... water with rigid ion passing resin in the exchanging cylinder, Ca2+Mg2+ in water is exchanged and absorbed by ... Na+ in resin, wiping off Ca2+Mg2+ and ... Mg2+, regeneration is washing resin layer using brine in salt box. Na+ in salt water exchange the rigid ion ... is used in textile printing and dyeing, paper making, laundry, bathing, food processing, quality of life water and ...