LUMISIL® 903 A/B
LUMISIL® 903 A/B is an addition-curing, low viscosity two-part silicone that cures to a flexible and highly transparent silicone rubber.
All surfaces must be clean and free of contaminants that will inhibit the cure of LUMISIL® 903. 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.
Component A of LUMISIL® 903 contains the platinum catalyst, component B the crosslinker. Even traces of the platinum catalyst may cause curing of the component containing the crosslinker. Therefore tools (spatula, stirrers, etc.) used for handling the platinum-containing component or the catalyzed compound must not come into contact with this component.
The two components should be thoroughly mixed at a 1:1 ratio by weight.
To eliminate any air introduced during mixing or trapped under components or devices a vacuum de-airing under a vacuum of 10 – 20 mm mercury for 5 – 10 min is recommended.
Curing time of addition-curing silicone rubber is highly dependent on temperature, silicone amount, size and heat sink properties of the substrate the silicone is applied on.
We recommend running preliminary tests to optimize conditions for the particular application.