Two, three or four component molding can work with automation just as easy as single component. Two types are manual transfer and rotating molds. Manual transfer requires the robot end-of-arm-tooling to remove the substrate from the first cavity, remove the finished parts from the second cavity and place the substrate into the second cavity (overmold).

This type of mold design requires a very large and complicated end-of-arm-tooling, usually a larger robot for payload and extended strokes, and will keep the mold open for approximately 6 seconds—all adding cost and time to a workcell.

The better solution is a rotary table mounted to the moving platen that rotates the mold B half to move the substrate to the overmold position. At this point, the robot can either allow the mold to rotate prior to entering or enter the mold to remove the finished parts, leave the mold and permit the mold to rotate.

This table is either hydraulic or servo activated. In either case, the rotation of this table should be controlled by the robot through the injection molding machine electrical interface. The ejector system needs to be independent for each half of the mold (the substrate and finished part). The robot will permit the finished part ejection while leaving the substrate in place.

A robot can be used if the second or third injection unit is mounted vertically over the fixed platen. The robot is mounted over the clamp end of the injection molding machine on floor stands and either picks parts from the top or the side through the injection molding machine safety gate.

Adding the rotary table may require a larger injection molding machine or extended tie bars to allow for the additional mold open dimension required for the rotary table and robot end-of-arm-tooling.