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Pineapple leaf fibers (PALF) were biopulped using Trametes versicolor, and the resulting biopulp was bleached with xylanase-enzymatic treatments. The biopulping was extensively described using determinations of fiber morphology, color, chemical composition, extractive content, and thermal stability using the structural characteristics determined by XRD and paper properties. The results showed that the chemical and enzymatic treatments shortened the fiber, almost to 50%, and the Kappa index decreased from 27 to 13. Cellulose and holocellulose contents increased from 65% to 74% and from 86% to 91%, respectively, but extractives, lignin (from 12% to 4%), pentosans (from 25% to 14%) and the crystallinity decreased from 58% to 67% in both chemical bleaching and further xylanase-enzymatic processing. Xylanase)enzymatic processing allowed us to obtain whiter (increased lightness color and decreased redness and yellowness tonality) and heavier paper, even though it presented decreased mechanical properties (decreased stress resistance, rupture length, tear resistance and index longitudinal tearing). The xylanase-enzymatic treatment with the best pulping and paper proper)ties is when the biopulp is treated with a xylanase enzyme concentration of 0.04% (w/w). [ABSTRACT FROM AUTHOR]

Terminalia catappa fibre dimensions were evaluated as raw material for pulp and paper production. Sapwood samples of T. catappa were collected from five matured trees with diameter at breast height (dbh) of 1.82m, 1.57m, 1.02m, 1.05m and 0.76m from stem portions of top, middle and base portions, respectively within Makurdi metropolis. The samples were air dried and sliver of 1cmx2cmx2cm dried sapwood were macerated in a test-tube containing equal volume of acetic acid and hydrogen peroxide in ration 1:1 at 100oC for 24 hours. Macerated solution of fibre was dropped on a slide and mounted on a Zeiss light microscope (standard 25) under 80 xs. Fifteen straight and unbroken fibres were randomly selected to the fibre dimensions. Derived indices were determined with standard formula. Fibre lengths of T. catappa ranged from 0.72 - 1.80mm. Fibre diameter was between 20.76µm and 16.25µm; mean lumen width ranged from 12.78µm - 8.35µm while mean cell wall thickness were 3.85µm - 6.28µm at different dbh and stem portions. Means of all fibre dimensions were not significant (p>0.05). Results on fibre indices ranged from 0.65 - 1.05 in Runkel ratio; 34.53% - 60.09% elasticity coefficient; 16.07% - 32.89% in rigidity coefficient; 22.00 - 36.73 in slenderness ratio; 0.37 - 0.47 in Luce's shape factor; 39.20 - 64.22 in F factors and 236.71in - 296.15in Solid factor. Means of all derived fibre indices were not significant (p>0.05). Results obtained have substantially proved Terminalia catappa to be very good raw material for pulp and paper production. [ABSTRACT FROM AUTHOR]

This study analyzed the effect that pulp fibers have on the surface softness component of hygiene paper. The surface softness component has more of an influence on the evaluation of subjective softness results than the bulk softness component. Using the surface softness measurement technique, this study aimed to evaluate the effect that fibers have on the softness of hygiene paper substrate via objective numerical values to measure the surface softness component of hand sheets composed of various pulp species. The results indicate that coarseness effects had the largest effect on softness among the various fiber characteristics, such as average fiber length, width and coarseness. As fiber coarseness increased, a rough surface formed, which resulted in an increase in the mean deviation from the average friction (MMD). Nonwood fibers had long fiber length and low coarseness, which enables the production of hygiene paper with high strength and softness. This study hopefully could lead to the development of various process technologies that may improve the softness of hygiene paper products. [ABSTRACT FROM AUTHOR]

Terminalia catappa fibre dimensions were evaluated as raw material for pulp and paper production. Sapwood samples of T. catappa were collected from five matured trees with diameter at breast height (dbh) of 1.82m, 1.57m, 1.02m, 1.05m and 0.76m from stem portions of top, middle and base portions, respectively within Makurdi metropolis. The samples were air dried and sliver of 1cmx2cmx2cm dried sapwood were macerated in a test-tube containing equal volume of acetic acid and hydrogen peroxide in ration 1:1 at 100oC for 24 hours. Macerated solution of fibre was dropped on a slide and mounted on a Zeiss light microscope (standard 25) under 80 xs. Fifteen straight and unbroken fibres were randomly selected to the fibre dimensions. Derived indices were determined with standard formula. Fibre lengths of T. catappa ranged from 0.72 - 1.80mm. Fibre diameter was between 20.76µm and 16.25µm; mean lumen width ranged from 12.78µm - 8.35µm while mean cell wall thickness were 3.85µm - 6.28µm at different dbh and stem portions. Means of all fibre dimensions were not significant (p>0.05). Results on fibre indices ranged from 0.65 - 1.05 in Runkel ratio; 34.53% - 60.09% elasticity coefficient; 16.07% - 32.89% in rigidity coefficient; 22.00 - 36.73 in slenderness ratio; 0.37 - 0.47 in Luce's shape factor; 39.20 - 64.22 in F factors and 236.71in - 296.15in Solid factor. Means of all derived fibre indices were not significant (p>0.05). Results obtained have substantially proved Terminalia catappa to be very good raw material for pulp and paper production. [ABSTRACT FROM AUTHOR]

Variations in wood properties such as basic density, tissue proportion, fibre dimensions and their derived indices, cellulose and lignin content of Melia dubia at five age gradations were examined to evaluate the suitability of the species for pulp and paper production. The study showed that basic density, fibre proportion, fibre length, cell wall thickness, slenderness ratio, solids factor, cellulose and lignin content increased with tree age. However, vessel proportion, fibre width and lumen width decreased. Most of the wood properties were found suitable for making good quality pulp and paper at the age of 4 and 5 years in comparison to other hardwood species among five age gradation. Hence, harvesting at fourth and fifth year of age is suggested in M. dubia for high pulp yield and better paper quality. [ABSTRACT FROM AUTHOR]

