What the difference between hot melt adhesive coating machine with other coating machine?

Ther are three kinds coating machine, one is water based glue coating machine, one is solvent base glue coating machine, the other one is hot melt PSA coating machine.

Solvent based glue coating machine use solvent based glue, need solvent and dry treatment, but this technology not good for environment, so use reducing now.

Water based adhesive coating machine, need water and dry treatment, good for enviroment,it uses widely now.

Hot melt PSA uses widely too, and still have good initial adhesive, good for environment function.Equipment cost lower than water based adhesive coating machine.