Press polishing and laminating plastic transparencies using polycarbonate pressing plates

Abstract

This invention relates to press polishing transparencies for lightweight aircraft comprising at least one exterior sheet of acrylic resin involving the use of a polycarbonate pressing plate against the acrylic resin sheet. Both the polycarbonate pressing plate and as many sheets of acrylic resin as are included in the laminate may be press polished while flat by pressurized engagement against a smoothly surfaced flat glass pressing mold. Then, the polycarbonate pressing plate and as many sheets of acrylic resin as are included in the transparency are sag bent to conforming shapes with optional vacuum forming. The polycarbonate pressing plate so shaped is used directly against an acrylic resin surface without any parting material therebetween to press polish the outward facing surface of the acrylic resin sheet(s) so shaped and simultaneously laminate the shaped acrylic resin sheets when the latter are assembled with one or more layers of flexible interlayer material. Certain acrylic resin sheets may be further treated, by embedding wire and/or fusing them together, prior to the press polishing while flat.

Dependencies are inferred from the claim text.