This may be just me. but I found using 91% alcohol content- Isopropyl alcohol is superior for 3d beds versus the lesser 70% content bottles. I rarely have adhesion problems anymore. really never did on pla, but on pteg is good always now. If you are printing PLA with a heated bed and you arent sticking you dont have a clean bed or your printer head is too high likely. Assuming you are using a smooth bed with pla.