employed, the mechanical strength properties exhibited a decline with an increase in the percentage of dammar in the hybrid resins, whereas the elasticity properties demonstrated an increase with this percentage. [ABSTRACT FROM AUTHOR]

To improve the utilization rate of flax straw and the clean treatment of livestock manure, an experimental study was conducted on the process and performance of making fibre paper films by mixing cow dung and flax straw fibre. Cow dung and flax straw were used as the main raw materials, and functional additives were not added. The whole technological process of the pretreatment, the beating process, the determination of the beating degree, the basis weight of the paper, papermaking, drying, sample cutting, and the determination and analysis of the related mechanical properties of the film-making materials were studied. In this study, the Box–Behnken experimental design principle in the response surface methodology was adopted, and the effect of each factor on the tensile strength and tear strength of fibre paper film made of mixed fibres was determined using the combined experimental design comprising four factors and three levels centres. The results showed that the optimum technological parameters were as follows: the beating degree of the cow dung fibre was 37 °SR, the beating degree of the flax straw fibre was 85 °SR, the paper basis weight was 80 g/m2, and the addition of flax straw fibre was 65%. At a drying temperature of 80 °C and a drying time of 8 min, under the conditions of the hybrid fibre paper film placed in the laboratory environment (humidity of 30%~40%, temperature of 18 °C) for 24 h, the measured tensile strength was about 8.26 MPa, and the tear strength was about 19.91 N/mm. This study provides a reference that can be used for the further study of fibre paper film. [ABSTRACT FROM AUTHOR]

Cellulose is classified as one of the most abundant biopolymers in nature. Its excellent properties have gained a lot of interest as an alternative material for synthetic polymers. Nowadays, cellulose can be processed into numerous derivative products, such as microcrystalline cellulose (MCC) and nanocrystalline cellulose (NCC). MCC and NCC have demonstrated outstanding mechanical properties owing to their high degree of crystallinity. One of the promising applications of MCC and NCC is high-performance paper. It can be utilized as a substitute for the aramid paper that has been commercially used as a honeycomb core material for sandwich-structured composites. In this study, MCC and NCC were prepared by extracting cellulose from the Cladophora algae resource. MCC and NCC possessed different characteristics because of their distinct morphologies. Furthermore, MCC and NCC were formed into a paper at various grammages and then impregnated with epoxy resin. The effect of paper grammage and epoxy resin impregnation on the mechanical properties of both materials was studied. Then, MCC and NCC paper was prepared as a raw material for honeycomb core applications. The results showed that epoxy-impregnated MCC paper outperformed epoxy-impregnated NCC paper with a compression strength of 0.72 MPa. The interesting result from this study is that the compression strength of the MCC-based honeycomb core was comparable to the commercial ones despite being made of a natural resource, which is sustainable and renewable. Therefore, cellulose-based paper is promising to be used for honeycomb core applications in sandwich-structured composites. [ABSTRACT FROM AUTHOR]

Paper-based friction material is a typical paper-based composite that is usually cured via hot-pressing. This curing method does not account for the effect of pressure on the matrix resin, resulting in uneven distribution of resin in the material and reducing the mechanical properties of friction materials. To overcome the above shortcomings, a pre-curing method was introduced before hot-pressing, and the effects of different pre-curing degrees on the surface morphology and mechanical properties of paper-based friction materials were studied. The pre-curing degree significantly affected the resin distribution and interfacial bonding strength of the paper-based friction material. When the material was cured at 160 °C for 10 min, the pre-curing degree reached 60%. At this point, most of the resin was in a gel state, which could retain abundant pore structures on the material surface without causing mechanical damage to the fiber and resin matrix during hot-pressing. Ultimately, the paper-based friction material exhibited improved static mechanical properties, decreased permanent deformation, and reasonable dynamic mechanical properties. [ABSTRACT FROM AUTHOR]

Paper pulp was produced by the kraft method using sorghum (Sorghum bicolor × S. bicolor sudanense) as the fibrous raw material. Two groups were cooked using active alkali at 10% and 14%. For each group, five sulfite ratios (0, 4, 8, 12, and 16%) were used, making a total of 10 different groups that were cooked. A literature study was conducted to determine the cooking temperature, the time needed to reach the maximum temperature, and the duration of cooking time at the maximum temperature. A total of 30 batches of paper were obtained from pulps without beating and from pulps beaten at values of 35 ± 2 °SR and 50 ± 2 °SR (Schopper Riegler) freeness. The aim was to determine the most suitable alkali and sulfite ratios by conducting standard tests for the yield, kappa number, and viscosity of the screened pulps and for the papers obtained from these pulps. The highest screened yield of cooked pulp was obtained under conditions of 14% active alkali and 12% sulfite. Since the mechanical properties of the paper obtained from this pulp were satisfactory when compared with those in the literature, it was concluded that these ratios could be recommended as a condition for cooking. [ABSTRACT FROM AUTHOR]

Highlights • Mechanical properties of waste papers are closely correlated with devolatilization. • Start of devolatilization caused a sudden decrease in relative storage modulus ( E ′ r). • Kinetics of storage modulus change is investigated referring to activation energy. • E ′ r can be predicted with mass loss ratio and CO 2 emission. Abstract This article details a correlation study on early devolatilization behaviors (drying & volatile emission at 25–240 °C) and the change in mechanical properties (expressed by viscoelasticity) of four types of waste papers. The early stage of devolatilization was investigated using the TG-FTIR and mechanical properties using the dynamic mechanical analysis (DMA) method. The results show that the elastic and viscous mechanical properties showed obvious correlations with free and bound water evaporation and volatile emission. The storage modulus (E ′) and loss modulus (E ″) of the papers decreased as temperature increased and at the two important temperatures, namely 100 °C, the start of bound water evaporation, and 150 °C, the start of devolatilization in TG & DTG curves, E ′ showed extrema. Especially the relative storage modulus ( E ′ r) exhibited a sudden decrease at around 150 °C, where the activation energy of thermochemical conversion jumps from low values to high values, indicating the start of devolatilization. CO 2 is the major compound of the volatiles and it is well correlated with E ′ r in exponential function model and can be used as an index for predicting the E ′ r of the waste papers in their early devolatilization stage; while during the drying stage, mass loss ratio can be used to predict E ′ r of the waste papers. [ABSTRACT FROM AUTHOR]

