Method and apparatus for winding a filter media pack

A method for forming a filter element having a coiled web of fluted filter media, wherein the web of fluted filter media is fed in a feed direction along a feed path to the mandrel, and the fluted filter media includes a plurality of flutes forming alternating peaks and valleys extending transverse to the feed direction and defining a pitch of the web, the method comprising:

• feeding the web of fluted filter media at a controlled, but not necessarily constant, linear speed onto a mandrel rotated by a winding motor providing a controlled, but not necessarily constant, driving torque to the mandrel, to thereby maintain a controlled, but not necessarily constant, tension on the web of fluted filter media as the web is wound onto the mandrel;
• feeding out a length of the web in the feed direction;
• severing the web a first time, by cutting through the web at one of the peaks of the fluted filter material using a cutter disposed at a fixed location along the feed path, with respect to the mandrel, to form a leading edge of the web;
• attaching the leading edge of the web to the mandrel;
• while driving the mandrel with a controlled driving torque, feeding out a length of web equal to an integer multiple of the pitch of the web;
• severing the web a second time, by cutting through the web at a peak of the fluted filter material using the cutter disposed at the fixed location along the feed path, with respect to the mandrel, to form a trailing edge of the web;
• prior to severing the web the second time, feeding out a length of web past the cutter including an over-feed distance from the cutter in the feed direction, with the over-feed distance being equal to an integer multiple of the pitch of the web;
• and
• drawing the web back past the cutter a distance equal to the over-feed distance, prior to severing the web the second time with the cutter.

An apparatus for forming a filter element having a coiled web of fluted filter media, the fluted filter media includes a plurality of flutes forming alternating peaks and valleys extending transverse to a feed direction and defining a pitch of the web wherein the apparatus comprising:

• a mandrel mounted for rotation about an axis of the mandrel;
• a web feeder for feeding the web of fluted filter media at a controlled linear speed onto the mandrel in the feed direction along a feed path to the mandrel;
• a winding motor operatively connected to the mandrel for providing a controlled driving torque to the mandrel, to thereby maintain a controlled tension on the web of fluted filter media as the web is wound onto the mandrel;
• a cutter disposed along the feed path between the feeder and the mandrel, for severing the web a first time by cutting through the web at one of the peaks of the fluted filter media to form a leading edge of the web, with the cutter being disposed at a fixed location along the feed direction, with respect to the mandrel;
• a controller operatively connected to the feeder, the cutter and the winding motor for controlling the feeder, cutter and winding motor in such a manner that, after the leading edge of the web is attached to the mandrel and the feeder feeds out a length of web equal to an integer multiple of the pitch of the web including an over-feed distance from the cutter in the feed direction, with the over-feed distance being equal to an integer multiple of the pitch of the web, while the winding motor drives the mandrel at a controlled driving torque, the cutter severs the web a second time by cutting through the web at a peak of the fluted filter media to form a trailing edge of the web;
• and
• an applicator for applying an adhesive sealant to the web at a point located along the feed path between the cutter and the mandrel and spaced beyond the over-feed distance.