A sustainable development requires the use of bio-based packaging materials because of ready availability and limited environment impact. The porous structure and hydrophilic nature of cellulose in paper based materials needs to be combined or laminated with other materials to overcome these limitations. The fiber found in the banana stems and leaves, it is possible to use these raw materials in pulp processing and banana flour can be produced into an edible film. The aim of the study was to discover a suitable method (wet lamination or dry lamination) for producing paper (stems, leaves, or a 1:1 ratio of mixed stems and leaves) lamination with banana film and to study their physical properties for packaging application. Banana flour (4%) solution was used as adhesive media between paper and film for wet lamination process where as the heating and compression were applied for dry lamination process. The results showed the efficiency of banana stems for paper production. However, there was an improvement in results when a 1:1 ratio of mixed stems and leaves was used due to an increase in tensile strength, elongation, and the L value. There was no significance in the water vapor permeability in all treatments. All treatments of paper lamination expressed 6 - 13% moisture content. The separation of film and paper layers occurred in dry lamination samples. The wet lamination of the leaf paper and mixed paper caused high tensile strength and elongation. Therefore, it could be used as an alternative and environmentally friendly method in the application of packaging materials. [ABSTRACT FROM AUTHOR]

With the increase in demand for wood and wood products, there is need to find alternative sources for the production of pulp and paper. Non wood plants have attracted interest due to their short growth cycles, moderate irrigation and fertilizer requirements and low lignin content. This study aimed at investigating the fibre characteristics of Agave sisalana for pulp and paper production. Leaves were collected from three sisal plant stands in Oyo State, Nigeria. The plant whorl was divided systematically into bottom, middle and top from which five leaves were randomly collected from each whorl position. The fibres of the leaves were extracted from which 2cm of fibres were taken from three positions on the leaf (top, middle and base). Extracted fibres were macerated and 3375 fibres were measured. The result shows that the fibre length of sisal increased with increasing length of the leaves from base to top with a mean value of 1.68mm. The fibre diameter and cell wall thickness averaged 16.98µm and 2.32µm respectively decreasing from the stem base to the top. The slenderness ratio averaged 99.4 while the coefficient of flexibility averaged 72.61. The highest value of the runkel ratio of Agave sisalana was 0.42. The fibres from sisal (Agave sisalana) leaves possess good fibre dimensions and derived values which will make it suitable for the production of high quality paper. [ABSTRACT FROM AUTHOR]

This study aimed to decelerate the weathering of paper from light by utilizing the antioxidant property of sodium ascorbate (SA), which is an ascorbic acid salt. Three different sessions of cooking were carried out by adding 2.5%, 5.0% and 7.5% of SA in proportion to the weight of a completely dried chip in addition to 24% NaOH in order to identify the influence of SA on cooking. It was observed that the pulp yield decreased when SA was added to the cooking. For that reason, it was decided to add SA into the control pulps instead of adding the digester. The same amount ofSA was added to the control. The SA-addedpulps were held in the agitator initially first for 2 hours and then 12 hours before making paper. So as to determine the influence of the treatment on the process. The paper was treated for 72, 144 and 256 hours and values of ΔL, Δa, Δb and ΔE were identified in order to determine the period of the SA's efficacy against weathering. The total discoloration in all the samples of paper, displayed an increase with an extension of the time period. The lowest discoloration after a 256-hour time period was seen in the sample group where 7.5% ofSA was added and soaked in the water. The final results indicated that the most appropriate concentration was 5% and that pulp suspension must be retained for 12 hours to improve mechanical properties. [ABSTRACT FROM AUTHOR]

Alkalophilic Cellulosimicrobium cellulans CKMX1 isolated from mushroom compost is an actinomycete that produces industrially important and environmentally safer thermostable cellulase-free xylanase, which is used in the pulp and paper industry as an alternative to the use of toxic chlorinated compounds. Strain CKMX1 was previously characterized by metabolic fingerprinting, whole-cell fatty acids methyl ester analysis, and 16S rDNA and was found to be C. cellulans CKMX1. Crude enzyme (1027.65 U/g DBP) produced by C. cellulans CKMX1, having pH and temperature optima of 8.0 and 60 °C, respectively, in solid state fermentation of apple pomace, was used in the production of bleached wheat straw pulp. Pretreatment with xylanase at a dose of 5 U/g after pulping decreased pulp kappa points by 1.4 as compared with the control. Prebleaching with a xylanase dose of 5 U/g pulp reduced the chlorine charge by 12.5%, increased the final brightness points by approximately 1.42% ISO, and improved the pulp strength properties. Xylanase could be substituted for alkali extraction in C–Ep–D sequence and used for treating chemically bleached pulp, resulting in bleached pulp with higher strength properties. Modification of bleached pulp with 5 U of enzyme/g increased pulp whiteness and breaking length by 1.03% and 60 m, respectively; decreased tear factor of pulp by 7.29%; increased bulk weight by 3.99%, as compared with the original pulp. Reducing sugars and UV-absorbing lignin-derived compound values were considerably higher in xylanase-treated samples. Cellulosimicrobium cellulans CKMX1 has a potential application in the pulp and paper industries. [ABSTRACT FROM AUTHOR]

Newly developed packaging paper made of biopulped pineapple leaf fiber (PALF) and poly(lactic acid)(PLA) was studied. PALF packaging sheets were solvent impregnated with PLA at different concentrations in order to improve their moisture barrier and mechanical performance. With the impregnation of PLA at a concentration of 4%, the packaging material exhibited a low moisture uptake and a high tear index. An electron micrograph of the sample at 4% impregnation revealed uniform and packed PLA reversed microsphere morphology. These results suggest that surface coating via biodegradable polymers, such as PLA, may be utilized for manufacturing packaging materials in industrial applications. This new packaging material could reduce the dependency on woodbased paper and plastic-based packaging. [ABSTRACT FROM AUTHOR]

