浆网速变化对纸张物理性能的影响

The Effect of Speeds of Jet and Wire on the Physical Properties of Paper Sheets Forming in a Dynamic Sheet Former

采用动态纸张成形器在不同浆网速条件下抄造纸张,利用抗张挺度取向(TSO)测试仪对纸张的TSO性能参数进行测定,同时检测纸张的紧度、透气度和抗张强度等指标,考察浆网速变化对成纸纵横向物理性能的影响。结果表明,随着网速的增加,纸张的纵向抗张挺度指数(TSIMD)和纵横向抗张挺度指数比(TSIMD/CD)增大,横向抗张挺度指数(TSICD)减小;浆速提高的情况下TSI变化规律与网速增加时相反;抗张强度变化趋势与TSI变化趋势相一致。随着网速的增加,纸张的紧度增大,透气度降低;改变浆速,纸张紧度和透气度变化规律不明显。纸张的匀度随着浆网速差的增加而提高。

The dynamic sheet former was used to form paper sheets with different jet and wire speeds. The TSO properties of the paper sheets were measured using TSO tester and the apparent density,air permeability and tensile index were determined to study the influence of a change in jet and wire speeds on physical properties both in machine direction（ MD） and cross-machine drection（ CD） of paper sheets. The results showed that the TSIMD（ MD tensile stiffness index） and TSIMD / CDincreased while the TSICDdecreased with the wire speed increasing,however TSI changed in opposite direction with increasing the jet speed. The tensile strength of paper sheets coincided with the TSI results when changing jet and wire speeds. The apparent density increased slightly and the air permeability greatly reduced as the wire speed increased but the changes were not obvious with changing jet speed. Formation of paper sheets improved with increasing the difference of jet and wire speeds.