1. Decorative led lamps usually has a much bigger size, we call it extra big size or super big size, the biggest decorative led lamp we are manufacturing is G600, diameter 600mm, very big, and much heavy, about 6Kg, all of our customer call it huge decorative led light bulb. This super big size led bulb has a size of diameter 150mm, and 250mm length. It is straw hat shape, with ripple on the glass. Inside is a 300mm length flexible soft led filament.
2. No matter big size or small size decorative led lamp, the glass bulbs are filled with helium gases, the reasons are as below:
1>. Normal air contains water, the water will change to fog if the led bulb is lighting on and creates heating, the fog will adhesive to the surface of the glass, it looks like there is smog inside the led lamp. Also, the moisture will accelerate the oxidation of the led filament. That is why the led light bulb can not be with normal air inside the glass bulb.
2>. Why we fill helium gas inside the glass bulb? Because helium is a kind of inert gas, it will stop the oxidation of the led filament. Also, when the bulb is lighting on, the led filament will creates heating, the heated helium gas will flow upward, and the low temperature helium will flow down ward, by this way, the helium gas will flow in a cycle inside the led bulb. The heated helium will take the heating to the glass, and glass transmit the heating to outside of the led bulb. So helium is an efficient heat sinking material for led bulb. Over high temperature will cause the damage of the filament led.
3>. Before we fill helium gas into led bulb, we have to vacuum the led bulb, more than 90% of the normal air must be exhausted. We make the led bulb vacuum by the glass tube which is at the bottom of the glass stem. Some times, the tube maybe break during production, then some normal air will flow into the bulb, these normal air will be changed to fog after about 2 hours. That is why we pack the finished decorative vintage led light bulb 3 hours later, we have to pick the defects out when we see there is smog inside the glass bulb.
4>. Why can not we use vacuum glass bulb for super big size decorative vintage led light bulb? Because vacuum can not transmit heating which is created from led filament, high temperature will cause damage of the filament led. Also, vacuum glass bulb is easy to explode. When the filament led is lighting on, it will create a lot of heating, the heat sinking must be efficiently to protect the filament led from being damaged by high temperature.