ELASTOSIL® SOLAR 2205

Encapsulation

• Potting agent for the pv industry
• Encapsulation of electronic components (e.g. Junction boxes or power inverters).
• Encapsulation of solar cells
• Lamination of solar modules

Processing

Surface preparation:

All surfaces must be clean and free of contaminants that will inhibit the cure of ELASTOSIL® SOLAR 2205. Examples of inhibiting contaminants are sulfur containing materials, plasticizers, urethanes, amine containing materials and organometallic compounds – especially organotin compounds. If a substrate’s ability to inhibit cure is unknown, a small scale test should be run to determine compatibility.

Mixing:

• ELASTOSIL® SOLAR 2205 is processed with ELASTOSIL® CAT PT, ELASTOSIL® CAT PT-F or ELASTOSIL® CAT UV as curing agent. The two components need to be thoroughly mixed at a 10:1 ratio by weight or volume. Mixing can happen either manually or by automatic metering lines equipped with static or dynamic mixing devices.
• ELASTOSIL® SOLAR 2205 contains the crosslinker, while the curing agents of the ELASTOSIL® CAT series contain the platinum catalyst. Since even traces of platinum catalyst may cause gelling of ELASTOSIL® SOLAR 2205, all tools (e.g. spatula, stirrers, mixing cups etc.) used for handling either the curing agents or the catalyzed mix must not come into contact with ELASTOSIL® SOLAR 2205 by mistake.

Material application:

To eliminate any air introduced during mixing, dispensing or trapped under components and devices a vacuum encapsulation is useful. Alternatively, ELASTOSIL® SOLAR 2205 and the respective curing agent can be deaerated individually prior use in order to remove absorbed air; applying a vacuum of 25-50 mbar for 10-15 min is recommended.

Curing:

• Though curing by heat is possible, ELASTOSIL® SOLAR 2205 typically is processed at room temperature. Preferred curing agents are ELASTOSIL® CAT PT and ELASTOSIL® CAT PT-F. Besides, ELASTOSIL® CAT UV allows a UV-activated curing of ELASTOSIL® SOLAR 2205. Please note: the curing time is highly dependent on the type of curing agent used, processing temperature and both the size and the heat sink properties of the components being encapsulated.
• For catalyzed mixtures containing ELASTOSIL® CAT UV as curing agent, the curing speed additonally depends on irradiance and irradiation time. The reactivity of ELASTOSIL® SOLAR 2205 can be adjusted within wide limits by adding WACKER® Catalyst EP or WACKER® Inhibitor PT 88 to suit the processing requirements of the particular application. WACKER® Catalyst EP increases reactivity, i. e. pot life and curing time are reduced. WACKER® Inhibitor PT 88 is a pot life extender and thus prolongs pot life and curing time.

Pigmentation:

ELASTOSIL® SOLAR 2205 is colorless, transparent and crystal clear. If necessary, the product can be pigmented by adding up to 2 wt. % of ELASTOSIL® COLOR PASTE FL.

Removal:

If removal of the silicone from machines or dispensing equipment is necessary, white spirit or similar nonpolar solvents are recommended. However, cleaning ideally should take place before the silicone is fully vulcanized. Cured silicone gel can be rubbed off and removed mechanically, if necessary in combination with a swelling agent (solvent).

• Product Rheology: Low viscosity
• Resistance: UV & weathering-resistant
• Resistance: UV stable
• Electrically insulating
• Highly transparent
• Liquid
• Vulcanizate: Optically clear

Uncured:

• Very low viscosity
• To be cured with ELASTOSIL® CAT PT, ELASTOSIL® CAT PT-F or ELASTOSIL® CAT CAT UV as curing agent
• 10 : 1 mixing ratio
• Fast curing at room temperature

Cured:

• Soft silicone rubber (Sh 00 range)
• Crystal clear vulcanisate
• Excellent resistance to UV light
• Very high light transmission in the range of 250 nm to 1100 nm
• Recommended service temperature range: -50 °C to +160 °C

• All values given for a mixing ratio of 10:1 by weight. Suitable curing agents: ELASTOSIL® CAT PT, ELASTOSIL® CAT PT-F and ELASTOSIL® CAT UV for catalyzed properties.
• Cured with ELASTOSIL® CAT PT-F in a mixing ratio of 10:1 by weight. Curing conditions: 20 min at 150 °C in a circulating air oven. 2 mm sheet, no post-curing for cured properties.