scholarly journals Industrial Application of Nanocelluloses in Papermaking: A Review of Challenges, Technical Solutions, and Market Perspectives

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 526 ◽  
Author(s):  
Ana Balea ◽  
Elena Fuente ◽  
M. Concepcion Monte ◽  
Noemi Merayo ◽  
Cristina Campano ◽  
...  
Keyword(s):  
Barrier Properties ◽  
Research Needs ◽  
Compromise Solution ◽  
Paper Properties ◽  
Exponential Increase ◽  
New Findings ◽  
Retention Aids ◽  
Product And Process ◽  
Technical Solutions ◽  
Paper Product

Nanocelluloses (NC) increase mechanical and barrier paper properties allowing the use of paper in applications actually covered by other materials. Despite the exponential increase of information, NC have not been fully implemented in papermaking yet, due to the challenges of using NC. This paper provides a review of the main new findings and emerging possibilities in this field by focusing mainly on: (i) Decoupling the effects of NC on wet-end and paper properties by using synergies with retention aids, chemical modification, or filler preflocculation; (ii) challenges and solutions related to the incorporation of NC in the pulp suspension and its effects on barrier properties; and (iii) characterization needs of NC at an industrial scale. The paper also includes the market perspectives. It is concluded that to solve these challenges specific solutions are required for each paper product and process, being the wet-end optimization the key to decouple NC effects on drainage and paper properties. Furthermore, the effect of NC on recyclability must also be taken into account to reach a compromise solution. This review helps readers find upscale options for using NC in papermaking and identify further research needs within this field.

scholarly journals Concept of Product Complexity Modeling in the Development of a Machine Shaft

2017 ◽  
Vol 8 (2) ◽  
pp. 91-98
Author(s):  
Jerzy Pokojski ◽  
Łukasz Woźnicki
Keyword(s):  
Design Process ◽  
Process Modeling ◽  
Process Models ◽  
Detailed Structure ◽  
Product Complexity ◽  
Speed Reducer ◽  
Design Process Modeling ◽  
Product And Process ◽  
Paper Product

AbstractIn the paper product and design process modeling on the basis of speed reducer is presented. The paper proposes to build the product and process models and parallel to that carry out the project activities as these models reflect the detailed structure of the projects.The most important feature of the proposed approach is its possibility to model only important parts of the models and to keep track of the development of their chronological paths. The approach may be treated as a partial CPM/MOKA model or as network-integrated CPM/MOKA models.

Application of modified cellulose nanofibrils as coating suspension on recycled paper using size press

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hakan Fidan ◽  
Ayhan Tozluoğlu ◽  
Ahmet Tutuş ◽  
Bayram Poyraz ◽  
Recai Arslan ◽  
...  
Keyword(s):  
Cellulose Nanofibrils ◽  
Barrier Properties ◽  
Coating Material ◽  
Compression Tests ◽  
Recycled Paper ◽  
Paper Properties ◽  
Lower Viscosity ◽  
Coating Suspension ◽  
End Use ◽  
Recycled Fibers

Abstract Cellulose based nanomaterials have the great potential to be applied to paper as bulk additive or coating material to improve overall final properties, especially in secondary fiber. In the present work, the effect of applying different kinds of cellulose nanofibrils (CNF) to papers obtained from recycled fibers using size press on physical, mechanical and barrier properties was investigated and compared with the sole use of starch as coating material. The coating process of CNF was carried out by the addition of size press grade starch to coating suspension. As a cellulose source, wheat straw was evaluated and CNF was obtained through oxidative and enzymatic pretreatments. Results indicate that starch/CNF suspension improves the overall paper properties. As a result of the deposition of coating suspension contains of 4 % wt. periodate-oxidized CNF onto paper surface, tensile and burst indices of papersheets increased as 52.2 % and 194.4 %. Significant decreases were observed in air permeability as 69.8 %. Compression tests also have been conducted to evaluate papersheets end-use properties. In comparison to the other pretreated CNF, due to is lower viscosity, applying periodate-oxidized CNF as size press significantly increased the mechanical properties of the papers fabricated from the recycled pulps.

