Abstract: Laminated safety glass panels comprising sheets of rigid transparent material, such as glass, polycarbonate, acrylic plastic, polyester and the like, alternating with interlayer materials, such as polyvinyl butyral, polyurethane and the like, are prepressed to remove entrapped air at the interfacial surfaces to prepare the assemblies for final lamination. When the relatively rigid plies to be laminated have unsmooth surfaces, such as wavy surfaces, or surfaces having imperfections due to the penetration of the sheet during thermal treatment by tongs or other solid members that engage the rigid transparent sheet during its heat treatment prior to assembly for lamination, the preliminary pressing performed by the prior art techniques is insufficient to prevent oil from an oil autoclave used in the final laminating step from penetrating into the interfacial surfaces between adjacent rigid and relatively flexible layers of the assembly to be laminated.

Abstract: Laminated safety glass panels comprising sheets of rigid transparent material, such as glass, polycarbonate, acrylic plastic, polyester and the like, alternating with interlayer materials, such as polyvinyl butyral, polyurethane and the like, are prepressed to remove entrapped air at the interfacial surfaces to prepare the assemblies for final lamination. When the relatively rigid plies to be laminated have unsmooth surfaces, such as wavy surfaces, or surfaces having imperfections due to the penetration of the sheet during thermal treatment by tongs or other solid members that engage the rigid transparent sheet during its heat treatment prior to assembly for lamination, the preliminary pressing as performed by the prior art techniques is insufficient to prevent oil from an oil autoclave used in the final laminating step from penetrating into the interfacial surfaces between adjacent rigid and relatively flexible layers of the assembly to be laminated.