Pulp and paper mills generate large amounts of waste organic matter that may be converted to renewable energy in form of methane. The anaerobic treatment of mill wastewater is widely accepted however, usually only applied to few selected streams. Chemical oxygen demand (COD) removal rates in full-scale reactors range between 30 and 90%, and methane yields are 0.30–0.40 m 3 kg −1 COD removed. Highest COD removal rates are achieved with condensate streams from chemical pulping (75–90%) and paper mill effluents (60–80%). Numerous laboratory and pilot-scale studies have shown that, contrary to common perception, most other mill effluents are also to some extent anaerobically treatable. Even for difficult-to-digest streams such as bleaching effluents COD removal rates range between 15 and 90%, depending on the extent of dilution prior to anaerobic treatment, and the applied experimental setting. Co-digestion of different streams containing diverse substrate can level out and diminish toxicity, and may lead to a more robust microbial community. Furthermore, the microbial population has the ability to become acclimated and adapted to adverse conditions. Stress situations such as toxic shock loads or temporary organic overloading may be tolerated by an adapted community, whereas they could lead to process disturbance with an un-adapted community. Therefore, anaerobic treatment of wastewater containing elevated levels of inhibitors or toxicants should be initiated by an acclimation/adaptation period that can last between a few weeks and several months. In order to gain more insight into the underlying processes of microbial acclimation/adaptation and co-digestion, future research should focus on the relationship between wastewater composition, reactor operation and microbial community dynamics. The potential for engineering and managing the microbial resource is still largely untapped. Unlike in wastewater treatment, anaerobic digestion of mill biosludge (waste activated sludge) and primary sludge is still in its infancy. Current research is mainly focused on developing efficient pretreatment methods that enable fast hydrolysis of complex organic matter, shorter sludge residence times and as a consequence, smaller sludge digesters. Previous experimental studies indicate that the anaerobic digestibility of non-pretreated biosludge from pulp and paper mills varies widely, with volatile solids (VS) removal rates of 21–55% and specific methane yields ranging between 40 and 200 mL g −1 VS fed. Pretreatment can increase the digestibility to some extent, however in almost all reported cases, the specific methane yield of pretreated biosludge did not exceed 200 mL g −1 VS fed. Increases in specific methane yield mostly range between 0 and 90% compared to non-pretreated biosludge, whereas larger improvements were usually achieved with more difficult-to-digest biosludge. Thermal treatment and microwave treatment are two of the more effective methods. The heat required for the elevated temperatures applied in both methods may be provided from surplus heat that is often available at pulp and paper mills. Given the large variability in specific methane yield of non-pretreated biosludge, future research should focus on the links between anaerobic digestibility and sludge properties. Research should also involve mill-derived primary sludge. Although biosludge has been the main target in previous studies, primary sludge often constitutes the bulk of mill-generated sludge, and co-digestion of a mixture between both types of sludge may become practical. The few laboratory studies that have included mill primary sludge indicate that, similar to biosludge, the digestibility can range widely. Long-term studies should be conducted to explore the potential of microbial adaptation to lignocellulosic material which can constitute more than half of the organic matter in pulp and paper mill sludge. [ABSTRACT FROM AUTHOR]

Highlights: [•] A method to increase both strength and stretchability of paper is proposed. [•] The layer-by-layer technique is used to build up a multilayer onto pulp fibres. [•] The addition of salt in the system is a critical parameter. [•] Hyaluronic acid/polyallylamine is the most efficient system. [•] Strain at break and strength of treated paper sheets are increased by a factor 3. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the influence of acetylation on properties of paper made using the chemi-mechanical pulp (CMP) process. Industrial unbleached CMP pulp was provided (before and after refining), and paper handsheets were made. After drying, the specimens were acetylated on a heated cylinder at 120 °C, with acetic anhydride without catalyst. Physical and mechanical properties including water absorption, porosity, printability, brightness, D-folding, breaking length, tear resistance, and burst strength of samples were measured and compared between treated samples and the controls. The results showed that acetylation intensity was increased by increasing reaction time. Water absorption exhibited a significant reduction due to acetylation. Brightness, D-folding, and burst showed an increasing trend as a function of the degree of acetylation. Tear resistance was decreased by acetylation. The refining process improved acetylation and decreased porosity. The results indicated that most of the important factors were significantly influenced and improved by both acetylation and the refining process. [ABSTRACT FROM AUTHOR]

Biomaterials from olive tree pruning are an abundant agricultural residue in various Mediterranean regions. A suggested use of this residue is its separation in a main fraction (trunks and stems with diameter > 1 cm) and a residual fraction (leaves and stems with diameter 1 < cm), using biorefinery procedures. The main fraction is cooked with ethanol, giving rise to a pulp, which can be used either in paper or in bioethanol production if before pulping the main fraction is subjected to a hydrothermal treatment. Pulping with 70% ethanol concentration, 185 °C for 80 min resulted in a pulp with a yield of 46.30% and a content of holocellulose, α-cellulose, and lignin of 77.17%, 62.49%, and 21.73%, respectively. The paper sheets obtained had a breaking length of 1168 m, a burst index of 0.44 kN /g, a tear index of 2.25 mN.m²/g, and a brightness of 43.66%. The pulp converted into bioethanol (by simultaneous hydrolysis and fermentation) achieved a conversion of 70 g bioethanol/100 g potential bioethanol. The residual fraction of olive tree prunings was subjected to combustion to produce thermal energy. The heating value was 18700 kJ/kg, the flame temperature range was 1094 to 2013 ºC, and the dew point temperature range of the flue gases was 47 to 53 °C. [ABSTRACT FROM AUTHOR]

