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Application of Enzymes in the Pulp and Paper Industry ...

The enzymatic pitch control method using lipase was put into practice in a large‐scale paper‐making process as a routine operation in the early 1990s and was the first case in the world in which an enzyme was successfully applied in the actual paper‐making process. Improvement of pulp drainage with enzymes is practiced routinely at mill ...

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Pulp Washing Influencing factors, Paper Pulping Process ...

Pulp Washing Process. The purpose of the pulp washing is to separate the waste from the pulp to facilitate the subsequent treatment of the slurry and the treatment of the waste, so it's very vital for improving quality of pulp in paper pulping process, there are some influencing factors we should care in pulp washing process.

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Introduction to Kraft Pulping and Bleaching Course - Virtual

The TAPPI Introduction to Kraft Pulping and Bleaching Course is the most comprehensive introductory to intermediate Kraft Pulp Manufacturing short course available.. It is now being offered in an interactive, blended learning format, which combines the best features of an in-person short course with the convenience of a distance eLearning course.

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The Pulp and Papaer Industry

Paper is made by pulping wood, bleaching this pulp and then spreading it out into sheets to make it into paper. At various stages of the process, chemicals are used to give the paper particular properties, such as the bleaching chemicals that make paper white (and which also enable it .

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Mechanical pulping - Valmet

CTMP (Chemi-ThermoMechanical Pulp) The CTMP processes provide excellent bulk properties of paper at a high production capacity. The key sub-processes in CTMP pulping cover all the way from chip preparation, high-consistency refining, steam recovery, fractionation, treatment of long fiber fraction, bleaching and dewatering to pulp storage prior to papermaking process or drying and baling for ...

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Bleaching of Pulp - Pulp and Paper Resources on the Web

Unbleached pulps exhibit a wide range of brightness depending on the pulping process and fibrous raw material used. The sulfite process produces the brightest pulp, up to 65% whereas Kraft, soda and semi-chemical may produced pulp of only 15% brightness.

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The Paper Making Process - unizg.hr

Pulp bleaching Initially, wood pulp has a brown or brownish colour. To obtain the brightness required for white papers, it has to be bleached. During this process of bleaching, the remaining lignin is removed as well. In practical terms, bleaching is a continuation of the chemical cooking process.

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The Pulp Bleaching Process and Purpose Of Paper ...

In the production process of paper manufacturing machine, pulp bleaching is necessary and indispensable for paper production line. In this article, you can find more details about pulp bleaching. Pulp bleaching is used to remove residue in the sizing agent, such as lignin and pigment. Pulp bleaching can promote pulp whiteness and make pulp have ...

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Paper Chemicals - List of Chemicals used in Papermaking

List of Chemicals used in Papermaking. Optical brightening agent – Paper that is derived from both natural or synthetic fiber pulp is not completely naturally white, so manufacturers often add agents that increase its fluorescence. This is done for majority of paper used today. Pigment – Coloring of paper is common, and it is done to all papers that have their specific purpose (wrapping ...

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Facts About the Use of Bleaching Agents in Tissue and ...

bleaching process is by far the technological choice for sustainable pulp and paper manufacturing globally; a shift that now represents more than 95 percent of worldwide pulp production. Domestically, ECF bleaching is recognized by the U.S. Environmental Protection Agency (EPA) as being the "Best Available Technology" to bleach paper products.

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PCF vs ECF: Chlorine Free Paper Matters - Southern ...

Mar 09, 2013· As such, recycled paper requires far less bleaching than paper. Currently, there are no paper pulp mills in the U.S. that are completely chlorine free. Making Greener Choices with Your Paper. When placing your next order for white paper, be sure to look for recycled paper .

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US20040035537A1 - Method for bleaching paper pulp - Google ...

Various types of paper pulp are bleached in two steps at atmospheric pressure and at a temperature of less than or equal to 100° C. The first step is carried out by bringing the raw pulp into contact with a mixture of peracetic acid and performic acid. The second step is carried out by treating the bleached pulp obtained from the first step, with a solution of sodium hydroxide and hydrogen ...

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Papermaking - Wikipedia

In 1844, Canadian Charles Fenerty and German F.G. Keller had invented the machine and associated process to make use of wood pulp in papermaking. This innovation ended the nearly 2,000-year use of pulped rags and start a new era for the production of newsprint and eventually almost all paper was made out of pulped wood.

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Handbook on Pulp and Paper Processing

process, neutral sulphite semi chemical process, thermo mechanical pulps for newsprint, zeta potential concept in paper sizing, sodium carbonate in alkali extraction during bleaching bamboo, maintenance engineering in pulp and paper industry, design and application of refiners in stock preparation, paper machine effluent etc.

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Pulp and Paper Manufacturing Processes in Papermaking Industry

How to change pulp to paper in paper manufacturing process. On the process of paper manufacturing process, in order to finally turn the pulp into paper, the pulp is fed or pumped into giant, automated papermaking machines. One common type is called the Fourdrinier machine, which was invented in England in 1807.

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PULP AND PAPER: BLEACHING AND THE ENVIRONMENT

The mill would have used a chlorine bleaching process and discharged organochlorines into the sea. Community groups are also concerned about the use of Australia's forest resources, particularly mature native hardwood forests, for pulp and paper making. Although this report is primarily an information document, the Commission also

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Chlorination bleaching process | pulp paper mill

Sep 21, 2015· Chlorination bleaching is the second stage of the pulp bleaching process. It is the cheapest bleaching agent for eliminating lignin. Elemental chlorine (EC) reacts selectively with the non carbohydrate compounds. It is another significant delignification process. It ruptures the lignin bonds and make important amount of chlorinated organic ...

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Bleaches - Chemistry Encyclopedia - structure, reaction ...

