Multi-glazed glasses are produced through connection of two or more layers of glass ( distance from each other by means of an aluminium spacer, and air or special gas which is injected between them ). To prevent the glasses from being steamy, a kind of desiccant ( silicagel ) is injected inside the spacers of the double-glazed glass. In order to improve the performance of heat insulation, argon is injected among the glasses; and in order to prevent gas emission and the penetration of outdoor moisture, maintaining adhesion and strength of the glasses, special glue ( polysulphides or silicon ) is injected around the double-glazed glasses, and completely isolated. The quality of the raw materials used in producing double-glazed glasses will play a crucial role in the quality of final product. Given the composite nature of the structure of double-glazed glasses, depending on the place where the glass uses and on its expected function, the strength and safety and performance of double-glazed glasses icluding heat and sound insulation may be improve by using different glasses, tempered or laminated glasses and/or aluminum spacers or warm edge with different thicknesses and various glues.