Modified Ionomer Sheet Provides Superior Backsheet Adhesion and Lamination Cycle Time for Thin Film Photovoltaic Modules

DuPont Photovoltaic Solutions (DPVS) announces commercialization of a new modified ionomer encapsulant sheet for use in photovoltaic module manufacturing. The new encapsulant material, branded as Himilan® ES sheet in Japan and as DuPont™ PV8600 Series encapsulant for the rest of the world, was developed for amorphous silicon and other thin film module technologies.

Unlike traditional ethylene vinyl acetate (EVA) encapsulants, this new offering needs no cure step, resulting in shorter lamination cycles and increased productivity - helping reduce module cost. It also offers increased moisture resistance for improved long-term module reliability.

"Ionomer-based sheets are fundamentally more resistant to moisture intrusion, current leakage and discoloring," said Steve Cluff, global business director - DuPont Encapsulants. "Their use in glass-glass module designs is well-established, but adhesion to polymer-based backsheets, such as DuPont™ Tedlar® and PET, required modifications that we've introduced in the new DuPont™ PV8600 Series sheets."

The new encapsulant technology was developed by DuPont-Mitsui Polychemical, a joint venture between DuPont and Mitsui Petrochemicals Industries, Ltd. Sharp Corporation, one of the world's largest solar panel manufacturers, is using the new DuPont encapsulant in thin-film solar cell modules produced at their solar cell plant in Sakai, Osaka, Japan.

The DuPont™ PV8600 Series sheets require no refrigeration or interleafing to prevent blocking, and their stiffer modulus is well-suited to high-speed automated manufacturing. Melt flow and excellent sealing characteristics of the ionomer help protect sensitive electronic components, bus-bars and interconnects during lamination. The ionomer sheet's post-melt toughness, stiffness, cut resistance and moisture resistance versus EVA also helps protect finished modules during final module production, installation and operation. By offering the potential to eliminate edge seals, the sheet gives manufacturers further ways to save manufacturing time and reduce costs. Outside of Japan, this material will be available for customer evaluation later in 2010.

DuPont™ PV8600 Series modified ionomer encapsulant is the latest in a broad and growing portfolio of products represented by DuPont Photovoltaic Solutions, which connects science and technology from across the company on a global scale to help support the dramatic growth in the photovoltaic industry. To learn more, please visit http://photovoltaics.dupont.com.

DuPont (www.dupont.com) is a science-based products and services company. Founded in 1802, DuPont puts science to work by creating sustainable solutions essential to a better, safer, healthier life for people everywhere. Operating in more than 90 countries, DuPont offers a wide range of innovative products and services for markets including agriculture and food; building and construction; communications; and transportation.