I recently bought some CREE LED bulbs, the kind pictured below, and while they are the same shape as glass incandescent bulbs, they seem to have some sort of cloudy and sticky rubber coating, as if the whole bulb had been dipped in silicone. What is this coating? What effects does it have?
It's done for anti-shatter, the silicone keeps the glass shards together.
According to their product sheet, "Safety coated glass for shatter resistance provides a protective shield to safely contain the glass if the bulb should break"
It first came out being used on incandescent bulbs for mechanic's trouble lights.
At its site, Cree advertises its lighting as having safety coated glass.
It is likely that this is a plastic material that will help contain the glass envelope if it is shattered. There are similar plastic membranes in the middle of car windshields that hold the glass fragments in place in the case of an accident.
