Material Utilization
Material costs and utilization are determined with the help of the following formulas:
Part Rough Mass = Part Finish Mass / Utilization
Rough mass is the quotient of the following:
• Finish mass (see formula below)
• Utilization (see formula below)
Utilization = ( 1 – Material Waste Factor ) * Mold Efficiency
Utilization depends on the following:
• Material waste factor (see formula below)
• Mold efficiency (machine property, typically 0.95)
Part Finish Mass = Part Volume * Material Density
Finish mass is the product of the following:
• Part volume (obtained from required PSO—see
Part Volume)
• Material density (listed in the Material Selection dialog)
Material Waste Factor = Runner Factor – Regrind Allowance
Material waste percentage is the difference between the following:
• Runner factor (see below)
• Regrind allowance (default of 0.25 specified in cost model variables or user-specified value—see
Additional User Inputs)
Runner factor is a function of the following:
• Runner volume (see below)
• Number of cavities (see
Number of Mold Cavities above)
• Part volume (obtained from required PSO—see
Part Volume)
runnerVolume = Number of Cavities *
( Part Length + Part Width ) * π * ( ( Nominal Wall Thickness + 1.5 )/2 )2
Runner volume is a function of the following:
• Number of cavities (see
Number of Mold Cavities below)
• Part length and width (obtained from cavity dimensions—see
Part Length, Width, and Height)
• Nominal wall thickness (see
Nominal Wall Thickness)