| 摘要 |
<p>A diesel soot particulate filter medium as subject of the present invention has an inflow side and an outflow side, and comprises at least n consecutive layers Lx of fiber media, x varying from 1 to n, n being more than 2. L1 provides the inflow side of the diesel soot particulate filter and Ln provides the outflow side of the diesel soot particulate filter medium. Each layer Lx has a porosity Px. All layers Lx, for which 1=x=n-1, have a substantially equal porosity to Ph, layer Ln having a porosity Ps, Ph being larger than Ps. Also according to the present invention, a diesel soot particulate filter medium comprises at least n consecutive layers Lx of fiber media, x varying between 1 and n, n being more than 3. L1 provides the inflow side of the diesel soot particulate filter and Ln provides the outflow side of the diesel soot particulate filter medium. For at least m layers LX<SUB>i</SUB>, 1=i=m, m being at least 1 and m being less than n/2, Lx<SUB>i</SUB> being different from Ln and LX<SUB>i</SUB> being different from L1 , PX<SUB>i</SUB> is smaller than its neighboring layers.</p> |
