Process for producing filters, for example for automatic gearboxes (transmissions)

摘要

For producing the filter comprising two housing half-shells and a disc-shaped filter medium, fastened in a sealing manner between the half-shells, the filter medium, whose edge is encapsulated by a reinforcing frame of a thermoplastic material, is positioned between the moved-apart mould halves of a blow mould and two sheets which consist of the same thermoplastic material as the reinforcing frame and have been brought into a plastically deformable state by blow moulding are placed against the mould halves of the opened blow mould and cover the mould cavities of the two mould halves. Together with the closing of the blow mould, the application of reduced pressure to the mould cavities causes the two sheets to be sucked into the mould cavities while undergoing plastic deformation and the edges of the two sheets, brought together in the closed blow mould, are bonded to each other and also to the reinforcing frame lying between them in a sealed and secured manner by thermoplastic fusion.