The title of the current Special Issue, "Feature Papers in Materials Simulation and Design", has identified the aims of this collection since its opening: the gathering of research works and comprehensive review papers that advance the understanding and prediction of material behavior at different scales, from atomistic to macroscopic, through innovative modeling and simulation. The paper by Chen et al. [[4]] aimed at studying the thermal properties and thermoelectric performance of imidazole-graphyne (ID-GY) by combining first principle calculations with the Boltzmann transport theory. The last paper by Cheng and Vescovini [[16]] presented instead an accurate and efficient numerical method for the analysis and design of Variable Stiffness (VS) laminates. Civalek et al. [[11]] developed an efficient eigenvalue algorithm for the axial vibration analysis of embedded short-fiber-reinforced micro-/nano-composite rods subjected to arbitrary boundary conditions. [Extracted from the article]

A crucial problem for laminate producers is the dimensional instability of decorative papers during soaking in aqueous solutions, but the source of this dilemma is not completely understood yet. In this study, eight commercial decorative papers of similar fiber composition and sizing were analyzed for their structural, physical, and mechanical properties. These properties were examined for their correlations to the dimensional stability of papers when moistened, as assessed by the wet stretch dynamics. Structure-to-property relationships were evaluated by principal component analysis (PCA). Within the set of parameters examined, PCA revealed that fiber orientation and the content of fillers/pigments influenced the wet expansion of paper web and affected its margins and dimensions in longitudinal and transverse directions of the paper machine. These variables are discussed within the context of decorative paper engineering in order to produce high performance papers with regular wet expansion properties. [ABSTRACT FROM AUTHOR]

We report on investigation of the mechanical properties of paper electronics (printed and made out of paper). One key objective of such paper electronics is to achieve ultraflexibility. Therefore, it is important to understand electrical functionality and reliability of paper electronics under various physical (mechanical) deformations. Here, we show the general mechanical properties of the cellulose paper used and its electrical behavior under applied strain, tackling the main effects that need to be identified when building paper-based systems, from product performance and stability perspective. An overview of the stress–strain behavior of silver ink on paper is discussed, and then, we tackle a more specific analysis of the performance variations of paper sensors made with recyclable household materials when exposed to various mechanical conditions of tensile and compressive bending. This paper is important for developing stable wearable sensors for incorporation into Internet of Everything applications. [ABSTRACT FROM PUBLISHER]

The mechanical performance of two commercial papers used as solid insulation in power transformers, namely standard Kraft and a thermally upgraded Kraft paper, were studied during accelerated aging in Luminol oil at 170 ?C. The results show a relationship between the degree of polymerization and the mechanical properties measured by tensile testing. A linear relationship was found between the mechanical properties of paper, the tensile index (Tidx), and the concentration of methanol present in the oil. The methanol chemical marker has been proven to be an accurate assessment tool for the aging of cellulosic paper. The results show a promising tool for correlating the methanol concentration in oil, as an indirect indicator, with the mechanical performance of the paper. This approach can be used to monitor the real state of the cellulose chains in the power transformer insulation paper. [ABSTRACT FROM AUTHOR]

The cost of specialized scientific equipment can be high and with limited funding resources, researchers and students are often unable to access or purchase the ideal equipment for their projects. In the fields of materials science and mechanical engineering, fundamental equipment such as tensile testing devices can cost tens to hundreds of thousands of dollars. While a research lab often has access to a large-scale testing machine suitable for conventional samples, loading devices for meso- and micro-scale samples for in-situ testing with the myriad of microscopy tools are often hard to source and cost prohibitive. Open-source software has allowed for great strides in the reduction of costs associated with software development and open-source hardware and additive manufacturing have the potential to similarly reduce the costs of scientific equipment and increase the accessibility of scientific research. To investigate the feasibility of open-source hardware, a micro-tensile tester was designed with a freely accessible computer-aided design package and manufactured with a desktop 3D-printer and off-the-shelf components. To our knowledge this is one of the first demonstrations of a tensile tester with additively manufactured components for scientific research. The capabilities of the tensile tester were demonstrated by investigating the mechanical properties of Graphene Oxide (GO) paper and thin films. A 3D printed tensile tester was successfully used in conjunction with an atomic force microscope to provide one of the first quantitative measurements of GO thin film buckling under compression. The tensile tester was also used in conjunction with an atomic force microscope to observe the change in surface topology of a GO paper in response to increasing tensile strain. No significant change in surface topology was observed in contrast to prior hypotheses from the literature. Based on this result obtained with the new open source tensile stage we propose an alternative hypothesis we term ‘superlamellae consolidation’ to explain the initial deformation of GO paper. The additively manufactured tensile tester tested represents cost savings of >99% compared to commercial solutions in its class and offers simple customization. However, continued development is needed for the tensile tester presented here to approach the technical specifications achievable with commercial solutions. [ABSTRACT FROM AUTHOR]

