Ceramic microsieves: influence of perforation shape and distribution on flow resistance and membrane strength

Ceramic microsieves with slit-shaped perforations were compared to sieves w ith circular-shaped perforations, regarding flow resistance and membrane st rength. Destructive tests show that the highest strength is obtained if the perforations are placed in a non-alternating pattern. Especially for slits , alternating patterns should be avoided as they make the structure unneces sarily flexible. The highest stress occurs at the edges of the membrane whe re it is attached to the support. Flexible structures bend stronger and the refore cause a higher stress at the edge, resulting in an easier rupture of the membrane. Our results show that ceramic microsieves with slits show a four to five-fold decrease in flow resistance for comparable strength relat ed to sieves with circular pores. (C) 2002 Published by Elsevier Science B. V.