Sección: X PULP OF WOOD OR OF OTHER FIBROUS CELLULOSIC MATERIAL; RECOVERED (WASTE AND SCRAP) PAPER OR PAPERBOARD; PAPER AND PAPERBOARD AND ARTICLES THEREOF
Capítulo: 47 Pulp of wood or of other fibrous cellulosic material; recovered (waste and scrap) paper or paperboard
Chapter 47


Pulp of wood or of other fibrous cellulosic material; recovered (waste and scrap) paper or paperboard

Note.

1.- For the purposes of heading 47.02, the expression “chemical wood pulp, dissolving grades”
means chemical wood pulp having by weight an insoluble fraction of 92% or more for soda or
sulphate wood pulp or of 88% or more for sulphite wood pulp after one hour in a caustic soda solution containing 18% sodium hydroxide (NaOH) at 20ºC, and for sulphite wood pulp an ash content that does not exceed 0.15% by weight.

GENERAL

The pulp of this Chapter consists essentially of cellulose fibres obtained from various vegetable materials, or from waste textiles of vegetable origin.



The most important pulp in international trade is wood pulp, termed "mechanical wood pulp", "chemical wood pulp", "semi-chemical wood pulp" or "chemi-mechanical pulp", according to its method of preparation. The woods mostly used are pine, spruce, poplar and aspen, but harder woods such as beech, chestnut, eucalyptus and certain tropical woods are also used.

Other materials used for making pulp include:

(1) Cotton linters.

(2) Recovered (waste and scrap) paper or paperboard.

(3) Rags (particularly cotton, linen or hemp) and other textile wastes such as old ropes.

(4) Straw, esparto, flax, ramie, jute, hemp, sisal, bagasse, bamboo and various other grasses and reeds.

Wood pulp may be brown or white. It may be semi-bleached or bleached by chemicals or may be unbleached. A pulp should be regarded as semi-bleached or bleached if, after manufacture, it has been subjected to any treatment intended to increase its degree of whiteness (brightness).

Apart from their use in the paper industry, some pulps (especially bleached pulps) serve as a source of cellulose in the manufacture of various products such as artificial textile materials, plastics, varnishes and explosives; they may also be used in cattle fodder.

Pulp is generally presented in baled sheets (whether or not perforated), wet or dry, but may sometimes be in slabs, in rolls or in the form of powder or flakes.

The Chapter does not cover:



(a) Cotton linters (heading 14.04).

(b) Synthetic paper pulps consisting of sheets of non-coherent polyethylene or polypropylene fibres (heading 39.20).

(c) Fibreboard (heading 44.11).

(d) Filter blocks, slabs or plates, of paper pulp (heading 48.12).

(e) Other articles of paper pulp (Chapter 48).

47.01 Mechanical wood pulp.

Mechanical wood pulp is obtained solely by a mechanical process i.e., by disintegrating or grinding wood, freed of its bark and sometimes of its knots, into its fibres by mechanical milling under a flow of water.

Milling without prior steam treating produces the so-called “white” mechanical wood pulp in which the fibres are broken and weakened. The wood may be steam treated before grinding, producing stronger fibres of brown colour (brown mechanical wood pulp).

Further development from the traditional grinding methods is the pulp referred to as refiner mechanical pulp where wood chips are shredded in a disc refiner by passing the chips between two closely spaced ridged plates, one or both of which may be rotating. One of the superior grades of this type of pulp is produced by refining wood chips after they have received preliminary heat treatment to soften them and allow an easier separation of the fibres with less fibre damage. The resultant pulp quality is superior to the traditional mechanical wood pulp.

Thus the main types of mechanical wood pulp are:

Stone groundwood (SGW) produced from roundwood or blocks in stone grinders at atmospheric pressure.

Pressurised stone groundwood (PGW) produced from roundwood or blocks in pressurised stone grinders.

Refiner mechanical pulp (RMP) produced from wood chips or wafers in refiners discharging at atmospheric pressure.

Thermo-mechanical pulp (TMP) produced from wood chips or wafers in refiners after high-pressure steaming of the wood.

It should be noted that some pulps produced in refiners may be chemically treated. Such pulps fall in heading 47.05.

Mechanical wood pulp is not generally used alone because the fibres are relatively short and would produce weak products. In paper-making it is more often mixed with chemical pulp. Newsprint is generally made from such a mixture (see Note 4 to Chapter 48).

47.02 Chemical wood pulp, dissolving grades.

This heading covers chemical wood pulp of dissolving grades only, as defined in Note 1 to this Chapter. This pulp is specially refined or purified to meet the requirements of its intended use. It is used for making regenerated cellulose, cellulose ethers and esters and products of these materials, such as plates, sheets, film, foil and strip, textile fibres and certain papers (e.g., paper of a kind used as a base for photosensitive paper, filter paper and vegetable parchment). According to the final use or to the end product, it is also called viscose pulp, acetate pulp, etc.

Chemical wood pulp is obtained by first reducing the wood to chips or particles which are then treated with chemicals. As a result of the treatment the greater part of the lignin and other non-cellulosic materials is removed.

The chemicals usually employed are sodium hydroxide (“soda” process), a mixture of sodium hydroxide and sodium sulphate, which is converted partly into sodium sulphide (“sulphate” process), calcium bisulphite or magnesium bisulphite, also known as calcium hydrogen sulphite or magnesium hydrogen sulphite respectively (“sulphite” process).

