R. Leccio, E. Miguel, J. Molinos, P.G. Obnimaga, K. Salvador, A.M. Tutor

I. IntroductionII. ObjectivesIII. HistoryIV. Uses and EconomicsV. Manufacture of PulpVI. Paper ManufactureVII. Structural BoardsVIII. ConclusionIX. References

Several attributes of paper, including itspedagogic and packaging value makes pulp andpaper industry uniquely positioned among themanufacturing industries.

In addition to its economic benefits, theconsumption of paper has cultural valueresulting from its function in the recording anddissemination of information. Because of this,pulp and paper consumption rates have beenused as an indicator of a nation's socioeconomicdevelopment.

Per Capita Distribution: World: 55 kg USA: 300 kg Africa: 7 kg

SOURCE: FAO

Paper and board consumption by world regions

PAPER PRODUCING FACTORY

PAPER MAKING MACHINERY

This report generally aims to present the paper and pulp industry. It will also present importance of the pulp and paper industry to the other industries which uses its products.Specific objectives are to:

a. present the importance of the industry, uses and economics.

b. present the raw materials used and the processes involved in the manufacture of the final products.

c. give the applications of the derived products from the pulp and paper industry.

2500 and 2000 BC

Papyrus Writings

105 AD

Rag and Linen Papers

14th Century

Bamboo-produced papers

14th Century

Guttenbergs Press

Fourdrinie machine

1799

Burgess and WattSoda Process

1853

1857

TilghmanSulfite Process

DahlKraft Process

1884

Pulp and paper production worldwide from 1980 to 1993

Paper and paperboard consumption as an indicator of economic development

Top pulp producer countries

Raw Materials Cotton and linen rags, once the major sources of fibers for paper have

now been largely supplanted by fibers from wood. Both hard(deciduous) and soft (coniferous) wood are used to make pulp, butsoftwood is preferred because the fibers are longer. Bark cannot beused because it is not fibrous and is difficult to bleach. Bark is removedat the pulp mill by one of two debarking methods. The first abrades offthe bark utilizing friction between pulpwood logs tumbled about in arotating, cylindrical drum. Stationary drums using cams to move thelogs about utilize the same principle. The bark is carried away in astream of water, strained out, and usually burned. The more generallyused method is hydraulic debarking. Recovered bark is oftencompressed before burning to reduce the water content and facilitatecombustion.

Pulping Process All processes used for pulping have the same goal to release the

fibrous cellulose from its surrounding lignin while keeping the hemicelluloses and celluloses intact, thereby increasing the yield of useful fibers.

There are many processes and variations of basic processes which can be used for making pulp from wood. The major processes are: sulfate or kraft process, groundwood and thermomechanical process, semichemical process, and sulfite process. There are also a host of new processes (solvent, oxygen, catalytic, and enzymatic processing) that have been suggested. Most are technically possible but economically unfeasible.

Pulping Process All processes used for pulping have the same goal to release the

fibrous cellulose from its surrounding lignin while keeping the hemicelluloses and celluloses intact, thereby increasing the yield of useful fibers.

There are many processes and variations of basic processes which can be used for making pulp from wood. The major processes are: sulfate or kraft process, groundwood and thermomechanical process, semichemical process, and sulfite process. There are also a host of new processes (solvent, oxygen, catalytic, and enzymatic processing) that have been suggested. Most are technically possible but economically unfeasible.

Types of Pulp Processing Sulfate (Kraft) Pulping

Soda Pulping

Sulfite Pulping

Semichemical, or NSSC, Pulping

Mechanical Pulping

Sulfate (Kraft) Pulping

is an alkaline process by which most pulp is presently made

material added to the cooking liquor for the kraft process isNa2SO4

Soda Pulping Same as kraft process; the difference is the

chemical solution used white liqour

a procedure similar to that used for sulfatepulp, except that the dissolving agent isNaOH/Na2CO3

Sulfite PulpingProducts :

Sulfite pulp

Waste sulfite liquor Despite the high quality pulp, the quantity of pulps produced

using this process is diminishing due to the water pollution it causes.

Woods used: spruce, hemlock, balsam

Two principal types of reactions in a sulfite process:

(1) sulfonation and solubilizing of lignin with bisulfate

(2) hydrolytic splitting of the cellulose-lignin complex

Magnesium Bisulfite Process

sulfur is melted

oxidized to SO2

SO2 is cooled quickly

absorption of gas in water

the digester is filled with chips

digester is heated with direct stream

washing of pulp with fresh water

weak red liquor/cooking is evaporated and

burnt MgO, SO2

MgO is slaked and pumped to the

cooling and acid tower

Magnesium Bisulfite Process

SO2 fresh SO2 liquor

pulp screening

the relatively pure pulp is

concentrated in thickeners

bleaching

milk of lime is added to neutralize

the mass

drying

Waste of Sulfite Liquor

Sodium-based

Recovery process is complex

Calcium-based

Ca or S cannot be recovered or reused

Ammonium-based

Ammonia cannot be recovered

Magnesium-based

Most preferred, convenient and simple to handle

Uses of sulfite waste liquor: Vanillin from lignin Tanning materials Road binders Core binders Food yeast

MECHANICAL PULPING Mechanical pulps are produced by grinding wood

against a stone or between metal plates, thereby separating the wood into individual fibers

The shearing action breaks cellulose fibers

The resulting pulp is weaker than chemically separated pulps

Methods Stone Groundwood Pulping (SGW) Refiner Mechanical Pulping (RMP) Thermomechanical Pulping (TMP) Chemi-Mechanical Pulping (CMP) Chemi-Thermomechanical Pulping (CTMP)

Stone Groundwood Pulping

Oldest and historically most common mechanical method

Fibers are removed from short logs by pressing them against a rotating abrasive cylinder.

