中浓压力筛筛鼓缝宽对烟草基片浆料分布及其物理性能的影响

Effect of Slot Width of Medium-Consistency Pressure Screen on Distribution of Tobacco Pulp and Properties of Tobacco Sheet

关键词:  烟草基片  中浓压力筛  浆料筛分  松厚度  抗张指数  柔软度

Key Words:tobacco sheet  medium-consistency pressure screen  slurry screening  bulk  tensile index  softness

摘要:为了分析不同筛鼓缝宽对烟草基片浆料分布和其物理性能的影响，采用中浓压力筛对烟草基片浆料进行处理，观察烟草基片筛前浆料、筛后良浆和尾浆的纤维组分分布，并分别检测其基片松厚度、抗张指数等物理性能。结果表明，与筛前浆料相比，筛后良浆16目以下组分占比明显降低，200目以上组分占比明显增加，纤维分布更加集中、均匀；筛后浆料基片的柔软性能有较大改善，松厚度有所提高，但抗张指数、撕裂指数分别下降。与旧筛（0.55 mm缝宽）相比，增大压力筛筛缝宽度后，筛后良浆纤维组分并未出现明显变化，但筛后浆料基片松厚度相比筛前基片提高了4.55%，大于采用旧筛时基片松厚度的提高幅度1.33%。尾浆纤维组分主要集中在16目以下范围，占比可达50%。尾浆基片松厚度优于筛前和筛后基片，但伸长率和柔软性能较差，抗张指数及撕裂指数与筛后基片相近，但低于筛前基片。

Abstract:The tobacco pulp was treated with a medium-consistency pressure screen to observe the distribution of the fiber fractions of pre-screen slurry，accepted stock and the tailings. At the same time，physical properties such as bulk and tensile index of the tobacco sheet were tested to analyze the effects of different screen slot widths on physical properties of the sheet. The experimental results showed that the fraction below 16 mesh after screening was significantly reduced，and the fractions above 200 mesh was significantly increased，so the fiber distribution was more uniform compared with the pre-screen slurry.The softness and bulk of the accepted stock sheet were improved，but the tensile index and tear index were decreased. When using the new screen with wider slot，the fiber fraction of the accepted stock did not show a significant change，but the bulk of the tobacco sheet was increased by 4.55% compared with the pre-screen sheet，indicating better results compared with the former screen (only 1.33% increase in bulk) .The tailings fraction mainly concentrated in the range below 16 mesh，accounting for up to 50%.The bulk of the sheet of tailings was the best compared to the pre-screen slurry and accepted stock，however its elongation and softness were relatively poor. Meanwhile，the tensile index and tear index of the sheet were similar to the sheet of accepted pulp but lower than the sheet of pre-screen pulp.