The product obtained is superior in fibre length and richer in cellulose than mechanical pulp made from the same raw material.

The manufacture of chemical wood pulp, dissolving grades, is achieved through extensive chemical and physiochemical reactions. In addition to whitening, its manufacture may require chemical purification, deresination, depolymerisation, ash reduction or adjustment of reactivity, most of which are combined in a complex bleaching and purification process.

47.03 Chemical wood pulp, soda or sulphate, other than dissolving grades.
Soda or sulphate pulps are produced by boiling the wood, usually in chipped form, in strongly alkaline solutions. For soda pulp the cooking liquor is a solution of sodium hydroxide; for sulphate pulp a modified sodium hydroxide solution is employed. The term “sulphate” came to be applied because sodium sulphate, part of which is converted into sodium sulphide, is used at a stage in the preparation of the cooking liquor. Sulphate pulp is by far the more important.

Pulps from these processes are used in the manufacture of absorbent products (such as fluffing and napkins for babies) as well as for papers and paperboards requiring high tearing resistance and tensile and bursting strength.

47.04 Chemical wood pulp, sulphite, other than dissolving grades.
The sulphite process generally employs an acid solution and takes its name from the various “sulphite” chemicals, such as calcium bisulphite (calcium hydrogen sulphite), magnesium bisulphite (magnesium hydrogen sulphite), sodium bisulphite (sodium hydrogen sulphite), ammonium bisulphite (ammonium hydrogen sulphite), which may be used during the preparation of the cooking liquor (see the Explanatory Note to heading 47.02). The solution also contains free sulphur dioxide. The process is used extensively for the treatment of spruce fibre.

Sulphite pulp is used, alone or mixed with other pulps, for various writing or printing papers, etc. It is also used, inter alia, for greaseproof or glazed transparent papers.

47.05 Wood pulp obtained by a combination of mechanical and chemical pulping processes.

This heading covers wood pulp manufactured by a combination of mechanical and chemical pulping processes. Such pulp is variously described as semi-chemical pulp, chemi-mechanical pulp, etc.

Semi-chemical pulp is produced in a two-part process in which the wood, generally in chips, is first chemically softened in digesters and then mechanically refined. It contains a great deal of impurities and ligneous matter and is used mainly for medium-quality papers. It is generally known as neutral sulphite semi-chemical (NSSC), bisulphite semi-chemical or kraft semi-chemical.

Chemi-mechanical pulp is produced in refiners from wood in chips, shavings, sawdust or similar forms. The wood is reduced to a fibrous state by the abrasive action induced by two closely spaced ridged plates or discs, one or both of which are rotating. Small amounts of chemicals are introduced as a pre-treatment or during refining in order to facilitate fibre separation. The wood may be subjected to steaming for different periods of time at different pressures and temperatures. Depending on the combination of processes employed in its manufacture, and the order in which the processes are carried out, chemi-mechanical pulp is also known as chemi-thermomechanical pulp (CTMP), chemi-refiner mechanical pulp (CRMP) or thermo chemi-mechanical pulp (TCMP).

Chemi-mechanical pulps are used, inter alia, in the production of newsprint (see Note 4 to Chapter 48). They are also used for making tissue and graphic paper.


The heading includes pulps known as screenings.



47.06 Pulps of fibres derived from recovered (waste and scrap) paper or paperboard or of other fibrous cellulosic material.
The important kinds of fibrous cellulosic material, other than wood, used for making pulps are mentioned in the General Explanatory Note.

Pulps of fibres derived from recovered (waste and scrap) paper or paperboard are usually presented in the form of dried, baled sheets and consist of heterogenous blends of cellulosic fibres. They may be bleached or unbleached. These pulps are obtained by a series of mechanical or chemical cleaning, screening and de-inking processes. Depending on the input material and the extent of the processing, they may contain small quantities of residues such as ink, clay, starch, polymer coatings or glues.

Pulps of this heading other than those derived from recovered (waste and scrap) paper or paperboard may be obtained by a mechanical process, a chemical process or a combination of mechanical and chemical processes.

47.07 Recovered (waste and scrap) paper or paperboard.


Waste of paper or paperboard covered by this heading includes shavings, cuttings, clippings, torn sheets, old newspapers and journals, proof-sheets, printers' rejects and similar material.

The heading also covers scrap articles of paper or paperboard.

Such waste and scrap is normally used for pulping and is often presented in compressed bales, but it should be noted that its possible use for other purposes (e.g., packing) does not exclude its classification in this heading.

Paper wool, however, even if manufactured from waste paper, is excluded (heading 48.23).
The heading also excludes waste and scrap of paper or paperboard, containing precious metal or precious metal compounds, of a kind used principally for the recovery of precious metal, e.g., waste and scrap photographic paper or paperboard containing silver or compounds thereof (heading 71.12).
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Subheading Explanatory Note.

Subheadings 4707.10, 4707.20 and 4707.30

Although, in principle, subheadings 4707.10, 4707.20 and 4707.30 cover sorted waste and scrap, classification in any one of these subheadings is not affected by the presence of small quantities of paper or paperboard of any other subheading of heading 47.07.

ULTIMO CAMBIO D.O.F.