Performance Requirements for Glass Tubes for LED Lights

The performance of the straight tube type LED light housing glass tube mainly includes appearance effect, light transmittance, haze, temperature and humidity resistance, humidity resistance, hardness, conductivity, expansion rate, curvature, and all-light color parameters.

The main indicators are as follows:

① Appearance: generally milky white, smooth surface, no bubbles, scratches, spots, etc;

②Transmittance: test calculation method, using the same light source to apply the same specifications of the transparent glass tube and milky white glass tube under the specified voltage and power, and use the integrating sphere to test the photoelectric color parameters to produce milky white and transparent light effects. This ratio is the light transmittance. Generally, the light transmittance is above 92%;

③ Fogging degree: Put the matching light source (lamp bead) device into the glass tube, and light it with the rated voltage and power. No light-emitting point (lamp bead) can be seen. Consistent performance, no obvious difference between light and dark;

④ Temperature resistance: Put the glass tube into a 150℃ high-temperature box. After 200 hours, it does not change color, burst or deform;

⑤ Water resistance: Place the glass in a constant temperature water bath at 60℃. After 24 hours, there will be no discoloration, cracks, deformation and other phenomena;

⑥ Fluctuation of expansion coefficient: the fluctuation of the expansion coefficient of the same batch of glass tubes is controlled within ±1×10-7/℃;

⑦ Conductivity: The inner and outer walls of the glass tube must be non-conductive;

⑧ Light color effect: The milky white glass tube and the transparent glass tube use the same light source to test the light color parameters, and the spectrum, color temperature, and color rendering index must not be significantly different;

⑨ Hardness: Taking T8 glass as an example, the total pressure required to test the vertical pressure with an ordinary glass pressure gauge is greater than 300N, depending on each manufacturer;

⑩ Bent pipe: Take T8-1.2 meters long glass pipe as an example, the bent pipe generally does not exceed 3°.

In the above performance, most manufacturers pay more attention to the influence of light transmittance, haze, temperature and humidity resistance, and light color.

The above information is provided by indoor COB LED chip factory.