Evaluation on Stability of Threshing and Redrying Lamina Structure Based on Grey Statistic Analysis

In order to explore the stability of lamina structure of threshing and redrying,eleven structure indexes of 295 samples from twenty tobacco redrying factories were analyzed by grey statistic analysis method.The results showed that percentage of middle lamina(12.7-25.4 mm) and percentage of small lamina(6.35-12.7 mm) belonged to unstable indexes,which most deviated from the target requirement.Dust rate and crude stem rate and the content of long particle(12.7 mm) and the percentage of lamina(6.35 mm) and the percentage of lamina(3.18 mm) belonged to slightly stable indexes and more deviated from the target requirement.The variation of moisture content and percentage of large lamina(25.4 mm) and fine particle content(1-6.35 mm) and stem content in lamina were stable,which accorded with requirements.The grey statistical coefficient was tested by Variance Analysis,thus the indexes threshold value should be reasonable.The percentage of middle lamina should be improved and percentage of small lamina should be decreased mainly and the slightly stable indexes should be paid attention to and the stable indexes should be continued for quality evaluation and process control.