For IPD 501 Project: Mold, Joe McClosky and I made a polyurethane wine stopper with overmolded silicone to make it seal. The design is functionally pretty basic. We added a gear at the top both as decoration and as a ring to pull the stopper out easily. The final product works pretty well despite a few pesky air pockets.
Design
The first sketch and material usage estimates. The water droplet design on top was deemed impossible with a 2-part mold.
The plan for the molds including air holes.
KeyShot Rendering of the design. Sadly we didn’t have any red dye so we couldn’t make it in Penn colors.
Manufacturing Process
Half of each positive was sealed to the bottom of the form with molding clay.
After the first half of the mold had set, the halves of the positive were put together with dowel pins. Wires and posts are rested on top of the positive to create air holes.
The finished molds. The finished part from the first mold fits into the second with a small gap for the overmold.
Freeman silicone molding rubber was mixed, degassed and poured into the forms.
The second half is poured.
A polyurethane part just out of the mold. We struggled a lot with visible parting lines and air pockets.
Carder C. House 