Abstract: This work aims at the characterization and the biorefinery of Hesperaloe funifera by means of the use of its three main components: separating hemicellulose by hydrothermal treatments; cellulose pulp by various pulping processes (soda, soda–anthraquinone, ethanolamine, ethyleneglycol, diethanolamine and diethyleneglycol); and exploitation of pulping liquor, rich in lignin, by pyrolysis and gasification processes. The contents in lignin, α-cellulose, holocellulose, hemicellulose, ethanol–benzene extractives, hot water solubles, 1% NaOH solubles and ash of H. funifera were found to be 7.3%, 40.9%, 76.5%, 35.6%, 4.0%, 13.5%, 29.5% and 5.9%, respectively. The mean fibre length, 4.19mm, exceeds those for some non-wood materials. By using sulfuric acid in the hydrothermal treatment (170°C, 0, 20min after reaching operating temperature, 8 liquid/solid ratio, and 0.3% sulfuric acid), gives a liquid fraction containing 4.62% of glucose, 10.56% of xylose, 1.28% of arabinose, and a solid fraction with a solid yield of 57.0%. The best pulp of Hesperaloe pulp was obtained by cooking with 10% NaOH and 1% anthraquinone at 155°C for 30min, exhibited good values of yield (48.3%), viscosity (737mL/g), Kappa number (15.2), tensile index (83.6Nm/g), stretch (3.8%), burst index (7.34kN/g) and tear index (3.20mNm2/g). Moreover, the soda–anthraquinone pulps of raw material are better than the pulps from solid fraction of hydrothermal treatments. Finally, acidification (pH 6) of soda–anthraquinone pulping liquor was carried out to separate lignin-rich solids, by which pyrolysis gave a gas containing 1.13% H2, 31.79% CO and 1.86% CH4 by weight. Gasification of the same sample provided a gas containing 0.18% H2, 24.50% CO and 17.75% CH4. [Copyright &y& Elsevier]

Abstract: The aim of this work was to chemically characterize orange tree prunings and use it in pulping and combustion processes. Soda-anthraquinone pulping of the main fraction of orange pruning (stems with a diameter >0.5cm) was simulated with polynomial and neurofuzzy models, that predicted pulp properties as a function of operating variables (155–185°C, 40–90min, soda concentration, 10–16%) with errors less than 20%. The heating values (16,870kJ/kg), the flame temperature (1150–2150°C) and dew point temperature of fuel gas (47–53°C) for the residual fraction from orange pruning (stems diameter <0.5cm and leaves) was determined and compared with other non-wood lignocellulosic materials. As a consequence the price of kJ obtained by combustion of this residual fraction is less than other lignocellulosic materials, much lower than those of fossil fuels. [Copyright &y& Elsevier]

Abstract: Wheat straw has been used as a pulping resource in China for many years. Wheat straw pulp (WSP) was widely used to substitute high quality chemical pulps such as those made from wood in producing writing and printing paper to reduce production cost of the resultant paper products and to improve paper smoothness without sacrificing paper strength. In this study, the process of co-refining of WSP and bleached hardwood kraft pulp (BHKP) was compared with the traditional separate refining and then blending these two pulps. The differences in refining energy consumption, the resultant pulp morphological and drainage properties, as well as the mechanical properties of the paper handsheets made of the resultant pulps were examined to explore the potential advantages of the co-refining process. The results show that the co-refining process has the potential to reduce refining energy consumption by at least 30% without affecting handsheet tensile and tear strength at a slightly lower re-wet tensile strength. [Copyright &y& Elsevier]

The improvements of adding sodium borohyride to the alkali sulfite–anthraquninone (AS–AQ) pulping process on properties of pulp and paper sheets was investigated. These properties were compared to those of the AS–AQ and the ethanol addition to AS–AQ (ASAE) pulping processes. The screened yield increased with alkali sulfite–antraquinone–sodium borohyride (ASAB) pulping process and kappa number decreased with respect to the AS–AQ process. Tensile and burst index of paper sheets improved with the ASAB pulping process, and the tear index for the ASAB pulping process was slightly decreased compared to that of the AS–AQ and ASAE pulping processes. It was determined that whiteness and brightness of papersheets decreased by adding sodium borohyride to the AS–AQ pulping process, whereas the opacity of papersheets did not change clearly compared to AS–AQ and ASAE pulping processes. [ABSTRACT FROM AUTHOR]

Abstract: The migration of components from paper into Tenax® was studied to determine the influence of molecular size and chemical character of the migrant and the influence of paper characteristics in the migration process. The Weibull model was applied because Fick’s 2nd law of diffusion gave poor fits in some cases. The migration pattern depended on the migrants molecular size and was independent of temperature in the studied range. The migration rate decreased with the migrant molecular size. The influence of the migrants character (polarity and vapour pressure) on the migration behaviour was also studied: nonpolar migrants with high vapour pressure presented low relative migration values and polar migrants presented high values of relative migration. Results indicated that the apparent partition coefficient between paper and the simulant Tenax® increased with the migrant vapour pressure and with both the paper grammage and the recycled pulp content. [ABSTRACT FROM AUTHOR]

