Investment Casting Foundry | Sand Casting Foundry from China

Stainless Steel Castings, Grey Iron Castings, Ductile Iron Castings

Mold Assembly in Castings

Mold assembly includes core setting, installation of chillers, core supports, and venting facilities, as well as securing the mold after assembly. The mold assembly for stainless steel investment castings focuses on wax pattern assembly and shell making, omitting the traditional steps of core setting, mold assembly, and sand mold fastening used in sand casting. In contrast, sand casting relies on core installation, parting surface alignment, and securing with weights or clamps to complete the assembly.

 

Core Setting

Principles for Core Setting:

1. Familiarize yourself with the process diagram.

2. Determine the sequence of core setting.

3. Inspect the quality of the sand cores.

4. Assemble the sand cores.

5. Inspect the cores after setting.

 

Mold Assembly and Alignment

Mold assembly is the final step in the molding process. If the mold assembly does not meet process requirements, it can lead to casting defects or even scrap.

Steps for Mold Assembly:

1. To prevent metal leakage, place fireproof mud strips or asbestos ropes around the parting line as needed.

2. During mold assembly, ensure the upper mold remains level, lowers slowly, and aligns accurately.

3. Check the alignment of the sprue with the runner in the lower mold, and ensure there is no risk of sand entrapment for the cores.

4. Inspect the parting line for a tight fit. If gaps are present, take measures to prevent metal leakage.

5. Secure the mold with weights or fasteners.

6. Place the pouring and riser cups, cover the sprue cup, and prepare for pouring.

To ensure dimensional accuracy of the casting and prevent issues such as sand entrapment or misalignment, positioning devices should be installed on the mold box.

Core Setting in Castings
Mold Assembly in Castings

Mold Tightening and Securing

To prevent the upper mold from being lifted due to the static pressure of the molten metal and the buoyancy of the sand core, the upper and lower molds must be secured together. The methods include using weights or bolts and bow clamps.

1. Weight Method:

A key parameter for weights is their mass. Weights should also have openings for pouring and ventilation. The load of the weights should be supported by the mold box walls to avoid damaging the sand mold.

2.Clamp Securing Method:

In mold box molding, fastening clamps are often used instead of weights to secure the mold. Fastening clamps are used in single-piece, small-batch, and mass production. In high-volume production lines, widely used clamps include swing-type box clamps, which feature high machining accuracy and require auxiliary mechanisms for tightening and releasing.

 

Lost foam castings typically do not require traditional fastening methods. They primarily use vacuum fastening, which ensures the stability of the sand mold through a vacuum environment.

 

 


Post time: Jan-03-2025