Factorial study of connections between process variables and kraft paper quality properties

2014 ◽  
Vol 29 (2) ◽  
pp. 286-293
Author(s):  
Mikael Håkansson ◽  
Johan E. Carlson
Keyword(s):  
Interaction Effects ◽  
Quality Parameters ◽  
Reliable Estimate ◽  
Process Variables ◽  
Paper Properties ◽  
Effect Analysis ◽  
Quality Properties ◽  
Five Factors ◽  
Paper Product ◽  
Paper Quality

Abstract By investigating how properties of a finished paper product are related to different process variables as well as pulp characteristics throughout the fiber line, the understanding of the process will increase. In this paper we investigate the correlation between some key paper quality parameters and five tunable process variables, along the entire fiber production line. A full two-level factorial experiment has been conducted, where five factors were varied. The factor settings were based on a laboratory replica of a specific kraft mill’s paper product. The mill replicate was then used as a center point in the factorial design and appropriate levels of the factors were set based on these center points. Several experimental runs could be simulated via a Monte Carlo approach making it possible to get a reliable estimate of the significance of each factor effect. Analysis of the results shows that there are interaction effects present between variables, and that these interaction effects can be utilized to achieve similar paper properties using different variable settings.

A multi-disciplinary approach to the development of intensive animal systems for Canada

1974 ◽  
Vol 3 ◽  
pp. 69-83 ◽  
Author(s):  
R. S. Gowe ◽  
G. R. Barr ◽  
H. F. Peters
Keyword(s):  
Great Difficulty ◽  
Reproductive Physiology ◽  
Memorial Lecture ◽  
Animal Nutrition ◽  
Animal Science ◽  
Exponential Increase ◽  
Scientific Disciplines ◽  
New Findings ◽  
High Esteem ◽  
Multi Disciplinary Team

It is indeed an honour to be asked to present the 1974 Sir John Hammond Memorial Lecture, and I face this honour with some trepidation knowing the high esteem held for Sir John and his outstanding contributions to world animal science. As most of you know, Sir John was somewhat of a one-man multi-disciplinary team himself, publishing and researching in the fields of animal breeding, reproductive physiology, meat science and animal nutrition. With the rapid and sometimes almost exponential increase in new findings in each of these areas, one person, even one of Sir John Hammond's stature, would now have great difficulty making significant contributions in the several scientific disciplines closely associated with animal production.

Composite filler by pre-flocculation of fiber fines and PCC and its effect on paper properties

2020 ◽  
Vol 35 (2) ◽  
pp. 251-260
Author(s):  
Hyun Kang ◽  
Jong Myoung Won ◽  
Byoung-Uk Cho
Keyword(s):  
Strength Properties ◽  
Ash Content ◽  
Paper Strength ◽  
Precipitated Calcium Carbonate ◽  
Paper Properties ◽  
Loading Method ◽  
Retention Aids ◽  
Composite Filler ◽  
Filler Retention ◽  
Better Than

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

scholarly journals Planning and governing nature-based solutions in river landscapes: Concepts, cases, and insights

AMBIO ◽  
2021 ◽  
Author(s):  
Christian Albert ◽  
Jochen Hack ◽  
Stefan Schmidt ◽  
Barbara Schröter
Keyword(s):  
Business Models ◽  
Ecosystem Processes ◽  
Research Needs ◽  
Special Issue ◽  
Landscape Development ◽  
Research Fields ◽  
Societal Needs ◽  
Governance Models ◽  
Landscape Scales ◽  
Technical Solutions

AbstractNature-based solutions (NBS), understood as actions that use ecosystem processes to address societal needs, can play important roles to future-proof river landscape development for people and nature. However, knowledge gaps exist how NBS can be planned and implemented at landscape scales. This Special Issue brings together insights and experiences from studies of assessing, planning, and implementing NBS in river landscapes in Europe and beyond. It addresses three research fields: (i) NBS effects, looking at the effectiveness of NBS to achieve ecological, social, and/or economic outcomes, (ii) NBS planning, focusing on approaches for planning and designing NBS, and (iii) NBS governance, relating to governance and business models for implementation. The twelve contributions deliver evidence on how NBS outperform conventional, rather technical solutions, provide guidance and tools to operationalize the NBS concept into practice, and showcase successful governance models of NBS in different contexts. The editorial ends with an outlook on further research needs.

