The invention relates to a method of creasing sheets (12) by using a creasing tool (14, 20, 21) cooperating with a counter element (22, 23), comprising the following steps: a creasing plate blank (24′) is provided with at least one creasing projection (26) by plastically deforming the material of the blank (24′) so as to form a creasing plate (24), the creasing plate (24) is mounted to a creasing tool (14, 20, 21), sheets (12) to be provided with at least one crease are advanced through a gap between the creasing tool (14, 20, 21) and the counter element (22, 23).

An apparatus for introducing transverse trapezoidal corrugations into a traveling web is provided, and includes a plurality of corrugating rollers for imparting corrugations to the web. In disclosed embodiments four such rollers are provided in a roller train defining respective first, second and third nips therebetween, wherein the teeth of the first and second rollers have rounded distal faces and those of the third and fourth rollers have flattened distal faces. Methods of yielding a trapezoidal corrugated web also are disclosed.

There is provided a system 1 of manufacturing a corrugated board, including: a corrugated-shape processing apparatus 4 for processing a board in a corrugated shape by curving the board; a shaping apparatus 5 for adjusting a corrugated board acquired by processing the board in a corrugated shape; and a stabilizing apparatus 6 for stabilizing the corrugated board being shaped in the corrugated shape, the corrugated-shape processing apparatus 4 including a first pressing jig 25 and a second pressing jig 27 each of which is in a roller-like shape provided on its surface with asperities to press a board into a corrugated board, being disposed facing each other, the shaping apparatus 5 including: a third pressing jig 45 and a fourth pressing jig 48 each of which has a surface with asperities in which a distance between adjacent apexes of the asperities is substantially identical to that of a surface with asperities of the corrugated board; and a heater 59, the stabilizing apparatus 6 including a fifth pressing jig 65 and a sixth pressing jig 68 each of which has a surface with asperities in which a distance between adjacent apexes of the asperities is substantially identical to that of a surface with asperities of the corrugated board after the heat-press process; and a cooling unit 69. As a result, a single board can be processed in a corrugated shape and a state of the corrugated shape can be maintained.

There is provided a system 1 of manufacturing a corrugated board, including: a corrugated-shape processing apparatus 4 for processing a board in a corrugated shape by curving the board; a shaping apparatus 5 for adjusting a corrugated board acquired by processing the board in a corrugated shape; and a stabilizing apparatus 6 for stabilizing the corrugated board being shaped in the corrugated shape, the corrugated-shape processing apparatus 4 including a first pressing jig 25 and a second pressing jig 27 each of which is in a roller-like shape provided on its surface with asperities to press a board into a corrugated board, being disposed facing each other, the shaping apparatus 5 including: a third pressing jig 45 and a fourth pressing jig 48 each of which has a surface with asperities in which a distance between adjacent apexes of the asperities is substantially identical to that of a surface with asperities of the corrugated board; and a heater 59, the stabilizing apparatus 6 including a fifth pressing jig 65 and a sixth pressing jig 68 each of which has a surface with asperities in which a distance between adjacent apexes of the asperities is substantially identical to that of a surface with asperities of the corrugated board after the heat-press process; and a cooling unit 69. As a result, a single board can be processed in a corrugated shape and a state of the corrugated shape can be maintained.

An apparatus for introducing transverse trapezoidal corrugations into a traveling web is provided, and includes a plurality of corrugating rollers for imparting corrugations to the web. In disclosed embodiments four such rollers are provided in a roller train defining respective first, second and third nips therebetween, wherein the teeth of the first and second rollers have rounded distal faces and those of the third and fourth rollers have flattened distal faces. Methods of yielding a trapezoidal corrugated web also are disclosed.

An apparatus for introducing transverse trapezoidal corrugations into a traveling web is provided, and includes a plurality of corrugating rollers for imparting corrugations to the web. In disclosed embodiments four such rollers are provided in a roller train defining respective first, second and third nips therebetween, wherein the teeth of the first and second rollers have rounded distal faces and those of the third and fourth rollers have flattened distal faces. Methods of yielding a trapezoidal corrugated web also are disclosed.

An apparatus is usable to manufacture a filter. The apparatus includes a pleats-forming unit, a first belt part, a second belt part, and a controller. The pleats-forming unit delivers a filter substrate in a first direction and then successively folds the filter substrate into alternate mountains and valleys. The first belt part is disposed downstream of the pleats-forming unit in the first direction. The first belt part contacts with the mountains and valleys of the filter substrate to compress the mountains and valleys of the filter substrate in the first direction. The second belt part is disposed downstream of the first belt part in the first direction. The second belt part pulls the mountains and valleys of the filter substrate in the first direction to form a predetermined pitch between each adjacent pair of the mountains or valleys. The control unit controls a traveling speed of the second belt part.

An apparatus is usable to manufacture a filter. The apparatus includes a pleats-forming unit, a first belt part, a second belt part, and a controller. The pleats-forming unit delivers a filter substrate in a first direction and then successively folds the filter substrate into alternate mountains and valleys. The first belt part is disposed downstream of the pleats-forming unit in the first direction. The first belt part contacts with the mountains and valleys of the filter substrate to compress the mountains and valleys of the filter substrate in the first direction. The second belt part is disposed downstream of the first belt part in the first direction. The second belt part pulls the mountains and valleys of the filter substrate in the first direction to form a predetermined pitch between each adjacent pair of the mountains or valleys. The control unit controls a traveling speed of the second belt part.

An apparatus for introducing transverse trapezoidal corrugations into a traveling web is provided, and includes a plurality of corrugating rollers for imparting corrugations to the web. In disclosed embodiments four such rollers are provided in a roller train defining respective first, second and third nips therebetween, wherein the teeth of the first and second rollers have rounded distal faces and those of the third and fourth rollers have flattened distal faces. Methods of yielding a trapezoidal corrugated web also are disclosed.