Dewatering properties of low grammage handsheets of softwood kraft pulps modified to minimize the need for refining

2018 ◽  
Vol 33 (3) ◽  
pp. 397-403 ◽  
Author(s):  
Hafizur Rahman ◽  
Per Engstrand ◽  
Peter Sandström ◽  
Björn Sjöstrand
Keyword(s):  
Energy Levels ◽  
Negative Influence ◽  
Strength Properties ◽  
Positive Influence ◽  
Pulp Yield ◽  
Paper Machine ◽  
Yield Increase ◽  
Tissue Paper ◽  
Hemicellulose Content ◽  
Tensile Index

Abstract Previous paper (Rahman et al. 2017) showed that the yield of softwood kraft pulp increased by the addition of either polysulfide or sodium borohydride because of higher hemicellulose retention. An increase in hemicellulose content can make dewatering more difficult as WRV of the pulp increases, but instead, an overall increase in pulp yield could improve dewatering as a sheet of a certain weight will contain fewer fibres, giving a more open sheet structure. It was therefore of interest to measure the dewatering properties of low grammage handsheets (20 g/m2) under conditions mimicking the tissue paper machine dewatering processes, and sheet strength properties, WRV, °SR and fibre dimensions were also studied. The results showed that the positive influence of overall yield increase dominated over the negative influence of an increase in hemicellulose content on the dewatering properties, particularly at lower refining energy levels. Moreover, higher yield and higher hemicellulose content pulps had a higher tensile index at the same dryness. A given tensile index was achieved with less refining energy. The results indicate that increased yield and hemicellulose content by modification of the kraft pulping process will result in a pulp with a potential to improve tissue paper quality.

Chemical, anatomical, and technology aspects of Eucalyptus benthamii and Eucalyptus dunii for use in an integrated pulp and paper mill

TAPPI Journal ◽  
2015 ◽  
Vol 14 (2) ◽  
pp. 73-81 ◽  
Author(s):  
GISELY SAMISTRARO ◽  
PETER W. HART ◽  
JORGE LUIZ COLODETTE ◽  
RICARDO PAIM
Keyword(s):  
Energy Levels ◽  
Black Liquor ◽  
Basic Density ◽  
Paper Mill ◽  
Frost Tolerance ◽  
Strength Properties ◽  
Kappa Number ◽  
Pulp Yield ◽  
Chemical Compositions ◽  
Physical Strength

Eucalyptus dunii has been commercially used in southern Brazil because of its relatively good frost tolerance and adequate productivity in the winter months. More recently, interest has grown in cultivating Eucalyptus benthamii Maiden & Cambage, which presents even superior frost tolerance compared to E. dunii and is highly productive as well. The quality of E. benthamii for pulp production is not yet proven. Thus, the chemical, anatomical, and technological aspects of pulp made from E. benthamii were compared with those of E. dunii for unbleached paper production. Samples of E. benthamii chips were obtained and analyzed for their basic density, chemical composition, higher heating value, trace elemental analysis, and chip size distribution. The chips were kraft cooked using conditions that produced a 74 ± 6 kappa number. The pulps were characterized for kappa number, yield, viscosity, and morphologic characteristics (e.g., length, wall thickness, and coarseness). Black liquor was analyzed for total solids, organics, inorganics, sodium sulfide, sodium hydroxide, and sodium carbonate. Brownstocks were beaten at five different energy levels in a Valley beater, and the physical strength properties of 120 g/m² handsheets were measured to develop a beater curve. The results of this study showed differences in delignification between the two woods and lower pulp yield for E. benthamii , which are related to their chemical compositions and basic densities. The E. benthamii studied in this work exhibited higher amounts of lignin and extractives, lower carbohydrate content, and lower basic density. However, cooking a blend of the two woods afforded good results in pulping and in physical pulp properties.

