Cleaning Formulas for Die Casting

The Cleaning process uses the formulas below.

Cycle Time = Process Time * Cycle Time Adjustment Factor

Cycle time is the product of the following:

• Process time (see formula below)

• Cycle time adjustment factor: specified by the cost model variable cycleTimeAdjustmentFactor; 1 in aPriori starting point VPEs.

Process Time = Blast Time + Reorient Time

The cleaning process time is the sum of the following:

• Blast Time (see formula below)

• Reorient Time. This is 0 for Tumble Blast machines. For Table Blast and Room Blast, this is the product of handling time per operator (elapsed handling time) and number of handling operators, which are interpolated from values looked up by mass in the lookup table tblHandlingTimes. Mass, for these purposes, is Mass Before Machining (see Material Cost and Utilization for Die Casting).

Blast Time = (Time per Load / Number of Parts in Load) * Design Complexity Factor

Blast time (formula Tumble Blast Cyce Time, Table Blast Cycle Time, or Room Blast Cycle Time) depends on the following:

• Time per load. For tumble and table blast machines, this is specified by the machine property Time per Load. For Room Blast machines, see the formula below.

• Number of parts per load. This is the maximum number of parts that fall within the machine’s limits for weight and volume (for tumble blast machines) or for weight and area (for table blast machines). For room blast machines, the number of parts is always 1. For more information, see Cleaning Machine Selection.

• Design complexity factor (see Design Complexity Factor)

Time per Load for Room Blast machines = ( External Surface Area / External Surafce Blast Rate) +

(Internal Surface Area / Internal Surface Blast Rate)

For room blast cleaning, process time depends on the following:

• External surface area (area of all sutfaces for which there is a non-obstructed IS_ACCESSIBLE_FROM relation)

• External surface blast rate (specified by the machine property External Surface Blast Rate)

• Internal surface area (area of all sutfaces for which there is no non-obstructed IS_ACCESSIBLE_FROM relation)

• Internal surface blast rate (specified by the machine property Internal Surface Blast Rate)

Additional Direct Costs = Shot Abrasive Cost / Final Yield

Additional direct costs consist of the cost for the abrasive used in the shot stream (including abrasive used for scrapped parts, amortized over all the parts in the current production scenario):

• Shot abrasive cost (see formula below)

• Final yield (see Yields For Die Casting)

Shot Abrasive Cost = Shot Consumption * Blast Power * Shot Unit Cost * Blast Time

Shot abrasive cost is the product of the following:

• Shot consumption (specified by the machine property Shot Consumption)

• Blast power(specified by the machine property Blast Power)

• Shot unit cost (specified by the tool shop variable shotUnitCost)

• Blast time (see formula above)