Ozone bleaching is a common practice in pulping, and also of eucalyptus, where it is usually applied in combination with bleaching sequences based on oxygen, hydrogen peroxide, or chlorine dioxide. Ozone has been proven to be a highly efficient and competitive bleaching chemical in terms of delignification efficiency, low costs, and reducing ecological impact. The objective of the present work was to evaluate technology with ozone/alkaline extraction (Z/E) and ozone/chlorine dioxide (Z/D) for bleaching of eucalyptus kraft pulp. Primarily, the impact of these bleaching steps on refinability and quality of pulp should be investigated. As reference, the sequence D*(EP)D (hot chlorine dioxide, extraction in presence of hydrogen peroxide, chlorine dioxide) was selected, which is considered as the state-of-the-art bleaching in elemental chlorine free (ECF) bleaching technology. Various bleaching sequences with ozone in their first step (Z/D(EP)DP, Z/D(EP)DD, Z/EDP, Z/EDD and A*Z/EDP) were found to provide kraft pulps of similar brightness and in similar yield as the reference sequence D*(EP)D. The kappa number, viscosity, and the contents of glucose and xylose, and hexenuronic acid of the pulps were also similar. In addition, the Z sequences resulted in a substantial reduction of the total chlorine dioxide consumption (more than 30.3% in all cases). The A*Z/EDP sequence, which proved to be the most efficient, yielded 87.5% ClO2 reduction. The studied bleaching sequences also resulted in substantially improved brightness reversal with regard to the reference sequence. The sequence A*Z/EDP was also the most efficient as regards the removal or organochlorines (OX) from the pulp and their reduction in the effluents (AOX). Ozone bleaching sequences improved paper strength, especially with the A*Z/EDP sequence. [ABSTRACT FROM AUTHOR]

Pulping and papermaking of Leucoena diversifolia by soda-anthraquinone-ethanol was studied using an experimental design in order to investigate the effects of cooking variables: temperature, time, soda concentration, ethanol concentration and wash-disintegrate temperature on the pulp yield and the physico-chemical characteristics of paper sheets (tensile index, burst index, tear index and brightness). Previously, in order to assess the potential of plants of this raw material grown over short periods, its results were compared with those of other leucaena varieties and the best crop among three grown for 1-3 years was selected. The results were evaluated using the response surface methodology with a view to identifying the most suitable operating conditions. In accordance with biomass production and the features of the raw materials and cellulose pulp obtained, the L. diversifolia grown for 2 years was found to be the most suitable choice for obtaining pulp and paper among the five leucaena varieties examined. Suitable physical characteristics of paper sheets (tensile index, burst and tear index) and acceptable yield pulping and brightness could be obtained by operating at medium temperature, active alkali concentration, pulping time, ethanol concentration and wash-disintegrate temperature. [ABSTRACT FROM AUTHOR]

Abstract  Variation in wood anatomy and biometric variables was studied in 14 7-year-old Eucalyptus globulus clones grown in a clonal trial in Arauco, Bio-Bio Region, Chile. Biometric characteristics were measured for each tree and the anatomical variables were measured at three radial positions by image analysis on transverse microsections cut from radial increment cores sampled at breast height. Results showed, that among clones wide ranges of variation were found for vessel frequency, vessel area and vessel coverage. However, narrow ranges of variation were found for fiber wall thickness, fiber diameter and lumen diameter. From pith to bark, mean vessel area and vessel coverage increased gradually, whereas the vessel frequency decreased. The fiber wall thickness did not differ significantly from pith to bark. Mean fiber and lumen diameters showed the same radial pattern, increasing from pith to the midpoint of the radius to reach a plateau close to the bark. Furthermore, important commercial volume gains that can exceed 100% were found. Considering the commercial importance of tree volume, vessel and fiber anatomy in the pulping and papermaking process, it is suggested that the information given in this study may be used as an additional criteria for the selection of E. globulus. [ABSTRACT FROM AUTHOR]

Abstract: The influence of operational variables in the pulping of vine shoots by use of ethylene glycol [viz. temperature (155–185°C), cooking time (30–90min) and ethylene glycol concentration (50–70% v/v)] on the properties of the resulting pulp (viz. yield, kappa number and viscosity) and paper sheets (breaking length, stretch, burst index, tear index and brightness) was studied. A central composite factorial design was used in conjunction with the software ANFIS Edit Matlab 6.5 to develop fuzzy neural model that reproduced the experimental results of the dependent variables with errors less than 5%. The model is therefore effective with a view to simulating the ethylene glycol pulping process. [Copyright &y& Elsevier]

Abstract: The paper manufacturing process remained unchanged for many centuries, until, in the nineteenth century, the crisis of rags led industrialized countries to patent new production processes with different raw materials. This study deals with this period of transition by analyzing four samples stored at the archives of Superintendency Beni Architettonici per il Paesaggio e per il Patrimonio Storico Artistico ed Etnoantropologico (BAPPDAD) of Venice Lagoon, based in the Palazzo Ducale. The samples were analyzed by FT-IR (ATR), SEM-EDS, HPLC-MS/MS and Py-GC/MS. These techniques allow the characterization of various raw materials and adhesives used in various stages of paper production. These analyses have found a gradual introduction of ground wood in the composition of papers from the mid-nineteenth century, and the use of rosin as glue only in more recent documents. [Copyright &y& Elsevier]

The main purposes of filler addition in papermaking are to improve paper properties and reduce cost. The cost reduction is attributed to the low cost of the filler itself and to the energy savings that occur during the papermaking process. In this work, the effects of clay filler addition on the energy savings during the papermaking process, including water drainage, pressing, and drying, were systematically investigated. Experimental results indicated that the addition of filler could dramatically increase the drainage rate and the water removal rates during pressing and drying. With 20% filler addition, the drainage time decreased by 20% compared to the unfilled paper. At a filler content of 23%, the solids content of the handsheets after pressing increased at least 5 absolute points, and the drying rates increased by 20%. All these improvements can offer considerable benefits for paper mills, including enhanced machine speeds and large energy savings. [ABSTRACT FROM AUTHOR]