Nonwood pulping: use of jute cuttings and caddis in Bangladesh

TAPPI Journal ◽  
2013 ◽  
Vol 12 (9) ◽  
pp. 41-46 ◽  
Author(s):  
M. SARWAR JAHAN ◽  
SUMON GOSH ◽  
M. MOSTAFIZUR RAHMAN ◽  
YONGHAO NI
Keyword(s):  
Physical Properties ◽  
Chlorine Dioxide ◽  
Raw Materials ◽  
Strength Properties ◽  
Economic Importance ◽  
Kappa Number ◽  
Pulp Yield ◽  
Tensile Index ◽  
Tear Index ◽  
Better Than

Utilization of jute cutting and caddis is of social and economic importance in Bangladesh. In this study, soda-anthraquinone, alkaline sulfite-anthraquinone, and neutral sulfite-anthraquinone processes were evaluated for jute-cutting and caddis pulping. The NS-AQ process showed favorable pulp yield and kappa number for both of these raw materials: 66.1% for jute cuttings and 59.9% for caddis at kappa no. 11. The physical properties of NS-AQ pulps were also better than those of soda-AQ and AS-AQ pulps. At 0SR 44, the tensile index of NS-AQ pulp was about 100 N.m/g for jute cutting and 70 N.m/g for caddis, and the tear index was similar. All pulps were bleached by D0EpD1 bleaching sequences. The NS-AQ pulp showed excellent bleachability. Its brightness reached 89.0% for jute cuttings and 85.0% for caddis using total chlorine dioxide of about 15 kg/ton. After bleaching, the strength properties of NS-AQ pulp were slightly better compared to soda-AQ and AS-AQ pulps.

scholarly journals Influence of tissue paper converting conditions on finished product softness

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 7178-7190
Author(s):  
António de Oliveira Mendes ◽  
Joana Costa Vieira ◽  
Ana Margarida Carta ◽  
Enrico Galli ◽  
Rogério Simões ◽  
...  
Keyword(s):  
Surface Analysis ◽  
The Other ◽  
Current Work ◽  
Paper Machine ◽  
Tissue Paper ◽  
Tensile Index

Tissue paper conversion consists of the transformation of base tissue papers into finished tissue products to meet specific demands. When base tissue paper arrives at the converting line, it already holds different requirements that were met during its manufacture in the paper machine (e.g., grammage, bulk, tensile index, etc.). However, what happens during converting can still influence the performance and quality of the finished products. The current work addresses this topic and aims to evaluate the influence of converting conditions on the final softness. For that, two 5-ply finished tissue products were analyzed using different methodologies for their proper characterization in terms of softness and surface analysis. The analyzed products are composed by the same base tissue papers, but some changes were applied on their settings in the converting line. In particular, the base tissue papers arrangement and the embossing pressure affected the finished products, resulting in one of them being softer and more pleasant to touch, with a global handfeel (HF) value of 75.3 units, and the other revealed to be rougher and less pleasant, with a global handfeel (HF) value of 68.0 units.

Does Diversity in The Boardroom Add Value to a Firm?

2018 ◽  
Vol 18 (5) ◽  
Keyword(s):  
Firm Performance ◽  
Panel Data ◽  
Firm Size ◽  
Significant Influence ◽  
Negative Influence ◽  
Positive Influence ◽  
Future Research ◽  
Board Composition ◽  
Board Diversity

This study examines whether board diversity affects firm performance. We investigate this study using panel data of a sample of S&P 500 firms during a 12 year period. After controlling for industry, firm size, and other board composition variables, we find that all three board diversity variables of interest – gender, ethnicity, and age have a significant influence on firm performance. While ethnicity and age have a positive influence on firm performance, it was found that gender has a negative influence. Implications for future research are discussed.

scholarly journals Machine Learning-Based Energy System Model for Tissue Paper Machines

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 655
Author(s):  
Huanhuan Zhang ◽  
Jigeng Li ◽  
Mengna Hong
Keyword(s):  
Neural Network ◽  
Energy Consumption ◽  
Gradient Boosting ◽  
Paper Machine ◽  
Steam Consumption ◽  
Tissue Paper ◽  
Paper Machines ◽  
Energy Consumption Model ◽  
Extreme Gradient Boosting ◽  
Consumption Model

