Pleated filter and method and apparatus for fabricating same

摘要

A filter for separating constituent components of fluids includes a plural-layer sheet-like member which is multiply pleated to provide layers of the same or different porosity or to provide structural support layers for pleating a soft or membrane-like filter layer. The multiple layers may be pre-joined or delivered from individual locations to a pneumatic conveyor passage of predetermined cross-section through which the adjacent layers are conveyed by a conveyor gas. The layers are crimped to form pleats by withdrawing the material at a lower linear speed than that at which it is supplied to the passage. Pleating is facilitated by venting the conveyor gas at a passage section of enlarged cross-section. The pleating material is subjected to a hot gas, such as steam, and then cooled by a cooling gas to effect bonding of the layers in the pleated state.