Sand casting refers to the method of producing castings in sand. Molding sand and core sand are usually made by mixing silica sand, clay or bonding material and water in a certain proportion. Molding sand and core sand must have “one strength and three properties”, that is, certain strength, air permeability, fire resistance and concession
- Before modeling, prepare modeling tools, select an appropriate sand box, clean the shape, and prepare sand;
- When placing the model, pay attention to the direction and position of the draft angle;
- When starting to fill the sand, first press the pattern with your hands, and plug the molding sand around the pattern with your hands to prevent the pattern from happening.
- If the sand box is higher. The molding sand should be filled in several times;
- When spring sand, the sand hammer should travel evenly according to a certain route, the force should be appropriate, and pay attention to the sand hammer not to be hit;
- After the lower sand mold is completed, a layer of non-viscous parting sand must be evenly sprinkled on the parting surface, and then the upper
- After the sand mold is smoothed, the vent holes should be evenly pierced above the projection surface of the pattern;
- The inner surface of the sprue cup should be polished, and the connection between it and the sprue should be repaired to a smooth transition surface;
- After the entire sand mold is completed, a piece of sand mud should be applied to the long-distance parting surface of the two adjacent right-angle edges on the outer wall of the sand box, and the box closing mark (also called the box closing line) should be made. Unpacking and moulding;
- When drawing the mold, first dip a brush with water and evenly brush it on the molding sand around the pattern to increase the humidity of this part of the molding sand; the drawing operation must be careful and stable;
- After the mold is drawn, the sand mold should be carefully repaired, and the inner runner should be opened at the same time;
- After the repair is completed, the box can be closed and ready for pouring.