Abstract: In this work, we characterized various unconventional pulping raw materials in terms of their contents in hollocelulose, α-cellulose, lignin, ethanol–benzene extractables, ash, and hot water and 1% soda solubles. Also, we characterized pulp obtained from each material by using an ethyleneglycol concentration of 65% at 180°C for 75min, followed by beating at 1500 revolutions in a PFI refiner—all of which are compatible with existing facilities for Kraft and soda pulping processes. We characterized vine shoots, cotton stalks, Leucaena leucocephala and Chamaecytisus proliferus as pulping raw materials and found Ch. proliferus and cotton stalks to be the best for the intended purpose on the grounds of their increased contents in holocellulose (79.73 and 72.86%) and α-cellulose (45.37 and 58.48%), and their decreased contents in ethanol–benzene extractables (2.64 and 1.42%), hot water solubles (2.79 and 3.33%) and 1% soda solubles (16.67 and 20.34%). These properties resulted in increased pulp yields and hence in efficient use of these two types of raw material. The paper sheets obtained of different pulps were characterized and those from Ch. proliferus found to be the best overall as they exhibited an increased breaking length (4644m), stretch (2.87%), burst index (2.46kN/g) tear index (0.33mNm2/g) and brightness (49.92% ISO); in addition Ch. proliferus pulp was obtained with a high yield (62.88%). On the other hand, vine shoots provided the poorest results among the studied raw materials. [Copyright &y& Elsevier]

Abstract: This paper reports on the influence of independent variables in the pulping of olive wood trimmings [viz. cooking temperature (165–195°C) and time (30–90min), ethanolamine concentration (5–15%), soda concentration (2.5–7.5%) and liquid/solid ratio (4–6)], on the yield and kappa number of the pulps and breaking length, burst index and tear index of the resulting paper sheets. By using a central composite factorial design, equations that relate each dependent variable to the different independent variables were obtained that reproduced the experimental results for the dependent variables with errors less than 15%. These equations could be used to find the suitable operations conditions, so that operating with not too high values of operating variables (with the consequent minor costs of capital and of operation) pulps could be obtained by acceptable strength properties. Optimizing pulp yield, the kappa number and the strength properties of the resulting paper sheets entails using rather different conditions in each case. Obtaining acceptably strong paper sheets while saving on immobilized capital through the use of smaller facilities and less chemical reagents entails using a medium soda concentration and low values of all other independent variables. In this way, the yield is 22.2% lower, the kappa number 42.5% higher, and the breaking length, burst index and tear index 6.2, 29.1 and 29.6%, respectively, lower than their optimum values; in any case, the strength properties increase although the pulp was suitably refining. [Copyright &y& Elsevier]

Abstract: This paper is concerned with the temperature field produced by a thermal printer head. Such heads are used to provide high quality prints of electronically stored images. In this system, a thin dye-layer, sandwiched between two copolymer sheets, is heated by a thermal head and dye diffuses into the receiver sheet producing a small dye-dot. The picture is made up of a large number of such dots. The basic aim is to determine the amount of dye which is eventually diffused into the receiver sheet when the heating is turned off and the system has cooled down. However, the amount of dye which diffuses into the receiver sheet depends on the temperature field because the diffusion coefficient is a sensitive function of temperature. In the thermal printer system, each head is heated by an electric current which is carried by gold leads. In this paper, we show that the heat loss through these leads has an important effect on the temperature field produced by the head and therefore, strongly influences the amount of dye transferred. [Copyright &y& Elsevier]

Abstract: The influence of temperature in the hydrothermal treatment of sunflower stalks on the composition of the liquid fraction obtained was examined. The remaining solid fraction was subjected to ethanol pulping in order to obtain pulp that was used to produce paper sheets. The pulp was characterized in terms of yield, kappa index, viscosity, and cellulose, hemicellulose and lignin contents; and the paper sheets in terms of breaking length, stretch, burst index and tear index. Hydrothermal treatment of the raw material at 190°C provided a liquid phase with maximal hemicellulose-derived oligomers and monosaccharide (glucose, xylose and arabinose) contents (26.9 and 4.2g/L, respectively). Pulping the solid fraction obtained by hydrothermal treatment at 180°C, with 70% ethanol at a liquid/solid ratio of 8:1 at 170°C for 120min provided pulp with properties on a par with those of soda pulp from the sunflower stalks, namely: 36.3% yield, 69.1% cellulose, 12.6% hemicellulose, 18.2% lignin and 551ml/g viscosity. Also, paper sheets obtained from the ethanol pulp were similar in breaking length (3.8km), stretch (1.23%), burst index (1.15kN/g) and tear index (2.04mNm2/g) to those provided by soda pulp. [Copyright &y& Elsevier]

Abstract: We characterized vine shoots, cotton stalks, Leucaena leucocephala and Chamaecytisus proliferus as pulping raw materials and found C. proliferus and cotton stalks to be the best for the intended purpose on the grounds of their increased contents in holocellulose (79.73% and 72.86%) and α-cellulose (45.37% and 58.48%), and their decreased contents in ethanol–benzene extractables (2.64% and 1.42%), hot water solubles (2.79% and 3.33%) and 1% soda solubles (16.67% and 20.34%). These properties resulted in increased pulp yields and hence in efficient use of these two types of raw material. The previous raw materials were pulped by using an ethyleneglycol concentration of 65% at 180°C for 75min, followed by beating at 1500 revolutions in a PFI refiner. The paper sheets obtained were characterized and those from C. proliferus found to be the best overall as they exhibited an increased breaking length (4644m), stretch (2.87%), burst index (2.46kN/g) tear index (0.33mNm2/g) and brightness (49.92% ISO); in addition C. proliferus pulp was obtained with a high-yield (62.88%). On the other hand, vine shoots provided the poorest results among the studied raw materials. [Copyright &y& Elsevier]

