The Rotational Molding process model uses the following costing rules:
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The complete rotational molding process is modeled as 3 stations: Load/Unload, Oven, and Cooling.
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Load and Unload cycle time computations account for core and insert installation and removal, mold clamping and unclamping, part removal, trimming, and mold cleaning time. Key geometric cost drivers include part surface area and mass, parting line perimeter length, and the perimeter length of holes that are trimmed or routed.
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Ideally, Oven Time is the rate-limiting portion of the entire 3-station cycle. If Load/Unload cycle times are computed to be greater than Oven Time, users can use the process setup options to increase the number of machine operators to lower the load/unload cycle time.
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Molds are assumed to be cast/machined aluminum (as opposed to cast/machined steel, or fabricated sheet metal). Tooling costs are driven primarily by part size and number of cores and inserts.
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By default, the rotational molding machine is assumed to be a 3-arm fixed carousel type machine. Other machine types are available for selection.
The Blow Molding process uses the following costing rules:
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A machine is considered acceptable if the following are true:
- Part size is within limits of a machine compatible mold.
- Machine clamp force is greater than or equal to required force.
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Number of cavities is optimized once a machine is selected.
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The cycle time model employs a “Maximum Wall Thickness” algorithm to calculate cooling time.
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Part must have at least one “spout” GCD.
For Rotational and Blow Molding, aPriori selects draw direction as it does for the Plastic Molding process group, with the following modification: Total Weight for a candidate draw direction is supplemented by Spout Weight, where:
Spout Weight = drawDirSpoutFactor(0.5), if any spout axis is orthogonal to the draw direction candidate; 0.0 otherwise