Fabricated tooling also referred to as fabricated rotational molding molds have a shorter lead time than cast aluminum tools and a lower cost. The mold fabrication process involves, cutting, forming, welding and finishing sheet metal. The final form that is created is a female form that matches the shape of the finished product.
The fabrication process is a specialized craft which requires years of experience and a healthy understanding of the rotational molding process. Most fabricated rotational molding tool makers have an extensive practical background in the actual plastic molding process. This allows them to understand the heat transfer characteristics and plastic flow properties.
Our in-house aluminum and steel welding equipment allows us to make modifications and adjustments to molds in a short time frame therefore reducing the burden on the customer.
2D or 3D design
A customer’s 2D or 3D drawing is used to plan and prepare the tooling design layout. The shrink factor of the plastic and vent hole location is factored into the drawing.
Fabricated rotational molding tools are either manufacured from aluminum, steel or stainless steel. There are pros and cons for each option.
The mold manufacturing process begins with the parting line location. This is the point at which the two tool cavities meet. The most commonly used style of parting line used is a flat bar parting line as it is easy to maintain and prevents excessive plastic build up.
Using 2D drawings the planned mold sections are either cut on a plasma cutter or are cut using a press. The maximum number of bends are used to minimize the number of lengthy welds. This increases the accuracy of the tool and assists in maintaining the shape of the mold. The individual pieces are then formed and welded to create the finished rotational molding mold.
Parting line match, fasteners, framing and surface finish
The final process is very similar to the cast aluminum manufacturing process. For more information reagarding this step, click here. (link to cast aluminum step 5.)