Abstract: Characterisation of membranes in order to determine how clean the membranes are is usually determined by (1) comparing the initial and final clean water flux (2) the product flux in the following run, (3) FTIR analysis, (4) streaming potential and (5) contact angles. However, these techniques do not provide information about where the remaining foulant resides. In this paper clean water flux results were combined with dye tests (Amido black) to reveal how clean the membranes really were after cleaning with both formulated and industrial cleaners. The dye tests not only identified the remains of protein foulant on the membrane after cleaning but also the presence of surfactant adsorbed to membranes and protein. Also, the dye tests showed for similar relative water fluxes (after fouling, cleaning and rinsing), for three different cleaners, the membranes were cleaned to vastly different degrees. In addition to this by combining the dye test results with the surface tension and pH of the cleaning solution, it was possible to determine the optimum pH and surface tension required for complete removal of protein deposits, without modifying the membrane too drastically. The role of sodium hydroxide (NaOH) and surfactant in the cleaner was investigated and it was found that for successful removal of proteins from membranes the cleaner needed to contain both NaOH and surfactant. [Copyright &y& Elsevier]

Abstract: The influence of operational variables in the pulping of vine shoots by use of ethanolamine [viz. temperature (155 to 185°C), cooking time (30 to 90min) and ethanolamine concentration (50 to 70%, v/v)] on the properties of the resulting pulp (viz. yield, kappa index and viscosity) and paper sheets (breaking length, stretch, burst index, tear index and brightness) was studied. A central composite factorial design was used in conjunction with the software ANFIS Edit Matlab 6.5 to develop fuzzy neural model that reproduced the experimental results of the dependent variables with errors less than 10%. The model is therefore effective with a view to simulating the ethanolamine pulping process. [Copyright &y& Elsevier]

Porapak has been studied as a solid-food simulant in experiments on paper and board packaging. Three samples of paper with different recycled pulp content and surface treatment, and of different grammage and thickness, were used for the studies. Kinetic behaviour from 25 °C to 100 °C and different contact times ranging from 5 min at 100 °C to 10 days at 25 °C were studied using Porapak or, occasionally, Tenax or milk powder. Similar results were obtained with Porapak and Tenax but those from Porapak were more stable with temperature. Porapak behaves as good solid-food simulant even at high temperature. [ABSTRACT FROM AUTHOR]

De-esterification and sulfonation reactions, which create new anionic groups in the middle lamella and primary wall layers, are the key chemical reactions in chemithermomechanical pulping. The effects of these reactions on the resulting fibre dimensions, refining energy demand, hand-sheet bulk and strength properties were assessed by laboratory-scale chemical pre-treatments and refining of Norway spruce chips. After pre-treatments with alkaline, sulfite, alkaline sulfite and alkaline peroxide liquors, a Wing defibrator-type batch refiner was used. The refining energy was measured. The degree of alkaline hydrolysis of acetyl and methyl ester groups in galactoglucomannans (GGMs) and pectins, and the degree of lignin sulfonation were determined. Hand-sheets were prepared and their physical properties were tested. The data were subjected to multivariate analysis and the order of significance of the chemical reactions towards pulp and paper properties was estimated. Chemical pre-treatments were found to increase the fibre length and the energy demand considerably. The fibre length and width after refining were strongly influenced by lignin sulfonation and pectin demethylation. GGM deacetylation had little influence on preserving the fibre dimensions in CTMP refining. The bulk, on the other hand, was highly influenced by GGM deacetylation. Peroxide reactions in alkaline peroxide treatments had no effect on the pulp and paper properties. [ABSTRACT FROM AUTHOR]

Abstract: The results of characterization for four different vine shoot varieties, grown using two different methods, revealed no significant differences in composition among vine varieties or between growing methods. The holocellulose content of vine shoots (67.14%) is lower than those of other non-wood raw materials (e.g. wheat straw, sunflower stalks, cotton stalks, etc.), but similar to those of pine and higher to those of olive trimmings. On the other hand, their lignin content (20.27%) is similar to those of eucalyptus and the non-wood raw materials. Also, their contents in cold-water, hot-water and 1% soda solubles, and ethanol–benzene extractables, are higher than for pine and eucalyptus. Soda, kraft, ethanol and ethylene–glycol pulping processes have low yields (29–47%) relative to the pulping processes applied to olive trimmings and wheat straw. Kraft pulp is that exhibiting the best properties, including a higher α-cellulose content (73.74%) than pulp from wheat straw or olive trimmings, but a higher lignin content (17.18%). Also, kraft pulp provides paper with the highest breaking length, burst index and tear index (viz. 1316m, 1.63kN/g and 1.59mNm2/g, respectively); these values, which are intermediate among those for olive trimmings, wheat straw and sunflower seeds, are low and can be substantially improved by appropriate refining of the pulp. [Copyright &y& Elsevier]

Abstract: The influence of temperature (150–170°C), pulping time (15–45min) and soda concentration (5–10%) in the pulping of abaca on the yield, kappa, viscosity, breaking length, stretch and tear index of pulp and paper sheets, was studied. Using a factorial design to identify the optimum operating conditions, equations relating the dependent variables to the operational variables of the pulping process were derived that reproduced the former with errors lower than 25%. Using a high temperature, and a medium time and soda concentration, led to pulp that was difficult to bleach (kappa 28.34) but provided acceptable strength-related properties (breaking length 4728m; stretch 4.76%; tear index 18.25mNm2/g), with good yield (77.33%) and potential savings on capital equipment costs. Obtaining pulp amenable to bleaching would entail using more drastic conditions than those employed in this work. [Copyright &y& Elsevier]

An experimental design was performed to study the influence of process variables (135–175 °C for temperature, 60–120 min for pulping time and 15–25% for active alkali) on the properties of pulps (yield, Kappa index, viscosity, 1% NaOH solubles, alcohol–benzene extractives holocellulose, lignin and α-cellulose contents and brightness) and paper sheets (stretch index, burst index, and tear index) obtained from olive trimming residues. Obtaining pulps with acceptably high physical and chemical properties entails operating at a temperature of 175 °C for 90 min and 25% of active alkali. The paper sheets obtained from olive trimming residues pulps that were produced in different degrees of refining are characterised for their stretch index, burst index, and tear index. An increase in the different parameters for the paper sheet upon increasing the degree of refining is found. All pulps reached between 33 and 39 kN m/kg in the stretch index, between 1.5 and 2 kN/g for the burst index and 0.7–2.5 N m2/g for the tear index and not in excess of the refining degree (<45 °SR). [Copyright &y& Elsevier]

