The molds we use in rotational molding are made by fabricating different metals or rolling, bending, and welding sheet metal that range from $6,000.00 to $50,000.00 depending on the size, design, and complexity of the detail work.
Aluminum alloys are framed in a cast iron or stainless steel frame, which is fitted with clips to fit into different types of molding machines.
The cage style framework allows the machine arms to latch onto it for manipulation near the ovens. It also protects the actual mold, so if the mold falls or hits something, the frame cage takes the impact and the mold retains its shape.
The actual molds are made of a soft aluminum. We take great caution and care to prevent damage to the mold.
Preventing water from getting into the mold is crucial. If this happens, the water electrifies in the aluminum, causing tiny holes called porosity that can lead to imperfections in the castings and even explosions in the ovens.
If a mold isn’t sealed completely, powdered resin can escape and the piece will not come out right. Any scratches or scrapes inside the mold will all transfer onto the castings, so each piece will have a scar in the shape of the scrape in the mold. Any mold left outside in the elements is subject to rusting and corrosion.
The molds weigh anywhere from 60 to 800 pounds and, unlike the durable resin products they create, are susceptible to degradation problems if improperly cared for.