Modified Ionomer Sheet Shortens Lamination Cycles in PV Manufacturing

DuPont Photovoltaic Solutions (DPVS) has announced commercialization of a new modified ionomer encapsulant sheet for use in photovoltaic (PV) 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 Ind. Ltd. Sharp Corp. 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 Photovoltaic Solutions

DuPont