With the global energy crisis and environmental pollution intensifying, tissue papermaking enterprises urgently need to save energy. The energy consumption model is essential for the energy saving of tissue paper machines. The energy consumption of tissue paper machine is very complicated, and the workload and difficulty of using the mechanism model to establish the energy consumption model of tissue paper machine are very large. Therefore, this article aims to build an empirical energy consumption model for tissue paper machines. The energy consumption of this model includes electricity consumption and steam consumption. Since the process parameters have a great influence on the energy consumption of the tissue paper machines, this study uses three methods: linear regression, artificial neural network and extreme gradient boosting tree to establish the relationship between process parameters and power consumption, and process parameters and steam consumption. Then, the best power consumption model and the best steam consumption model are selected from the models established by linear regression, artificial neural network and the extreme gradient boosting tree. Further, they are combined into the energy consumption model of the tissue paper machine. Finally, the models established by the three methods are evaluated. The experimental results show that using the empirical model for tissue paper machine energy consumption modeling is feasible. The result also indicates that the power consumption model and steam consumption model established by the extreme gradient boosting tree are better than the models established by linear regression and artificial neural network. The experimental results show that the power consumption model and steam consumption model established by the extreme gradient boosting tree are better than the models established by linear regression and artificial neural network. The mean absolute percentage error of the electricity consumption model and the steam consumption model built by the extreme gradient boosting tree is approximately 2.72 and 1.87, respectively. The root mean square errors of these two models are about 4.74 and 0.03, respectively. The result also indicates that using the empirical model for tissue paper machine energy consumption modeling is feasible, and the extreme gradient boosting tree is an efficient method for modeling energy consumption of tissue paper machines.

scholarly journals Concerns or Desires Post-Pandemic: An Extended MGB Model for Understanding South Korean Residents’ Perceptions and Intentions to Travel to China

2021 ◽  
Vol 18 (5) ◽  
pp. 2542
Author(s):  
Guanghui Qiao ◽  
Xiao-li Zhao ◽  
Luqi Xin ◽  
Seokchool Kim
Keyword(s):  
Mass Media ◽  
Latent Variables ◽  
Structural Equation ◽  
Mainland China ◽  
Negative Influence ◽  
Positive Influence ◽  
Extended Model ◽  
South Korean ◽  
Structural Relationships ◽  
China Post

In this study, we examined South Korean residents’ travel-related behavioural intention for mainland China post-COVID-19 using an extended model of goal-directed behaviour. To do so, we integrated South Korean residents’ perceptions of country image (PCI), mass media, and concerns about travel into the framework of the original model of goal-directed behaviour (MGB). Structural equation modelling was used to identify the structural relationships among the latent variables. The results show that mass media had a positive influence on South Korean residents’ perception of China’s image, a negative influence on residents’ concerns, and a positive influence on residents’ behavioural intentions for travel overseas. Meanwhile, PCI had a positive influence on residents’ attitude towards travel overseas. The theoretical and practical implications of the study are discussed.

Dynamic-head space GC-MS analysis of volatile odorous compounds generated from unbleached and bleached pulps and effects on strength properties during ageing

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Izhar Alam ◽  
Swati Sood ◽  
Chhaya Sharma
Keyword(s):  
Volatile Compounds ◽  
Paper Mill ◽  
Strength Properties ◽  
Degree Of Polymerization ◽  
Ambient Conditions ◽  
Bleached Pulp ◽  
Tensile Index ◽  
Ms Analysis ◽  
Odorous Compounds ◽  
Unbleached Pulp

Abstract Mixed hardwood unbleached (UB) and final bleached (FB) pulp along with the pulp of intermediate bleaching stages from an integrated paper mill have been undertaken for this study. Headspace GC-MS analysis of these pulps was made to identify the odorous compounds which are volatile organic compounds (VOCs), generated during ageing for 60 days. The result showed that a number of pre-generated VOCs such as aliphatic hydrocarbons and aldehydes are observed in the pulp sample which might be came from the process and it has been observed that upon ageing at ambient conditions, some acid functionalized VOC were generated in the pulp. The generation of these VOCs were established by ATR-FTIR analysis and the results showed that intensity of peak absorbance near 3340  cm − 1 {\text{cm}^{-1}} and 1641  cm − 1 {\text{cm}^{-1}} which represents the –OH stretching of acidic functional group and C=O stretch of aldehyde and acidic functional groups increased after ageing. Generation of acid functionalized volatile compounds were observed more in bleached pulp than in unbleached pulp. Degree of polymerization (DP) is pretty much related to the strength of paper. DP of both unbleached and bleached pulp gets reduced upon ageing while more reduction were observed in bleached pulp. Bleached pulps are more prone to degrade as compared to the unbleached pulp in terms of strength properties such as tensile index, breaking length, burst and double fold were observed. 12.3 % and 21.8 % reduction in tensile index was observed for UB and final bleached FB pulp respectively. Burst index of UB and FB pulp were found reduced to 23.8 % and 41.9 % respectively due to ageing. Reduction in the mechanical and optical properties was also observed in intermediate bleaching stages. There is much evidence for the contribution of VOCs to the degradation of paper. The results are strongly suggested that acid functionalized volatile compounds can have strong effects on degradation of cellulosic paper.