The presence of toxic metals on paper pulp and the migration of these metals to food from the food package is receiving significant attention. The final exposure levels for consumers depend on two main processes. First the potential of metals to bind paper pulp during manufacture. Second, the metal potential to migrate from paper to food during storage and use.Binding and unbinding processes are modelled for cadmium kinetics through kinetic approaches.The cadmium concentration in paper pulp is estimated from the cadmium concentration in the water–pulp liquor during manufacture, the temperature, and contact time. Two food simulants have been employed for desorption studies, water and acetic solution (3%, w/w). As expected, under acidic conditions desorption is total and rapid (close to 100% desorption reached in a few minutes). However, the desorption of cadmium into the neutral food simulant depends on the initial cadmium concentration in the paper pulp, temperature and contact time. Surface response curves for each combination are presented.Temperature did not affect cadmium binding, but played a significant role for the desorption processes into the neutral food simulant.The proposed equations offer a good fitting of the experimental values, with p<0.001 and residuals within a factor of 3 for over 99% of the measured data. These models allow estimations of the expected exposure levels in consumers, on the basis of manufacture and use conditions. Linking the expected exposure with toxicity thresholds, such as the admissible daily intake (ADI), would allow a scientific assessment of the maximum acceptable cadmium levels in water–pulp liquors during manufacture and in the final paper pulp on the basic of the use patterns of each food packaging material. [Copyright &y& Elsevier]

In this work, a number of handsheets made from unbeaten and unbleached kraft, refiner mechanical and cotton linter pulps and crack propagations on paper samples under monotonic loading, were analyzed and possible links with the properties of fibrous networks were investigated. Crack initiation and propagation on the tested paper strips were also investigated under a scanning electron microscope to determine visually the state of the paper matrix under applied loads. Furthermore, paper samples were subjected to a series of mechanical tests, such as tearing resistance, folding endurance and tensile strength. The primary goal of this study concentrated on determining the fatigue life responses of paper samples under cyclic loading. An empirical equation for the fatigue life responses of paper samples tested was developed. It was found that paper, being a heterogeneous composite material, responds differently to applied loads depending on the properties of its constituent individual fibers and the nature of interfiber bonding in its structure. Kraft handsheets, for instance, showed the highest mechanical properties, followed by samples made from refiner mechanical pulps and cotton linters respectively. Overall, the equation developed proved to be a good way of predicting the fatigue life of paper materials subjected to variable loads. [ABSTRACT FROM AUTHOR]

Promoting the application of environmentally friendly packaging such as those made out of paper-pulp requires a basic understanding of the mechanical behaviour of paper-pulp (material) as well as that of packaging (product). In this paper, results from the investigation to determine the mechanical properties of paper-pulp packaging are presented. This includes the determination of tensile and compressive strength of paper-pulp packaging and also to find out whether this material exhibits high variation in the earlier properties. Experiments were conducted on paper-pulp packaging used for the packaging of video recorders. Specimen testing as well as testing of functional elements of packaging (rib separated from packaging support) is explored. In addition to the testing on real world paper-pulp packaging samples, FEM modelling and analysis is carried out using the rib similar to those used in testing. Based on this numerical modelling, effect of change in geometry of rib on its mechanical behaviour is explored. [Copyright &y& Elsevier]

The influence of independent variables in the pulping of wheat straw by use of an ethanol–acetone–water mixture [processing temperature and time, ethanol/(ethanol + acetone) value and (ethanol + acetone)/(ethanol + acetone + water) value] and of the number of PFI beating revolutions to which the pulp was subjected, on the properties of the resulting pulp (yield and Shopper–Riegler index) and of the paper sheets obtained from it (breaking length, stretch, burst index and tear index) was examined.By using a central composite factor design and the BMDP software suite, equations that relate each dependent variable to the different independent variables were obtained that reproduced the experimental results for the dependent variables with errors less than 30% at temperatures, times, ethanol/(ethanol + acetone) value, (ethanol + acetone)/(ethanol + acetone + water) value and numbers of PFI beating revolutions in the ranges 140–180 °C, 60–120 min, 25–75%, 35–75% and 0–1750, respectively.Using values of the independent variables over the variation ranges considered provided the following optimum values of the dependent variables: 78.17% (yield), 15.21 °SR (Shopper–Riegler index), 5265 m (breaking length), 1.94% (stretch), 2.53 kN/g (burst index) and 4.26 mN m2/g (tear index).Obtaining reasonably good paper sheets (with properties that differed by less than 15% from their optimum values except for the burst index, which was 28% lower) entailed using a temperature of 180 °C, an ethanol/(ethanol + acetone) value of 50%, an (ethanol + acetone)/(ethanol + acetone + water) value of 75%, a processing time of 60 min and a number of PFI beating revolutions of 1750. The yield was 32% lower under these conditions, however.A comparison of the results provided by ethanol, acetone and ethanol–acetone pulping revealed that the second and third process-which provided an increased yield were the best choices. On the other hand, if the pulp is to be refined, ethanol pulping is the process of choice. [Copyright &y& Elsevier]

Presents a study on the influence of unbleached pulp content on the permanence and durability of paper produced under alkaline conditions and containing calcium carbonate as a filler. Optical and color stability; Behavior towards light; Surface characteristics.

Presents a study which made paper sheets from a papyrus plant after pulping in order to obtain a suitable pulp for document conservation. Delignification of papyrus by the pulping processes; Details of papyrus reinforcement technique; Consolidation of brittle papyrus.