Sand Moulding Process.

The process of manufacturing rivets through the sand moulding process began today. The initial step was given through the making of the mold. Therefore, it was necessary to manufacture the proper sand with the following proportions, by weight: 100 sand to 20 clay and 4 water.

In figure 1, the preparation of the lower molding box assembly is shown and in Figure 2 the upper box already shown is shown in the lower box.

                         Figure 1 – Bottom box assembly                                 

Source: Own

Figure 2 - Upper box assembly

Source: Own

During the demolding of the crate, to remove the model, some problems occurred, among them: The breaking of some bodies of the rivets and the collapse of the sand, as shown in Figure 3. This is due to the fragility of the material used to make the model and the need for a greater amount of clay to allow greater consistency of the sand.

Figure 3 – Demolding failure.

Source: Own

Therefore, some measures were taken to solve such problems, among them: The body of the rivets that were tree-mounted was cut and more clay was added to increase the consistency of the sand.

In figure 4, the lower molding box is shown, using as a model only the rivet body and not the rivet in the trees. The surface of the lower carton was covered with talcum powder to facilitate separation of the cartons, preventing sand from the lower carton from coming into contact with the sand of the upper carton. In Figure 5, the upper carton assembly is shown after opening the feed channels.

                    Figure 4 - Reworked Bottom Box                      

Source: Own

Figure 5 – Mold with feeding channel

Source: Own

After the feeding channel was opened, it was time to spill the molte step (Figure 6).

Figure 6 - Leakage of the aluminum in the sand mold.

Fonte: Própria

This step consisted in filling the mold with the cast aluminum, as shown in the Video below and after solidifying it will have the dimensions of the projected rivet.

After the solidification of the part inside the mold (Figure 7), it was removed to obtain the part that was not yet the final, because it was necessary to remove the feed channels.

Figure 7 - Form solidified and ready for demolding.

Source: Own

After the withdrawal of the channels the rivets shown in Figure 8 were obtained.

Figure 8 - Obtained rivets.

Source: Ouw