Unlike ordinary vacuum devices, vacuum insulated glass is made up of 2 panes of a large glass with very small air space in between. For instance, a piece of one square meter vacuum insulated glass has only 150 ml air space while the surface area for outgassing is 2㎡. As baking under high temperature cannot totally eliminate the surface outgassing issues, it is necessary to place getters in the vacuum chamber to improve and maintain the level of vacuum as well as prolong the useful life of vacuum insulated glass.
Also known as degasser, it is a material used in vacuum electron devices and vacuums scientific research as an agent to absorb the gas. The primary function of the getter is to raise the degree of vacuum in a vacuum chamber quickly and maintain the desired vacuum degree for a long time. There are two types of getters: a vaporized getter and a non-evaporable getter. The vaporized getter, usually a volatile metal, instantly reacts with any residual gas, and then condenses on the cool walls of the tube in a thin coating, the getter spot or getter mirror, which continues to absorb gas; the non-evaporable getter uses a clean approach. After the material is “activated”, while maintaining its solid form (i.e. Not being evaporated), it turns into the getter that absorbs gas directly.
To ensure the clarity of the vacuum insulated glass, only a non-evaporable getter is used. Depending on the activation temperature, the non-evaporable getter can be divided into low-temperature getter and high-temperature getter. The low-temperature getter works at room temperature with an activating temperature of 450±100℃; the high-temperature getter is activated at 850±100℃ and has an optimal operating temperature at 400±50℃. While vacuum insulated glass will mostly used at room temperature, a low-temperature getter is a good fit.