Sha Lizheng

Application of computer image processing techniques on the research of silk air filter paper

Computer image processing techniques were used to analyse the flocculation of silk fibers and the formation of paper, and to provide a basis for the improvement of the processing technology of silk air filter paper. The results showed that there was a good corresponding relationships between the flocculation characteristics of silk fibers and the formation, the pore size distribution and the air permeability of its paper. When the beating degree was 300SR, the flocculation of silk pulp was severe, and the formation of its paper was very poor, the minimum pore size area of its paper was 7.41 ∼9.11µm, and the pore size and the air permeability of its paper was very large. With the increase of the beating degree, the flocculation of silk pulp decreased, and the formation of its paper was improved and its pore size decreased. When the beating degree of silk pulp reached 500SR, the minimum pore size area of its paper was 2.21∼2.82µm, and the proportion of pores size ranging from 2.21 to 6.36µm was 98.53%, the pore size distribution of its paper was better, and the air permeability of its paper decreased,but it could still meet with the requirements of air filter paper.

Notice of Retraction Study of CPAM/ bentonite microparticle retention system on reducing pollution load of papermaking white water

In order to investigate the effects of CPAM/bentonite microparticle retention system on reducing pollution load of papermaking white water, the dynamic drainage jar was used to simulate the wet end of low grammage fresh-keeping case board production. The turbidity and CODcr of the filtrate were measured to express the pollution load of white water. Results showed that the turbidity and CODcr of white water in CPAM/bentonite microparticle retention system were similar to that in CPAM monocomponent system when CPAM dosage was less than 0.02%, and that the CPAM/bentonite microparticle retention system had no significant retention effects unless the dosage of CPAM was larger than 0.02%. The turbidity and CODcr of white water in CPAM/bentonite microparticle retention system reached the minimum value when the dosage of CPAM and bentonite were 0.04% and 0.2%, respectively. The stir speed should be controlled below 750 rpm in the case of CPAM and bentonite were added into pulp suspension, otherwise, the formed flocs could be destroyed, which resulting in higher turbidity and CODcr of white water.