eq. (A.348)
This unit operation simulates extrusion of polymeric resins. It also can be used to model extrusion of foods and other products.
The following equation is used for equipment sizing: (Rosato and Rosato, p. 165):
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eq. (A.348) |
where:
● R is the mass throughput (kg/h),
● D is the screw diameter (cm),
● h is the depth of the metering section (cm),
● g is the specific gravity of the resin,
● N is the screw rotational velocity (rpm), and
● a is a constant whose value depends on the units of the other variables.
In Design Mode, the following equation is solved for the screw diameter. If the calculated diameter exceeds the maximum screw diameter, then, the program assumes multiple, identical units operating in parallel with a screw diameter of less than the maximum.
In Rating Mode, the screw diameter is specified and the above equation is solved for the screw rotational velocity. If the calculated value exceeds the maximum allowable value, a warning message is displayed advising the user to increase the number of units operating in parallel and/or reduce the operating throughput.
To account for electricity consumption, the user can either specify the power demand (in kW) or the specific power requirement (in kW/kg-h). In the second case, the specific power requirement times the mass operating throughput yields the power consumption.
1. Donald V. Rosato and Dominick V. Rosato, “Injection Molding Handbook”, 2nd Edition, Chapman Hall.
The interface of this operation has the following tabs:
● Oper. Cond’s, see Extrusion: Oper. Conds Tab
● Labor, etc, see Operations Dialog: Labor etc. Tab
● Description, see Operations Dialog: Description Tab
● Batch Sheet, see Operations Dialog: Batch Sheet Tab
● Scheduling, see Operations Dialog: Scheduling Tab