Environment friendly chalk and a manufacturing method thereof

Abstract

The invention relates to environment friendly chalk and a manufacturing method thereof. The method includes steps of providing calcium sulfate powder, calcium carbonate powder, talcum powder, sepiolite powder, montmorillonite powder and titanium dioxide powder, separately sieving each type of powder to remove components the particle size of which is greater than 150 microns and components the particle size of which is less than 10 microns, blending 50-70 parts by weight of the calcium sulfate powder, 20-30 parts by weight of the calcium carbonate powder and 10-20 parts by weight of the talcum powder with water to obtain slurry the solid content of which is not more than 60%, adding 2-4 parts by weight of the sepiolite powder, fully stirring the mixture, adding 1-3 parts by weight of the montmorillonite powder, maintaining at a temperature of 50-60 DEGC for 10-20 min, adding 2-4 parts by weight of the titanium dioxide powder, supplementing water and fully stirring the mixture until the solid content is 45-55% by weight, adding into a mold, molding, drying and demolding to obtain the chalk. The chalk is advantaged by being light, moisture-proof, low in dust, high in rupture strength, and the like.

Description

Technical field [0001] The present invention relates to chalk and a manufacturing method thereof. More specifically, the present invention relates to environmentally friendly chalk and a manufacturing method thereof. Background technique [0002] Chalk is a highly used writing instrument that is used in many situations, the most commonly used place is in school classrooms. Even today when electronic display devices such as projectors are becoming more and more popular, chalk is still widely used due to its low price, usage habits and convenience. Just like the emergence of knives and forks has not made chopsticks disappear, chalk has been used as a tool for thousands of years. , still plays a decisive role in teaching. [0003] As everyone knows, respecting teachers and respecting Taoism is one of our excellent traditional cultures. The seven-foot podium is the stage for teachers to dedicate themselves. Chalk is the most important tool for teachers. In line with the traditi...

AI Technical Summary

Problems solved by technology

[0005] Although the concept of dust-free chalk has been proposed now, this chalk often adopts organic solvents. For example, CN201310386442.X provides a kind of green environmental protection dust-free chalk, wherein polyvinyl acetate emulsion, polyvinyl alcohol, etc. Although the organic solvent solves the problem of chalk dust, it brings another organic solvent to cause the air pollution problem caused by the decomposition and volatilization of the organic solvent, and the chalk dust is rarely dispersed due to the small amount of chalk dust. Because Causing chalk dust to carry organic solvents into the environment, causing a wider range of environmental pollution

[0006] The simplest composition of chalk is plaster of paris and water. Although there is no organic pollution problem in this kind of chalk composition, the density is too large, which makes writing laborious, and the teacher's long-term use is easy to cause finger strain

In order to reduce the weight of chalk, fillers are often added therein in the prior art, but the increase of fillers will cause the chalk mechanical strength to be low and easy to break, which has also caused a large amount of waste or residual chalk tips discharged into the environment. It increases the amount of chalk and chalk dust discharged into the environment, so such chalk is also not environmentally friendly

[0007] In the case of adding fillers, sometimes in order to increase the mechanical strength of the chalk, it is proposed to add a binder to the chalk ingredients, but the binder itself is often an organic substance, or requires an organic solvent to assist in dissolution, which easily leads to organic pollution. question

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