Zhiheng chalk is an improved product of ordinary chalk, which refers to the elimination of chalk dust pollution in the classroom. It just adds grease or polyalcohol as a binder to ordinary chalk, and then adds fillers with a larger specific gravity, such as clay, marl, cement, etc. This can increase the specific gravity and volume of the chalk dust, which is not easy However, in practical applications, its effect on reducing chalk dust pollution is not very obvious. Teaching chalk gives teachers a healthy class. Adding trace chemical raw materials to the main ingredients increases the proportion. The chalk is written on the blackboard to reduce dust and cleanliness. It avoids occupational diseases caused by chalk foam entering the internal organs through breathing.
Add a small amount of smoothing agent and binder, the chalk will not stick to your hands and clothes, there is no white mark on the fingers of the teacher after a lesson, and there is no need to wash your hands.
Add a small amount of moisture-proof agent, it will not deteriorate after long-term storage. Ordinary chalk is easy to absorb moisture when stored for a long time, the hardness decreases, and writing is easy to break.
The blackboards used in schools include cement boards, wooden boards, and frosted glass boards. Due to the degree of smoothness of the blackboard surface, the hardness of the chalk is also different. The new generation of chalk can change its hardness at will, it will not slip or break easily when used on various blackboards, and it is fluent, labor-saving, and feels good in hand.
The following are various colors of chalk and lime powder: