不同粒径女贞子粉体的吸湿性研究

Study on moisture absorption of different particle sizes of Fructus Ligustri Lucidi powder

考察不同粒径女贞子吸湿性变化。在25℃、相对湿度为75%条件下测定女贞子粉体的吸湿百分率,并采用数学模型对其吸湿性变化进行拟合,同时根据不同湿度下的吸湿平衡曲线测定其临界相对湿度。结果表明,女贞子粉体目数增大,吸湿速率加快,24目与50目粉体、80目与100目粉体差异不显著,各目数女贞子粉体在8 h后吸湿百分率急剧增加,约在72 h达到吸湿平衡;威布尔或Ritger-Pappas数学模型能较好地拟合女贞子粉体的吸湿变化。24目、50目、65目、80目、100目女贞子粉体的临界相对湿度依次减小,分别为69.3%、68.7%、68.0%、67.6%、67.2%、。该结果为女贞子粉体目数、生产与储存环境湿度的选择提供了试验依据。

In order to investigate moisture absorption of different particlesizes of Fructus Ligustri Lucidi, the moisture absorptionpercentage was determined at 25 -C and relative humidity of 75%, and the relationship between the moisture absorption percentage and time was showed by constructing mathematical model. The critical relative humidity of different particle sizes of Fructus Ligustri Ltlcidi was determined according to its moisture absorbent equilibrium curves under different relative humidity. The resuhs indicated thal the moisture absorption rate of different sizes of Fructus Ligtatri Lucidi increased with mesh, but the differences between 24 mesh and 50 mesh, and between 80 mesh and 100 mesh were not significant. The moisture absorption percentage of diffc, rent sizes of Fructta Ligustri Ltzcidi powder increased rapidly 8 h later, and moisture absorbent equilibrium was achieved 72 h later. Weibull distribution or Ritger-Pappas mathematical model was appropriate for it. The critical relative humidity of 24 mesh, 50 mesh, 65 mesh, 80 mesh and 100 mesh of Fructus Ligustri Lucidi powder was 69.3%, 68.7%, 68.0%, 67.6%and 67.2%, respectively. It laid an experimental foundation for choosing mesh, production and storage humidity of different particlesizes of Fructus Ligustri Lucidi powder.