Bleaching pulp and paper dioxins. In fact, the most abundant dioxin produced by the pulp and bleaching process, 2,3,7,8-tetrachlorodibenzo- p -dioxin (2,3,7,8-TCDD), has been found to be both a carcinogen and a deadly toxin . Thus, chlorine as a bleaching agent is being replaced by the safer bleaching agents chlorine dioxide and hydrogen peroxide.

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Washing & Bleaching System for Paper paper pulper Machine

The paper pulp was separated from the black liquor to wash out and purify the paper pulp which was produced by the reaction of alkali lignin in the cooking process, so as to facilitate the selection and bleaching of the paper pulp. At the same time, the paper pulp was washed sufficiently and the cooking waste liquor with high concentration and ...

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Dioxin: paper's trace; chlorine bleaching of wood pulp ...

Feb 18, 1989· In response to growing concern over the paper-dioxin connection, the New York City-based American Paper Institute, representing the paper-making industry, announced in November that its members would voluntarily institute changes at wood-pulp mills -- such as limiting the chlorine used in bleaching--to reduce the formation of dioxins and furans.

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History of Washi – Hiromi Paper, Inc.

Papermaking was introduced to Japan more than 1,300 years ago. The Chronicles of Japan, Nihon Shoki, written in the year 720, state that the Chinese methods of making ink and paper were introduced to Japan by the Korean Buddhist priest, Doncho, in 610. The Prince Regent Shotoku found Chinese paper too fragile and encouraged the use of kozo (mulberry) and hemp fibers, which were already ...

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Chemical Pulping - an overview | ScienceDirect Topics

Paper made from chemical pulps is sometimes also known as wood-free paper that is not to be confused with tree-free paper, but rather implies the breakdown of the wood structure including its matrix majority lignin. If white paper is desired, bleaching with peroxides, hydrosulfites, and chlorine dioxide increase the brightness of the pulp.

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Paper Making Lab - shodor

*Try the bleaching process on moderately heavily printed toner paper. Make sure to pulp for 30 seconds or less. Does the bleaching process have any effect on the toners? Why or why not? *For one of the types of wastepaper that does bleach (e.g. a colored copy paper or a corrugated box) try to determine how much bleaching agent is needed to ...

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Sponsored by Paper Bleaching 101: The Basics

Bleaching is the process of making pulp white to improve print-ing properties and its ability to absorb liquids. Bleaching also attacks some contaminants to reduce stray dark colored parti-cles in the final sheet of paper. Bleaching processes add significantly to the total cost of making pulp. Also, the environmental impact of bleaching has the ...

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FLOW SHEET- PULP AND PAPER MANUFACTURING

PULP WASHER Digested pulp is washed to remove impurities and chemicals. This is carried out in several stages with recirculated water. The use of hot water at the last stage of washing facilitates washing and results in a dryer pulp coming off the washer. Washing also must be carried out after bleaching to remove chemicals.

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Papermaking - Wikipedia

In 1844, Canadian Charles Fenerty and German F.G. Keller had invented the machine and associated process to make use of wood pulp in papermaking. This innovation ended the nearly 2,000-year use of pulped rags and start a new era for the production of newsprint and eventually almost all paper was made out of pulped wood.

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Chemical Reactions: Paper Making – Chemistry

Jan 21, 2018· If oxygen based bleaching agents is used, the lignin is modified and does not dissolve in water and stay with the pulp; In acidic sizing, which is the process of making paper liquid resistant, Rosin (C19H29COOH), a natural resin from pine trees reacts with alum (aluminum sulfate {A12(SO4)3}) to create aluminum rosinate, which is a liquid ...

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The Use of Chlorine in Paper Making – Bleaching of Wood Pulp

Jul 09, 2018· The process of doing it is called bleaching of wood pulp, which is a chemical process. In this process, the wood pulp's color is enlightened and whiten. The output product of this wood pulp bleaching is paper. This process can also be done by using other material than wood, such as bamboo and kenaf. Here you may also read about:

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Chlorination bleaching process | pulp paper mill

Sep 21, 2015· Chlorination bleaching is the second stage of the pulp bleaching process. It is the cheapest bleaching agent for eliminating lignin. Elemental chlorine (EC) reacts selectively with the non carbohydrate compounds. It is another significant delignification process. It ruptures the lignin bonds and make important amount of chlorinated organic ...

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Basics of Pulp Bleaching - University of Tennessee

Light Absorption by Pulp Sheets ¾The product of molar extinction coefficient and concentration is replaced by k, the absorption coefficient ¾The visible light absorbed by lignin is in the blue range (400-500 nm), making it appear yellow. ¾Bleaching removes lignin and therefore decreases the absorption coefficient in this range. It is measured at

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Process Control in Pulp and Paper Production | Knick

After each bleaching process, the pulp is washed and must be checked for bleaching residue by pH measurements before it comes into contact with other chemicals in the next tower. Low maintenance and developed for media with high debris loads and extreme ionic strength, Memosens SE 571 is used for pH monitoring after each wash.

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Bleaches - Chemistry Encyclopedia - structure, reaction ...

Bleaching pulp and paper dioxins. In fact, the most abundant dioxin produced by the pulp and bleaching process, 2,3,7,8-tetrachlorodibenzo- p -dioxin (2,3,7,8-TCDD), has been found to be both a carcinogen and a deadly toxin . Thus, chlorine as a bleaching agent is being replaced by the safer bleaching agents chlorine dioxide and hydrogen peroxide.

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Basic Overview of Pulp and Paper Manufacturing Process ...

Paper production is basically a two-step process in which a fibrous raw material is first converted into pulp, and then the pulp is converted into paper. The harvested wood is first processed so that the fibres are separated from the unusable fraction of the wood, the lignin. Pulp making .

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