Heading 4703 : 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.
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