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Thursday, October 15, 2020 | History

2 edition of influence of chemical additives on the refining of papermaking pulps found in the catalog.

influence of chemical additives on the refining of papermaking pulps

J. C. Roberts

influence of chemical additives on the refining of papermaking pulps

by J. C. Roberts

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  • 36 Currently reading

Published by PIRA,paper & board division in Leatherhead .
Written in English


Edition Notes

Statementby J.C. Roberts and P. Williams.
ContributionsWilliams, P., Printing Industries Research Association.
The Physical Object
Pagination53p. :
Number of Pages53
ID Numbers
Open LibraryOL19832075M

Thus, the removal of hemicelluloses from wood chips or bleached pulps can be expected to have a significant influence on the charge properties of the cellulosic fibers. For the retention of cationic papermaking additives, the amount of charged groups located on the fiber surface or near the surface (so called subsurface) is most important. Enzymatic modification of papermaking properties of chemical, mechanical, and recycled pulps has been widely studied during the past decades. The main aims have been to improve the strength properties of fibers through increased fibrillation or to affect the amount of fines in pulp to increase the drainage or water retention of pulp.

Refining (or Beating)- Fibres are subjected to mechanical action to develop their optimal papermaking properties Addition of Chemical Additives and Auxiliaries -A wide variety of mineral and chemical substances added, to improve strength and quality of paper or to assist the papermaking process. Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibers from wood, fiber crops, waste paper, or with water and other chemical or plant-based additives, pulp is the major raw material used in papermaking and .

Bleachability of pulps produced using urea was better compared to the reference pulp (without using urea). There was improvement in final pulp brightness by %, whiteness by % and increase in bleached pulp viscosity by ~1 Cp. Refining energy requirement was lower in case of urea pulps (at same CSF level) as compared to the pulp. Papermaking - Papermaking - Processes for preparing pulp: Mechanical or groundwood pulp is made by subjecting wood to an abrading action, either by pressing the wood against a revolving grinding stone or by passing chips through a mill. The wood fibres are separated and, to a considerable degree, fragmented. Chemical wood pulp is made by cooking wood chips with chemical solutions in .


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Influence of chemical additives on the refining of papermaking pulps by J. C. Roberts Download PDF EPUB FB2

Pulp and Paper Industry: Chemicals features in-depth and thorough coverage of Chemical additives in the Pulp and Paper Industry. It discusses use of Enzymes "Green Chemicals" that can improve operations in pulp and paper, describes Chemicals demanded by the end user and many key and niche players such as Akzo Nobel NV, Eka Chemicals AB, Ashland, Inc., BASF, Buckman Laboratories.

Refining of chemical pulp Targets of refining Refining or beating of chemical pulps is the mechanical treatment and modification of fibers so that they can be formed into paper or board of the desired properties.

It is one of the most important unit operations when preparing papermaking fibers for high-quality papers or paperboards. Alongside the traditional aspects of pulping and papermaking processes, this book also focuses on biotechnological methods, which is the distinguishing feature of this book.

It includes wood-based products and chemicals, production of dissolving pulp, hexenuronic acid removal, alternative chemical recovery processes, forest products biorefinery.

Chemical pulps are generally used for fabrication of high-quality papers with high mechanical properties and better brightness in comparison to mechanical pulps (Smook, ). Table 1. Resume of publications related to application of CNF as a bulk additive into papermaking by: Influence influence of chemical additives on the refining of papermaking pulps book pulp refining on tissue paper properties chemical additives, Optimizing the formation of magazine papers produced at a speed of m/min on Yankee type papermaking machines.

Refining degree of Kamloops Kraft pulp increases °SR when refining PFI revolutions, and the water retention value increases by %, the dye loading increases with mg/g, the. Chapter 2—The Pulp and Paper Making Processes 19 with steam (chemical thermomechanical pulp uses chemicals and steam for pretreatment).

After further refining in a second stage, the pulp is screened, cleaned, and most of the process water is removed in preparation for papermaking.

The invention is a process by which one can either increase the overall degree of refining of a pulp used in a paper machine, or maintain at its target value the degree of refining of this pulp while reducing the amount of enzyme needed to achieve this degree of refinement.

The process of the invention comprises the steps which consist in adding to the pulp a cellulolytic enzyme, at a rate of. Chemical pulp For the production of wood pulp, the pure fibre has to be set free, which means that the lignin has to be removed as well.

