Ferroelectric dual and multiple layer compound and method for its manufacture

摘要

Making two-layer ferroelectret (3) or multi-layer ferroelectret with voids involves: introducing clearance (4a) into one surface side of polymer film element (1) using removal method; applying first covering (2) to the surface side of the element comprising clearances; and joining the element and covering to form polymer film composite. The clearances are closed while voids are formed with the proviso that with two- or multi-layer ferroelectret excludes three-layer ferroelectrets with a perforated middle layer made of polytetrafluoroethylene between two fluoroethylene propylene layers. Producing a two-layer ferroelectret (3) or multi-layer ferroelectret with voids involves: a) introducing at least one clearance (4a) into at least one surface side of a polymer film element (1) using a method of removal; b) applying a first covering (2) to the surface side of the polymer film element comprising clearances formed in step (a); and c) joining the polymer film element and the covering to form a polymer film composite. The clearances are closed while voids are formed with the proviso that with the two- or multi-layer ferroelectret excludes three-layer ferroelectrets with a perforated middle layer made of polytetrafluoroethylene (PTFE) between two fluoroethylene propylene (FEP) layers. Independent claims are included for the following: (1) a two- or multi-layer ferroelectret with voids comprising at least a first polymer film element with at least one surface side comprising clearances, and at least a first covering, where the covering is arranged on a first surface side of the polymer film element comprising clearances, and the clearances are closed by the covering while voids are formed, with the proviso that with the two- or multi-layer ferroelectret excludes three-layer ferroelectrets with a perforated middle layer made of PTFE between two FEP layers; and (2) a piezoelectric element containing a two- or multi-layer ferroelectret, where the polymer film element and/or the covering comprise at least two polymer films joined to one another.