Standard Production Process for Sand Casting with Coated Sand

1. Sand inlet temperature: 125 ± 5 ℃, with the upper limit set for cold weather and the lower limit set for hot weather;

2. Mixing and milling time: 75 ± 5 seconds. Take the lower limit when there is less resin and the upper limit when there is more resin;

3. Silane dosage: 2-4 ‰. For example, when adding 150 kg sand, add 60ml and dilute to 150-200ml. Add the exothermic sand immediately when it enters the sand mixer, and then add the resin after 5 seconds;

4. Timing of adding graphite powder: resin should be added for 55-60 seconds, with a dosage of 0.1-0.2 of the original sand. For example, when adding 150kg sand, about 200g should be added. Too little will not work, and too much will affect the strength;

5. The preparation ratio of Ulotopine aqueous solution is 1:3, which means adding 75 kg of water to 25 kg of atropine (one bag);

6. Dosage of Ulotopine: Add 10-12% of the resin according to the calculation amount;

7. The time for blowing cold air is generally within the range of 30-50 seconds, until the ammeter pointer of the sand mixer rises and returns to its original position;

8. The optimal mixing time for calcium stearate is 8-10 seconds.