Fungi damage valuable documents mechanically, chemically and aesthetically because they form hyphae, excrete pigments and organic acids, generating particular local conditions that modify the physical-chemical properties of the different documentary supports. The aims of this research were to determine the fungal genera associated with the paper documents biodeterioration and to demonstrate the biofilm formation and the damages. Sampling was done from documents with signs of biodeterioration using sterile cotton swabs. After serial dilutions from the samples, plates with Extract Malt Agar were inoculated and incubated at 30 °C for 7 days. Additional little fragments of the damage zone from each analyzed document were observed using stereomicroscopy, environmental scanning electron microscopy (ESEM) and scanning electron microscopy (SEM). To evaluate the biodeterioration potential risk the strains were grown on cellulose, the acids production and pigments secretion were evaluated too. The genera Aspergillus, Cladosporium, Fusarium and Scopulariopsis were predominant. Isolated strains excreted acids into the culture medium; most of them grew well on cellulose and a few excreted pigments. The formation of a mature biofilm and the production of extracellular polymeric substances by fungi, as well as a dense biofouling mainly formed by dust mites, were evidenced by the SEM and ESEM observations. Also the observations showed that these strains were able to attach to paper fibre causing damage on them. The observation under optical microscopy of dead insect found inside the book showed fungal adhesion on the insect body and SEM support that this adhesion was formed by Aspergillus sp. [ABSTRACT FROM AUTHOR]

The physical and mechanical properties of cement bonded board produced from Chasmanthera dependens and waste paper was investigated in this study. Boards were produced at 50:50, 60:40 and 70:30 levels of blending proportions of paper-fiber by weight, 800kg/mm³ and 1000kg/m³levels of board density and a constant mixing ration of 4:2 of cement-paper and fiber respectively. The boards were cut into test samples and physical and mechanical tests were carried out. The effect of Blending Proportion and Board Density on Water Absorption (WA), Thickness Swelling (TS), Modulus of Rupture (MOR) and Modulus of Elasticity (MOE) were determined using British standard 373. The mean values for WA ranged from 6.45-14.60%, TS ranged from 0.17-3.71%, MOE ranged from 93.90-946.03Nmm² while MOR ranged from 0.30-2.02Nmm2. The results showed that increase in board density and blending proportion led to decrease in TS and WA but also resulted in increase in MOE and MOR. The study suggests that Chasmanthera dependens and waste paper are suitable for the manufacture of cement board. [ABSTRACT FROM AUTHOR]

Predicting paper properties based on a limited number of measured variables can be an important tool for the industry. Mathematical models were developed to predict mechanical and optical properties from the corresponding paper density for some softwood papers using support vector machine regression with the Radial Basis Function Kernel. A dataset of different properties of paper handsheets produced from pulps of pine (Pinus pinaster and P. sylvestris) and cypress species (Cupressus lusitanica, C. sempervirens, and C. arizonica) beaten at 1000, 4000, and 7000 revolutions was used. The results show that it is possible to obtain good models (with high coefficient of determination) with two variables: the numerical variable density and the categorical variable species. [ABSTRACT FROM AUTHOR]

In papermaking, blending or mixture of fibres is one of the ways to enhance mechanical properties of paper. The objective of this study was to evaluate the properties of paper manufactured from mixture of oil palm empty fruit bunch (EFB) and kenaf fibres. The papers were prepared according to 10, 30, 50 and 70 percentages of kenaf whole stem blended into oil palm empty fruit bunch fibres. The preparation and testing of papers were carried out based on TAPPI Test Methods. Results showed that using kenaf whole stem fibres improved the mechanical properties of the blended papers and complied with the standard requirement for writing and printing grade paper. [ABSTRACT FROM AUTHOR]

Ignition of waste paper sludge at elevated temperatures to produce electricity in power generation plants utilizing fluidized bed combustion generates paper sludge ash. Due to the high concentration of lime and gelignite in paper sludge ash, it is expected that it will play a vital role as a cementitious material. This paper investigates the use of paper sludge ash to improve the mechanical properties of the granular materials, which are suitable to subbase course for road and building constructions. Also, a comparison study with the use of Portland cement as an additive to granular materials has been covered. The mechanical properties were evaluated by conducting the California bearing ratio test for the two adopted methods. Moreover, the compressive strength of the samples using paper sludge ash and cement are investigated. In accordance to the California bearing ratio test, 4% paper sludge ash was indicated as the optimum ash content at which the California bearing ratio value increased by 173% and 111% in comparison with untreated material and 6% cement, respectively. On the other hand, and by means of the compressive strength, the granular materials with 4% paper sludge ash has compressive strength higher than those with 6% cement. [ABSTRACT FROM AUTHOR]

