Zinc oxide is an additive to cement that reduces the hardening time of cement and improves the waterproof performance of cement. In the production of glass and ceramics, zinc oxide can be used as a flux to lower the sintering temperature of glass and ceramics. Zinc oxide added with aluminum, gallium and nitrogen has a transparency of 90% and can be used as a glass coating to allow visible light to pass through while reflecting infrared rays. The paint can be applied inside or outside the window glass to achieve thermal or thermal insulation. Wooden Interior Doors Jiekai Industrial And Trading Co., Ltd. , http://www.gosdoors.com