A method of manufacturing a filter comprises the steps of assembling multiple layers of filtration material on top of one another to form an assembly; holding the assembly between an ultrasonic weld horn and a weld nest so that the assembly has a marginal area outside of an edge formed on either the nest or the weld horn; and operating the weld horn so as to cause the marginal area to be cut off from the assembly at the edge and to simultaneously seal together the layers of filtration material of the remaining assembly at the edge. A filter made by the process and an apparatus used to practice the process are also disclosed.