Embossed fluid filter element

1. A fluid filter element comprising:

an embossed flat filter material which is folded so as to define a plurality of substantially adjacent walls, each wall defining a planar surface between two adjacent fold lines, said wall having an embossing comprising:

a first embossing row having a centrally located elongated positive embossment and a distal embossment at each end of the positive elongated embossment, wherein at least one distal embossment is negative; and

a second embossing row spaced from and parallel to the first embossing row, the second embossing row having two elongated embossments, wherein one elongated embossment is negative and one is positive, wherein the elongated embossment of the first row has a greater dimension along the first embossing row than transverse to the first embossing row and wherein the elongated embossments of the second row have a greater dimension along the second embossing row than transverse to the second embossing row, and wherein said first embossing row and said second embossing row define a straight diagonal line of embossing free filter material extending continuously between the fold lines, wherein spaces are defined along the first embossing row between the centrally located positive embossment and each of the distal embossments, wherein a space is defined along the second embossing row between the two elongated embossments, and wherein the spaces of the first embossing row and the space of the second embossing row which is adjacent to the first embossing row are not horizontally aligned with each other.

2. The filter element of claim 1 , wherein the second embossings are substantially uniformly spaced.

3. The filter element of claim 1 , wherein said walls define wall edges each having at least two fold lines.

4. The filter element of claim 1 , wherein said first embossing row and said second embossing row are formed in alternating sequence.

5. The filter element of claim 1 , wherein said first embossing row further comprises a plurality of centrally located elongated embossment selected from the group consisting of positive embossment, negative embossment and combinations thereof.

6. The filter element of claim 1 , wherein the elongated embossment of the first row has the same length as the elongated embossments of the second row.

7. The filter element of claim 1 , wherein the spaces of the first embossing row and the space of the second embossing row which is adjacent to the embossing row are aligned with each other along a line which is diagonal to the first and second embossing rows.

8. A fluid filter element comprising:

an embossed flat filter material which is folded so as to define a plurality of substantially adjacent walls, each wall defining a planar surface between two adjacent fold lines, said wall having an embossing comprising:

a first embossing row having at least two elongated embossments including at least one positive embossment and at least one negative embossment and a space between the at least two elongated embossments, wherein the elongated embossments have a greater dimension along the first embossing row than transverse to the first embossing row; and

a second embossing row spaced from and parallel to the first embossing row, the second embossing row having at least two elongated embossments, including at least one positive elongated embossment and at least one negative elongated embossment and a space between the at least two elongated embossments; wherein the elongated embossments of the second embossing row have a greater dimension along the second embossing row than transverse to the second embossing row, and wherein said first embossing row and said second embossing row define a straight diagonal line of embossing free filter material which extends continually between the side edges, and wherein the space of the first embossing row and the space of the second embossing row which is adjacent to the first embossing row are not horizontally aligned with each other.