Method and apparatus for forming filter element

An apparatus for bending and cutting a tape-like material, comprising:

• two pairs of forming and cutting rollers each having a plurality of circumferentially spaced concave and convex portions at an outer surface thereof for bending said tape-like material to a corrugated shape having successive bends at gradually varying distances from one another along the material defining a pitch and a gradually varied amplitude, while said tape-like material is passed between said pairs of forming and cutting rollers, said gradually varied amplitude defining maximum and minimum amplitudes of said corrugated material,
• a first pair of cutters positioned in said first pair of forming and cutting rollers for cutting a predetermined portion of the material along an axial direction thereof and a predetermined part of the material along the width thereof, and
• a second pair of cutters positioned in said second pair of forming and cutting rollers for cutting the same portion of the material along the longitudinal direction where said first pair of cutters cut and the remaining part of the width of the material so that the material is separated by the second pair of cutters.

An apparatus for bending and cutting a tape-like material, comprising:

• at least one pair of forming and cutting rollers for forming and cutting the tape-like material having an outer surface with a plurality of circumferentially spaced concave and convex portions, adjacent pairs of said concave and convex portions defining a roller surface corresponding to the corrugated portions to be formed from a tape-like material, said rollers bending said tape-like material to a corrugated shape having successive bends at gradually varying distances from one another along the material to define gradually varying material amplitudes and a material pitch corresponding to the outer surface of said rollers, each of said forming and cutting rollers including an annular groove formed in the outer surface thereof, and
• a guide plate provided between adjacent forming and cutting rollers for guiding the material, a pair of said guide plate being received in said annular groove.