This machine is for folding round, trapezoidal or square/rectangular filter paper
It has a melting and dropping glue system
Create a regular distance between the folds

This arrangement of folds in the filter paper will allow the liquid to pass through it very quickly and give you a lot of surface area on which to collect the solid “impurity”.

Paper air filters prevent entry to airborne problems while raising overall indoor air quality. A paper air filter is also used to keep internal air from becoming uncomfortable or unsafe. The air circulating in a house needs to filtration, especially when there are residents who smoke or furry pets.
A folding machine is a machine used primarily for the folding of paper. Folding is the sharp-edged bending of paper webs or sheets under pressure at a prepared or unprepared bending point along a straight line according to specified dimensions and folding layouts.
Filter paper has thousands of tiny holes that allow the liquid molecules to pass through. The filtered liquid is called the filtrate. The larger solid particles, in this case, the sand grains are unable to pass through and are left on the paper.