• Three-dimensional WO 2 /MoO 2 @P, N-CNTs were prepared by the Self-template method. • Highly conductive and hollow structure of WO 2 /MoO 2 @P, N-CNTs avoided aggregation of NiCo-LDH. • IMSC devices were prepared by fully screen-printed technology. • IMSCs demonstrated excellent energy density (0.0590 mWh cm−2), cycling stability (100% capacity retention after 10,000 cycles) and mechanical stability (lighting the bulb under extremely distorted conditions). In-plane micro-supercapacitors (IMSCs) have greater promise for use in flexible wearable electronics than traditional stacked configurations due to their ease of integration and conformability. Nickel-cobalt layered double hydroxide (NiCo-LDH) has garnered significant interest as a stellar material for supercapacitors because of its affordable price, regular morphology, and high theoretical capacity. Unfortunately, the intrinsic poor conductivity of LDH materials prevents supercapacitors from achieving long-term stable cycling and the desired energy density. This research successfully applies the self-templated approach to prepare carbon nanotubes (CNTs) with heterogeneous architectures and numerous phase interfaces, thereby mitigating this disadvantage. Carbon nanosheets adorned with WO 2 and MoO 2 nanoparticles assemble the CNT with a typical three-dimensional structure. When combined with LDH in a suitable ratio, the composite electrode's conductivity significantly improves, providing increased capacity and cycling stability. Compared to commercial CNTs, the larger size of the prepared WO 2 /MoO 2 @P, N-CNTs serves a superior supporting and connecting role, thereby preventing the NiCo-LDH from aggregating. Under the best conditions, the composite electrode demonstrates a capacity of 1237 C/g at 1 A g−1 and an optimal capacity retention of more than 92%. For the IMSC devices, the composite materials as the positive electrode achieve an energy density of 0.0590 mWh cm−2, and no capacity degradation is observed after 10,000 cycles. In addition, bending tests have demonstrated the mechanical stability of the IMSCs. Therefore, this strategy of mixing highly conductive WO 2 /MoO 2 @P, N-CNTs can effectively improve the conductivity of the composite material and the mechanical properties of the overall device. Furthermore, this concept can be further extended to the preparation and application of other wearable devices. [ABSTRACT FROM AUTHOR]

Mechanical properties of fiber-based materials, such as paper, are governed by the heterogeneous microstructure induced by the formation process. For example, in paper materials during tensile tests, lower strains are observed in the flocs (fiber aggregates where the basis weight is larger than the average one) than in the antiflocs (complement of flocs). To explain such behavior, we investigated the mechanical and structural properties of both flocs and antiflocs. Using tensile tests on flocs and antiflocs, we measured their elastic modulus and found that the elastic modulus of flocs was larger than the antiflocs' one. To understand these differences, a multiscale structural analysis was conducted on 3D X-ray images of flocs and antiflocs at two different spatial resolutions. We found that the floc was thicker than the antifloc, whereas the microscale analysis showed the studied floc and antifloc exhibited the same bulk porosity. Then, it was concluded that the difference in elastic modulus between flocs and antiflocs is mainly due to their thickness difference. [ABSTRACT FROM AUTHOR]

Multilayer panels that have paper cores with hexagonal cells continue to have a limited application in furniture production. In contrast, there are no sandwich honeycomb panels with cores containing rectangular cells employed in this industry. Such cores should distinguish themselves by strong orthotropic advantages, in particular, for designing shelves and partitions of cabinet furniture. Hence, the objective of this study was to determine the effect of core rectangular paper cells on the mechanical properties of three-layer furniture panels. The authors decided to ascertain relative density and elasticity constants of the designed cells. The results of empirical experiments of cell elasticity moduli were compared with the results of the analytical calculations. The impact of sample width on their mechanical properties was determined. It was demonstrated that cores with hexagonal cells in furniture panels could be replaced by cores with rectangular cells. [ABSTRACT FROM AUTHOR]

Preservation of documentary heritage is one of the biggest challenges facing paper conservators today. The singular properties of bacterial cellulose (BC) lead us to propose to reinforce paper with BC sheets. In the first part of this study, the reinforcing capability of BC was tested on model papers of well-known fiber composition. The aim of the present study was to verify the suitability of rebuilding degraded old papers with BC. The degraded papers were characterized before and after the reinforcement. In addition, lined samples were characterized before and after an aging process in order to study the stability in time. The same methodology was used with Japanese paper (JP), a material commonly used by paper conservators, in order to compare both materials as reinforcement. Mechanical properties of paper lined with BC are as good as those obtained with JP. Papers lined with BC have more marked modifications on their optical properties than those restored with JP. Nevertheless, letters in books lined with BC are more legible. Moreover, only the papers restored with BC show high changes in porosity. The aging process leads to a slight decrement in burst index. Changes on tear index and optical properties with the aging process depend on the paper to be restored. This study suggests that BC improves deteriorated paper quality, without altering the information contained therein, and that this improvement is maintained over time. Hence, BC is a promising alternative material for the restoration of paper. [ABSTRACT FROM AUTHOR]

Copyright of Fibres & Textiles in Eastern Europe is the property of Sciendo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sandwich-structured nanocomposites have the potential to improve the mechanical and electrical properties of materials simultaneously. Nanofibrillated cellulose (NFC) modified paper sheet (denominated as N) and softwood paper sheet (denominated as P) are used to prepare insulating paper. Different kinds of insulating paper with the structures of PPP, NNN, NPN and PNP are prepared. Tensile strength, DC conductivity, dielectric response, space charge and breakdown strength are measured. The activation energies of prepared materials are calculated through DC conductivity at 30, 50, 70, and 90 °C. The mechanism for sandwich structure regulating the mechanical and breakdown properties of insulating paper is discussed. Oil impregnated N/P/N paper has a remarkable improvement on tensile strength, conductivity, and DC breakdown strength, which provides a promising scheme to obtain the insulating paper with outstanding tensile and breakdown strength. [ABSTRACT FROM AUTHOR]

This is a review of studies on various types of paper-based epoxy composites currently being designed and developed for technological use. The concept of designing composite materials is very significant for small to large industry and it is important where initiation of repairing work is now being considered for engineering applications. This composite material is of interest due to its advantages compared with others, including low environmental effects and low cost for a wide range of works. This review aims to provide an overview of morphological, physical and mechanical properties of various paper sheetsbased epoxy composites and details of achievements made. From this approach, this paper also presents the preliminary study of SEM results of paper sheets-based epoxy composites designed for repairing work applications. It has been found that a well-arranged laminated paper sheet layers could help the bond strength with epoxy matrix. Thus, this paper sheet-based epoxy composite can be considered as an easiest way, cheap and biodegradable that can be used for various small repairing works in structural and automotive applications. [ABSTRACT FROM AUTHOR]