To achieve this, the wood chips are cooked in a chemical solution. In case of wood pulp obtained by means of chemical pulping, we differentiate between sulphate and sulphite pulp, depending on the chemicals used. Smith, D. C., "Chemical Additives for Improved Compression Strength of Unbleached Board," Proc.

TAPPI Papermakers Conf., (). Strazdins, E., "Chemicals Aids Can Offset Strength Loss in Secondary Fiber Furnish Use," Pulp Paper 58 (3): 73 (). intensive processes in the paper-making industry (Ghosh, ).

Improving the drainage ability of the wet paper web could result in energy savings in the drying section of the paper machine. Mechanical refining and enzymatic refining of pulp, the structure and.

In the second stage after refining, the pulp is screened, cleaned, and most of the process water is removed in preparation for paper making.

Paper Pulp Bleaching Process Raw pulp contains an appreciable amount of lignin and other discoloration, it must be bleached to produce light colored or white papers preferred for many products. The change in surface chemical composition can introduce more negative charges to the fiber surface, and this may affect the retention of cationic chemical additives on fibers in the papermaking process.

Table 2. Effects of LC Refining on Surface Chemical Compositions of Extracted (E) and Un-Extracted Pulp and Fiber Samples. Full Article.

Improved Bleached Chemical Reed Pulp Properties Using Atmospheric High Consistency Refining. Yulong Wang, a, * Chunxia Tang, a Yanxin Liu, a, b Yue Wang, a Benping Lin, a Hongwei Zhu, c and Chunjing Liu c The influence of atmospheric high consistency refining (AHCR) on the properties of bleached chemical reed pulp was investigated.

Fiber quality, water retention value (WRV. Abstract. To obtain a suitable refining process for Pinus massoniana cellulose fibers (PMCF) and China fir cellulose fibers (CFCF), the effects of the beating gap and the pulp consistency on the physical properties and the morphology of the two cellulose fibers were investigated.

The results showed that the physical properties of the PMCF and the CFCF were well affected by the beating gap and. An Escher-Wyss conical refiner at the SCA R&D Centre in Sundsvall, Sweden was used for LC refining. The pulp consistency during refining was about 2%, the amount of pulp used in each batch was kg dry weight and the edge load was Ws/m.

The pulp suspension was re-circulated until the target level of refining energy was obtained. The effects of refining history and recycling times of NSSC pulp as a representative of semi-chemical pulps were studied. The results indicated that NSSC behaved as would be expected for a.

Pratima Bajpai, in Biermann's Handbook of Pulp and Paper (Third Edition), Abstract. This chapter presents the general background of pulp and paper industry, history of papermaking followed by an overview of pulping and papermaking processes.

It describes the important milestones in the papermaking industry, such as invention of paper and development of papermaking machine. Chemical pulps tend to cost more than their mechanical pulp counterparts, which is largely due to the lower yield, often 40–50% of the original wood depending upon the source of fiber.

Generally, most wood sources contain 40–50% cellulose, 15–25% lignin, and 20–35% hemicelluloses. Introduction and the Literature -- 2. Wood and Fiber Fundamentals -- 3. Pulping Fundamentals -- 4. Kraft Spent Liquor Recovery -- 5.

Pulp Bleaching -- 6. Refining and Pulp Characterization -- 7. Paper and Its Properties -- 8. Stock Preparation and Additives for Papermaking -- 9. Paper Manufacture -- Fiber from Recycled Paper -. This week as we continue on in our paper making process series, we will be discussing the refining process of the pulp.

In case you missed it before, the previous blogs are First Steps of Papermaking, Debarking, and Pulping Process. In modern TMP (Thermo/mechanical pulp) plant the refining process is 2 stage or ideally 3 stage which means the pulp is fed through two or three .Abstract.

During sequential bleaching operations, pulp fiber properties are gradually changed due to mechanical and chemical treatments. In this study, the correlations between pulp or fiber properties such as kappa number, viscosity, total charge, fiber length, and zero-span tensile strength as well as Scott bond of elemental chlorine free (ECF) bleached softwood kraft pulps was investigated.Cellulose nanofibers (CNF) have been proposed by several authors as a reinforcing additive for papermaking pulps; their use allows one to avoid mechanical refining of pulp fibers, which damages.