scholarly journals Filling the void of family leadership: institutional support to business model changes in the Italian Industry 4.0 experience

2021 ◽  
Author(s):  
Marco Cucculelli ◽  
Ivano Dileo ◽  
Marco Pini
Keyword(s):  
Business Model ◽  
Industry 4.0 ◽  
Manufacturing Industry ◽  
Business Models ◽  
Institutional Support ◽  
Negative Influence ◽  
Positive Influence ◽  
External Support ◽  
Family Management ◽  
Family Leadership

AbstractWe examine whether the probability of innovating a company’s business model towards the Industry 4.0 paradigm is affected by external institutional support and family leadership. Industry 4.0 is the information-intensive transformation of global manufacturing enabled by Internet technologies aimed at reinventing products and services from design and engineering to manufacturing. Using a sample of 3000 firms from a corporate survey on the manufacturing industry in Italy, our results showed that family leadership has a significant positive influence on the adoption of Industry 4.0 business models, but only in terms of family ownership. By contrast, family management has a negative influence on the probability of adopting a new business model. However, this negative influence is almost totally offset by the presence of the Triple Helix, i.e. the external support by public institutions and universities, which counterbalances the lower propensity of family managers to adopt Industry 4.0 business models. This supporting role only occurs when institutions and universities act together.

An experimental study of the influence of riblets on transition

1996 ◽  
Vol 315 ◽  
pp. 31-49 ◽  
Author(s):  
G. R. Grek ◽  
V. V. Kozlov ◽  
S. V. Titarenko
Keyword(s):  
Experimental Study ◽  
Three Dimensional ◽  
Negative Influence ◽  
Positive Influence ◽  
Linear Stage ◽  
Turbulent Transition ◽  
Transition Structures ◽  
Stage Transition ◽  
Tollmien Schlichting ◽  
Laminar Turbulent Transition

An experimental study of the effect of riblets on three-dimensional nonlinear structures, the so-called Λ-vortices on laminar-turbulent transition showed that riblets delay the transformation of the Λ-vortices into turbulent spots and shift the point of transition downstream. This result is opposite to the negative influence of such ribbed surfaces on two-dimensional linear Tollmien-Schlichting waves (the linear stage of transition). Thus, the ribbed surface influences laminar-turbulent transition structures differently: a negative influence on the linear-stage transition structures and a positive influence on the nonlinear-stage transition structures. It is demonstrated that transition control by means of riblets requires special attention to be paid to the choice of their location, taking into account the stage of transition.

scholarly journals Lagged Ensembles, Forecast Configuration, and Seasonal Predictions

2013 ◽  
Vol 141 (10) ◽  
pp. 3477-3497 ◽  
Author(s):  
Mingyue Chen ◽  
Wanqiu Wang ◽  
Arun Kumar
Keyword(s):  
Lead Time ◽  
Geographical Location ◽  
Seasonal Prediction ◽  
Skill Score ◽  
Negative Influence ◽  
Positive Influence ◽  
Prediction Skill ◽  
Ensemble Size ◽  
Seasonal Forecasts ◽  
Ensemble Forecasts

Abstract An analysis of lagged ensemble seasonal forecasts from the National Centers for Environmental Prediction (NCEP) Climate Forecast System, version 2 (CFSv2), is presented. The focus of the analysis is on the construction of lagged ensemble forecasts with increasing lead time (thus allowing use of larger ensemble sizes) and its influence on seasonal prediction skill. Predictions of seasonal means of sea surface temperature (SST), 200-hPa height (z200), precipitation, and 2-m air temperature (T2m) over land are analyzed. Measures of prediction skill include deterministic (anomaly correlation and mean square error) and probabilistic [rank probability skill score (RPSS)]. The results show that for a fixed lead time, and as one would expect, the skill of seasonal forecast improves as the ensemble size increases, while for a fixed ensemble size the forecast skill decreases as the lead time becomes longer. However, when a forecast is based on a lagged ensemble, there exists an optimal lagged ensemble time (OLET) when positive influence of increasing ensemble size and negative influence due to an increasing lead time result in a maximum in seasonal prediction skill. The OLET is shown to depend on the geographical location and variable. For precipitation and T2m, OLET is relatively longer and skill gain is larger than that for SST and tropical z200. OLET is also dependent on the skill measure with RPSS having the longest OLET. Results of this analysis will be useful in providing guidelines on the design and understanding relative merits for different configuration of seasonal prediction systems.

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