Groundwood (soft coniferous species such as spruce and balsam) is used chiefly for cheaper grades of paper and board where permanency is not required.

Involves no chemical treatment.

Stone Groundwood Pulping

Refiner Mechanical Pulping

Wood chips or sawdust are fed through the center of a disc refiner, where they are shredded into finer pieces as they are pushed out through progressively narrower bars and grooves.

Refiner Mechanical Pulping

Thermomechanical Pulping

A modification of RMP is thermomechanical pulping (TMP)

Chips are steamed before and during refining, usually under pressure.

Cleaner and stronger compared to groundwood pulp

Thermomechanical Pulping

Chemi-Mechanical Pulping / Chemi-Thermomechanical Pulping

Earliest Method: Pre-steaming logs before boiling them in chemical

pulping liquors, then grinding them in stone grinders to produce chemi-groundwood pulps

Modern Method: Uses disc refiners with chemical treatment (e.g.,

sodium bisulphite, sodium hydroxide) either prior to, during or after refining.

Chemi-Mechanical Pulping / Chemi-Thermomechanical Pulping

Referred either:

Chemi-mechanical pulps (CMP) Carried out at atmospheric pressure

Chemi-thermomechanical pulps (CTMP), Carried out at elevated pressure.

New Pulping Processes

Solvent Pulping uses a variety of solvents such as ethanol, phenol, and

other delignifying solvents that contain no sulfur.

Holopulping uses chlorine dioxide as pulping agent.

Straight oxygen and nitric acid pulping have also been suggested as a new pulping process.

Other Processes:

Secondary Fiber Pulping

Rag Pulping

Dissolving Pulp

Secondary Fiber Pulping

Employs repulping of recycled paper.

Secondary fiber is worth 5 times its value as waste paper.

Multi-ply cylinder board is the largest single use of secondary fiber.

Secondary Fiber Pulping

Six Major Grades:

Chipboard Mill board Folding boxboard Combination Manila board Container board Setup board

Rag Pulping

Cotton (in the form of rags or cotton linters) is the oldest material used for making paper.

Major source of raw materials from textile manufacturing plants and clothing manufacturers.

Paper made from rags has much longer storage life than that made of wood fiber.

Dissolving Pulp Posttreatment of high-quality sulfite pulp with

sodium hydroxide or from pre-hydrolyzed sulfatepulp.

Used to make cellulose derivatives (essentially pure -cellulose).

Cotton linters are used as its raw material since it is almost pure -cellulose.

Wet Process Pulps lack in desirable properties

Proper surface

Opacity

Strength

Feel

Beating The paper is stronger, denser, more

uniform, more opaque and less porous. Fiber bonds are increase

Refining Pulp is deformed, defibered and dispersed,

but not cut. Conical refiner or Jordan engine is the

frequently used refiners.

Jordan engine

Conical Refiner

Filler Gives the paper a smoother surface, more

whiteness and improved printability and opacity

Naturally occurring

Talc and special clays

Manufactured materials

Titanium dioxide, precipitated calcium carbonate and some silico-aluminates

Sizing Improves resistance from liquid

Stock sizing

forms a gelatinous film on the fiber which loses its hydration water to produce a hardened surface

commonly used sizing is rosin soap from tall oil

Sizing Tub sizing

applied to paper to produce a firm nonporous surface

common tub sizes are modified starches and plastic materials

improves the ability of paper to take ink well, resist moisture and withstand erasure

Wet process paper machines Two types

Fourdrinier machine

Cylinder machine

Both machines form the paper by draining water from a dilute fiber mix through a fine screen

Fourdrinier Machine

Fourdrinier Machine

Cylinder Machine

Cylinder Machine

Dry Process Because of the cost and complexity of

drying equipments, dry process is put intoconsideration. Pilot plants were built tostudy paper making by dry processes.However, difficult problems of the processhave not been resolved.

Specialty Papers Papers are classified according to broad use. Special industrial papers are those not

falling into the specific broader use category.

Specialty Papers These papers are the following:

cigarette; filter; glassine; food containers such as paper plates, cans, cups,

and wrappers coated with plastic or aluminium foil; Sanfordized bag material called Clupak; vegetable

parchment; wallpaper surfaced-waxed paper

Papermakers are currently working withtextile manufacturers to develop papersuitable for disposable surgical gloves andbed sheets. Cost of these materials is lowerthan that of conventional woven cloth.

Fiber Boards

used for furniture but also in paneling.

Particle Boards used in subflooring, core stock for veneered furniture and decorative

paneling

Paper Based Laminates are used in the building industry and decorations

Manufacture

Paper and pulp industry occupies an important position in the economyfor its extended role in industrialization and social sector development.The industry today can be divided into two main sectors according to thetypes of products manufactured. Pulp is generally manufactured in largemills in the same regions as the fiber harvest (i.e., mainly forest regions).Most of these mills also manufacture paper - for example, newsprint,writing, printing or tissue papers; or they may manufacture paperboards.

Separate converting operations are usually situated close to consumermarkets and use market pulp or paper to manufacture bags,paperboards, containers, tissues, wrapping papers, decorative materials,business products and so on.

Austin, G. T. (1984). Shreves Chemical Process Industries. McGraw Hill Inc.

Forest Industries (2013). Global Paper Consumption is Growing. Retrieved from http://www.forestindustries.fi/industry/paper_cardboard_converted/paper_pulp/Global-paper-consumption-is-growing-1287.html

Encyclopaedia of Occupational Health and Safety (1994). Pulp and Paper Industry. Retrieved from http://www.ilocis.org/documents/chpt72e.htm.