Product Announcement from Wacker Chemical Corp.
ELASTOSIL® Solar 2200 is a two-component liquid silicone rubber which vulcanizes to form a transparent silicone elastomer. The silicone contains adhesion-promoting additives which ensure optimum bonding to all substrates typically used in the manufacture of thin-film modules. As a result, it readily bonds to glass and flexible films made from a variety of materials including aluminum, polyethylene terephthalate (PET), polyethylene naphthalate (PEN) or activated ethylene tetrafluoroethylene copolymer (ETFE) without the need for a primer.
The rubber system has been specially formulated to provide a long pot life at room temperature, combined with rapid vulcanization when heat is applied. The reactivity range of this new encapsulant allows module manufacturers to produce flexible modules cost-effectively using continuous roll-to-roll processing techniques which are more familiar in the textile and paper industry. This type of roll lamination permits application of the silicone encapsulant, feed of the front film and vulcanization of the silicone rubber to be performed in a single, continuous, automated process. ELASTOSIL® Solar 2200 may be applied to the film to be laminated with the aid of a doctor blade or transfer roller.
In its cured state, the silicone elastomer bonds the composite layers into a stable laminate and provides the thin-film modules with an effective moisture barrier. ELASTOSIL® Solar 2200 is electrically insulating, permanently flexible across a temperature range from -50 to +200 °C and virtually chemically inert. Furthermore, the vulcanized silicone is extremely resistant to weathering and UV radiation, so there is no risk of yellowing, and it does not release any corrosive substances.
As a leading supplier of raw materials, WACKER has been an important partner of the solar industry for many years. In addition to hyperpure polysilicon, the starting material for crystalline solar cells, the Munich-based chemical company also produces silicones which are used as potting materials, adhesives and sealants or encapsulants in solar cells and modules.