In metal casting machinery, the sand mold is assembled and prepared through a series of steps. First, a pattern or model of the desired object is created using wood, metal, or other materials. This pattern is then placed in a flask, which is a box-like frame with an open top and bottom.
Next, a mixture of sand and a bonding agent, such as clay, is prepared. This mixture is called molding sand. The molding sand is carefully packed around the pattern in the flask, ensuring that it completely covers the pattern and fills any cavities. This process is known as ramming.
After the sand is packed, the pattern is removed from the flask, leaving behind a cavity in the shape of the desired object. To ensure proper venting, channels called sprues and gates are also formed in the sand mold, allowing for the flow of molten metal.
The sand mold is then prepared for casting by drying it thoroughly. This is usually done in an oven or by allowing it to air dry. Drying helps remove any moisture from the sand, preventing steam from forming and causing defects in the final casting.
Once the sand mold is completely dry, it is ready for casting. Molten metal is poured into the mold through the sprue, filling the cavity and taking the shape of the desired object. After the metal solidifies, the sand mold is broken apart, revealing the newly cast metal object.
Overall, the assembly and preparation of the sand mold in metal casting machinery involves creating a pattern, packing molding sand around the pattern, forming sprues and gates, drying the mold, and finally pouring molten metal into the mold for casting.