A cellulose-based oil adsorbent was developed utilizing the waste paper PS-16 (mixed kraft cuttings) via a simple modification process. Through mechanical treatment and spray with polyethylene wax and alkyl ketene dimer, it was found that the product was significantly more hydrophobic than the raw material, with a water contact angle of 125.6°. The capability of the product to absorb engine oil, kerosene, and xylene was studied and compared with other cellulose-based adsorbents. The adsorbent had an excellent performance with a high absorbing ability of 16 to 28 times its own weight. Up to 92.8% of the oil in the adsorbents could be easily recycled and collected by manual squeezing. The adsorbent could be reused over eight cycles, and the sorption capacity remained constant. Therefore, this adsorbent is expected to be a promising oil sorbent for potential applications like oil spill clean-ups. [ABSTRACT FROM AUTHOR]

The purpose of this work was to determine the optimal duration of free swelling for refined unbleached kraft pine pulp. Free swelling is the effect of water sorption by cellulose fibres without their simultaneous mechanical treatment (e.g. refining). The second purpose was to determine the possibility of improving the mechanical properties of paper by testing various combinations of refining and free swelling processes. The pulp SR value and water retention value (WRV) of the fibres were tested. As regards paper properties, the tensile index and tear index were tested. Based on the results obtained, it was found that for the pulp tested, refined to 35 °SR, the optimal time of free swelling was 70 min. It was also proved that the free swelling had a significant impact on both the WRV of fibres and the mechanical parameters of paper tested. For the scheme in which refining was followed by free swelling, a 7% increase in the tear index was obtained. However, an 11% increase in the tear index was attained for the scheme with three refining stages, followed by free swelling after each refining. [ABSTRACT FROM AUTHOR]

Magnesium hydroxide (Mg(OH)2) nanosheets were explored as an effective material for the restoration and conservation of paper-based cultural archives and compared with the commonly used Ca(OH)2 nanoparticles. The (Mg(OH)2) nanosheets were applied to filter paper as a reference, as well as to new and old paper samples. The effectiveness of Mg(OH)2 nanosheets was evaluated by (i) a pH test of the surface and the bulk extracts, (ii) measuring the alkaline reserve and correlating it with the enhancement in life expectancy, and (iii) in terms of mechanical strength. The alkaline reserve test indicated an increase in the alkaline buffer, which resulted in markedly reduced acidic content of the samples. It was inferred from the improved properties that Mg(OH)2 nanosheets coated the paper as a lamination sheet and protected it as the first line of defense against acidic environmental attack. Moreover, its presence within the paper acted as an alkaline reserve and also as reinforcement in the form of an inorganic nanosheet. The results suggest that the nanosheets are an innovative, compatible, and efficient material for the consolidation and restoration of old and new paper samples. [ABSTRACT FROM AUTHOR]

In this study, we investigated the compatibility of kraft paper and plastic wastes. Also, the physical and mechanical properties of the paper-plastic composite were determined. Pulverized kraft paper wastes and fine sachet water particles were weighed and mixed together using different mixing ratios (50% of paper & 50% of plastic (1:1), 33% of paper & 67% of plastic (1:2) and 25% of paper & 75% of plastic (1:3)). The method of composite production employed was extrusion method. The results of water absorption (WA) conducted on the paper-plastic composite material ranged between 0.03% - 0.16% and 0.03% - 0.20% for 2 and 24 hours respectively. The average values obtained for thickness swell (TS) ranged between 0.00% - 0.23% and 0.00% - 0.33% for 2 and 24 hours respectively. The average values obtained for tensile modulus ranged between 0.11GPa to 0.33GPa and the average values obtained for tensile strength ranged between 9.99MPa to 15.12MPa. The result obtained from this study shows that kraft paper wastes and water sachet wastes can be utilized as a composite material as they were compatible. In addition, 25% of paper & 75% of plastic waste (1:3) gives the best mixing ratio as indicated by the result with the most dimensionally stable and high strength properties. [ABSTRACT FROM AUTHOR]

In this work, the physical and mechanical properties of bleached Eucalyptus pulp reinforced with nanofibrillated cellulose (NFC) are compared with those of traditional beaten pulp used in the making of writing/printing and offset printing papers. For this purpose, three different types of hardwood slurries were prepared: beaten pulps, unbeaten pulps reinforced with NFC, and slightly beaten pulps also reinforced with NFC. Physical and mechanical tests were performed on handsheets from these different slurries. The results showed that adding NFC to unbeaten pulps results in physical and mechanical properties similar to those in pulps used for printing/writing papers. Nevertheless, the best results were obtained in slurries previously beaten at slight conditions and subsequently reinforced with NFC. These results demonstrate that the addition of NFC allows a reduction in beating intensity without decreasing the desired mechanical properties for this specific purpose. [ABSTRACT FROM AUTHOR]

Copyright of Studies in Conservation is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Enzymatic and chemical deinking not only significantly influence the optical and mechanical properties of deinked paper, but also influence the pulp properties and wastewater effluent generated. Both enzymatic and chemical deinking of mixed office wastepaper (MOW) and old newspaper (ONP) showed improvement in brightness (1.4-4.7 units), tensile index (1-14%), burst index (1.2-3.8%), freeness (1.9-2.9%), and residual ink removal (31.1-51.2%) but caused loss in opacity (0.1-2.6%) and tear index (0.1-9.6%). Chemical Oxygen Demand (COD) analysis indicated that effluent produced from enzymatic deinking were about 33.9% and 33.8% lower compared to chemical deinking of ONP and MOW, respectively. Meanwhile, Biological Oxygen Demand (BOD5) obtained from enzymatic deinking of MOW and ONP were 47.1% and 39.3% lower compared to the chemical deinking process, respectively. The results obtained in this work demonstrated that the quality of the pulp and paper obtained from enzymatic deinking process was better than that from the chemical deinking process. This suggests that enzymatic deinking has high potential as an alternative to the chemical method. [ABSTRACT FROM AUTHOR]

