Treatment of high pH in a Pulp Bleaching sequence to produce Pulp that has a low G.P. and a low number of Copper, for use in the manufacture of Lyocell

摘要

A process of high pH and low pH to reduce the polymerization degree of Pulp that has a hemicellulose content of at least 7%. High pH is higher than 8, and the low pH is 2 to 8. The process of high pH reduces the degree of polymerization without substantially increasing the number of Copper.The process of low pH requires a subsequent Treatment with Alkali to reduce the number of Copper of the Pulp is less than 2. The process can be implemented in plants with a Pulp Bleaching Sequence that has one or more stages and D. at the end of the Bleaching sequence, it provides a Pulp that has a degree of polymerization of 200 to 1.Copper 100, a Number less than 2, and hemicellulose content of at least 7%. The Pulp can be used for Lyocell fibres.