己烯糖醛酸对麦草浆ECF漂白的影响

The effect of HexA on wheat pulp ECF bleaching

己烯糖醛酸(HexA)在不同纸浆中含量不同,它容易与二氧化氯漂白剂发生反应,影响二氧化氯漂白效果。可以用酸水解处理纸浆减少HexA的含量,提高二氧化氯的漂白效率。酸处理的最佳工艺条件:pH值3～4,温度80℃左右,时间60min。HexA的脱去不仅能够增加纸浆的白度,而且提高白度的稳定性,纸浆的白度提高2%ISO,返黄值降低0.1个单位。

The content of 4-deoxy-β-L-thero-hex-4enopyranosyluronic acid（HexA） varies in pulps from different raw materials, it can react with chlorine dioxide easily, and influence bleaching effect.Acid can be used to reduce the content of HexA by acid hydrolysis of pretreated pulps.Acid pretreatment can reduce the content of HexA, and improve the efficiency of chlorine dioxide in bleaching.The best conditions of acid treatment are as follow：pH 3～4, temperature about 80℃, time 60min.Removal of the HexA can improve the brightness and brightness stability.With the increasing of removal ratio, the degree of the brightness increases, and the degree of color reversion changes smaller, with the brightness degree increased about 2%ISO, and the P.C.value decreased about 0.1 units.