Dr. Ondrej Tyc is currently a postdoctoral researcher at IoP and his specialization is in the area of mechanical characterization of NiTi samples. The Coatings Editorial Board and Editorial Team would like to congratulate the winner of the Coatings 2023 Best Paper Award (Article). This paper is the outcome of a joint collaboration of two groups from the Institute of Physics (IoP) and the Institute of Plasma Physics (IPP), Czech Academy of Sciences in Prague, Czech Republic. [Extracted from the article]

This article presents a comparative study of two types of transformer solid insulation: standard Kraft and thermally upgraded Kraft papers. The paper samples were impregnated with two different fluids, namely a synthetic dielectric ester fluid, Midel 7131, and a synthesized mineral oil, Luminol Tri. The impregnated papers were submitted to, accelerated aging at 150°C, temperature higher than the temperatures found inside transformers, for extended periods. The results show that for the first hours of aging, the cellulose depolymerization was similar for all the four studied cases. At a specific point, the paper samples aged in the ester fluid exhibited a lower depolymerization exceeding the 8000 hours of aging without reaching the levelling-off degree of polymerization (LODP). A similar trend was observed through the decrease of mechanical properties of papers in the ester-based oil. However, the difference in performance of both fluids was amplified due to the temperature used; at lower temperatures the difference should be smaller. Additionally, a relationship between the degree of polymerization and the mechanical properties accessed by the tensile testing was obtained regardless of the type of paper or oil. The total acidity in the ester fluid was higher than in mineral oil. Methanol, a chemical marker that is closely linked to the rupture of 1,4-ß-glycosidic bonds of cellulose, showed a partial sensitivity to the cellulose aging in the ester fluid. Furan (C4H4O) content was monitored during the aging and its concentration was found to be sensitive to the depolymerization along with the decrease in the mechanical properties of cellulose papers regardless of the type of paper. More importantly, its concentration was found to be dependent on the type of oil. More investigations are needed to further confirm the importance of furan as an indirect indicator of the mechanical performance along with its correlation with the depolymerization of paper aged in ester fluids. [ABSTRACT FROM AUTHOR]

Two investigative stages are presented in this study, which aim to establish basic standards for the use of calcined paper sludge (CPS) in the stabilization of soils. The soils were stabilized with CPS and with mixtures of CPS and cement (C). The total percentage of binder was between 3 and 6% by weight. The blending ratios (by weight) of the CPS:C mixtures were 50∶50 and 25∶75. The first stage took place in the laboratory, and the second stage, in the field, involved in situ stabilization of 250 m of subgrade using dry-mix methods. The bearing capacity of the stabilized soils was determined in the laboratory. In the second stage, the densities of the subgrade were measured in the field following compaction and deflections at 7 days. Furthermore, the evolution of its unconfined compressive strength (UCS) was measured over 90 days. The results reveal optimal mechanical behavior of the stabilized soil at CPS:C ratios of approximately 25∶75. [ABSTRACT FROM AUTHOR]

In this paper, polysiloxane is used to modify insulation paper cellulose, and molecular dynamics methods are used to evaluate the glass transition temperature and mechanical properties of the paper before and after the modification. Analysis of the static mechanical performance of the model shows that, with increasing temperature, the elastic modulus of both the modified and unmodified cellulose models decreases gradually. However, the elastic modulus of the modified model is greater than that of the unmodified model. Using the specific volume method and calculation of the mean square displacement of the models, the glass transition temperature of the modified cellulose model is found to be 48 K higher than that of the unmodified model. Finally, the changes in the mechanical properties and glass transition temperature of the model are analyzed by energy and free volume theory. The glass transition temperatures of the unmodified and modified cellulose models are approximately 400 K and 450 K, respectively. These results are consistent with the conclusions obtained from the specific volume method and the calculation of the mean square displacement. It can be concluded that the modification of insulation paper cellulose with polysiloxane will effectively improve its thermal stability. [ABSTRACT FROM AUTHOR]

To model advanced 3-D forming strategies for paper materials, the effects of environmental conditions on the mechanical behavior must be quantitatively and qualitatively understood. A tensile test method has been created, verified, and implemented to test paper at various moisture content and temperature levels. Testing results for one type of paper for moisture contents from 6.9 to 13.8 percent and temperatures from 23 to 168 degrees Celsius are presented and discussed. Coupled moisture and temperature effects have been discovered for maximum stress. Uncoupled effects have been discovered for elastic modulus, tangent modulus, hardening modulus, strain at break, tensile energy absorption (TEA), and approximate plastic strain. A hyperbolic tangent function is also utilized which captures the entire one-dimensional stress-strain response of paper. The effects of moisture and temperature on the three coefficients in the hyperbolic tangent function may be assumed to be uncoupled, which may simplify the development of moisture- and temperature-dependent constitutive models. All parameters were affected by both moisture and temperature with the exception of TEA, which was found to only be significantly dependent on temperature. [ABSTRACT FROM AUTHOR]

