Times

Times such as labor time and cycle time are calculated as described below.

Labor Time = Cycle Time x Number of Operators

Labor time is the product of the following:

• Cycle time (see formula below)

• Number of operators (specified by machine property, typically 0.5)

Cycle Time = (Injection Time + Cool Time + Ejection Time ) / Number of Cavities

Cycle time is computed by default, but can be specified by the user—see Additional User Inputs. If calculated, it is a function of the following:

• Injection time (see formula below)

• Cool time (see formula below)

• Ejection time (see formula below)

• Number of cavities (see Number of Mold Cavities)

This value is adjusted by multiplying by the cost model variable cycleTimeAdjustmentFactor (which defaults to 1—see Process Defaults and Thresholds).

Injection Time = ((Number of Cavities x Part Volume) + Runner Volume) / Adjusted Injection Rate

Injection time is function of the following:

• Number of cavities (see Number of Mold Cavities)

• Part volume (obtained from GCD extraction)

• Runner volume (see Material Utilization)

• Adjusted injection rate (see formula below)

Adjusted Injection Rate = Injection Rate x 0.25

Adjusted injection rate is one quarter of the injection rate of the machine.

Cool Time = 0 – ((Nominal Wall Thickness^2) / (2 x π x Material Thermal Diffusivity) x ln(π/4) x

(Eject Deflection Temperature – Mold Temperature) / (Melting Temperature – Mold Temperature)

Cool time is a function of the following:

• Nominal wall thickness (see Nominal Wall Thickness)

• Material properties (listed in the Material Selection dialog):

o Thermal diffusivity

o Eject deflection temperature (temperature at which the part can be ejected from the mold without deformation)

o Melting temperature

o Mold temperature (required temperature of the mold to support proper molten polymer flow)

Ejection Time = Dry Cycle Time of Machine x 1.5

Ejection time is 50% greater than the machine dry cycle time.