Improved Tunnel Resistance of Silvered-Polymer Mirrors

This report documents the research performed at the Solar Energy Research Institute (SERI) during fiscal year 1991 to develop ways to prevent delamination failure (known as tunneling) of silvered-polymer reflector materials. Several promising approaches have been identified and demonstrated that substantially reduce such failures. These approaches include (1) use of Tedlar edge tape rather thanthe recommended ECP-244 tape, (2) thermal treatment of laminated reflector/substrate constructions, and (3) application of silver to the polymer film through an alternative deposition process. Approaches 1 and 2 offer readily available engineering solutions to the delamination problem. Approaches 2 and 3 provide tunnel resistance over the entire surface of the reflector material, including theedges.