Fiber classification of aramid fibrids was carried out using a Bauer-McNett fiber classifier, and the molecular weight and thermal properties of different sizes of aramid fibrids were determined with viscometry and differential scanning calorimetry (DSC), respectively. Aramid handsheets were made from different sizes of aramid fibrids and aramid short fibers, and the relationship between mechanical strength of aramid handsheets and thermal properties of aramid fibrids was examined. In addition, aramid papers from four different sources were also investigated to elucidate the relationship between their thermal properties and mechanical strength. It was found that aramid fibrids passing through 30-mesh screens and remaining on 50-mesh screens and aramid fibrids with narrower molecular weight distribution are suitable for the production of high-strength aramid papers. Lower crystallinity and wider molecular weight distribution are important contributors to the lower mechanical strength of domestic aramid paper when compared to that of Nomex paper. [ABSTRACT FROM AUTHOR]

Abstract We developed a paper-type electrode for the next-generation wearable devices by complementary hybridization of methyl cellulose and carbon nanotubes (CNTs). The large-scale hybrid paper was fabricated using an incomparably simple and low-cost solution process. Structural features, surface hydrophobicity, and chemical interaction between CNTs and cellulose of the hybrid papers were systematically explored by adjusting the concentration of CNTs. The hybrid papers demonstrated superb mechanical durability even under highly strained conditions such as folding, crumpling and re-flattening regardless of the concentration of CNTs. The electrical properties of the CNTs/methyl cellulose were well-preserved even when folded as origami or submerged in water. [ABSTRACT FROM AUTHOR]

The ability to increase the filler content of paper without significantly sacrificing its mechanical strength is of high interest for papermakers. In this work, three samples of ground calcium carbonate (GCC), differing in size and in brightness, modified with silica via the sol-gel method, were used as fillers in papermaking. Handsheets were produced using a eucalyptus kraft pulp furnish and with a filler amount near 20%. It was found that not only were the strength properties of the handsheets produced with the modified GCCs always significantly better than those obtained with the unmodified GCCs (e.g., the tensile index exhibited improvements of 16 to 20%), but bulk also was increased (by 7 to 13%). Some decreases in the light scattering and opacity values were noted when using the modified GCC, but the brightness was roughly the same. The enhanced fiber-to-filler bonding may be attributed to the hydrogen bonding between the cellulosic fibers and the hydroxyl groups of the silica coating the calcium carbonate particles. [ABSTRACT FROM AUTHOR]

Inorganic fillers are usually used in papermaking industry to reduce production costs and enhance paper optical properties. As an attempt to improve fillers application in papermaking, carboxymethyl cellulose (CMC) and poly aluminum chloride (PAC) were used to encapsulate precipitated calcium carbonate (PCC) filler and modify its surfaces. In the first step, the optimum conditions for filler treatment (i.e. pH, CMC and PAC contents) were obtained. Through the second step, different amounts of CMCencapsulated PCC were added to fiber suspension and some hand-sheets were made. Then, the effect of modified filler addition in different levels of 20, 25, and 35% on mechanical and optical properties of paper was investigated. The PAC dosage was found to be a critical factor for effective encapsulation of PCC fillers by carboxymethyl cellulose. When the dosages of CMC and PAC were 4% and 0.8% (based on the dry weight of PCC), respectively, filler modification caused to improve significantly the retention by more than twice. Strength properties of the hand-sheets fabricated with the CMC/PAC-modified PCC were also found to be significantly better than those obtained with the unmodified PCC at similar levels of filler content. In addition, the brightness and opacity of the filled papers at 30% addition of CMC-modified fillers were strikingly enhanced to 88,45 and 77%, respectively. SEM observations of the filled papers also demonstrated that CMC-encapsulated filler particles were clustered and retained efficiently onto the fiber network. The present method for modification of PCC may provide an alternative approach to increase the filler amount in the paper structure by alleviating filler drawbacks. [ABSTRACT FROM AUTHOR]

The study compares conventional and recycled office paper, based on experimental work. To confront the market needs, we have to find alternatives in respond to enormous necessity and application of office paper. Therefore, one way in dealing with the problem is to replace or just decrease the use of paper made entirely from primary components, mainly wood fibres (deciduous and conifer). We analysed mechanical, optical, structural and microscopic properties of conventional and recycled office papers. Experiments were performed on three conventional and three recycled office papers attainable on the market. The results obtained from measurements confirm the presumption that the mechanical and surface properties of recycled office paper can be collated and they discern from conventional office paper. [ABSTRACT FROM AUTHOR]

Abstract  In this paper it is shown that the well known special orthotropy of paper, explained by micromechanical models of complex bodies, actually corresponds to a special case of orthotropy of a plane elastic body. The existence of this special orthotropy was predicted by the author in a previous work. [ABSTRACT FROM AUTHOR]

Durability is a very important property of currency and currency paper because currency is circulated in the public for a very long time. The effect of circulation time on the physical properties of currency was investigated. In addition, a crumpling treatment procedure was adopted to simulate the circulation of currency in public. The air permeance of currency that was subjected to eight rounds of crumpling treatment was compared with that of actual circulated currency. As the circulation time increased, the basis weight, thickness, air permeance, and b* value increased. On the other hand, the stiffness and the L* value decreased as the circulation time increased. Regarding the air permeance, the slope of the plot was greater than the slopes of other physical properties measured. Air permeance of the samples after the crumpling treatment was greater than that of the circulated currency, which indicated that the crumpling process resulted in more severe changes in air permeance than the crumpling that occurs during the actual circulation of currency. [ABSTRACT FROM AUTHOR]