Dental Cements: Reactor Response

1988 ◽  
Vol 2 (1) ◽  
pp. 142-144 ◽  
Author(s):  
M.L. Swartz
Keyword(s):  
Current Status ◽  
Future Research ◽  
In Vitro Test ◽  
Research Needs ◽  
Glass Ionomer Cements ◽  
Glass Ionomer ◽  
Relative Resistance ◽  
New Findings ◽  
Vitro Test

This paper is in response to Dr. Dennis Smith's paper, which dealt with the current status of dental cements and recommendations with respect to future research needs. Interest in cements and research in this area have mushroomed with the development of polycarboxylate and glass-ionomer cements. Despite this increased research, there still exist significant voids, which can only be elucidated by further concerted research efforts, both laboratory and clinical. With newer systems -e.g., the polycarboxylate and glass-ionomer cements—properties such as modulus of elasticity, which were of little concern with the phosphate cements, have now assumed clinical relevance. Also, the need persists to develop an in vitro test that reflects the relative resistance of cements to disintegration in the oral cavity. Finally, greater efforts should be expended by the research community to disseminate new findings to the dental practitioner in order that the patient population may benefit from the latest advances in materials.

scholarly journals Art Paper for Large Wood Relief Block Printing – A Paper Development Study

2021 ◽  
pp. 1-18
Author(s):  
Klaus Dölle ◽  
Hélène Rainville
Keyword(s):  
Kraft Pulp ◽  
Process Development ◽  
Paper Machine ◽  
Large Wood ◽  
Machine Direction ◽  
Paper Properties ◽  
Softwood Kraft Pulp ◽  
Bottom Side ◽  
Egg Shell ◽  
Paper Product

Wood relief block printing was developed in China in the seventh century and is used today for many art printing applications. The presented research project describes the development of an art paper product applicable for large wood relief block printing from laboratory scale to large semi commercial production of art paper for printing image sizes of up to 44-inch (1118 mm) by 96-inch (2400 mm) at outdoor steam roller printing events or smaller indoor printing press applications. The improvement of the paper properties from laboratory development, small laboratory paper machine and semi commercial paper machine run for the production of the final art paper showed an improvement throughout the process development for the optical and mechanical paper properties and exceeded the set values set by the artist using the art paper. The produced art paper with a basis weight of 260 g/m² and a thickness of 171 µm is produced from a mixture of 70% northern bleached hardwood Kraft pulp and 30% northern bleached softwood Kraft pulp. The ISO brightness of the art paper off-white (egg-shell) colour was at 63.2% and the ISO color value for L, a, b. at 90.8, 1.1, and 12.6 respectively. The art papers surface roughness and porosity as a parameter for ink attachment and penetration is for the top side 2179 ml/min and for the bottom side (wire side) 2326 ml/min, whereas porosity was measured at 1668 ml/min. Bending stiffness in machine direction and cross machine direction was measured at 157mN and 70 mN respectively. Burst strength was measured at 2.24 kPA·m²/g.

SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

1977 ◽  
Vol 35 ◽  
pp. 308-309
Author(s):  
K. W. Robinson
Keyword(s):  
Tension Wood ◽  
Wood Fiber ◽  
Strength Properties ◽  
Fiber Morphology ◽  
Paper Properties ◽  
Pure Cellulose ◽  
Short Rotation ◽  
Hardwood Trees ◽  
Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

Organization of tight junctions in the choroid plexus epithelium

1978 ◽  
Vol 36 (2) ◽  
pp. 336-337
Author(s):  
B. Van Deurs ◽  
J. K. Koehler
Keyword(s):  
Choroid Plexus ◽  
Present Report ◽  
Freeze Fracture ◽  
Barrier Properties ◽  
Cell Junctions ◽  
Structural Basis ◽  
Apical Surface ◽  
Choroid Plexus Epithelium ◽  
Solid Nitrogen ◽  
Special Composition

The choroid plexus epithelium constitutes a blood-cerebrospinal fluid (CSF) barrier, and is involved in regulation of the special composition of the CSF. The epithelium is provided with an ouabain-sensitive Na/K-pump located at the apical surface, actively pumping ions into the CSF. The choroid plexus epithelium has been described as “leaky” with a low transepithelial resistance, and a passive transepithelial flux following a paracellular route (intercellular spaces and cell junctions) also takes place. The present report describes the structural basis for these “barrier” properties of the choroid plexus epithelium as revealed by freeze fracture.Choroid plexus from the lateral, third and fourth ventricles of rats were used. The tissue was fixed in glutaraldehyde and stored in 30% glycerol. Freezing was performed either in liquid nitrogen-cooled Freon 22, or directly in a mixture of liquid and solid nitrogen prepared in a special vacuum chamber. The latter method was always used, and considered necessary, when preparations of complementary (double) replicas were made.

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