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)