A report on Pulp (paper)PaperKraft process and Pulp mill

Structure of fibres of pulp
Paper products: book, toilet paper, ruled paper, carton, egg box
International Paper: Kraft paper mill
A pulp mill in Äänekoski, Central Finland
Pulp at a paper mill near Pensacola, 1947
Paper products: book, toilet paper, ruled paper, carton, egg box
Woodchips for paper production
Woodchips for paper production
Fibres in wood pulp
Hemp wrapping paper, China, c. 100 BC
A roll of kraft paper
International Paper Company, pulp mill
Mechanical pulping process
The microscopic structure of paper: Micrograph of paper autofluorescing under ultraviolet illumination. The individual fibres in this sample are around 10 µm in diameter.
net reaction in depolymerization of lignin by SH− (Ar = aryl, R = alkyl groups).
Pulp mill at Blankenstein (Germany)
International Paper Company, a pulp mill that makes fluff pulp for use in absorbent products with the kraft process
Paper mill in Mänttä-Vilppula, Finland
Forchem tall oil refinery in Rauma, Finland.
Paper money from different countries
Card and paper stock for crafts use comes in a wide variety of textures and colors
A book printed in 1920 on acidic paper, now disintegrating a hundred years later.

The kraft process (also known as kraft pulping or sulfate process) is a process for conversion of wood into wood pulp, which consists of almost pure cellulose fibers, the main component of paper.

- Kraft process

Pulp can be manufactured using mechanical, semi-chemical, or fully chemical methods (kraft and sulfite processes).

- Pulp mill

Wood and other plant materials used to make pulp contain three main components (apart from water): cellulose fibres (desired for papermaking), lignin (a three-dimensional polymer that binds the cellulose fibres together) and hemicelluloses, (shorter branched carbohydrate polymers).

- Pulp mill

The competing chemical pulping process, the sulfate, or kraft, process, was developed by Carl F. Dahl in 1879; the first kraft mill started, in Sweden, in 1890.

- Pulp (paper)

It was not until the introduction of wood pulp in 1843 that paper production was not dependent on recycled materials from ragpickers.

- Paper

A pulp mill is a manufacturing facility that converts wood chips or other plant fibre source into a thick fiberboard which can be shipped to a paper mill for further processing.

- Pulp (paper)

The kraft process, invented in the 1870s and first used in the 1890s, is now the most commonly practised strategy; one of its advantages is the chemical reaction with lignin produces heat, which can be used to run a generator.

- Paper

Various byproducts containing hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfide, and other volatile sulfur compounds are the cause of the malodorous air emissions characteristic for pulp mills utilizing the kraft process.

- Kraft process

It is normally delivered as sheeted bales of 250 kg. The reason to leave 10 percent moisture in the pulp is that this minimizes the fibre to fibre bonding and makes it easier to disperse the pulp in water for further processing to paper.

- Pulp (paper)

Paper made from mechanical pulp contains significant amounts of lignin, a major component in wood.

- Paper
Structure of fibres of pulp

1 related topic with Alpha

Overall

Worldwide pulp production by type of bleaching used: chlorine (Cl2), elemental chlorine free (ECF) and total chlorine free (TCF)

Bleaching of wood pulp

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Worldwide pulp production by type of bleaching used: chlorine (Cl2), elemental chlorine free (ECF) and total chlorine free (TCF)

Bleaching of wood pulp is the chemical processing of wood pulp to lighten its color and whiten the pulp.

The primary product of wood pulp is paper, for which whiteness (similar to, but distinct from brightness) is an important characteristic.

While the results are the same, the processes and fundamental chemistry involved in bleaching chemical pulps (like kraft or sulfite) are very different from those involved in bleaching mechanical pulps (like stoneground, thermomechanical or chemo-thermomechanical).

Lignin is the main source of color in pulp due to the presence of a variety of chromophores naturally present in the wood or created in the pulp mill.