The aim of this study was to improve the electrical resistivity, mechanical properties, and interfacial properties between the carbon fiber (CF) and cellulose of conductive paper containing 10% CF so as to better meet the demands for electric heating wood floors. With waterborne polyurethane (WPU) treatment and nitrogen plasma modification methods, the interfacial properties between CF and cellulose were improved dramatically. Fourier transform infrared spectrometry (FTIR) revealed that the plasma modification method reduced the C-H contents and introduced numerous polar groups onto the CF surface. Scanning electron microscopy (SEM) showed that the CF modified by WPU and plasma had good adhesion with cellulose. The tensile index, tensile energy absorption index, and burst index of the paper were enhanced because of the plasma and WPU coating. The carbon fiber and WPU method presented good synergistic action with respect to mechanical properties and electrical resistivity, and the lowest electrical resistivity of conductive paper was reduced from 0.68 Ω•cm² to 0.44 Ω•cm². [ABSTRACT FROM AUTHOR]

It is challenging to design complex structures and calculate their dimensions only on the basis of theory. This issue was resolved efficiently by the FEM. Using the applicable test, the mechanical properties of the materials used in the damper are estimated, effectively guiding the design of the device and boosting its vibration-reducing performance. A large-load unmanned aerial vehicle (UAV) airborne radar is the subject of this research article. According to particular use case, vibration dampers for the radar-mounting platform are designed using passive vibration isolation technology to reduce aircraft vibration transmission to the radar. A conference paper has already presented prior research on the same topic. Earlier research confirmed the vibration-isolating efficacy of the T-type rubber isolator, which can greatly improve the operational conditions of the airborne radar. In contrast, earlier studies relied more on experimental validation and did not use numerical simulations. This research's primary objective is the development of a T-type rubber isolator, whose vibration reduction performance is proven using FEM and experiments. Utilizing a suitable simulation analysis method to investigate the vibration reduction of an unmanned aerial vehicle's (UAV) airborne component is a crucial technical task. By comparing multiple material models, a more precise model for characterizing rubber was developed. [ABSTRACT FROM AUTHOR]

Natural fibers are gaining much interest in composite materials because of their potential to replace conventional glass fibers. In particular, unidirectional flax fiber composites have shown excellent mechanical properties with different thermoset matrices. However, few data are available when they are made with a biodegradable thermoplastic matrix. This paper compares the mechanical properties of two types of unidirectional flax composites using polylactic acid as the matrix: one made with layers of aligned flax rovings alone and the other containing an additional paper layer fabricated using paper making techniques. The results show that specific tensile properties of the flax/PLA (252 MPa·cm 3 ·g −1 ) and flax-paper/PLA (217 MPa·cm 3 ·g −1 ) composites are similar to those made using woven glass fabrics impregnated with epoxy (227–278 MPa·cm 3 ·g −1 ). Very high impact strength (600 J/m) was also obtained for UD flax-paper composites compared to unreinforced resin (15 J/m). Together these mechanical properties are promising for industrial applications of this new reinforcement. [ABSTRACT FROM AUTHOR]

The aim of this work is to introduce recycled paper in HDPE matrix composites, an interesting alternative to traditional recycling process for paper. This strategy allows both re-using paper and reducing the amount of virgin polymer used in the same volume. For this application, the recycled paper goes through a micronization process, which uses simultaneously the action of impact and friction. The production of the composite is realized either by traditional injection moulding or by turbomixing. The best fibres' dispersion was obtained by turbomixing and the composites produced in this way have been additivated with maleated polyethylene (MAPE) in the amounts of 1, 3 and 5 wt%. The resulting composites with 10 wt% fibres were characterized from the morphological and mechanical point of view. Tensile tests revealed a rather constant stiffness and some improvement of strength with respect to the neat matrix, also indicating that the best results were obtained by the addition of 1 wt% MAPE. SEM micrographs evidenced that, in the absence of additive, fibre-matrix interface was rather weak. In addition, the samples with added MAPE appear to experience a reduction in microporosity, which was confirmed also by water absorption test. [ABSTRACT FROM AUTHOR]

Preventive Conservation (PC) aims to minimize the risk of irreversible damage to cultural artifacts caused by environmental factors. Strategies for PC include implementing environmental recommendations and monitoring conditions. However, environmental monitoring alone is not enough, and predictive analysis is needed to assess the risk of damage. The collection "Preventive Conservation, Predictive Analysis and Environmental Monitoring" presents technological advances in studying material degradation and environmental monitoring. Papers cover topics such as paper degradation, wood degradation, canvas paintings, dyed textiles, sensor electronics, wireless communications, cloud computing, and machine learning. The collection provides valuable insights for the design of preventive conservation strategies. [Extracted from the article]

This document is an editorial introducing a special issue of the journal "Materials" titled "Advances in Thermal and Mechanical Properties of Polymeric Materials." The issue features papers on various topics related to the thermomechanical and electrical properties of polymers and their composites. The papers cover subjects such as the use of waste polyethylene in composites, predicting thermal comfort in sportswear, the impact of water temperature on viscoelastic pipes, and the effects of pressure and temperature on material density and thermal conductivity. Other papers discuss luminescent hybrid materials, behavior of plaster-based composites against water, properties of thermoplastic starch nanocomposites, decontamination of recycled polypropylene, mechanical properties of 3D-printed composites, combustion of fuels and waste materials, production of parts with varied transparency using polypropylene injection molding, and thermal conductivity of filaments used in fused deposition modeling. The editorial concludes by congratulating the authors and inviting scientists to contribute to future issues. It is important to note that the opinions and data presented in the document are those of the individual authors and contributors, and not of MDPI or the editor. MDPI and the editor disclaim responsibility for any harm caused by the ideas, methods, instructions, or products mentioned in the content. [Extracted from the article]