Mixing ratio: (weight ratio) sand: resin: curing agent = 100: 2.5: 0.5 Curing agent: sodium chloride: urea: water = 1: 3: 3: Sand mixing: sand is mixed with curing agent for 5 minutes, and resin is mixed for 2 minutes before use. Core shooting pressure: 0.5 ~ 0.7Mpa