Materials: Empty bottles for sprays; asbestos material for ordinary erasers
Method: Fill the bottle with clean water, then stick the asbestos material on the bottle and it’s OK!
Usage: First spray some water mist on the blackboard with a nozzle, not too much! Then wipe it with asbestos
Principle: Because the spray is water mist, it will not Turn the dust into a paste and avoid raising the dust at the same time.
Disclaimer: Patent protection, if you mass produce, you will have to pay tax! Thank you